Characteristics of posterior zone I retinopathy of prematurity

ObjectiveTo report the demographic profile and clinical characteristics of retinopathy of prematurity (ROP) in posterior Zone I.MethodsIn a partly retrospective (ten years) and partly prospective (one year) study, we analysed the demographic profile and clinical characteristics of babies with ROP in posterior Zone I.ResultsThe study included 130 eyes of 67 infants with a mean gestational age and birth weight of 29.3 (+/- 2.2) weeks and 1217.3 (+/- 381.9) grams, respectively. All babies had received unblended oxygen. In 47 of 51 (91.1%) babies, the weekly weight gain was <100 g (details were not available in 16 babies). The ROP subtypes included aggressive, threshold, hybrid, stage 4, and atypical types in 78 (60%), 20 (15.4%), 11 (8.5%), 15 (11.5%), and 6 (4.6%) eyes, respectively. Fibrovascular proliferation, when present, was prominent nasally, occasionally overriding the disc margin. Extensive arteriovenous tortuosity was more prominent than vascular dilatation. Atypical observations included bleb-like detachment (6 eyes; 4.6%) and candle wax-like preretinal deposits (23 eyes; 17.7%).ConclusionsRetinopathy of Prematurity in posterior Zone I in this cohort was strongly associated with 100% unblended oxygen supplementation, poor weight gain, and multiple systemic co-morbidities. ROP in posterior zone 1 has a distinct profile with several atypical characteristics different from ROP in other zones.