Neural constraints on visual acuity in proliferative diabetic retinopathy.
Purpose: Visual acuity (VA) in normally sighted individuals is highly correlated with equivalent intrinsic blur, a measure of the amount of blur within the visual system that is generated by optical and neural sources. This study assessed the extent to which VA, equivalent intrinsic blur, optical bl...
| Publicado en: | Optometry & Vision Science Vol. 91; no. 2; pp. 194 - 200 |
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| Autores principales: | , , , , , |
| Formato: | research Journal Article |
| Publicado: |
Wiley-Blackwell
2014 Feb
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=107881707&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 107881707 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 10405488 1X24 jtl: Optometry & Vision Science issn: 10405488 maglogo: N pubinfo: dt: 2014 Feb vid: 91 iid: 2 pid: 480 pub: Wiley-Blackwell place: Malden, Massachusetts artinfo: ui: 107881707 107881707 NLM24317136 2012457643 10.1097/OPX.0000000000000128 NLM24317136 PMC3946839 107881707 ppf: 194 ppct: 6 formats: tig: atl: Neural constraints on visual acuity in proliferative diabetic retinopathy. aug: au: McAnany, J Jason Wanek, Justin Zelkha, Ruth Lim, Jennifer I Chau, Felix Shahidi, Mahnaz affil: *PhD tMS tMD Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois. sug: subj: Diabetic Retinopathy Physiopathology Neurons Physiology Vision Disorders Physiopathology Visual Acuity Physiology Diagnosis, Eye Adult Aged Female Human Male Middle Age Adult: 19-44 years Aged: 65+ years Middle Aged: 45-64 years Female Male ab: Purpose: Visual acuity (VA) in normally sighted individuals is highly correlated with equivalent intrinsic blur, a measure of the amount of blur within the visual system that is generated by optical and neural sources. This study assessed the extent to which VA, equivalent intrinsic blur, optical blur, and neural blur are abnormal in subjects with proliferative diabetic retinopathy (PDR) and characterized the relationships among these parameters.Methods: Best-corrected VA of 10 subjects with PDR (ages 25 to 68) and 10 normally sighted individuals (ages 46 to 63) was measured for tumbling E optotypes. The Es were either unblurred or blurred through convolution with Gaussian functions of different widths. Values of equivalent intrinsic blur (σ(int)) and unblurred VA (MAR0) were derived using a standard model. Optical blur (σ(opt)), a measure of blur generated by higher-order aberrations, was quantified using Shack-Hartmann aberrometry. An index of neural blur (η) was defined as 1--σ(opt)/σ(int), which represents the remaining blur once the contributions of σ(opt) to σ(int) have been accounted for.Results: Log MAR0 and log σ(int) were correlated significantly (r = 0.98, p < 0.05) for the PDR subjects and the values of these parameters ranged from normal to more than a factor of 2 above the upper limit of normal. In comparison, log MAR measured for the most blurred E was elevated by a relatively small amount for all PDR subjects and was not correlated significantly with log σ(int) (r = 0.40, p = 0.25). MAR0, σ(int), and η differed significantly between the PDR subjects and the controls (all p < 0.05) but σ(opt) did not (p = 0.50).Conclusions: Subjects with PDR and VA loss had higher than normal equivalent intrinsic blur that resulted primarily from neural blur elevations, suggesting that neural blur is an important factor that limits VA in these patients. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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