The preliminary results of the Early Treatment for Retinopathy of Prematurity study1 and the new guidelines for the treatment of retinopathy of prematurity are of great importance. The published article has a plethora of data that may be sometimes difficult to evaluate. However, the main question that should be asked is the question of the trade-off. We will treat more eyes that will do well without treatment, but we will save more eyes from blindness. But how many additional laser treatments shall we perform to save 1 eye? I have combined some data from the article into a Table to estimate the answer. Table 3 in the article indicates the number of eyes in the control group that progressed to threshold for each international classification of retinopathy of prematurity (ICROP) category. From this table, one can easily calculate the number of eyes that will not progress to threshold. These eyes, if treated early, are actually treated unnecessarily. On the other hand, looking at Table 8 in the article (functional outcome by treatment group), one can see the failure rate for the early treatment and for the conventional treatment groups for each ICROP category. The difference between these values indicates the percentage of eyes saved by the early treatment. The same is true for Table 9 (structural outcome by treatment group).
Averbukh E. The Evidence Supporting the Early Treatment for Type 1 Retinopathy of Prematurity Needs Further Evaluation. Arch Ophthalmol. 2005;123(3):406. doi:10.1001/archopht.123.3.406-a