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  • 1.
    Abdulhusen, Maria
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Binokulärseende hos elitidrottare: En studie om djupseende, ackommodationsfacilitet och vergensfacilitet2011Självständigt arbete på grundnivå (kandidatexamen), 15 poäng / 22,5 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte: Syftet med denna studie var att ta reda på om elitidrottare som spelar en bollsport har bättre djupseende, bättre förmåga att kunna ändra fokus mellan olika avstånd och mer uthålliga ögonmuskler än personer som inte spelar någon bollsport alls.

    Metod: Mätningarna utfördes på femton innebandyspelare som spelar på elitnivå och femton personer som inte spelar någon bollsport. Medelåldern var 22 år i båda grupperna. Först fick varje försöksperson svara på en enkät, sedan mättes visus upp monokulärt och binokulärt på 3 m med en logMAR visustavla. Efter det mättes djupseendet med Randot stereotest på 40 cm och sedan mättes försökspersonens förmåga att kunna ändra fokus mellan olika avstånd. Detta gjordes på 40 cm med en flipper med styrkorna ±2,00D. Sista mätningen var att få ett mått på hur uthålliga försökspersonens ögonmuskler var, detta gjordes på 40 cm med en flipper av styrkorna 3Δ Bas In/ 12Δ Bas Ut.

    Resultat: Medelvärdet på djupseendet i respektive grupp visade ingen statistisk signifikant skillnad mellan de båda grupperna (p=0,70). Det fanns en signifikant skillnad på medelvärdet mellan de båda grupperna när det gäller förmågan att kunna ändra fokus mellan olika avstånd (p=0,02). Medelvärdet på uthålligheten av ögonmusklerna visade ingen signifikant skillnad mellan de båda grupperna (p=0,08).

    Slutsats: Studien visade att innebandyspelare på elitnivå har bättre förmåga att ändra fokus mellan olika avstånd. Studien visade även att innebandypelare på elitnivå inte har mer uthålliga ögonmuskler eller bättre djupseende än de som inte spelar någon bollsport alls.

  • 2.
    Akram, Muhammad Nadeem
    et al.
    University of South-Eastern Norway, Norway.
    Baraas, Rigmor C.
    University of South-Eastern Norway, Norway.
    Baskaran, Karthikeyan
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Improved wide-field emmetropic human eye model based on ocular wavefront measurements and geometry-independent gradient index lens2018Ingår i: Optical Society of America. Journal A: Optics, Image Science, and Vision, ISSN 1084-7529, E-ISSN 1520-8532, Vol. 35, nr 11, s. 1954-1967Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    There is a need to better understand the peripheral optics of the human eye and their correction. Current eye models have some limitations to accurately predict the wavefront errors for the emmetropic eye over a wide field. The aim here was to develop an anatomically correct optical model of the human eye that closely reproduces the wavefront of an average Caucasian-only emmetropic eye across a wide visual field. Using an optical design program, a schematic eye was constructed based on ocular wavefront measurements of the right eyes of thirty healthy young emmetropic individuals over a wide visual field (from 40° nasal to 40° temporal and up to 20° inferior field). Anatomical parameters, asymmetries, and dispersion properties of the eye’s different optical components were taken into account. A geometry-independent gradient index model was employed to better represent the crystalline lens. The RMS wavefront error, wavefront shapes, dominant Zernike coefficients, nasal-temporal asymmetries, and dispersion properties of the developed schematic eye closely matched the corresponding measured values across the visual field. The developed model can help in the design of wide-field ophthalmic instruments and is useful in the study and simulations of the peripheral optics of the human eye.

  • 3.
    Alahamami, Mastour A.
    et al.
    Indiana University, USA.
    Elsner, Ann E.
    Aeon Imaging, USA;Indiana University, USA.
    Baskaran, Karthikeyan
    Indiana University, USA.
    YoussefAgha, Ahmed H.
    Indiana University, USA.
    Brahm, Shane
    Indiana University, USA.
    Young, Stuart B.
    Indiana University, USA.
    Litvin, Taras V.
    University of California Berkeley, USA.
    Ozawa, Glen Y.
    University of California Berkeley, USA.
    Cuadros, Jorge
    University of California Berkeley, USA.
    Muller, Matthew S.
    Aeon Imaging, USA.
    Investigation of Photoreceptors in Diabetic Macular Edema2014Ingår i: IOVS, Orlando, Florida, USA, 2014, Vol. 155(13)Konferensbidrag (Refereegranskat)
    Abstract [en]

    Abstract Purpose: To evaluate the photoreceptor integrity in diabetic patients with macular edema using spectral domain optical coherence tomography (SD-OCT) Methods: We compared macular thickness in diabetic patients with and without macular edema to determine the role of damage to the external limiting membrane (ELM) or photoreceptors. Diabetic patients were selected from the screening study of > 2000 minority patients seen at Eastmont Wellness Center, Oakland, CA. Patients underwent photoscreening with a Canon Cr-DGi nonmydriatic camera (Tokyo, Japan) and an iVue OCT (Optovue Inc, Fremont, CA). Retinal scans of 70 diabetic patients, age range 33-68 yr., were selected so that A) 50% of patients had clinical significant macular edema (CSME), as diagnosed by the presence of hard exudates within 1 disc diameter from the fovea in the color photos, B) the full range of central macular thicknesses in our population was included. And C) patients with CSME were the same age as those not diagnosed with CSME. We graded the retinal scans according to the external limiting membrane (ELM) integrity; 6 patients had damaged ELM and the remaining 64 had intact ELM. Similarly, we graded the retinal scans according to the photoreceptor integrity; 14 patients had damaged photoreceptors and the remaining 56 had intact photoreceptors Results: Average retinal thickness was 254 µm (±57.4) and 356 µm (±95.9) in patients with intact and damaged ELM, respectively; and was 240 µm (±30.0), and 363 µm (±90.0) in patients with intact and damaged photoreceptors, respectively. Retinal thickness means were significantly greater for patients with damaged compared with intact ELM ( P=0.031). Similarly, Retinal thickness means in patients with damaged photoreceptors were significantly greater compared to patients with intact photoreceptors ( P = 0.0001). We also observed that all 6 patients who have damaged ELM were diagnosed with CSME, but were not significantly older than the diabetic patients not diagnosed with CSME ( P = 0.393) Conclusions: ELM and photoreceptor layer damage are found more often when retinal thickness exceeds 355 µm. It is not known if this outer retinal damage is the result of the edema or whether there is more edema because the outer retinal blood brain barrier is failing

  • 4. Alahamami, Mastour A.
    et al.
    Elsner, Ann E.
    Indiana University School of Optometry, USA.
    Muller, Matthew S.
    Aeon Imaging, USA.
    Baskaran, Karthikeyan
    Indiana University School of Optometry, USA.
    Gast, Thomas J.
    Indiana University School of Optometry, USA.
    Litvin, Taras V.
    Indiana University School of Optometry, USA.
    Ozawa, Glen Y.
    University of California Berkeley, USA.
    Cuadros, Jorge
    University of California Berkeley, USA.
    Haggerty, Bryan P.
    Indiana University School of Optometry, USA.
    Malinovsky, Victor E.
    Indiana University School of Optometry, USA.
    Clark, Christopher A.
    Indiana University School of Optometry, USA.
    Brahm, Shane
    Indiana University School of Optometry, USA.
    Young, Stuart B.
    Indiana University School of Optometry, USA.
    Comparison of cysts in red and green images for diabetic macular edema2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Purpose: To improve the detection of macular cyst with photoscreening, we tested whether in a population of largely minority patients the red channel image from a color fundus camera visualizes cysts in diabetic macular edema better than the green channel image. In assessing diabetic retinas for clinically significant macular edema, the presence of cysts must be judged with respect to the central macula. Some grading programs use red free images, often derived from green channel images, to enhance visualization of retinal vessel damage or macular pigment, but some red and near infrared instruments have detected cysts better than short wavelength techniques. Methods: We evaluated macular cysts in 13 diabetic patients diagnosed with clinically significant macular edema, age range 33-68 years. Diabetic patients were selected from the screening study of >2000 underserved patients seen at Eastmont Wellness Center, Oakland, CA. Patients underwent photoscreening with a nonmydriatic color fundus camera (Canon Cr-DGi, Tokyo, Japan) and SD-OCT (iVue, Optovue Inc, Fremont, CA). The color fundus images for those patients were transformed into red and green channels to evaluate the appearance of macular cysts in red channel images and green channel images. The region of each cyst was compared SD-OCT scans (Adobe Photoshop CS5.1, San Jose, CA). Only cysts touching the central 1 mm around the fixation from the SD-OCT scans were sampled. Results: The average size of retinal cysts in red channel images, 124.57 µm (±106.96), was significantly greater than in green channel, 59.44 µm (±76.6), (p<0.006). Entire cysts could not be seen in 5 eyes in the green channel images. Conclusions: Our results indicate that the grading of cysts in the central macular might be improved by incorporating red channel images. There are a number of potential factors that could make cysts less visible in the green channel images, including poorer light penetration through to the deeper retina or macular pigment. Anterior segment issues impact more on green channel images. This population includes mostly minority patients who have dark fundi, and darker images.

  • 5.
    Alhamami, Mastour
    et al.
    Indiana University, USA.
    Elsner, Ann
    Indiana University, USA;Aeon Imaging, USA.
    Malinovsky, Victor
    Indiana University, USA.
    Clark, Christopher
    Haggerty, Bryan
    Indiana University, USA.
    Ozawa, Glen
    University of California, USA.
    Cuadros, Jorge A
    University of California, USA ; EyePACS, USA.
    Baskaran, Karthikeyan
    Indiana University, USA.
    Gast, Thomas
    Indiana University, USA;Aeon Imaging, USA.
    Litvin, Taras
    University of California, USA.
    Muller, Matthew
    Aeon Imaging, USA.
    Brahm, Shane
    Indiana University, USA.
    Young, Stuart
    Indiana University, USA.
    Miura, Masahiro
    Tokyo Medical University Ibaraki Medical Center, Japan.
    Comparison of Cysts in Red and Green Images for Diabetic Macular Edema2017Ingår i: Optometry and Vision Science, ISSN 1040-5488, E-ISSN 1538-9235, Vol. 94, nr 2, s. 137-149Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose: To investigate whether cysts in diabetic macular edema are better visualized in the red channel of color fundus camera images, as compared with the green channel, because color fundus camera screening methods that emphasize short-wavelength light may miss cysts in patients with dark fundi or changes to outer blood retinal barrier.

    Methods: Fundus images for diabetic retinopathy photoscreening were acquired for a study with Aeon Imaging, EyePACS, University of California Berkeley, and Indiana University. There were 2047 underserved, adult diabetic patients, of whom over 90% self-identified as a racial/ethnic identify other than non-Hispanic white. Color fundus images at nominally 45 degrees were acquired with a Canon Cr-DGi non-mydriatic camera (Tokyo, Japan) then graded by an EyePACS certified grader. From the 148 patients graded to have clinically significant macular edema by the presence of hard exudates in the central 1500 [mu]m of the fovea, we evaluated macular cysts in 13 patients with cystoid macular edema. Age ranged from 33 to 68 years. Color fundus images were split into red, green, and blue channels with custom Matlab software (Mathworks, Natick, MA). The diameter of a cyst or confluent cysts was quantified in the red-channel and green-channel images separately.

