QUANTIFICATION OF CYSTOID CHANGES IN DIABETIC MACULOPATHY

Purpose. In patients with diabetic macular edema and cysts, quantifica tion of the extent of the cystoid formation has been difficult. This s tudy was performed to introduce reliable measurements of cysts, the qu antification of the extent, and its relation to visual acuity. Methods . Fluorescein angiography generated with a scanning laser ophthalmosco pe provided detailed recognition not only of the foveal microvasculatu re, but also of well-demarcated cystoid formations in the early phases . The sampling area included the central 2.5 degrees of the fovea. Usi ng digital image analysis, two independent observers estimated the are a covered by cysts, the number of cysts, and the foveal avascular zone (FAZ). Results. Twenty-three subjects with diabetes and macular cysts were enrolled in the current study. The mean area of the cysts was 0. 315 +/- 0.241 mm(2) (0.05 mm(2) to 0.9 mm(2)), and the number of cysts ranged from 1 to 7. Both parameters, area of cysts (r(2) = 0.61), and number of cysts (r(2) = 0.48) showed a significant correlation with v isual acuity (P < 0.01), whereas FAZ (0.08 to 0.58 mm(2)) showed no si gnificant correlation with visual acuity. Conclusion. Fluorescein angi ography allows a reproducible quantification of the extent of macular cysts. The relation of visual acuity to the number of cysts and to the area covered by the cystoid formation is highly significant. Thus, bo th these measures can provide an objective criterion for the estimatio n of visual prognosis and an outcome for evaluation therapy techniques .