Outcomes of a protocol-based management for zone 1 retinopathy of prematurity: the Indian Twin Cities ROP Screening Program report number 2

Purpose: To report the outcomes of zone 1 aggressive posterior retinopathy of prematurity (ROP) treated with aggressive laser photocoagulation by a protocol-based approach over a 10-year period.

Design: Prospective, interventional case series.

Setting: Tertiary eye institute and neonatal intensive care units in the twin cities of Hyderabad and Secunderabad in South India.

Study population: Babies screened under the Indian Twin Cities Retinopathy of Prematurity Screening (ITCROPS) program between January 1, 1997 and March 31, 2007.

Intervention: Multiple sessions of laser photocoagulation at any sign of plus disease with abnormal shunt vessels with or without neovascularization in zone 1.

Outcome measure: Based on the anatomic status of the retina at the final follow-up, the outcome was classified into good (completely regressed with no vitreoretinal changes), fair (regression with vitreoretinal distortion), or poor (progression into partial or total retinal detachment involving macula). Descriptive statistics (mean and range) were used for gestational age at birth, birth weight, and post-conceptional age at first presentation and at the first intervention. Trends in incidence of zone 1 ROP over 1 decade were analyzed. Outcomes were expressed in terms of proportions and 95% confidence interval (CI).

Results: Of the 3654 babies screened, 227 eyes of 115 babies were detected to have zone 1 aggressive disease, defined as zone 1 retinal vessels having abnormal closed-loop shunts, dilation and tortuosity, flat new vessels, or rapid progression. Laser was performed in 169 eyes. Disease regressed with good outcome in 142 eyes (84%) (95% CI, 77.6-89.2) and progressed to poor outcome in 13 eyes (7.69%) (95% CI, 4.1-12.8), while fair outcome was seen in 6 eyes (3.55%) (95% CI, 1.3-7.5). Thus 148 babies (87.5%) (95% CI, 81.6-92.14) had a favorable outcome. The outcomes in 8 treated eyes (4.7%) lost to follow-up were unknown.

Conclusions: Zone 1 aggressive ROP has a good outcome if the screening is done early; intervention is prompt and adequate, with frequent follow-up until complete regression is achieved.