—Dr Charles' letter contains both specific and general criticism. His specific comments relate to the frequency of follow-up visits in the deferral group and to the reporting of results. His criticism of the design of the study is more general and expresses concern for the impact of this trial on surgical practice. We would like to respond to each of these comments.
—We share Dr Charles' view that patients should be followed up closely for the development of macular detachment. The follow-up schedule presented in our report is that of regular follow-up visits required of all patients for data collection. Additional unscheduled visits were carried out as required for patient management according to the judgment of the responsible vitreoretinal surgeon participating in the Diabetic Retinopathy Vitrectomy Study. At regular and unscheduled visits, ultrasonography was required if the retina was not visible ophthalmoscopically. For patients undergoing deferred vitrectomy,
Diabetic Retinopathy Vitrectomy Study-Reply. Arch Ophthalmol. 1986;104(4):486-488. doi:10.1001/archopht.1986.01050160038004