Natural history of diabetic macular streak exudates: evidence from a screening programme

BACKGROUND/AIMS—Diabetic retinopathy screening guidelines recommend referral to an ophthalmologist if there is exudate within one disc diameter of the fovea. Many of these patients, however, have resolution of small amounts of exudate without treatment. This study aimed to assess whether patients with minimal streak or dot exudates within one disc diameter of the fovea can be monitored in a screening programme without compromising visual acuity. METHODS—A retrospective review of records and Polaroid photographs obtained by one screening centre over a 10 year period was performed. Outcomes measured were referral rates, alteration of Snellen visual acuity, and the need for macular photocoagulation treatment. RESULTS—55 patients (74 eyes) fulfilled entry criteria (37 streak and 37 dot exudates). Mean follow up was 56.1 months (range 12-127 months). Twenty five patients (30 eyes) were referred to an ophthalmologist. 13 eyes (17.6%) required macular photocoagulation treatment. Four eyes (5.4%) lost two or more lines of Snellen acuity over the follow up period (three from macular oedema and one from macular ischaemia). There was no relation between the presence or resolution of minimal exudate and visual loss (p>0.2). CONCLUSION—It is appropriate to monitor eyes with streak or dot macular exudates at 6-9 monthly intervals in a screening programme.