In the multicenter cryotherapy study for treatment of acute ROP (ICROP), threshold, i.e., treatment requiring ROP, was defined as stage 3 plus disease in zone II or zone I with at least 5 continuous clock hours or at least 8 cumulative clock hours of stage 3 disease, i.e., extraretinal proliferations (Table 5.2, Fig. 5.1b) . Using this criterion, a favorable functional outcome at îyear was achieved in 73% of zone II disease eyes, and in 12% of zone I disease eyes, compared to 46% of zone II disease eyes that were not treated, and 6% zone I disease eyes that were not treated . Despite this considerable success compared to the natural history, the number of unfavorable outcomes was still high.
Was this article helpful?