Abstract
Purpose :
Epiretinal Membranes (ERMs) are thin sheets of avascular fibrocellular membranes that can develop on the inner surface of the retina. ERMs can be asymptomatic or they can deleteriously affect the macula and result in metamorphopsia and vision loss. The main objectives of this study were to evaluate color vision as a functional endpoint of ERMs, and quantify cone-specific (L, M, and S) contrast sensitivity in patients with ERMs using cone-contrast test (CCT), a computer-based tool designed to measure color visual function. We hypothesized that macular distortion from ERM with normal visual acuity is associated with reduced color contrast sensitivity.
Methods :
A retrospective review of medical records was performed for cases of ERM evaluated by CCT. Seventy patients (140 eyes) with an ERM in at least one eye were included. Presence of ERMs were confirmed by dilated retinal exam, typical fundus appearance, and optical coherence tomography (OCT). Severity and grading of ERMs were determined and performed manually by two retina specialists. Visual acuity, ocular dominance, intraocular pressure, and CCT evaluation were also documented during standard eye exam. Linear regression using a generalized estimating equation and two-tailed t-test were used for statistical analysis.
Results :
M-cone sensitivity was significantly decreased (p=0.027) in the grade 2 ERM group compared to the control group. Both M-cone and S-cone sensitivity were significantly decreased in the grade 3 ERM group compared to the control group (p=0.001 and p=0.01, respectively). Interestingly, L-cone sensitivity was significantly decreased in the grade 1 ERM group compared to the control group; however, there was no significant difference in L-cone sensitivity between the grades 2 and 3 ERM and control groups.
Conclusions :
Low grade ERMs (trace and grade 1) generally do not impact color vision function; however, high grade ERMs (grades 2 and 3) can diminish color vision function, which correlates with an abnormal foveal contour. Our findings suggest that in future studies, CCT can serve as an alternative clinical endpoint in patients with ERMs. A larger prospective study investigating the natural history of color vision function in ERMs is warranted. More sensitive tests to assess changes in cellular function are needed to detect early vision changes associated with ERM.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.