Grating visual acuity results in the early treatment for retinopathy of prematurity study

Objective: To compare grating (resolution) visual acuity at 6 years of age in eyes that received early treatment (ET) for high-risk prethreshold retinopathy of prematurity (ROP) with that in eyes that underwent conventional management (CM). Methods: In a randomized clinical trial, infants with bilateral, high-risk prethreshold ROP (n=317) had one eye undergo ET and the other eye undergo CM, with treatment only if ROP progressed to threshold severity. For asymmetric cases (n=84), the high-risk prethreshold eye was randomized to ET or CM. Main Outcome Measure: Grating visual acuity measured at 6 years of age by masked testers using Teller acuity cards. Results: Monocular grating acuity results were obtained from 317 of 370 surviving children (85.6%). Analysis of grating acuity results for all study participants with high-risk prethreshold ROP showed no statistically significant overall benefit of ET (18.1% vs 22.8% unfavorable outcomes; P=.08).Whenthe 6-year grating acuity results were analyzed according to a clinical algorithm (high-risk types 1 and 2 prethreshold ROP), a benefit was seen in type 1 eyes (16.4% vs 25.2%; P=.004) undergoing ET, but not in type 2 eyes (21.3% vs 15.9%; P=.29). Conclusion: Early treatment of eyes with type 1 ROP improves grating acuity outcomes, but ET for eyes with type 2 ROP does not. Application to Clinical Medicine: Type 1 eyes should be treated early; however, based on acuity results at 6 years of age, type 2 eyes should be cautiously monitored for progression to type 1 ROP. Trial Registration: clinicaltrials.gov Identifier: NCT00027222