    Results: Cyst identification gave complete agreement between red-channel images and the standard full-color images. This was not the case for green-channel images, which did not expose cysts visible with standard full-color images in five cases, who had dark fundi. Cysts appeared more numerous and covered a larger area in the red channel (733 +/- 604 [mu]m) than in the green channel (349 +/- 433 [mu]m, p < 0.006).

    Conclusions: Cysts may be underdetected with the present fundus camera methods, particularly when short-wavelength light is emphasized or in patients with dark fundi. Longer wavelength techniques may improve the detection of cysts and provide more information concerning the early stages of diabetic macular edema or the outer blood retinal barrier.

  • 6.
    Allen, Peter M.
    et al.
    Anglia Ruskin University, UK ; Vision Cooperative Research Centre, Australia.
    Radhakrishnan, Hema
    Vision Cooperative Research Centre, Australia ; University of Manchester, UK.
    Price, Holly
    Anglia Ruskin University, UK ; Vision Cooperative Research Centre, Australia.
    Rae, Sheila
    Anglia Ruskin University, UK ; Vision Cooperative Research Centre, Australia.
    Theagarayan, Baskar
    Anglia Ruskin University, UK ; Vision Cooperative Research Centre, Australia.
    Calver, Richard I.
    Anglia Ruskin University, UK ; Vision Cooperative Research Centre, Australia.
    Sailoganathan, Ananth
    National Institute of Ophthalmic Sciences, Malaysia.
    Latham, Keziah
    Anglia Ruskin University, UK.
    O'Leary, Daniel J.
    Anglia Ruskin University, UK ; Vision Cooperative Research Centre, Australia.
    A randomised clinical trial to assess the effect of a dual treatment on myopia progression: the Cambridge anti-myopia study2013Ingår i: Ophthalmic & physiological optics, ISSN 0275-5408, E-ISSN 1475-1313, Vol. 33, nr 3, s. 267-276Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To evaluate the effect of a dual treatment modality for myopia, by improving accommodative functions, on myopia progression.

    METHODS: A double blind randomised control trial was conducted on 96 subjects. The treatment modality for the trial employed custom designed contact lenses which control spherical aberration in an attempt to optimise static accommodation responses during near-work, and a vision-training programme to improve accommodation dynamics. Myopia progression was assessed over a 2 year period using cycloplegic autorefraction and biometry.

    RESULTS: The mean progression was found to be -0.33 Dioptres (D) over the 2 years of the study. There was no interaction between contact lens treatment and vision training treatment at 24 months (p = 0.72). There was no significant treatment effect of either Vision Training or Contact Lens Spherical Aberration control on myopia progression.

    CONCLUSIONS: This study is unable to demonstrate that the progression of myopia can be reduced over a 2 year period by either of the two treatments aimed at improving accommodative function. Neither treatment group (contact lens or vision training) progressed at a slower rate over the 2 years of the study than did the appropriate control group.

  • 7.
    Allen, Peter M.
    et al.
    Anglia Ruskin University, UK.
    Radhakrishnan, Hema
    University of Manchester, UK.
    Rae, Sheila
    Anglia Ruskin University, UK.
    Calver, Richard I.
    Anglia Ruskin University, UK.
    Theagarayan, Baskar
    Anglia Ruskin University, UK.
    Nelson, Paul
    Prism Training Consultancy, UK.
    Osuobeni, Ebi
    Anglia Ruskin University, UK.
    Sailoganathan, Ananth
    Anglia Ruskin University, UK.
    Price, Holly
    Anglia Ruskin University, UK.
    O'Leary, Daniel J.
    Anglia Ruskin University, UK.
    Aberration control and vision training as an effective means of improving accommodation in individuals with myopia.2009Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 50, nr 11, s. 5120-5129Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE: To test the efficacy of a novel dual treatment for improving accommodative accuracy and dynamics in young persons with myopia.

    METHODS: Ninety-three young persons with myopia (mean spherical equivalent, -3.0 +/- 1.8 D; age 16.8 +/- 2.1 years; spherical aberration +0.06 +/- 0.04 microm) participated in the study. Custom-designed soft contact lenses were used to alter ocular SA to -0.10 microm to improve accommodative accuracy and reduce any lag of accommodation. A vision training regimen was performed for 18 minutes per day for up to 6 weeks to improve speed of dynamic accommodation. Control groups had contact lenses with no added SA and/or no exercises. To avoid any effects of natural levels of negative aberration on the results of the study, all participants who had negative SA were excluded.

    RESULTS: The treatment contact lenses produced a significant reduction in lag of accommodation (P < 0.05) at all proximal viewing distances measured. The vision training measurement and treatment resulted in a significant increase in distance facility rate for all groups compared with their own baselines (P < 0.05). Near facility rate improved in the vision training treatment group only compared with its baseline (P < 0.05). Both positive and negative response times for distant viewing were significantly shorter in all groups after training compared with their baseline values (P < 0.05). At near, the positive response times were decreased significantly (P < 0.05) in both groups, whereas the negative response times decreased significantly only in the vision training treatment group.

    CONCLUSIONS: After 3 months, the dual treatments (altering SA and vision training) used in the study were effective in modifying accommodation. The static accommodative response to targets at proximal distances was increased by the altered SA contact lenses and rates of dynamic accommodation improved with vision training.

  • 8.
    Alm, Håkan
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Är svenska optikerbutiker tillgängliga för rörelsehindrade människor?2009Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Legitimerade optiker står under Hälso- och sjukvårdslagen och har därmed samma skyldigheter som övrig hälso- och sjukvårdspersonal. En optiker ska således kunna ta emot och erbjuda sina tjänster till alla människor. Studiens syfte var att undersöka hur väl detta fungerar i praktiken. Detta gjordes genom att undersöka optikerbutiker och bedöma dess tillgänglighet för rullstolsburna människor. Undersökningsgruppen bestod av 20 optikerbutiker fördelade på en mindre respektive en större sydsvensk stad. En enkät konstruerades utifrån studiens syfte som butikerna fick svara på samt en checklista skapades innehållande följande bedömningsområden: dörrar, korridorer, gångar, dörröppnare, trösklar samt trappsteg. Resultatet visade på stora brister i tillgänglighet. Endast 20 % av butikerna klassades som tillgängliga och enkätsvaren visade att var femte optiker någon gång ej haft möjlighet att undersöka en patient på grund av dess funktionshinder. Studien visar att de svenska optikerbutikerna inte lever upp till Hälso- och sjukvårdslagens krav på ”vård på lika villkor för hela befolkningen”.

  • 9.
    Amylon, Lisa
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Jämförelse av ögonansträngning vid läsning på papper och på mobilskärm2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte: Syftet med den här studien var att jämföra Digital Eye Strain-symptom mellan läsning på papper och mobiltelefon. Att undersöka om det som tidigare studier har visat i skillnad mellan läsning på papper och en datorskärm även gäller mobiltelefoner och hur mycket våra ögon påverkas när det gäller ansträngning, trötthet och andra ögonrelaterade symptom. 

    Metod: Deltagarna (n=16) fick läsa i 20 minuter tyst, antingen på papper eller en smartphone-skärm. Avståndet fick de själva bestämma. De läste samma bok med samma typsnitt och storlek på båda medierna. Direkt efter de hade läst i 20 minuter fick de fylla i ett frågeformulär som bestod av tio frågor kring deras upplevda ögonsymptom under uppgiften.

    Resultat: Studien visade på signifikanta skillnader i medelvärdet mellan papper och mobiltelefon på tre av symptomen: suddig syn vid tittande på texten (p=0,016), ansträngda ögon (p=0,023) samt trötta ögon (p=0,015). I alla tre fallen var symptompoängen högre efter läsning på mobilskärm än efter läsning på papper. Det fanns ingen signifikant skillnad mellan de övriga sju symptomen. Det var även en signifikant skillnad i läsavstånd med ett betydligt mindre avstånd till mobiltelefonen än till pappret.

    Slutsats: Studien visar att symptomen efter användning av mobiltelefon upplevs som svårare än efter läsning på papper. De tre symptom som skilde sig signifikant var alla högre efter läsning på mobilskärmen.

  • 10.
    Andersson, Linda
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Hanteringsträning - tidsåtgång och trygghetskänsla för patienter vid isättning och urtagning av mjuka kontaktlinser2009Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 11.
    Aronsson, Catrin
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Hur skiljer sig ackommodationsamplituden mellan Nicaragua och Sverige?2011Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte: Syftet med denna undersökning var att mäta ackommodationsamplitud i Nicaragua och Sverige för att se om det är någon signifikant skillnad mellan länderna i åldersgrupperna mellan 8 år och 40 år. Värdena som togs fram jämfördes sedan med publicerad litteratur för att undersöka hur denna studies värde skiljer sig från dessa, samt vilken av de tidigare studierna som var mest lik denna studies framtagna värde på ackommodationsamplitud i förhållande till åldern.

    Metod: Mätningarna skedde på 113 personer i Nicaragua och 113 personer i Sverige. För att vara med i denna studie krävdes det att försökspersonerna översteg 8 år och understeg 40 år. Mätningarna genomfördes med push-up metoden med hjälp av en mätsticka med figuroptotyp i form av en fågel.

    Resultat: Av de mätningar som genomfördes blev genomsnittet av ackommodationsamplitud 10,3 D (strandard avvikelse ±9,7 D) i Nicaragua och 11,5 D (standard avvikelse ±6,5 D) i Sverige. Ingen signifikant skillnad finns mellan länderna, det vill säga land (Nicaragua eller Sverige) har ingen påverkan på ackommodations amplitud enligt denna studie. Signifikans finns dock mellan ålder och ackommodation, en bekräftelse på att ålder påverkar ackommodationen har således observerats.

    Slutsats: Någon signifikant skillnad i ackommodationsamplitud mellan Nicaragua och Sverige kunde enligt denna studie ej påvisas. I jämförelsen mellan avvikelserna från både Duane och Donders tabeller jämte denna studie kan det avläsas att tabellerna har underskattat mängd ackommodationsamplitud.

