Objective: The purpose of the study is to assess the possible benefits of early laser treatment for posterior retinopathy of prematurity (ROP) and to provide data concerning the natural history of posterior ROP.
Design: The study design was a prospective, multicenter, randomized trial.
Participants: A total of 19 infants with prethreshold posterior ROP were studied.
Intervention: Randomization to immediate indirect laser photocoagulation or observation, with application of laser photocoagulation for those control eyes reaching threshold disease, was performed.
Main outcome measures: Patients were assessed at 3 months and the anatomic outcome recorded along with any adverse treatment effects.
Results: An unfavorable structural outcome developed in 3 (16%) of 19 early treatment eyes compared with 3 (18%) of 17 for those treated only if threshold disease was reached. Of the 17 control eyes, 15 (88%) reached threshold disease. Progression to threshold occurred within 1 week in all but two eyes. All 12 control eyes with posterior ROP and any amount of extraretinal fibrovascular proliferation progressed to threshold disease.
Conclusions: Although the number of patients studied is too small to reach statistical significance, the likelihood of a favorable outcome for eyes with prethreshold posterior ROP treated immediately with laser photocoagulation is comparable to that obtained by withholding treatment until threshold disease is reached. There is a high probability of progression from prethreshold to threshold disease, usually within 1 week or less.