Association of macular involvement with proliferative retinopathy in Type 2 diabetes

Aims To determine whether documented evidence of pre-existing maculopathy i s present in Type 2 diabetic patients who require photocoagulation or vitre ctomy for proliferative disease. This is a retrospective case notes review. Methods The study was performed at Queen's Medical Centre, UK. All patients listed in the laser register and operating theatre register over 5 years ( March 1994 to March 1999) who had undergone pan retinal photocoagulation (P RP) for diabetic retinopathy, in one consultant firm, were studied. The med ical records of patients who had undergone vitrectomy as their first treatm ent for proliferative diabetic retinopathy in a vitreo-retinal firm over th e 5 years were examined. The proportion of patients with documented maculop athy before development of proliferative retinopathy was determined. Results All except 1/134 or 0.7% (95% confidence interval 0.1-4.5%) patient s had documentation of macular signs in at least one eye prior to the patie nt's first session of PRP. Of the remaining 133, 104 (78%) had had focal or grid photocoagulation of the macula. The median time between the documenta tion of maculopathy before the first PRP treatment session was 16 months (i nterquartile range 7-36). Fourteen patients had vitrectomy and endolaser pe rformed as the initial treatment for proliferative disease. All patients ha d documented maculopathy before the onset of proliferative disease. Conclusions The results of this study suggest that in Type 2 diabetes, prol iferative disease occurs relatively late compared with maculopathy. In such patients, maculopathy is almost invariably present when proliferative dise ase is detected.