Structural outcomes of eyes with threshold retinopathy of prematurity treated with laser therapy or cryotherapy

Abstract

Aim: To determine the structural outcomes of threshold retinopathy of prematurity treated with laser photocoagulation or cryotherapy and to identify risk factors for retreatment and significant structural changes.

Patients and methods: This was a retrospective analysis of the medical records of infants with threshold retinopathy of prematurity treated with laser photocoagulation or cryotherapy from 1997 to 2002 with at least 6 months of treatment follow-up.

Results: Forty one eyes of 21 infants were treated for threshold retinopathy of prematurity during the study period. All eyes had zone II disease. Seven of the 41 eyes (17%) had significant structural changes, 6 eyes (15%) had moderate dragging of retinal vessels, 3 eyes (7%) had dragging of the optic disc, 1 eye (3%) had macular ectopia, and 1 eye (3%) had retinal pigment epitheliopathy of the macula. No patients had retinal detachment, macular fold, or retrolental tissue. Nine of 39 eyes (23%) needed retreatment, owing to either persistence (7 eyes) or recurrence (2 eyes) of threshold disease. Cryotherapy appeared to be more likely to result in significant anatomic changes but was less prone to result in retreatment.

Conclusions: No infant had an unfavorable anatomic outcome defined by the Cryotherapy for Retinopathy of Prematurity Cooperative Group study. This result may be attributed to the absence of zone I disease in the patients in this study, advances in neonatology, change in treatment modality, and increasing experience with treatment. Laser treatment and cryotherapy are safe and effective for the treatment of threshold retinopathy of prematurity and their roles are not mutually exclusive. Each modality has its advantages and disadvantages, but they can act together to achieve good structural and functional outcomes.