This study found that although cataract development is a potentially devastating complication after laser photocoagulation for retinopathy of prematurity (ROP), some patients develop cataracts without treatment, suggesting that laser treatment of ROP cannot always be blamed for cataract development.
The authors write that whereas cataracts have been a well-recognized complication of stage 4 or 5 ROP, the incidence of cataract development after treatment at earlier stages has not been firmly established.
They examined the incidence of cataract development by six months’ corrected age in preterm infants from the Early Treatment for Retinopathy of Prematurity (ETROP) trial.
Of 401 randomized infants, 366 patients were followed, and eight eyes of seven patients (1.9 percent) developed cataracts by six months’ corrected age. Among these patients, the mean birth weight was 754 g, and the mean gestational age was 25.7 weeks. Mean gestational age at treatment was 36.3 weeks for early treatment patients and 39.5 weeks for conventionally-managed patients.
Three early-treatment eyes and five conventionally-managed eyes developed cataracts. Of the conventionally managed eyes, three with and two without laser treatment developed a cataract. All six treated eyes had plus disease when treated. Three eyes had ROP in zone 1, whereas the other 3 had ROP in zone 2. All eyes were treated using a diode laser.
They note that in the six eyes that developed cataracts after laser treatment, there was some evidence that anterior segment ischemia may have caused cataract development. By six months’ corrected age, one eye showed corneal opacification, one eye was found to have iris atrophy, two eyes had shallow anterior chambers, and three eyes had evidence of iris synechiae. At the time of treatment, four of the six eyes had persistent pupillary vessels, and all had plus disease, suggesting that the presence of these findings may be associated with cataract development.
They conclude that even in the absence of complications at the time of laser treatment or lack of immediate postoperative cataract changes, the risk of cataract development remains, and close follow-up is warranted until at least six months’ corrected age and likely beyond.