Prospective randomized clinical trials offer an outstanding means of evaluating the benefits and risks of a medical or surgical intervention. Results generated from various well-designed clinical trials in ophthalmology, such as the Diabetic Retinopathy Study1 and the Macular Photocoagulation Study,2 have provided ophthalmologists with evidence on which to base management decisions. A variety of other factors also influence a physician's decision to recommend a particular course of action, including personal experience, the experience of colleagues, epidemiologic study findings, case series reports, and data from retrospective studies. However, many of these additional resources may have inherent biases. The enforcement of strict eligibility criteria and the randomization process performed within the context of a prospective controlled clinical trial reduce such biases, or at least balance them equally between the treatment arms of the study, and thus provide us with a more accurate assessment of a particular therapy.
Despite the relative
Bressler NM. Submacular SurgeryAre Randomized Trials Necessary?. Arch Ophthalmol. 1995;113(12):1557-1560. doi:10.1001/archopht.1995.01100120087016