  • 12.
    Arthur, Edmund
    et al.
    Indiana University, USA.
    Young, Stuart B.
    Baskaran, Karthikeyan
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Elsner, Ann E.
    Muller, Matthew S.
    Gast, Thomas J.
    Haggerty, Bryan P.
    Clark, Christopher A.
    Brahm, Shane
    Litvin, Taras V.
    Ozawa, Glen Y.
    Cuadros, Jorge
    Individual Retinal Layer Thickness in Diabetic Patients with Clinically Significant Macular Edema: A Gender Based Analysis2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    Purpose: To compare segmented retinal layer thicknesses between male and female diabetics with clinically significant macular edema (CSME). This study expands our earlier analysis of central macular thickness (CMT) measurements in diabetic males vs. females. Methods: Diabetic retinopathy screening of 2080 diabetics from Alameda County, CA, indicated 142 patients with CSME, as judged by EyePACS certified graders using color fundus images (Canon CR6-45NM). Of the 2080 diabetics, 1784 were imaged with SD-OCT (Optovue iVue). From the 142 patients, we selected 11 males with good fixation, CMT > 300 µm, and no other ocular complications, along with 11 females with the greatest values of CMT while controlling for age, HbA1c and diabetes duration. Manual segmentation of retinal layers using custom software (Mathworks Matlab) of the SD-OCT images of these subjects was done. We analyzed thicknesses for regions 1 deg - 2 deg for nasal and temporal retina in a B-scan centered on the fovea. A 2 X 2 ANOVA probed the differences in thickness for gender, meridian, and their interaction. We also analyzed the central 1 mm of the outer retinal layers, and performed t-tests. Results: Males had significantly thicker nerve fiber layer (NFL) (13.30 ± 2.85 µm) than females (10.13 ± 6.13 µm) and ganglion cell layer-inner plexiform layer (GCL-IPL) (62.54 ± 21.18 µm) than females (48.07 ± 25.91 µm), p < 0.05. There was no effect of meridian and no interaction (p > 0.05). All other layers except the retinal pigment epithelium (RPE) were thicker for males than females even though these were not significant (p > 0.05). There were no significant differences for the layers of the outer retina, which were highly variable and distorted by cysts. Conclusion: Outside the fovea, NFL and GCL-IPL thicknesses were significantly higher in males than females.

  • 13.
    Arthur, Edmund
    et al.
    Indiana University, USA.
    Young, Stuart B.
    Bowersox Vision Center, Shelbyville, USA.
    Elsner, Ann E.
    Indiana University, USA.
    Baskaran, Karthikeyan
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Papay, Joel A.
    Indiana University, USA.
    Muller, Matthew S.
    Aeon Imaging, LLC, Bloomington, USA.
    Gast, Thomas J.
    Indiana University, USA;Aeon Imaging, LLC, Bloomington, USA.
    Haggerty, Bryan P.
    Indiana University, USA.
    Clark, Christopher A.
    Indiana University, USA.
    Malinovsky, Victor E.
    Indiana University, USA.
    Brahm, Shane G.
    Peter Christensen Health Center, Lac Du Flambeau, USA.
    Litvin, Taras V.
    University of California, USA.
    Ozawa, Glen Y.
    University of California Berkeley, USA.
    Cuadros, Jorge A.
    University of California Berkeley, USA.
    Central Macular Thickness in Diabetic Patients: A Sex-based Analysis2019Ingår i: Optometry and Vision Science, ISSN 1040-5488, E-ISSN 1538-9235, Vol. 96, nr 4, s. 266-275Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    SIGNIFICANCE The pathological changes in clinically significant diabetic macular edema lead to greater retinal thickening in men than in women. Therefore, male sex should be considered a potential risk factor for identifying individuals with the most severe pathological changes. Understanding this excessive retinal thickening in men may help preserve vision. PURPOSE The purpose of this study was to investigate the sex differences in retinal thickness in diabetic patients. We tested whether men with clinically significant macular edema had even greater central macular thickness than expected from sex differences without significant pathological changes. This study also aimed to determine which retinal layers contribute to abnormal retinal thickness. METHODS From 2047 underserved adult diabetic patients from Alameda County, CA, 142 patients with clinically significant macular edema were identified by EyePACS-certified graders using color fundus images (Canon CR6-45NM). First, central macular thickness from spectral domain optical coherence tomography (iVue; Optovue Inc.) was compared in 21 men versus 21 women without clinically significant macular edema. Then, a planned comparison contrasted the greater values of central macular thickness in men versus women with clinically significant macular edema as compared with those without. Mean retinal thickness and variability of central macular layers were compared in men versus women. RESULTS Men without clinically significant macular edema had a 12-μm greater central macular thickness than did women (245 ± 21.3 and 233 ± 13.4 μm, respectively; t40 = −2.18, P = .04). Men with clinically significant macular edema had a 67-μm greater central macular thickness than did women (383 ± 48.7 and 316 ± 60.4 μm, P < .001); that is, men had 55 μm or more than five times more (t20 = 2.35, P = .02). In men, the outer-nuclear-layer thickness was more variable, F10,10 = 9.34. CONCLUSIONS Underserved diabetic men had thicker retinas than did women, exacerbated by clinically significant macular edema.

  • 14.
    Arvidsson, Emma
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Skiljer sig blinkfrekvensen vid läsning på olika medier?2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte: Syftet med den här studien var att undersöka om Spontaneous Eye Blink Rate (SEBR) skiljde sig åt vid läsning på utskrivet papper, surfplatta eller smartphone. Det jämfördes också huruvida fullständiga och ofullständiga blinkningar skiljde sig åt vid läsning på de olika medierna.

    Metod: Deltagarna (n=29) fick läsa tre olika texter på utskrivet papper, surfplatta och smartphone samtidigt som de filmades. I efterhand granskades samtliga videos två gånger för att räkna fullständiga blinkningar, ofullständiga blinkningar och totalt antal blinkningar (SEBR).

    Resultat: Den här studien visade att där finns en signifikant skillnad av totalt antal blinkningar vid läsning på utskrivet papper och surfplatta (p=0,03), där blinkningar/minut sjönk med 14,9% vid läsning på utskrivet papper, jämfört med surfplatta. För ofullständiga blinkningar fanns en statistiskt signifikant skillnad mellan utskrivet papper och surfplatta (p=0,02), där antalet ofullständiga blinkningar/minut ökade med 30,0% vid läsning på surfplatta, jämfört med utskrivet papper. Vid läsning på surfplatta och smartphone fanns en signifikant skillnad gällande ofullständiga blinkningar (p=0,01), där antalet ofullständiga blinkningar/minut ökade med 42% vid läsning på surfplattan, jämfört med smartphone. 

    Slutsats: Spontaneous Eye Blink Rate skiljer sig vid läsning på papper och surfplatta. Ofullständiga blinkningar är flest vid läsning på surfplatta. Inga signifikanta skillnader finns mellan utskrivet papper och smartphone.  

  • 15.
    Arvidsson, Marie-Louise
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Vilken läshastighet ger den svenska versionen av internationellt standardiserade läshastighetstexter?2010Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Bakgrund - Att läsa en tidning är en självklarhet för många  idag. Det är en naturlig del av vardagen att tillgodogöra sig skriftlig information. Det här är inte en självklar sanning. Många med nedsatt syn behöver använda hjälpmedel som förstorande optik och starkare belysning m m för att klara den här vardagliga situationen. Hur mäts läsförmågan som den synskadade har? Det finns olika lästester för det här syftet.  Testerna som finns sedan tidigare består av enstaka meningar i olika storlekar. I det EU-baserade AMD-Read projektet togs det fram ett set med 10st  nya  längre läshastighetstexter. Eftersom de här nyare texterna (IReST) består av längre sammanhängande meningar i varje lässtycke så finns möjligheten att mäta den faktiska läshastigheten som den synskadade har.  Det går att jämföra resultat före och efter korrektion eller synträning. Texterna finns standardiserade på finska, franska, tyska, engelska, portugisiska och arabiska.

    Syfte - Syftet med denna studie är att utvärdera den svenska versionen av IReST texterna. Frågeställningen var om de tio svenska texterna gav ett jämförbart resultat i läshastighet.

    Metod – 25 friska normalseende personer 19-35 år deltog i studien. Deltagarna fick en och en läsa de 10 läshastighetstexterna högt under tidtagning och röstinspelning. Texterna lästes i slumpvis ordning.

    Resultat -  Två av de tio texterna tog signifikant längre tid att läsa mot de övriga åtta. När det gäller antal fellästa tecken/minut fanns det ingen signifikant skillnad mellan de tio texterna.

  • 16.
    Baptista, Antonio M. G.
    et al.
    University of Minho, Portugal.
    Joel, Monteiro
    Centro Hospitalar do Alto Ave, Portugal.
    Vieira, Marco
    Centro Hospitalar do Alto Ave, Portugal.
    Reimão, Pedro
    Centro Hospitalar do Alto Ave, Portugal.
    Rocha, Paulo
    University of Porto, Portugal.
    Rocha-Sousa, Amandio A.
    University of Porto, Portugal.
    Freitas, Cristina
    Hospital de Braga, Portugal.
    Macedo, António Filipe
    University of Minho, Portugal.
    Marques, Ana Patricia
    Nova University of Lisbon, Portugal.
    Santana, Rui
    Nova University of Lisbon, Portugal.
    Causes of Vision Impairment in Portugal: A hospital based study2015Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 56, nr 7, artikel-id 2118Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose 

    Causes of vision impairment (VI) are influenced by factors such as race or socio-economic circumstances. Because of this collecting national information is important for planning reduction of vision loss. The aim of this study was to determine causes of vision impairment in a population visiting ophthalmology departments in public hospitals in Portugal.

    Methods 

    This study was designed according with the guidelines of the Vancouver Economic Burden of Vision Loss Group (IOVS, 2010, V51/4/1801). Recommendations are to collect hospital data during 1 year to determine causes of VI. We selected four public hospitals that are expected to have over 120-140K appointments per year. Files are analysed weekly to detect patients with vision impairment. Inclusion criteria are: visual acuity with the current refractive correction equal or less than 0.5 (20/40) in the better-seeing eye and/or a visual field of less than 20 degrees. Patients were selected by trained hospital staff (medics and orthoptists) and inserted in a database. Diagnoses were classified according the ICD9. Data collected included fundamental demographic information, main diagnosis, secondary diagnosis and comorbidities.

    Results 

    We have now 2462 patients selected that correspond to 4 to 33 weeks of data collection. The number of weeks is variable because we did not start all hospitals simultaneously. From the current number of cases detected, 58% are female, 1.9% are under 20, 8.2% are between 20 and 50 and 89.9% are 50 years or older. The leading causes of vision impairment among these patients are diabetic retinopathy (DR), cataract (C), glaucoma (GC) and age-related macular degeneration (AMD). Using the North American definition of VI the proportions are 26.8% for DR, 25.5% for C, 10.4% for GC and 8.2% for AMD. The remaining causes of VI have percentages below 5% and in total they correspond to approximately 29% of the cases detected.

    Conclusions 

    Our results show that the most common causes of vision impairment are eye diseases related with systemic conditions and aging of the population. Vision impairment was relatively low under the age of 20 and the causes were mostly inherited diseases. Numbers reported now will be more accurate at the end of the study but they already highlight the importance of targeting conditions such as diabetes.

