The Cryotherapy for Retinopathy of Prematurity Study (Cryo-ROP Study) showed for the first time that a therapy for threshold stage 3+ ROP was beneficial.1 Since the Cryo-ROP Study was designed, undertaken, and reported, both argon and diode indirect ophthalmoscopic laser systems have been developed that make treatment of the peripheral avascular retina theoretically safer with less attendant stress on the infant. Several studies suggest that laser therapy is as effective as cryotherapy.2-4 To confirm this in the manner of the Cryo-ROP Study would require a large randomized study, something that clearly seems impractical in view of the growing satisfaction with laser therapy for ROP.
The randomized clinical trial has an outstanding track record in ophthalmology and remains the gold standard for evaluating drug and surgical therapies. Metaanalysis, however, is gaining increasing acceptance as a method of summarizing the results of a number of trials and ultimately may also
Laser Therapy for Retinopathy of Prematurity. Arch Ophthalmol. 1994;112(2):154-156. doi:10.1001/archopht.1994.01090140028007