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Clinical Impact of Objectively Determined Peripheral Refractive Error Correction on Low-Contrast Resolution Acuity
Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. (Vision Enabling Lab)ORCID iD: 0000-0002-8365-0601
Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences. (Vision Enabling Lab)ORCID iD: 0000-0002-3745-0035
Biomedical & X-Ray Physics. (Visual Optics Group)
Biomedical & X-Ray Physics. (Visual Optics Group)
Show others and affiliations
(English)Manuscript (preprint) (Other academic)
Keyword [en]
Visual acuity; Low-contrast resolution acuity; Off-axis refractive errors; Peripheral vision; Off-axis
National Category
Ophthalmology
Research subject
Natural Science, Optometry
Identifiers
URN: urn:nbn:se:lnu:diva-22561OAI: oai:DiVA.org:lnu-22561DiVA: diva2:571045
Available from: 2012-11-21 Created: 2012-11-21 Last updated: 2017-02-17Bibliographically approved
In thesis
1. Optimal Use of Peripheral Vision
Open this publication in new window or tab >>Optimal Use of Peripheral Vision
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
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.

Place, publisher, year, edition, pages
Kalmar, Växjö: Linnaeus University Press, 2012
Series
Linnaeus University Dissertations, 108/2012
Keyword
off-axis refractive errors, peripheral aberrations, aberrometers, central visual field loss, preferred retinal locus, eccentric viewing, absolute central scotoma, adaptive optics, eccentric correction.
National Category
Ophthalmology
Research subject
Natural Science, Optometry
Identifiers
urn:nbn:se:lnu:diva-22562 (URN)978-91-86983-94-9 (ISBN)
Public defence
2012-12-20, N2007, Smålandsgatan 26E, Kalmar, 10:00 (English)
Opponent
Supervisors
Available from: 2012-11-23 Created: 2012-11-21 Last updated: 2016-04-27Bibliographically approved

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CiteExportLink to record
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Citation style
  • apa
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