  • 17.
    Baptista, António M. G.
    et al.
    University of Minho, Portugal.
    Sousa, Raul A. R. C.
    Rocha, Filomena A. S. Q.
    Sepúlveda Fernandes, Paula
    Macedo, António Filipe
    University of Minho, Portugal.
    The macular photostress test in diabetes, glaucoma, and cataract2013Ingår i: 8th Iberoamerican Optics Meeting and 11th Latin American Meeting on Optics, Lasers, and Applications, SPIE - International Society for Optical Engineering, 2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Purpose. The photostress recovery time test (PSRT) has been widely reported as a helpful screening clinical tool. However, the poor standardization of its measurement technique remains to be a limitation among clinicians. The purpose of this study is to apply a recommended clinical technique to measure the PSRT in some of the most commons eye diseases to ascertain whether these diseases affect the PSRT values. Methods. One hundred and one controls and 105 patients, with diagnosed diabetes (without visible signs of diabetic retinopathy), primary open angle glaucoma (POAG) or cataracts underwent photostress testing. The test was performed with a direct ophthalmoscope for illuminating the macula for 30 seconds. Participants belonged to three age classes: A, B and C; and were divided into four groups: control, diabetic, POAG and cataract. The age range for A, B and C classes were respectively 43-54, 55-64 and 65-74 years. The groups were also further compared within each age class. In addition, the influence of age on PSRT was evaluated using the control group. Results. Results demonstrate that PSRT changes with age (p<0.02). In class A, diabetic group had a faster PSRT than control group, (mean ± standard deviation) 20.22±7.51 and 26.14±8.34 seconds. The difference between these groups was statistical significant (t-test, p=0.012). Cataract and POAG groups did not affect the PSRT significantly. Conclusions. The technique used for the Photostress showed that diabetics, younger than 54 years, may have faster PSRT and that, aging delays PSRT

  • 18.
    Baskaran, Karthikeyan
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Optimal Use of Peripheral Vision2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    People who lose their central vision have to rely on their peripheral vision for all visual tasks. The ability to resolve fine details in the periphery is reduced due to retinal limitations and the optical aberrations arising from the use of off-axis vision. The aim of this work is to improve vision by enhancing the image quality at the preferred retinal locus by means of correcting the optical errors. The focus of this thesis has been to measure and correct peripheral optical errors, as well as to evaluate their impact on resolution acuity in both normal and central visual field loss subjects.

     In order to measure peripheral optics we employed a COAS HD VR open view aberrometer which is based on the Hartmann-Shack principle. Psychophysical methods were used to evaluate peripheral grating resolution acuity. We assessed the repeatability of the wavefront sensor in measuring the peripheral ocular aberrations. The symmetry of peripheral ocular aberrations between the left and right eyes was examined. The influence of age on peripheral ocular aberrations was also investigated. We evaluated peripheral vision with sphero-cylindrical correction in healthy eyes and performed the first adaptive optics aberration correction at the preferred retinal locus of a single central visual field loss subject.

     We found that the aberrometer was repeatable and reliable in measuring peripheral ocular aberrations. There was mirror symmetry between the two eyes for most of the peripheral aberration coefficients. Age had a significant influence on peripheral ocular aberrations; there were larger amounts of higher-order aberrations in old eyes than in young eyes. Peripheral low contrast resolution acuity improved with peripheral refractive correction in subjects who had higher amounts of off-axis astigmatism. Finally, adaptive optics aberration correction improved both high and low contrast resolution acuity measured at the preferred retinal locus of the single low vision subject.

     Because of their versatility, open view aberrometers will hopefully be a standard clinical instrument at low vision clinics as they allow for measurements to be rapidly performed at any location in the visual field. The existence of off-axis astigmatism should be better communicated within the low-vision rehabilitation community. Currently, the off-axis refractive errors can be corrected with conventional methods and we hope that the higher-order aberrations can also be corrected in a more realistic ways in the future.  

     In conclusion, this thesis has shown that peripheral visual function can be improved by optical correction. The findings of this thesis have broadened the knowledge of peripheral optical errors and their influence on vision.

  • 19.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Calabrèse, Aurélie
    Castet, Eric
    Moreno, Laura
    Silva, Marta
    Macedo, António Filipe
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Scoring reading parameters: an inter-rater reliability study using the MNREAD test2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    Aim: Estimating MNREAD parameters such as Critical Print Size (CPS) and Maximum Reading Speed (MRS) - using the time taken to read blocks of text - often requires subjective analysis of the reading profile. Depending on the rater, parameters may be over- or under-estimated, resulting in difficult or even impossible between-study comparisons. The aim of this project was to evaluate the inter-rater reliability of MNREAD parameters in subjects with visual impairment. Methods: Reading times for the Portuguese version of the MNREAD chart from 32 subjects, reading binocularly were analyzed. Reading speed was computed by a single experimenter (AFM) using reading time and number of errors. Based on reading speeds, three experimented raters (AFM, AC and KB) computed MRS and CPS using the following method. CPS was defined as the print size at which subsequent smaller print sizes were read at 1.96 x standard deviation slower than the mean of the preceding print sizes; MRS was estimated as the mean reading speed for sentences in print larger than the CPS. Inter-rater reliability was assessed using intra-class correlation (ICC) coefficient for both MRS and CPS for all three raters. Results: Near acuity range was 0.14-1.9 logMAR. The average measure ICC for CPS was 0.896 with a 95% CI from 0.814 to 0.946 (p< 0.001). The average measure ICC for MRS was 0.984 with a 95% CI from 0.970 to 0.992 (p< 0.001). Conclusion: A high degree of reliability was found between the three raters for both CPS and MRS. Even though some small variability exists this may be due to raters’ high-level experience with MNREAD data. Future directions will involve: 1) including more raters with various level of experience in MNREAD rating; 2) investigating the degree of inter-rater reliability for raters using different estimation methods.

  • 20.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Ekblad, Johan
    SYAB, Kalmar.
    Inde, Krister
    Indenova, Karlstad.
    Melis-Dankers, Bart
    Royal Dutch Visio, Centre of Expertise for Blind and Partially Sighted People, Netherlands.
    Driving performance in participants with quadrantanopia and hemianopia in Sweden: a closed circuit driving track study2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    Background: The ability to drive a car is one of the important aspect of a person’s independent lifestyle. People with visual field defects after stroke or traumatic brain injury (TBI) have more limitations in driving. In Sweden, they are not allowed to drive and their driving licenses are revoked. The Swedish transport agency does not allow any on-road test for them to prove their practical fitness to drive. Therefore, the aim was to evaluate driving performance in participants with visual field defects after TBI in a closed circuit driving track.Methods: Eleven participants with varying degrees of quadrantanopia and hemianopia after TBI were recruited for this study. The mean age of the participants was 58 ±13.7 years (37 - 73 years). All participants underwent 10 weeks of explorative saccadic training at the hospital prior to driving assessment. Driving performance were assessed by two driving instructors and they graded the participants from 1 (fail) to 5 (excellent) on the following five categories: maneuvering the vehicle, safety margin, traffic rules, scanning for potential hazards and reacting to situations. The subject passed the driving test only if they scored 3 or more in each category.Results: Five (45%) out of 11 participants passed the driving test and they were adjudged as fit to drive. Remaining six (55%) participants failed at least in one category. Three of them failed in visual scanning, two failed in maneuvering and one failed in both the aforementioned categories as well as safety margin.Discussion: A rehabilitation program aimed at improving safe driving should be implemented and an on-road assessment of fitness to drive should be allowed in Sweden for this population in future.Conclusion: The decision on practical fitness to drive cannot be based solely on the presence of visual field defect and an on-road assessment is required.

  • 21.
    Baskaran, Karthikeyan
    et al.
    Indiana University, USA.
    Elsner, Ann E.
    Indiana University, USA ; Aeon Imaging, USA.
    Muller, Matthew S.
    Aeon Imaging, USA.
    Haggerty, Bryan P.
    Indiana University, USA.
    Papay, Joel A.
    Indiana University, USA.
    Gast, Thomas
    Indiana University, USA ; Aeon Imaging, USA.
    Litvin, Taras V.
    University of California Berkeley, USA.
    Ozawa, Glen Y.
    University of California Berkeley, USA.
    Cuadros, Jorge
    University of California Berkeley, USA.
    Petrig, Benno L.
    Aeon Imaging, USA.
    Stability of fixation in diabetes patients with and without clinically significant macular edema2014Konferensbidrag (Refereegranskat)
    Abstract [en]

    Purpose - Eye diseases affecting central vision impair fixation and interfere with day-to-day tasks such as reading. Diabetic retinopathy and clinically significant macular edema (CSME) are leading causes of visual impairment in diabetes patients. The aim of this study is to find whether diabetic patients with CSME have poorer fixation stability compared to patients without CSME, by analyzing the fundus images obtained from the Laser Scanning Digital Camera (LSDC).

    Methods - Two hundred underserved, diabetic patients were screened for diabetic retinopathy at the Eastmont Wellness Center within the EyePACS telemedicine network, using LSDC. One eye of each patient who had diabetic retinopathy was included in this study. Non-mydriatic color fundus photos were classified for presence of CSME by two independent, certified EyePACS graders. The first 50 patients (25 males &amp; 25 females) with CSME were selected and 50 (27 males &amp; 23 females) diabetic patients without CSME were selected as controls. Mean age was 59 (±9) years for patients with CSME and was 55 (±10) years for patients without CSME. The subjects included 53% Hispanics, 26% African Americans and 21% other. A series of 20 images (36 deg field, 1024 X 1024 pixels, and 850 nm) were acquired at 11 fps. Eye positions were obtained by selecting a region of interest in the first image of each series and aligning the remaining images to that region by cross-correlation. The bi-contour ellipse area (BCEA) and the standard deviation of the Euclidean distance (SDED) were used to quantify fixation stability.

    Results - The fixation stability for patients with CSME was significantly worse than for those without CSME (t test: p &lt; 0.001, 0.007 for BCEA and SDED, respectively). The mean fixation stability obtained by the BCEA metric was 2.74 (±0.40) log(minArc2) and 2.34 (±0.42) log(minArc2) for patients with and without CSME, respectively. For SDED the mean was 48.4 (±28.8) microns and 34.6 (±20.4) microns for patients with and without CSME, respectively. The correlation with age was not significant for either group (R2 = 0.052, 0.011).

    Conclusions - Diabetic patients with CSME had poorer fixation stability than patients without CSME for both metrics. Fixation stability is a potential tool for assessing macular function and could be used for tracking the treatment and progression of macular edema.The LSDC images provide one method to quantify fixation stability rapidly.

