The Effects of Severe Myopia on the Properties of Sampling Units in Peripheral Retina.
Significance: Poor peripheral visual acuity in myopia may reflect, in part, photoreceptor misalignment with the exit pupil of the eye. We speculate that if such misalignment causes sufficient visual deprivation and/or disrupts retinal feedback processes, it may influence eye growth itself.Purpose: I...
| Published in: | Optometry & Vision Science Vol. 95; no. 4; pp. 399 - 405 |
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| Main Authors: | , , , |
| Format: | research Journal Article |
| Published: |
Wiley-Blackwell
Apr2018
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| Online Access: | View this record in EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=128850612&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 128850612 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 10405488 1X24 jtl: Optometry & Vision Science issn: 10405488 maglogo: N pubinfo: dt: Apr2018 vid: 95 iid: 4 pid: 480 pub: Wiley-Blackwell place: Malden, Massachusetts artinfo: ui: 128850612 128850612 NLM29554010 128850612 10.1097/OPX.0000000000001199 NLM29554010 128850612 ppf: 399 ppct: 6 formats: tig: atl: The Effects of Severe Myopia on the Properties of Sampling Units in Peripheral Retina. aug: au: Nagra, Manbir Gilmartin, Bernard Logan, Nicola S. Anderson, Stephen J. affil: Centre for Applied Vision Research, City, University of London, London, United Kingdom. sug: subj: Retina Physiopathology Myopia Physiopathology Visual Acuity Physiology Refraction, Ocular Human Male Psychometrics Imaging, Three-Dimensional Myopia Ophthalmoscopy Magnetic Resonance Imaging Retina Middle Age Validation Studies Comparative Studies Evaluation Research Multicenter Studies Middle Aged: 45-64 years Male ab: Significance: Poor peripheral visual acuity in myopia may reflect, in part, photoreceptor misalignment with the exit pupil of the eye. We speculate that if such misalignment causes sufficient visual deprivation and/or disrupts retinal feedback processes, it may influence eye growth itself.Purpose: It is known that myopic eyes have a reduced peripheral resolution acuity relative to emmetropic eyes, though it remains unclear how mechanical stretching of the retina in myopia impacts on peripheral visual performance. Our aim was to determine how retinal stretching affects the properties of sampling units in peripheral vision.Methods: Three-dimensional magnetic resonance imaging provided a depiction in vivo of ocular shape, allowing the inter-eye ratio of retinal image surface areas and the relative alignment of surfaces to be determined in our observer, who was unique in having severe myopia in the right eye (~21 D) but only modest myopia in the left (~3 D). Visual performance was assessed for the detection and direction discrimination of drifting sinusoids positioned 40° in the temporal retina. Applying the sampling theorem to our measures, we estimated the density and cut-off frequency of the underlying sampling units.Results: The retinal image surface area of the right eye was 40% larger than that of the left and was rotated 8.9° anticlockwise relative to the left eye's image surface. In agreement with a linear stretch model of myopia, the sampling density of the right eye was reduced by approximately the same ratio as that predicted from the inter-eye MRI data, namely, 1.18. However, the cut-off frequency (cycles/mm) of the right eye was approximately half that of the left, a reduction that cannot be explained solely by a linear areal expansion of retinal sampling units.Conclusions: Poor peripheral acuity in severe myopia may be caused, at least in part, by receptoral misalignment with the exit pupil. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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