Posterior to the ridge laser in zone 2 stage 3 retinopathy of prematurity with plus disease: Efficacy and safety

Purpose: This study aimed to ascertain the efficacy and safety of an additional posterior to the ridge laser for treatable zone 2 stage 3 retinopathy of prematurity (ROP). Methods: This study was a retrospective chart review of infants undergoing laser treatment for ROP at a single center from March 2014 to March 2022. The chart review specifically searched for infants treated for zone 2 stage 3 ROP with plus disease, where additional posterior to the ridge laser was performed. Results: Seventy-eight eyes of 45 infants met the inclusion criterion. The mean birth weight and gestational age were 1166.09 ± 329.66 gm and 29 ± 2 weeks, respectively. Group 1 comprised 52 eyes treated for high-risk prethreshold stage 3 ROP, while group 2 comprised 26 eyes treated for threshold ROP. 532-nm frequency-doubled Nd:YAG laser (Nidek, Japan) was used in all eyes. Apart from the standard laser to the avascular retina, an additional three rows of laser were applied posterior to the ridge in all eyes during the primary laser sitting (except in two eyes where it was performed as a rescue treatment 2 weeks after the first sitting). No complications were observed during or immediately after the laser procedure. A favorable outcome was achieved in 98.07% of eyes with prethreshold ROP and 76.92% of eyes with threshold ROP. Overall, a favorable outcome was achieved in 71 (91.02%) of the 78 eyes. Conclusion: Posterior to the ridge laser performed in the primary sitting along with the standard laser for treatable stage 3 ROP in zone 2 is safe and effective. Further prospective studies are needed to study this underutilized approach.