Decreased Retinal Sensitivity Overlying Choroidal Nevi

Ocul Oncol Pathol. 2021 Sep;7(4):287-293. doi: 10.1159/000515561. Epub 2021 May 6.

Abstract

Purpose: To report retinal function findings on the choroidal nevus.

Methods: Prospective descriptive case series of 7 patients (n = 7 eyes) presenting a melanocytic choroidal lesion consistent with choroidal nevus and no other ocular disease. Baseline evaluation included measurement of best-corrected visual acuity (BCVA), color and near-infrared fundus pictures, and spectral-domain OCT (Heidelberg Engineering). Retinal function was tested with microperimetry (MAIA; CenterVUE, Padova) using a standard grid (µP1) and a linear grid (µP2) that distribute test points on retinal areas that overlaid the choroidal lesion as well as lesion-free areas equidistantly to the fovea in 3 parallel lines. mfERG was performed following the International Society for Clinical Electrophysiology of Vision (ISCEV) recommendation using a 61-hexyagon protocol.

Results: BCVA was 20/25 (0.1 logMAR) or better in all 7 eyes. Microperimetry showed central stable fixation on all eyes, with mean ± SE sensitivity threshold significantly decreased on retinal areas overlaying the lesions (µP1): 21.8 ± 0.6 dB versus 25.2 ± 0.9 dB on nonaffected retinal areas (p < 0.001). Sensitivity was also decreased on µP2: 23.7 ± 0.2 dB for areas overlying the nevi and 25.7 ± 0.3 dB for the nonaffected retina (p < 0.001). mfERG responses showed no focal amplitude or implicit-time changes on the retina in the topographical region corresponding to the nevus for all patients.

Conclusion: Our results indicate that choroidal nevi may cause significant retinal sensitivity impairment, as shown by microperimetry, but preserved mfERG response indicates that the retinal function may be only partially impaired.

Keywords: Choroid; Microperimetry; Multifocal electroretinogram; Nevus; Tumor; Uvea.