We thank the authors for their interest and comments. One theme that emerges from these letters is concern about treatment of eyes where spontaneous involution of retinopathy of prematurity (ROP) might otherwise occur. Computations provided by Dr Averbukh offer a “saved to treated ratio” in an effort to evaluate the amount of unnecessary treatment in the Early Treatment for Retinopathy of Prematurity (ETROP) study. Dr Vander and colleagues calculate a number needed to treat (NNT) and suggest that, at least for zone II high-risk prethreshold eyes, further analysis should be performed before recommending this as a standard-of-care intervention. Dr Jalali and colleagues offer a different method for calculating an NNT. All these computations are problematic for a number of reasons.
Good WV, Hardy RJ. The Dilemma of Exercising Clinical Judgment in the Treatment of Retinopathy of Prematurity—Reply. Arch Ophthalmol. 2005;123(3):409-410. doi:10.1001/archopht.123.3.409