Transscleral vs transpupillary diode laser photocoagulation for the treatment of threshold retinopathy of prematurity

Objective: To evaluate the efficacy and safety of transscleral diode laser photocoagulation for the treatment of threshold retinopathy of prematurity (ROP). Patients: Fifty eyes of 25 preterm infants (birth weight, 510-1200 g [864+/-178 g {mean+/-SD}]; gestational age, 24-29 weeks [26.7+/-1.7 weeks]) with threshold ROP were treated with diode laser photocoagulation (wavelength, 810 nm). One eye of each infant was treated transsclerally while the fellow eye had transpupillary coagulation using the laser indirect ophthalmoscope. Follow-up ranged from 2 to 22 months (10.0+/-5.3 months). Main Outcome Measure: The regression of acute ROP and the incidence of adverse treatment effects. Results: In 25 (100%) of the eyes treated transpupillarly and in 24 (96%) of the eyes treated transsclerally, ROP regressed after a single or a second laser treatment and the outcome was a flat, attached retina. One eye (4%) with disease in zone I failed to improve after transscleral laser treatment and ROP progressed to stage 4B with a partially attached retina, although additional retinal detachment surgery with an encircling band was performed. No adverse side effects as a result of diode laser treatment were noted except for a small amount of retinal-preretinal bleeding in the ridge in 9 (36%) of the transsclerally and in 5 (20%) of the transpupillarly coagulated eyes. There were no adverse side effects leg, cataract formation) in the anterior segments of the eyes. Conclusions: The results suggest that transscleral diode laser coagulation is as effective in the treatment of threshold ROP as transpupillary diode laser photocoagulation. Only minor side effects were noted. Transscleral diode laser photocoagulation seems to be an advantageous treatment method if transpupillary treatment bears an increased risk of cataract formation.