Dataset Information

Resolution acuity across the visual field for mesopic and scotopic illumination.

ABSTRACT: We investigated the classical question of why visual acuity decreases with decreasing retinal illuminance by holding retinal eccentricity fixed while illumination varied. Our results indicate that acuity is largely independent of illuminance at any given retinal location, which suggests that under classical free-viewing conditions acuity improves as illumination increases from rod threshold to rod saturation because the retinal location of the stimulus is permitted to migrate from a peripheral location of maximum sensitivity but poor acuity to the foveal location of maximum acuity but poor sensitivity. Comparison with anatomical sampling density of retinal neurons suggests that mesopic acuity at all eccentricities and scotopic acuity for eccentricities beyond about 20° is limited by the spacing of midget ganglion cells. In central retina, however, scotopic acuity is further limited by spatial filtering due to spatial summation within the large, overlapping receptive fields of the A-II class of amacrine cells interposed in the rod pathway between rod bipolars and midget ganglion cells. Our results offer a mechanistic interpretation of the clinical metrics for low-luminance visual dysfunction used to monitor progression of retinal disease.

SUBMITTER: Wilkinson MO

PROVIDER: S-EPMC7545082 | biostudies-literature | 2020 Oct

REPOSITORIES: biostudies-literature

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Resolution acuity across the visual field for mesopic and scotopic illumination.

Wilkinson Michael O MO Anderson Roger S RS Bradley Arthur A Thibos Larry N LN

Journal of vision 20201001 10

We investigated the classical question of why visual acuity decreases with decreasing retinal illuminance by holding retinal eccentricity fixed while illumination varied. Our results indicate that acuity is largely independent of illuminance at any given retinal location, which suggests that under classical free-viewing conditions acuity improves as illumination increases from rod threshold to rod saturation because the retinal location of the stimulus is permitted to migrate from a peripheral l ...[more]

PMID: 33007081

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Project description:ImportanceCorrelates for Bruch membrane alterations are needed for interventional trials targeting the Bruch membrane in pseudoxanthoma elasticum (PXE).ObjectivesTo quantify mesopic and scotopic light sensitivity and identify its microstructural correlates associated with a diseased Bruch membrane in patients with PXE.Design, setting, and participantsA prospective, single-center, cross-sectional case-control study was conducted at a tertiary referral center from January 31, 2018, to February 20, 2020. Twenty-two eyes of 22 patients with PXE and 40 eyes of 40 healthy individuals were included. Data analysis was completed March 15, 2020.ExposuresMesopic and dark-adapted 2-color fundus-controlled perimetry (microperimetry) and multimodal retinal imaging including spectral-domain optical coherence tomography (SD-OCT) and OCT angiography were performed. Perimetry thresholds were analyzed using mixed models, and structure-function correlation with SD-OCT data was performed using machine learning.Main outcomes and measuresObserved dark-adapted cyan sensitivity loss as measure of rod photoreceptor dysfunction, as well as mean absolute error between predicted and observed retinal sensitivity to assess the accuracy of structure-function correlation.ResultsOf the 22 patients with PXE included in this study, 15 were women (68%); median age was 56.5 years (interquartile range, 50.4-61.2). These patients exhibited mesopic (estimate, 5.13 dB; 95% CI, 2.89-7.38 dB), dark-adapted cyan (estimate, 9.08 dB; 95% CI, 6.34-11.82 dB), and dark-adapted red (estimate, 7.05 dB; 95% CI, 4.83-9.27 dB) sensitivity losses. This sensitivity loss was also evident in 9 eyes with nonneovascular PXE (mesopic: estimate, 3.21 dB; 95% CI, 1.28-5.14 dB; dark-adapted cyan: 5.93 dB; 95% CI, 3.59-8.27 dB; and dark-adapted red testing: 4.84 dB; 95% CI, 2.88-6.80 dB), showing a distinct centrifugal pattern of sensitivity loss with preserved function toward the periphery. Retinal function could be predicted from microstructure with high accuracy (mean absolute errors, of 4.91 dB for mesopic, 5.44 dB for dark-adapted cyan, and 4.99 dB for dark-adapted red). The machine learning-based analysis highlighted an association of a thinned inner retina and putative separation of the pigment-epithelium-photoreceptor complex with sensitivity loss.Conclusions and relevanceIn this study, among 22 patients with PXE, those with and without choroidal neovascularization exhibited reductions of retinal sensitivity being most pronounced in dark-adapted cyan testing. This finding suggests that pathologic characteristics of this Bruch membrane disease may be dominated by rod photoreceptor degeneration and/or dysfunction. A putative pigment-epithelium-photoreceptor separation may further impair rod function, while inner retinal abnormalities appear to be correlated with overall dysfunction.

Project description:PurposeTo assess the relationship of binocular visual function tests with binocular approximations using data from the Collaborative Initial Glaucoma Treatment Study (CIGTS).DesignCase series based on existing data from a clinical trial.ParticipantsSix hundred seven patients with newly diagnosed open-angle glaucoma from the CIGTS.MethodsMonocular visual field (VF) and visual acuity (VA) tests were performed at baseline and every 6 months thereafter. Binocular tests of visual function (Esterman VF score, binocular VA) were added to the CIGTS protocol 3 years into the study. The binocular approximations of binocular visual function were better or worse eye, average eye, better or worse location, and binocular summation or pointwise binocular summation. Associations between binocular tests and binocular approximations to represent binocular visual function were assessed with Pearson's correlations (r), as was the relationship between vision-related quality of life (VR QOL; Visual Activities Questionnaire [VAQ] and the 25-item National Eye Institute Visual Function Questionnaire [NEI VFQ-25]) and binocular tests or binocular approximations of visual function.Main outcome measuresBinocular visual function (VF and VA) and VR QOL.ResultsFive hundred seventy-five patients underwent at least 1 binocular visual function test. The Esterman score was correlated significantly with all binocular approximations of VF, with r values ranging from 0.31 (worse-eye mean deviation [MD]) to 0.42 (better-eye MD; P < 0.0001 for all). Binocular VA showed stronger correlations with binocular approximations, with r values ranging from 0.65 (worse-eye VA) to 0.80 (binocular summation; P < 0.0001 for all). Correlations between the VAQ and Esterman score were stronger in 7 of 9 subscales (r = -0.14 to -0.25; P < 0.05 for all) than correlations with all 7 binocular approximations. In contrast, correlations between the VAQ and binocular VA (r = -0.07 to -0.21) were weaker in all subscales than those with better-eye, average-eye, and binocular summation of VA (r = -0.12 to -0.25), but not different from worse-eye values. These trends also were found in relevant subscales of the NEI VFQ-25.ConclusionsWe found limited benefit in binocular testing of VA in the clinical setting as a means of approximating a patient's reported visual functioning. In contrast, we found some benefit in performing binocular VF testing, because the results correlated more closely with reported functioning than binocular approximations.

Dataset Information

Resolution acuity across the visual field for mesopic and scotopic illumination.

Publications

Resolution acuity across the visual field for mesopic and scotopic illumination.

Similar Datasets

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