Safety and efficacy of limited laser therapy for type I mid-zone II retinopathy of prematurity

Laser photocoagulation of the entire avascular retina is a conventional therapy for the proliferative stage of retinopathy of prematurity (ROP). Limited lasers in number, localized at the avascular area posterior to the ridge might similarly regress aberrant retinal neovascularization. The study aims to evaluate the safety and efficacy of an innovative modified posterior half avascular area laser therapy for type I mid-zone II ROP. In a prospective comparative study, 48 eyes of 24 premature infants with bilateral symmetric type 1 zone II ROP were included for laser photocoagulation. The first eye received standard panavascular photocoagulation. In the second eye, laser photocoagulation was applied to the posterior half of the retinal avascular area, sparing the anterior half retinal avascular area. The retreatment rate was determined as a main outcome measure through weekly funduscopic examination. Fundus photography and refractive measurement were obtained at the last follow-up. The mean birth weight of the infants was 1341.04 ± 353.55 g. The infants’ mean postmenstrual age (PMA) at the time of intervention was 38.25 ± 2.95 weeks. In 2 (8.33%) infants, both eyes were retreated with complete regression without further recurrence. No adverse events were observed during mean PMA follow-up of 54.47 ± 4.09 weeks. The mean spherical equivalent was comparable between the two groups at the last follow-up (P = 0.794). Limited laser photocoagulation demonstrated a safety and efficacy profile similar to that of standard therapy in type I ROP in the mid-zone II. A randomized clinical trial is mandatory to validate the results.