An analysis of lesion size and location in newly diagnosed cytomegalovirus retinitis

Abstract

Objective To investigate the size and distribution of lesions in newly diagnosed cytomegalovirus retinitis (CMVR). Design Retrospective, observational case series. Participants Fundus photographs of 252 newly diagnosed CMVR lesions in 173 eyes of 130 patients (123 male, 7 female). Methods Thirty-five millimeter (60°) color transparencies were digitized. A montage of the retina was assembled for each involved eye and was superimposed on a specially designed map of the postequatorial retina. Cytomegalovius retinitis lesions were delineated, and the size and location of each lesion was measured. The size of newly diagnosed CMVR lesions was computed in terms of percent postequatorial retinal surface area (PERSA), and the location of lesions was plotted on a polar coordinate system. Main outcome measures Size and location of patches of newly diagnosed CMVR. Results The median lesion size was 3% PERSA. Peripheral CMVR lesions were larger than posterior ones ( P < 0.001). The mean number of lesions was 1.6 per eye. The total area of CMVR involvement ranged from 1% to 76% PERSA, with a median of 5% PERSA. There was no difference between left and right eyes in the distribution of lesion centers ( P = 0.27). The concentric distribution of lesion centers appeared to be homogeneous, except for fewer centers in the most peripheral 14° ( P < 0.001), and a greater than expected number of lesion centers in the macula (central 11.6°, P < 0.001). Eyes of patients with unilateral retinitis had 1.3 lesions per involved eye compared with eyes of patients with bilateral retinitis, which had 1.6 lesions per eye ( P = 0.003). Conclusions Most newly diagnosed CMVR lesions were small. Peripheral lesions were larger than more posterior lesions. Variations from a homogeneous distribution of lesions were noted only at the extreme peripheral and central locations and are probably explained by ascertainment bias. The macula was not spared from new CMVR lesions in this patient population.