Retinopathy of Prematurity in Zone I posterior (Zone Half): Neonatal Profile, Clinical characteristics, and outcomes

Objective: To report the demographic profile,clinical characteristics, and outcomes of retinopathy of prematurity (ROP) in Zone I posterior. Methods In a partly retrospective (ten years) and partly prospective (one year) study, we analyzed the demographic profile, clinical characteristics, treatment type, recurrences, and outcomes of babies with ROP in Zone I posterior. Results The 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 with a poor weight gain in the majority.The ROP subtypes included aggressive,threshold, hybrid, stage 4, and atypical type in 78, 20, 11, 15, and 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(n = 6 eyes), candle wax-like preretinal deposits (n = 23 eyes), and large arteriovenous shunts (n = 9eyes). Primary treatment included intravitreal anti-VEGF in 119 eyes and laser in 11 eyes. Among those with follow-upfor more than 6 months, the recurrence was seen in 48.3% (n = 29) of eyes with anti-VEGF; with additional laser treatment, the outcome was favorable in 90.5% (n = 116) of eyes. Conclusions Zone I posterior ROP has a distinct profile with several atypical characteristics; it differsfrom ROP in other zones. Primary anti-VEGF treatment is beneficial but inadequate; most babies need additional laser or surgery.Improved neonatal care, earlier screening, and a combination of intravitreal anti-VEGF and laser are recommended.