Objective: To characterize the process of involution of threshold retinopathy of prematurity after transpupillary diode laser photocoagulation.

Methods: Retrospective case series. Methods: Neonates with threshold retinopathy who underwent diode laser photocoagulation of the peripheral avascular retina. Methods: A retrospective chart review was done of the weekly examination records of infants treated for threshold disease. Features that were studied included the presence of residual stage 3 neovascularization, plus disease, and development of retinal detachment (RD). Methods: Timing of full involution and/or development of an RD.

Results: Of 262 eyes of 138 infants treated, full involution without RD was seen in 8%, 43%, 64%, 73%, and 86% of eyes at postoperative weeks 1, 2, 3, 4, and 9+/-3, respectively. Retinal detachments were diagnosed cumulatively in 0%, 1.5%, 4.2%, 6.5%, and 14% of eyes at weeks 1, 2, 3, 4, and 9+/-3, respectively.

Conclusions: Full involution of laser-treated threshold retinopathy of prematurity required more than 2 weeks in more than half of treated eyes. Most RDs were not detected until > or =3 weeks after treatment.