  • 22.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Inde, Krister
    Ekblad, Johan
    Melis-Dankers, Bart
    Closed circuit driving performance in persons with quadrantanopia and hemianopia in Sweden2016Ingår i: Scandinavian Journal of Optometry and Visual Science, ISSN 1891-0882, E-ISSN 1891-0890, Vol. 9, nr 2, s. 14-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In Sweden, persons with homonymous visual field defects (HVFDs) are not allowed to drive and usually their driving licences are revoked. Although earlier studies (de Haan et al. 2014; Elgin et al. 2010) have shown that HVFDs do not necessarily impair practical fitness to drive, the Swedish transport agency does not allow them any on-road driving testing to prove their practical fitness to drive. The aim of this study was to evaluate driving performance in participants with visual field defects after acquired brain injury in a closed circuit driving track. Eleven former drivers with varying degrees of quadrantanopia and hemianopia after acquired brain damage were recruited for this study from the stroke rehabilitation department at Kalmar County Hospital. The median age of the participants was 55 years and their age ranged from 37 to 73 years. Driving performance was assessed by two experienced driving instructors. They graded the participants on a scale from 1 (major faults) to 5 (excellent) on the following five categories: manoeuvring the vehicle, risk assessment, traffic rules, visual scanning and situation awareness. The subject would pass the driving test only if they had scored 3 or more in each category. The subjects who passed the closed circuit driving track test were evaluated further with a driving simulator. Five (45%) out of 11 participants passed the driving test and were adjudged as fit to drive. The remaining six (55%) participants failed in at least one category. Three failed in visual scanning, two failed in manoeuvring and one failed in both the aforementioned categories as well as risk assessment. Three subjects who passed the closed circuit driving track test were also evaluated in a driving simulator. Out of the three subjects, only one was able to complete and pass the evaluation while the remaining two participants aborted the evaluation due to simulator sickness. Homonymous visual field defects do not necessarily impair fitness to drive. Therefore, an on-road assessment of practical fitness to drive should be allowed in Sweden for this population in the near future. The decision on practical fitness to drive cannot be based solely on the presence of visual field defects. A rehabilitation program aimed at improving safe driving should be put into practice with an on-road driving training and assessment procedure. It should be developed and implemented by experienced traffic inspectors as a complementary part of the decision to either issue or revoke a driving licence for this population.

  • 23.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Inde, Krister
    SMS Projektgrupp, .
    SYAB Kalmar, .
    SMS resultatrapporten2015Rapport (Refereegranskat)
  • 24.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Macedo, António Filipe
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Calabrèse, Aurélie
    Aix-Marseille University, France.
    Rater and algorithm data of maximum reading speed (MRS) and critical print size (CPS) of 101 low vision participants.2019Dataset
  • 25.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Macedo, António Filipe
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO). University of Minho Braga, Portugal.
    He, Yingchen
    University of Minnesota, USA.
    Hernandez-Moreno, Laura
    University of Minho Braga, Portugal.
    Queirós, Tatiana
    Hospital de Braga, Portugal.
    Mansfield, J. Stephen
    SUNY College at Plattsburgh, USA.
    Calabrèse, Aurélie
    Aix-Marseille University, France;CNRS, France.
    Scoring reading parameters: An inter-rater reliability study using the MNREAD chart2019Ingår i: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 14, nr 6, s. 1-14, artikel-id e0216775Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose First, to evaluate inter-rater reliability when human raters estimate the reading performance of visually impaired individuals using the MNREAD acuity chart. Second, to evaluate the agreement between computer-based scoring algorithms and compare them with human rating. Methods Reading performance was measured for 101 individuals with low vision, using the Portuguese version of the MNREAD test. Seven raters estimated the maximum reading speed (MRS) and critical print size (CPS) of each individual MNREAD curve. MRS and CPS were also calculated automatically for each curve using two different algorithms: the original standard deviation method (SDev) and a non-linear mixed effects (NLME) modeling. Intra-class correlation coefficients (ICC) were used to estimate absolute agreement between raters and/or algorithms. Results Absolute agreement between raters was ‘excellent’ for MRS (ICC = 0.97; 95%CI [0.96, 0.98]) and ‘moderate’ to ‘good’ for CPS (ICC = 0.77; 95%CI [0.69, 0.83]). For CPS, inter-rater reliability was poorer among less experienced raters (ICC = 0.70; 95%CI [0.57, 0.80]) when compared to experienced ones (ICC = 0.82; 95%CI [0.76, 0.88]). Absolute agreement between the two algorithms was ‘excellent’ for MRS (ICC = 0.96; 95%CI [0.91, 0.98]). For CPS, the best possible agreement was found for CPS defined as the print size sustaining 80% of MRS (ICC = 0.77; 95%CI [0.68, 0.84]). Absolute agreement between raters and automated methods was ‘excellent’ for MRS (ICC = 0.96; 95% CI [0.88, 0.98] for SDev; ICC = 0.97; 95% CI [0.95, 0.98] for NLME). For CPS, absolute agreement between raters and SDev ranged from ‘poor’ to ‘good’ (ICC = 0.66; 95% CI [0.3, 0.80]), while agreement between raters and NLME was ‘good’ (ICC = 0.83; 95% CI [0.76, 0.88]). Conclusion For MRS, inter-rater reliability is excellent, even considering the possibility of noisy and/or incomplete data collected in low-vision individuals. For CPS, inter-rater reliability is lower. This may be problematic, for instance in the context of multisite investigations or follow-up examinations. The NLME method showed better agreement with the raters than the SDev method for both reading parameters. Setting up consensual guidelines to deal with ambiguous curves may help improve reliability. While the exact definition of CPS should be chosen on a case-by-case basis depending on the clinician or researcher’s motivations, evidence suggests that estimating CPS as the smallest print size sustaining about 80% of MRS would increase inter-rater reliability.

  • 26.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Olsson, Roger
    Theagarayan, Baskar
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Effect of accommodation on peripheral refraction in myopes and emmetropes using a COAS-HD VR open field aberrometer.2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    Purpose To investigate the effect of accommodation on both central and peripheral refractive errors in myopes compared to emmetropes using a COAS-HD VR open field aberrometer. Methods 15 myopic subjects (-1.50 D to -8.25 D) and 14 emmetropic subjects (+0.75 D to -0.25 D) participated in this study. The mean age of the myopic group was 24.3 ± 5.7 years and for the emmetropic group was 23.9 ± 5.7 years. Central and peripheral refraction were measured with a COAS-HD VR open field instrument at seven different eccentricities from 0° to ± 30° in 10° steps for three different accommodative demands 0.33 D, 2.50 D and 4.0 D during monocular viewing. The myopic subjects were corrected with soft contact lenses and the measurements were performed on the right eye for a 3 mm pupil diameter for both groups. Relative peripheral refractive error (RPRE) was calculated for all three accommodative demands for both groups. Results Repeated measures ANOVA showed no significant difference in RPRE across eccentricities or between accommodation demands in the myopes (pÂż0.05). The myopic group had minimal hyperopic shift in the periphery for all three accommodative demands. The largest mean hyperopic shift was 0.37 D at 30° nasal retina for an accommodative demand of 4.0 D. On the other hand, the emmetropic group became relatively myopic at peripheral eccentricities, from 20° onwards for all three accommodative demands. The largest mean myopic shift was 1.01 D at 30° temporal retina for an accommodative demand of 2.50 D. Conclusion In the myopic group, we did not find any significant reduction in hyperopic shift in the periphery with accommodation. The emmetropic group showed myopic shift in the periphery for all three accommodative demands with temporal retina being more myopic than nasal retina.

  • 27.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Rosen, R.
    Lewis, Peter
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Unsbo, P.
    Gustafsson, Jörgen
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Benefit of Adaptive Optics Aberration Correction at Preferred Retinal Locus2012Ingår i: Optometry and Vision Science, ISSN 1040-5488, E-ISSN 1538-9235, Vol. 89, nr 9, s. 1417-1423Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE.: To investigate the effect of eccentric refractive correction and full aberration correction on both high- and low-contrast grating resolution at the preferred retinal locus (PRL) of a single low-vision subject with a long-standing central scotoma. METHODS.: The subject was a 68-year-old women with bilateral absolute central scotoma due to Stargardt disease. She developed a single PRL located 25 degrees nasally of the damaged macula in her left eye, this being the better of the two eyes. High- (100%) and low-contrast (25 and 10%) grating resolution acuity was evaluated using four different correction conditions. The first two corrections were solely refractive error corrections, namely, habitual spectacle correction and full spherocylindrical correction. The latter two corrections were two versions of adaptive optics corrections of all aberrations, namely, habitual spectacle correction with aberration correction and full spherocylindrical refractive correction with aberration correction. RESULTS.: The mean high-contrast (100%) resolution acuity with her habitual correction was 1.06 logMAR, which improved to 1.00 logMAR with full spherocylindrical correction. Under the same conditions, low-contrast (25%) acuity improved from 1.30 to 1.14 logMAR. With adaptive optics aberration correction, the high-contrast resolution acuities improved to 0.89/0.92 logMAR and the low-contrast acuities improved to 1.04/1.06 logMAR under both correction modalities. The low-contrast (10%) resolution acuity was 1.34 logMAR with adaptive optics aberration correction; however, with purely refractive error corrections, she was unable to identify the orientation of the gratings. CONCLUSIONS.: Correction of all aberrations using adaptive optics improves both high- and low-contrast resolution acuity at the PRL of a single low-vision subject with long-standing absolute central scotoma

  • 28.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Theagarayan, Baskar
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Carius, Staffan
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Gustafsson, Jörgen
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Influence of age on peripheral aberration2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    The purpose of this study is to compare peripheral higher order aberrations in young

    and old emmetropic eyes across the horizontal (±40°) and inferior (–20°) visual field.

    Introduction

     

     

    People with central visual field loss use eccentric fixation for various visual tasks.

    Recently studies have shown that the correction of lower order aberrations (defocus &

    astigmatism) can improve eccentric vision in subjects with central visual field loss

    (CFL)[1]. The CFL subjects mostly correspond to older age groups who use eccentric

    fixation angles up to 20°–30°. While there have been studies comparing the off-axis

    lower order aberrations in normal young and old subjects[2], there is only one recent

    study, which has compared off-axis higher order aberrations in normal young and old

    emmetropic eyes up to 20° (horizontal and vertical) eccentricity[3]. In this study we

    have measured off-axis aberrations in a group of 10 young (23 ± 3 years) and 10 old

    (57 ± 4 years) emmetropes. The aberrations of the right eye were measured using

    COAS-HD VR Hartmann-Shack aberrometer in steps 10° out to ± 40° horizontally and

    –20° inferiorly in the visual field. Subjects rotated the eyes to view the fixation targets,

    which were red light emitting diodes, placed at 3 meter from the eye. The aberrations

    were quantified for a pupil area 5 mm in diameter.

    Discussion

     

     

    Mixed between-within subject’s analysis of variance of the horizontal coma C13

    showed that there was a statistically significant difference between age groups

    (p<0.05). The coma increased linearly in both groups from nasal to temporal visual

    field. The rate of change was greater in the old (slope = –0.027 μm/deg) compared

    to the young (slope = –0.012 μm/deg) emmetropes. In the inferior visual field,

    vertical coma C-13 changed linearly in both groups with higher values in old (slope =

    0.015 μm/deg) compared to young (slope = 0.006 μm/deg). The mean spherical

    aberration was positive in older emmetropes (0.053 μm) compared to young

    emmetropes (-0.030 μm). The HO RMS showed a quadratic increase in the

    periphery for both age groups. The HO RMS was greater in older emmetropes but it

    was not statistically significant (p>0.05) when compared to young emmetropes.

     

    Conclusions

     

     

    Our results show that there is an increase in coma, spherical aberration, and HO

    RMS with age in the periphery.

