OCT Diagnosis of Cystoid Macular Edema in Patients With Retinal Thinning From Retinitis Pigmentosa

Abstract

Purpose: : To demonstrate that measurement of central foveal thickness with OCT alone is not adequate for the diagnosis of cystoid macular edema (CME) in patients with retinal thinning from retinitis pigmentosa.

Methods: : Stratus OCT (Carl Zeiss Meditec, Dublin, CA) was used to measure nerve fiber layer thickness, foveal thickness, and macular volume in 59 eyes of 30 patients with retinitis pigmentosa. CME was defined in cases based on the presence of intraretinal fluid that disrupted the normal retinal laminations in two or more line scans as detected within fast macular scans.

Results: : A total of twenty eyes were found to have CME. Of the eyes with edema, foveal thickness measurements ranged from 224 to 718 microns (average =357.7). In eyes without edema, the range was from 99 to 273 (average = 190.7). Bilateral edema was found in 8 individuals. In 87.5% of these cases the extent of macular edema (as judged by central thickness) between the two eyes of the same individual were within 20%. Of note, in the eyes with CME, 5 out of the 18 eyes (27.8%) had a foveal thickness of 250 microns or less.

Keywords: edema • retinal degenerations: hereditary • imaging/image analysis: clinical