Purpose: To evaluate the success of and timing for intervention in retinopathy of prematurity (ROP).
Patients and methods: Eighty-two eyes of 50 children with stage 3 ROP were divided into two groups based on severity. Cryotherapy or laser therapy was performed soon after the detection of threshold stage in the first group of 40 eyes and at a prethreshold stage in the second group of 42 eyes. The patients were observed from 4 months to 2 years and regression or progression was noted. Unfavorable outcomes including macular and disc drag and the progression of ROP to stages 4 and 5 were correlated with birth weight, gestational age, age at threshold, and age at intervention.
Results: Regression of ROP occurred in 75 (91.46%) of the eyes. An overall unfavorable outcome occurred in 14 (17.07%) of the eyes, 11 of which reached threshold during the critical period of 37 to 39 postconceptional weeks of age. Of the cases (n = 14) with an unfavorable outcome, 9 eyes (22.5%) were in the group treated in the threshold stage (n = 40) and 5 eyes (11.9%) were in the group treated at a prethreshold stage (n = 42). The mean birth weight, gestational age, age at threshold, and age at intervention in the favorable and unfavorable outcome groups were 953.2 +/- 2.19 g and 1,059.57 +/- 2.62 g, 28.63 +/- 2.03 weeks and 28.36 +/- 1.98 weeks, 38.04 +/- 2.13 weeks and 37.71 +/- 1.13 weeks, and 38.32 +/- 2.34 weeks and 38.25 +/- 1.05 weeks, respectively.
Conclusion: Early intervention at a prethreshold stage of ROP or at a younger postconceptional age (ie, younger than 37 weeks) may decrease the incidence of an unfavorable outcome.