  • 29.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Theagarayan, Baskar
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Carius, Staffan
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Gustafsson, Jörgen
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Measurement of Off-axis Refraction with a Commercial Open Field Aberrometer2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Purpose:

    People with central visual field loss (CFL) use their remaining peripheral vision in order to see better when performing various visual related tasks. At large off-axis angles, the eccentric vision can be limited both by the low resolution capacity of the peripheral retina and by the optical aberrations caused due to oblique angles. Previous work has shown that eccentric correction of induced off-axis astigmatism can improve vision in a preferred retinal location (PRL) for people with CFL. However, the eccentric refraction is often difficult to determine with traditional refractive methods. This work therefore shows the use of a commercially available wavefront sensor to measure fast and reliable off-axis refraction. Data on off-axis refraction is also of interest in the field of myopia research.

    Methods:

    We used the new open-field high-definition complete ophthalmic analysis system, COAS HD -VR, to evaluate off-axis refraction. Using the special Vision Research tool in this system stimulus (fixation objects) can be presented in a large part of the visual field. The instrument can measure out to 40 degrees in the horizontal visual field and 20 degrees in the vertical visual field with a range from sphere +7 D to − 17 D. It measures astigmatism up to 10 D. This instrument also allows natural binocular viewing without obstacles. Aberrations of the right eye of 30 emmetropes (24 ± 4 years) were studied. Off-axis refraction and higher order (HO) aberrations were measured in steps of 10° out to ± 30° in the horizontal visual field

    Results:

    The first data on young emmetropic eyes with this new instrument showed promising results for low (LO) and higher order (HO) aberrations in the peripheral visual field. Of the LO aberrations, astigmatism increased significantly with the off–axis angle, from 0.25 D at 10° Nasal to 1.65 D at 30° Nasal. In the HO aberrations, coma (C13) showed a linear increase across the horizontal visual field (p < 0.05)

    Conclusions:

    The COAS HD-VR shows promising results and good usability for future research in evaluation of off-axis refraction. In future we believe the aberrometer can be used clinically to measure off-axis refractions in low vision patients.

  • 30.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Theagarayan, Baskar
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Carius, Staffan
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Gustafsson, Jörgen
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Ocular Aberrations in the Peripheral Visual Field With a Commercial Open-View Aberrometer2010Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 51, nr 5, artikel-id 3951Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PurposeThe interest in off-axis aberrations has increased with the discovery of a possible link between myopia development and peripheral optics. The most common technology to measure the off-axis aberrations is a Shack-Hartmann wavefront aberrometer. This is the first study to report peripheral aberrations in a large sample of emmetropic population with a commercial open-view Shack-Hartmann aberrometer. MethodsThe commercial open-view Shack-Hartmann aberrometer COAS-HD VR was used to measure the aberrations in the peripheral vision. Aberrations of the right eye of 30 emmetropes (24 {+/-} 4 years) were studied. Off-axis aberrations were measured in steps of 10{degrees} out to {+/-} 30{degrees} in the horizontal visual field. The subjects turned their eye to view the off-axis fixation target (light emitting diode placed at 3 meters) during the measurement. The resulting wavefront aberrations were parameterized with Zernike coefficients for a 5 mm diameter pupil. All analyzes are reported according to optical society of America (OSA) recommended standards. ResultsAberrations from the 2nd to 6th order and the total higher-order root-mean-square (HO RMS) were analyzed using one-way ANOVA. The defocus C02 was significantly myopic in the nasal visual field (+20{degrees}, +30{degrees}) whereas there was no significant difference in the temporal visual field. Astigmatism C22 increased quadratically from {+/-}10{degrees} in the periphery and coma C13 showed a linear increase across the horizontal visual field (p < 0.05). The spherical aberration C04 and the total HO RMS showed a significant change at {+/-}30o. ConclusionsOur results showed that in young emmetropes there was a significant increase of HO RMS at {+/-}30{degrees}, which is expected. Astigmatism, horizontal coma, and spherical aberration vary systematically across the horizontal visual field in agreement with Seidel theory. The findings of our study with a large sample of emmetropic population agree with the previous studies done with laboratory built aberrometers.

  • 31.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Theagarayan, Baskar
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Carius, Staffan
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för datavetenskap, fysik och matematik, DFM.
    Gustafsson, Jörgen
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Repeatability of Peripheral Aberrations in Young Emmetropes2010Ingår i: Optometry and Vision Science, ISSN 1040-5488, E-ISSN 1538-9235, Vol. 87, nr 10, s. 751-759Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE.: The purpose of this study is to assess the intrasession repeatability of ocular aberration measurements in the peripheral visual field with a commercially available Shack-Hartmann aberrometer (complete ophthalmic analysis system-high definition-vision research). The higher-order off-axis aberrations data in young healthy emmetropic eyes are also reported.

    METHODS.: The aberrations of the right eye of 18 emmetropes were measured using an aberrometer with an open field of view that allows peripheral measurements. Five repeated measures of ocular aberrations were obtained and assessed in steps of 10 degrees out to +/-40 degrees in the horizontal visual field (nasal + and temporal -) and -20 degrees in the inferior visual field. The coefficient of repeatability, coefficient of variation, and the intraclass correlation coefficient were calculated as a measure of intrasession repeatability.

    RESULTS.: In all eccentric angles, the repeatability of the third- and fourth-order aberrations was better than the fifth and sixth order aberrations. The coefficient of variation was <30% and the intraclass correlation coefficient was >0.90 for the third and fourth order but reduced gradually for higher orders. There was no statistical significant difference in variance of total higher-order root mean square between on- and off-axis measurements (p > 0.05). The aberration data in this group of young emmetropes showed that the horizontal coma (C13) was most positive at 40 degrees in the temporal field, decreasing linearly toward negative values with increasing off-axis angle into the nasal field, whereas all other higher-order aberrations showed little or no change.

    CONCLUSIONS.: The complete ophthalmic analysis system-high definition-vision research provides fast, repeatable, and valid peripheral aberration measurements and can be used efficiently to measure off-axis aberrations in the peripheral visual field

  • 32.
    Baskaran, Karthikeyan
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Unsbo, Peter
    Biomedical and X-Ray Physics.
    Gustafsson, Jörgen
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Influence of age on peripheral ocular aberrations.2011Ingår i: Optometry and Vision Science, ISSN 1040-5488, E-ISSN 1538-9235, Vol. 88, nr 9, s. 1088-1098Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE.: To compare peripheral lower and higher order aberrations across the horizontal (±40°) and inferior (-20°) visual fields in healthy groups of young and old emmetropes. METHODS.: We have measured off-axis aberrations in the groups of 30 younger (24 ± 3 years) and 30 older (58 ± 5 years) emmetropes. The aberrations of OD were measured using the COAS-HD VR Shack-Hartmann aberrometer in 10° steps to ±40° horizontally and -20° inferiorly in the visual field. The aberrations were quantified with Zernike polynomials for a 4 mm pupil diameter. The second-order aberration coefficients were converted to their respective refraction components (M, J45, and J180). Mixed between-within subjects, analysis of variance were used to determine whether there were significant differences in the refraction and aberration components for the between-subjects variable age and the within-subjects variable eccentricity. RESULTS.: Peripheral refraction components were similar in both age groups. Among the higher order coefficients, horizontal coma (C3) and spherical aberration (C4) varied mostly between the groups. Coma increased linearly with eccentricity, at a more rapid rate in the older group than in the younger group. Spherical aberration was more positive in the older group compared with the younger group. Higher order root mean square increased more rapidly with eccentricity in the older group. CONCLUSIONS.: Like the axial higher order aberrations, the peripheral higher order aberrations of emmetropes increase with age, particularly coma and spherical aberration.

  • 33.
    Bengtsson, Rickard
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Utveckling av program för utvärdering av binokulära problem2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 34.
    Berg, Marie
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Refraktionsförändringar under läkningsprocessen efter kataraktoperation2008Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats
    Abstract [sv]

    ABSTRAKT

    Vid katarakt blir linsen grumlig och detta kan leda till synnedsättning och bländningsbesvär. Behandlingen är kirurgisk och går ut på att den grumliga linsen avlägsnas och ersätts med en ny intraokulär lins. Extraktionsmetoden, då ögat öppnades upp och linsen togs ut, användes fram till 1980-talet och ersattes då av fakotekniken som använder ultraljud för att sönderdela och suga ut linsen. Tack vare den nya tekniken kunde de stora snitten, på minst 8-10 mm, minskas ned till 1,5 mm. De små snitten självsluter sig och behöver inte sys och på så sätt kan den inducerade astigmatismen nästan undvikas helt. Med hjälp av biometri kan rätt styrka på den intraokulära linsen, (IOL), räknas ut och den postoperativa refraktionen bestämmas i förväg. Komplikationerna har blivit färre med ny och säkrare teknik men ett kvarvarande problem är de refraktionsförändringar som kan ske postoperativt. Om linskapseln krymper efter operation kan det leda till en ändring av IOLs placering i ögat. Axiallängdsmätning, material och design på IOLs är också bidragande till oönskade refraktionsförändringar.

    Syftet med denna studie var att ta reda på refraktionsförändringarna under läkningsprocessen från första återbesöket en vecka efter operation till första besök hos optiker minst en månad senare.

    Remissvaren har samlats in på Ögonkliniken i Kalmar och all data har förts in i ett Exceldokument för att analyseras. I studien ingick 82 kataraktopererade ögon. Resultatet visade på en statistiskt signifikant myopisering på i genomsnitt -0,085 D vilket tolkas som en framåtflyttning av linsens position postoperativt. P-värdet blev 0,045. 48 opererade ögon hade en refraktionsförändring på ≥ 0,25 D och 15 av dessa hade en förändring på ≥ 0,50 D. Den största förändringen var på -1,25 D. Det hittades inget samband mellan refraktionsförändringarna och ålder, kön eller antal dagar som gått mellan mätningarna. Slutsatsen är att refraktionen i genomsnitt inte ändras nämnvärt mellan en vecka och en månad postoperativt och att en månad då är en god marginal tills en glasögonbeställning görs.

    2008:O3

  • 35.
    Bergkvist, Emma
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    En jämförelse mellan två tekniker vid utvärdering av Meiboms körtlar2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Syfte: Syftet med denna studie var att jämföra tryck med Meibomian Gland Evaluator (MGE) med tryck manuellt med fingret vid utvärdering av Meiboms körtlar. Ytterligare syfte med studien var att utvärdera korrelation mellan Ocular Surface Disease Index (OSDI) enkät och gradering av meibumets kvalitet och sekretion.

    Metod: I studien deltog 30 personer i åldrarna 20–76 år med en medelålder på 51,8±19,8. Personer med uttalade problem med torra ögon uteslöts ur studien. Först utfördes en utvärdering av sekretion och kvalitet av Meiboms körtlar med MGE på höger öga och manuellt med tummen på vänster öga. Efter det fick personerna fylla i en OSDI enkät. Slutligen utfördes utvärdering av sekretion och kvalitet av Meiboms körtlar med manuellt tryck på höger öga och med MGE på vänster öga. Utvärdering av kvalitet och sekretion utfördes med hjälp av graderingsskalor med poäng från 0–3. 

