Applying number-needed-to-treat (NNT) analysis to ophthalmic clinical trials

The purpose of this study is to provide a summary of the actual medical treatment effects reported by commonly cited ophthalmic randomized, controlled trials during the last 25 years to better educate individual patients and the public as a whole regarding their outcomes.

The author conducted a retrospective literature review.

A review of English-language literature containing major ophthalmic studies was performed. Number-needed-to-treat analysis was applied to published results of reviewed studies.

Many current recommendations for ophthalmic treatment of various eye diseases show only moderate or limited treatment effects. Although these recommendations may provide improved outcomes over the natural courses of the diseases, they often do not have excellent outcomes that are apparent to patients or consistent with provider expectations, and the number needed to treat to attain positive outcomes remains high for some interventions.

Eye care providers should be aware of the limitations of ophthalmic treatments published in well-known studies to provide more informed recommendations for their patients and the public at large.