Objective: To evaluate ophthalmologists' management of diabetic patients. Methods: A multiple-choice questionnaire was mailed to all ophthalmologists in New York (1985), Florida (1990), and Massachusetts (1993 and 1996). Questions included practice patterns, methods used in examination, use of photography and fluorescein angiography, indications for laser treatment, and intervals for follow-up of selected conditions. Responses were tabulated and compared between surveys and with the American Academy of Ophthalmology Preferred Practice Pattern. Results: In this first report, we detail follow-up patterns of various grades of retinopathy. Physicians increasingly used duration of diabetes as a criterion in determining the length of follow-up for adults, despite persistent ambiguities for children. There were notable changes over time in nearly all aspects of follow-up for both general ophthalmologists and retina specialists. Retina specialists were less likely to treat proliferative disease, more likely to follow up patients with preproliferative disease sooner, and used longer followup intervals for short-duration diabetic patients, whereas a small percentage of general ophthalmologists continued to recommend treatment for background disease. Conclusion: There were noticeable trends toward Diabetes 2000 recommendations over time, although there remained many areas where further education appeared warranted.