    Resultat: Medianvärden för sekretion och kvalitet med MGE och manuellt på höger och vänster öga gav liknande resultat. Enligt p-värden var det ingen statistisk signifikant skillnad mellan teknikerna i något av fallen. Studien visade en positiv korrelation mellan OSDI poäng och gradering av meibumets sekretion (r=0,47; p=0,01). Ingen statistisk signifikant korrelation kunde påvisas mellan OSDI poäng och gradering av meibumets kvalitet (r=0,32; p=0,09).

    Slutsats: Studien visade att det inte finns någon statistisk signifikant skillnad mellan de två teknikerna. Studien visade positiv korrelation mellan OSDI enkät och gradering av meibumets sekretion. Studien visade att det inte finns någon statistisk signifikant korrelation mellan OSDI enkät och gradering av meibumets kvalitet.

  • 36.
    Berglund Pilgrim, Caroline
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Near Point of Convergence: A Comparison of Four Different Target types2010Självständigt arbete på grundnivå (yrkesexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Purpose: The purpose of this study was to determine if there were any differences between four different target types when measuring the near point of convergence in adults.

    Methods and Material: The near point of convergence was measured in 35 subjects with a visual acuity of at least 1.0 (6/6) in each eye and without any strabismus. The targets used were: the tip of a pen, an accommodative target, the RAF line target and a penlight viewed through red-green filters. Both break and recovery points were assessed for the different techniques. Each target was used twice in consecutive order. The line target from RAF ruler was copied on to a small plastic ruler in order to be able to use the same ruler for measuring the results. All subjects were fitted with their best correction in the trial frame after a complete refraction. The measurements were taken to the nearest 0.25cm.

    Results: There was no difference found between NPC break values for the different target types in the control group. The NPC values were found to be 5.0/7.4 in the control group and 10.8/18.2 in the anomalous group. The accommodative target was found to give more remote values (11.5cm) than expected in comparison to the other targets in the anomalous group.

    Conclusion: In patients with normal NPC, the measurements can be taken with line target or Acc. target. Patients with receded NPC values should be evaluated with penlight and red-green glasses or at least twice with the tip of a pen. 

  • 37.
    Bergman, Esther
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    The effect of dynamic exercise on macular perfusion measured with OCTA2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 38.
    Blixt, Evelina
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Utvärdering av torra ögon med hjälp av Tearscope-plus och enkäten TERTC-DEQ2010Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Bakgrund och syfte: Många upplever idag att de har symtom på torra ögon som exempelvis grusiga, brännande, rinnande eller kliande ögon. Torra ögon kan ha en negativ påverkan på dagliga aktiviteter som till exempel läsning, bildskärmsarbete, bilkörning och tv-tittande. Idag finns det flertalet väletablerade frågeformulär man kan använda sig av på sin klinik som ett extra instrument i sin undersökning. Syftet med studien var att utvärdera om resultatet från frågeformuläret TERTC-DEQ stämmer överense med de kliniska fynd som fås med hjälp av Tearscope-plus. Med hjälp av Tearscope-plus utvärderas tårfilmen och med frågeformuläret kan personer med olika grad av torra ögon upptäckas.

    Metod: I studien deltog 11 kvinnor och 18 män med en medelålder på 52,3 ± 8,2 år. Försökspersonerna undersöktes med hjälp av Tearscope-plus där en gradering av deras lipidskikt gjordes. Efter undersökningen fick försökspersonerna besvara TERTC-DEQ.

    Resultat: I denna studie var det 72,4 % som hade normala ögon och 27,6 % som hade symtom på torra ögon. Wave pattern var den vanligaste förekommande typen av lipidskikt. En trend kunde ses mellan en tjockare lipidskiktstyp och högre summa på TERTC-DEQ samt mellan en högre summa på TERTC-DEQ och ökad ålder.

    Slutsats: Denna studie visar att Tearscope-plus är ett bra instrument vid utvärdering av lipidskiktet. Att introducera frågeformulär i utvärderingen av torra ögon ger bra information för vidare behandling. Resultaten av denna studie tyder på att man inte kan använda sig av enbart dessa båda instrument för utvärdering av ett torrt öga.

  • 39.
    Blomqvist, Robert
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Relationship between Diabetes Mellitus, Dry Eye Disease and Cornea        : A review2011Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Background: Diabetes Mellitus (DM) is a group of metabolic diseases characterized by hyperglycemia and its association with dry eye and cornea is becoming more common among the world population. Prevalence concerning both Diabetes and Dry Eye Disease (DED) are predicted to grow rapidly and Diabetes Mellitus in particular, not only in the developing world but also in low-income countries spreading down the population in age. This expresses itself as a clinical problem in Medicine and Ophthalmology and may grow in significance as more treatment is needed in the future.

    Aim: To investigate whether there is correlation or not by reviewing recent literature between dry eye disease and diabetes mellitus and how this may affect us and be treated in a clinical way with future prevalence in both DM and DED in mind.

    Result and conclusion: Clinical studies tell us that the clinical manifestations of DM like ocular surface problems are connected to DED in a strong way. DM seems to accelerate DED-related ocular problems, not only uncontrolled but also with controlled glycemia-levels giving DM another dimension of problems to dissolve. Age is known a main factor of DED and DM, together with duration of the disease, it seems to affect manifestations of the cornea in an accelerated way. DM has a negative effect concerning tear secretion-deficiency and peripheral neuropathy leading to corneal epitheliopathy with hyperosmolarity, recurrent erosions, persistent epithelial defects, microbial keratitis and wound healing-delays. This may give DM a correlation to DED in almost every aspect that DED is classified and diagnosed by.

  • 40.
    Blüthl-Larsson, Dinah
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Emmetropisering ochrefraktionsutveckling hos barn samtförväntade värden vid 9-11 års ålder2009Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Syfte: Syftet med denna studie var att ta reda på vad man kan förvänta sig för refraktionsfel av barn genom att undersöka en åldersgrupp från nio till elva år med Mohindra närretinoskopi. Resultaten skulle sedan jämföras med fem andra studier gjorda inom området. Syftet var vidare att fördjupa sig inom emmetropisering och refraktionsutveckling.

    Metod: 77 barn från tre skolor i Vadstena kommun i åldrarna 9 till 11 år undersöktes under april 2009 med Mohindra närretinoskopi. De sfäriska ekvivalenta refraktionsmedelvärdena togs fram och jämfördes med likvärdiga resultat från fem andra studier genomförda i olika länder.

    Resultat: De sfäriska ekvivalenta medelvärdena var för 9-, 10- och 11-åringar +1.29 D, +0.97 D respektive +1.22 D för pojkarna och +1.00 D, +1.22 D respektive +0.92 D för flickorna i Vadstena. I de asiatiska studierna var medelvärdena mot mer myopi medan den svenska och chilenska studien liknade medelvärdena från studien i Vadstena.

    Slutsats: Resultatet av denna undersökning visar att refraktionsutvecklingen tenderar att gå mot mer negativa värden med ökande ålder, dock är det långt ifrån alla barn som blir myopa när de börjar skolan. Asiatiska barn visar myopa medelvärden av refraktionen medan bland annat svenska barn visar hyperopa värden.

  • 41.
    Borg, Caroline
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Variationen i corneal kurvatur över dagen2009Självständigt arbete på grundnivå (kandidatexamen)Studentuppsats (Examensarbete)
    Abstract [sv]

    För att en skarp bild ska kunna avbildas på retina krävs det att cornea och lins är transparenta men även att de innehar kvalitativa egenskaper i brytning. Fel i corneal kurvatur är en av orsakerna till refraktiva fel hos ögat. Kurvaturen kan mätas med en keratometer eller en topograf, vilken den sist nämnda även har stor betydelse bland annat vid kontaktlinstillpassning, refraktiv kirurgi och till hjälp vid diagnostisering av flera sjukdomstillstånd.

    Syfte: Syftet med den här studien var att undersöka om kurvaturen ändras under dagen, på en 8-timmars period, och i så fall hur mycket.

    Metod: Corneal kurvatur studerades på 16 ögon, 7 män och 9 kvinnor, med en median ålder på 24 år. Mätningarna utfördes med en Topcon CA-100F Corneal Analyzer, tre gånger under en dag, med fyra timmars mellanrum. Nio punkter på cornea jämfördes specifikt, vilka var apex samt 1 och 2 mm därifrån; superiort, temporalt, inferiort och nasalt.

    Resultat: Studien visade att cornea var flatast på morgonen och blev kupigare under dagen på alla mätpunkter förutom superiort. Förändringen var större på punkterna 2 mm från apex än 1 mm i alla riktningar förutom den temporala. Den totala variationen i snitt för alla punkter var en kurvaturminskning på 0,0332 ±0,07 mm och en genomsnittlig ökning i brytkraft på 0,17 ±0,35 D.

    Slutsats: Studien visar en signifikant förändring i corneal kurvatur och brytkraft under dagen. Dock var variationen i kurvatur individuell och därför ses en viktig roll i att ta topografibilder på varje enskild patient.

  • 42.
    Boström, Johanna
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Pettersson, Lovisa
    ,Karolinska Institutet.
    Baskaran, Karthikeyan
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Källmark, Fredrik
    Källmarkskliniken, Stockholm.
    Gierow, Peter
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för medicin och optometri (MEO).
    Meibography: Inter-rater reliability2016Ingår i: 8th International Conference on the Tear Film & Ocular Surface: Basic Science and Clinical Relevance: Conference Program & Abstract Book, 2016, s. 47-Konferensbidrag (Refereegranskat)
    Abstract [en]

    Purpose. The tear film lipid layer holds an important role in maintaining the integrity and health of the anterior surface of the eye. The meibomian glands found in eyelids are responsible for producing most of the lipids of the tear film. Dysfunction of the meibomian glands leads to increased evaporation of tears, which may lead to dry eye. Meibography is a method used for assessing the drop out of meibomian glands. The aim of this study was to evaluate the reliability between two different examiners when rating meibography images. Methods. The Sirius 3D scheimpflug camera (C.S.O., Florence, Italy) was used to photograph the everted upper and lower eyelids of the right and left eye of 52 subjects. The grade of meibomian gland loss was subjectively graded using the five-grade Meiboscale (Pult, 2012) and the percentage of gland loss was calculated using Phoenix Meibography software (version 3.0.1.021, bon Optic VertriebsGmbH, Lübeck, Germany). Data was analyzed using MedCalc for Windows (version 16.4.3, MedCalc Software, Ostend, Belgium). Results. The inter-rater reliability for the Meiboscale grade of meibomian gland loss was calculated using weighted Cohen’s kappa (linear weights). The result for all 208 images was Kw = 0.542 (95 % CI 0.454 to 0.630), which indicates a moderate agreement. The inter-rater reliability for the percentage of meibomian gland loss was calculated using intraclass correlation coefficient. The result for all 208 images was ICC = 0.794 (95 % CI 0.737 to 0.839), which indicates a substantial agreement. Conclusions. Imaging is an invaluable tool when managing patients in clinical practice. When performing meibography to evaluate meibomian gland loss, using software to calculate the percentage of gland loss gives a better inter-rater agreement than subjective grading of the images.

