Objective: The goal of this study was to determine whether there was a significant difference between the visual outcomes of eyes with threshold retinopathy of prematurity (ROP) treated with trans-scleral cryotherapy compared to those treated with laser photocoagulation.
Design: Extended follow-up study of a prospective, randomized clinical trial.
Participants: Fifty-two patients with bilateral threshold ROP participated. Follow-up data were available for 25 of these patients.
Intervention: Patients were randomized to receive cryotherapy in one eye and laser photocoagulation in the other eye.
Main outcome measures: The best-corrected visual acuity of each eye was measured. Best-corrected visual acuities of 20/50 or better were classified as "good" clinical outcomes, whereas those 20/60 or worse were considered "poor" outcomes. A secondary outcome of this study was the spherical equivalent (SE) of each eye's most recent refraction.
Result: At an average follow-up point of 5.8 years (range, 4.3-7.6 years), the odds that an eye treated with laser had a good clinical outcome were 6.91 times greater than for eyes treated with cryotherapy (95% confidence interval, 1.70-28.0; n = 21). Additionally, the laser-treated eyes were less myopic with a mean SE of-3.05 diopters compared to a mean SE of -5.08 diopters for the cryotherapy-treated eyes (P = 0.0072, n = 23).
Conclusion: The authors' study suggests that laser photocoagulation for threshold ROP was more likely to result in a good clinical outcome with better final visual acuity and less myopia compared to cryotherapy treatment.