Comparing the Outcome of Single Versus Multiple Session Laser Photoablation of Flat Neovascularization in Zone 1 Aggressive Posterior Retinopathy of Prematurity

In Brief Purpose: To compare single versus 2-session laser photoablation for flat neovascularization in cases with Zone 1 aggressive posterior retinopathy of prematurity. Methods: Twenty-nine Asian Indian infants with aggressive posterior retinopathy of prematurity were randomized; each eye received 1 of 2 methods (29 each in Group A or B) proposed by the PHOTO-ROP group. Group A underwent single session laser to the avascular retina underlying the flat neovascularization by direct laser over the fronds. Group B underwent laser in 2 sessions; first, laser was delivered to the avascular periphery up to the flat neovascularization and 7 days later to the avascular bed exposed by the retraction of the fronds. Outcome and complications between the two groups were compared. Results: Mean birthweight and gestational ages were 1,276 g and 30.1 weeks, respectively. All eyes showed favorable outcome at a minimum 12-month follow-up. Hemorrhages after laser (41.4% vs. 17.2%, P < 0.001) were more common in the single laser group. Large hemorrhages (>1 disk diameter) seen in Group A took longer than 8 weeks to resolve and developed focal fibrosis. Conclusion: This study demonstrates that the two-staged laser procedure produces fewer and smaller hemorrhages and no fibrosis compared with a single session. Both methods have comparable favorable outcomes in Asian Indian infants. This randomized prospective study comparing single versus 2-session laser photoablation of the flat neovascularization complex in eyes with Zone 1 aggressive posterior retinopathy of prematurity suggests that although both methods have a comparable and favorable outcome, the 2-staged laser protocol produces significantly fewer complications.