  • 43.
    Byrmo, Linda
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Effect of soft contact lens power on intraocular pressure measurement.2009Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 44.
    Carlsson, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Den Perifera Synskärpan med Normal och Omvänd Polaritet2008Självständigt arbete på grundnivå (kandidatexamen)Studentuppsats
    Abstract [sv]

    Bakgrund: Vid förlust av den centrala synskärpan måste personer använda sig av den perifera delen av näthinnan, så kallad excentrisk fixation. Personen måste medvetet fokusera vid sidan av objektet så att bilden faller in på deras BNP, bästa näthinneplatsen. Användningen av den perifera delen av näthinnan innebär en försämrad synskärpa. Försämringen beror på att fotoreceptorerna är färre och placerade längre ifrån varandra. De aberrationer som uppkommer vid excentrisk fixation såsom sned astigmatism, koma, defokus och högre gradens aberrationer inverkar också på synskärpan. För att få den bästa möjliga perifera synskärpa har det visat sig att synsvaga personer föredrar att använda sig av omvänd polaritet, det vill säga vita bokstäver på svart bakgrund, om det finns möjlighet att välja.

    Syfte: Syftet med detta arbete var att undersöka om det var någon skillnad i den perifera synskärpan mellan normal och omvänd polaritet med optotypen Landolt C.

    Metod: Studien gjordes på 30 testdeltagares friska vänsterögon i en vinkel på 20 grader från makula. För att bestämma den perifera synskärpan för de båda polariteterna användes metoden: perifer visuell evaluering, PVE.

    Resultat: Resultatet visade att majoriteten av deltagarna uppnådde bäst visus vid normal polaritet. De stora standardavvikelserna hos försökspersonerna gör dock att resultatet inte är statisktiskt signifikant.

    2008:O4

  • 45.
    Carlsson, Mats
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Hur korrigering av excentriska synfel påverkar perifer visus2011Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 46.
    Carlsson, Stina K.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Effects of adenosine and acetylcholine on the lacrimal gland2011Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    A balanced tear film is essential for a healthy ocular surface. Insufficient tear production may result in dry eye, a common disorder in the elderly population. Dry eye causes significant discomfort in the patients and may lead to visual impairment and ocular infections. The lacrimal gland secretes water, proteins and electrolytes to the aqueous layer of the tear film. Lacrimal gland secretion is tightly regulated by e.g. neuronally released acetylcholine. The effect of acetylcholine on lacrimal gland secretion was recently found to be potentiated by adenosine. Adenosine is an important signaling molecule acting upon the adenosine receptors: A1, A2A, A2B and A3.

    The aim of this thesis was to study effects of adenosine and acetylcholine on intracellular signaling pathways and lacrimal gland secretion. Cholinergic stimulation of secretion was shown to be regulated by the mitogen activated protein kinase p38, a protein previously not known to be involved in exocrine secretion. p38 was activated in response to cholinergic stimulation and inhibition of p38 significantly diminished cholinergic secretion.

    When investigating adenosine effects, potentiation of cholinergic secretion was observed by activation of the A2B receptor in addition to the previously studied A1 receptor. An A2 receptor agonist increased cholinergic rabbit lacrimal gland protein secretion at several concentrations. The increase was inhibited by antagonism of the A2B receptor, but not the A2A receptor. When investigating the intracellular signaling pathways following adenosine and acetylcholine receptor activation, adenosine was shown to increase of cAMP levels. An additional increase in cAMP levels was observed after parallel adenosine and cholinergic receptor activation. Inhibition of Ca2+ release from the endoplasmic reticulum had inhibitory effects of cholinergic stimulation of secretion. In addition, the expression of adenosine receptors in a mouse model of autoimmune dry eye was investigated. The results showed a lymphocyte dependent upregulation of A2A receptors in diseased mice compared to controls.

    In conclusion, the results in this thesis provide significant contributions in the search of dry eye therapeutics through studies of adenosine and acetylcholine receptor activation.

  • 47.
    Carlström, Sebastian
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Jämförelse av två vågfrontsanalysatorervid mätning av den högre ordningensaberrationer2010Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
  • 48.
    Carneiro de Freitas, Rui
    et al.
    Hospital de Braga, Portugal.
    Freitas, Cristina
    Hospital de Braga, Portugal.
    Leite, Ricardo
    Hospital de Braga, Portugal.
    Sousa, Keissy
    Hospital de Braga, Portugal.
    Mendes-Ferreira, José
    Hospital de Braga, Portugal.
    Soares, Andreia
    Hospital de Braga, Portugal.
    Rubin, Gary S.
    UCL-Institute of Ophthalmology, UK.
    Rocha-Sousa, Amandio A.
    University of Porto, Portugal.
    Santana, Rui
    Nova University of Lisbon, Portugal.
    Macedo, António Filipe
    University of Minho, Portugal.
    Prevalence of Visual Impairment in Portugal: study design and initial results2015Ingår i: Investigative Ophthalmology and Visual Science, ISSN 0146-0404, E-ISSN 1552-5783, Vol. 56, nr 7, artikel-id 2119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Purpose 

    Information about the prevalence of visual impairment is fundamental to define policies that deal with vision loss. The aim of this study is to determine the prevalence of visual impairment (VI) in the population looking for eye care in public hospitals in Portugal.

    Methods 

    We designed an observation, cross-sectional prospective study (Prevalence and Costs of Visual Impairment in Portugal: PC-VIP study) to investigate the prevalence of VI in patients attending outpatient appointments in four public hospitals in Portugal. Hospital selected provide from general eye care (3-6 ophthalmologists) to high-specialized eye care (40+ ophthalmologists) that in total have between 120-140K hospital appointments per year. Files of patients are analysed weekly to detect patients with VI. Inclusion criteria were: visual acuity equal or worse than 0.5 (USA definition 20/40) in the better eye and/or a visual field of less than 20deg. Cases are selected by trained hospital staff and inserted in a database. Data collected included demographic information, acuity from both eyes, qualitative information about visual field (good, reduced, requires investigation), main diagnosis, secondary diagnosis and comorbidities. Diagnoses were classified according with ICD9.

    Results 

    We have now detected 2462 cases of VI that correspond to 4 to 33 weeks of data collection. The number of weeks is variable because collection did not start simultaneously in all sites. From the number of cases detected, 58% were female, 1.9% were under 20y, 8.2% were between 20y and 50y and 89.9% were ≥50y. The mean prevalence of visual impairment was 13.6% (SD=5.6) using the USA definition and it was 7.0%(SD=4.1) using the WHO definition (acuity equal or worse than 0.3 or ~20/63). With a methodology that controls for demographics the lowest and highest estimates were calculated. Considering the USA definition, the prevalence in the general population would be in the range 0.4 -0.4% (age<40y) and 0.8-2.4% (age>=40y). Considering WHO definition, it would be 0.2-0.5% (age<40y) and 0.4-1.0% (age>=40y).

    Conclusions 

    A hospital-based study can provide effective estimates of the prevalence of visual impairment in a population. Estimates for the country are in agreement with the expected results that can be deducted from neighbour countries and self-reported visual impairment in census 2001.

  • 49.
    Classon, Lisa
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Vanor och compliance hos kontaktlinsbärare:  En enkätstudie2011Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Bakgrund: Många studier gällande compliance har genomförts och flertalet har visat att nivån av compliance är låg. De huvudsakliga områdena där compliance brister är handhygien, rengöring av linsetui, överbärande av kontaktlinser, brist på fullgod uppföljning och felaktigt användande av linsvätskor. Några av dessa områden har tagits upp i denna studie.

    Syfte: Syftet med examensarbetet var att undersöka hur kontaktlinsbärandet ser ut hos ett litet antal Internetanvändande personer i Sverige. Personernas vanor och compliance studerades i relation till tidigare studier inom detta område.

    Metod: En webbenkät med, för syftet, relevanta frågor skapades i webbprogrammet Google Docs. Enkäten bifogades i en länk och presenterades som ett evenemang på Facebook. Personer som använde kontaktlinser uppmanades att svara på enkäten. Resultaten från enkäten samlades i Google Docs och därifrån kunde svaren analyseras.

    Resultat: Enkäten gav 84 svar. Majoriteten var kvinnor och studerande. Vanligast var användandet av månads-/tvåveckorslinser och på en daglig basis. Både kvinnor och män valde i högre grad att köpa sina kontaktlinser hos optiker men män var något överrepresenterade för köp av kontaktlinser på Internet. 22,6 % uppgav att de ofta bar samma par kontaktlinser längre än rekommenderat, 40,5 % gjorde en linskontroll varje år, 31,0 % sov med linser ibland, 13,1 % visste inte om deras kontaktlinser var godkända att sova i och 61,9 % uppgav att de någon eller några gånger behövt avstå från att använda kontaktlinser på grund av ögonproblem.

    Slutsats: Denna studie visade, likt andra studier, att non-compliance är ganska vanligt. Ett fortsatt arbete med att höja nivån av compliance är viktigt för att undvika allvarliga komplikationer och för att minska antalet användare som avbryter sitt bärande.

  • 50.
    Crossland, Michael D.
    et al.
    Anglia Ruskin University, UK ; Moorfields Eye Hospital NHS Foundation Trust, UK.
    Silva, Rui S.
    University of Minho, Portugal.
    Macedo, António Filipe
    University of Minho, Portugal.
    Smartphone, tablet computer and e-reader use by people with vision impairment2014Ingår i: Ophthalmic & physiological optics, ISSN 0275-5408, E-ISSN 1475-1313, Vol. 34, nr 5, s. 552-557Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    PURPOSE:

    Consumer electronic devices such as smartphones, tablet computers, and e-book readers have become far more widely used in recent years. Many of these devices contain accessibility features such as large print and speech. Anecdotal experience suggests people with vision impairment frequently make use of these systems. Here we survey people with self-identified vision impairment to determine their use of this equipment.

    METHOD:

    An internet-based survey was advertised to people with vision impairment by word of mouth, social media, and online. Respondents were asked demographic information, what devices they owned, what they used these devices for, and what accessibility features they used.

    RESULTS:

    One hundred and thirty-two complete responses were received. Twenty-six percent of the sample reported that they had no vision and the remainder reported they had low vision. One hundred and seven people (81%) reported using a smartphone. Those with no vision were as likely to use a smartphone or tablet as those with low vision. Speech was found useful by 59% of smartphone users. Fifty-one percent of smartphone owners used the camera and screen as a magnifier. Forty-eight percent of the sample used a tablet computer, and 17% used an e-book reader. The most frequently cited reason for not using these devices included cost and lack of interest.

    CONCLUSIONS:

    Smartphones, tablet computers, and e-book readers can be used by people with vision impairment. Speech is used by people with low vision as well as those with no vision. Many of our (self-selected) group used their smartphone camera and screen as a magnifier, and others used the camera flash as a spotlight.

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