Purchase this article with an account.
NP Blair, M Shahidi, WW Lai, R Zelkha; Diabetic Macular Edema: Correlation Between Microaneurysms and Retinal Thickness . Invest. Ophthalmol. Vis. Sci. 2002;43(13):537.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: Microaneurysms are commonly believed to be causally related to retinal thickening in diabetes, especially by leaking. Accordingly, laser exposures are often directed at microaneurysms to treat diabetic macular edema. We tested the hypothesis that thicker areas of retina in diabetic macular edema have more microaneurysms per unit area than less thick areas. Methods: We performed retinal thickness analysis with a prototype instrument on 10 eyes of 10 diabetics with macular edema. We compared the thickness at each 200 x 200 micrometer location in a 6 x 6 mm area of macula to corresponding locations in 22 normal eyes. The mean (SD ) age, sex (m/f), and eyes (r/l) were 51 (13) and 57 (10), 5/5 and 14/8, and 3/7 and 11/11 in the diabetics and normals, respectively. Maps of four levels of relative retinal thickness (0.70 to 1.10, 1.01 to 1.30, 1.31 to 1.50, and 1.50 to 2.00 times normal) in the diabetics were superimposed on fluorescein angiograms from the same eyes. Two graders counted the microaneurysms in zones with each thickness level. Results: The correlation between the counts by the two graders was 0.94. The means (SD) of the microaneurysms per mm2 were 1.4 (0.9), 1.5 (1.3), 1.1 (1.1), and 1.4 (2.2), respectively, in the above zones (P=0.900). Conclusion: We found no greater concentration of microaneurysms in the more edematous retinal areas in diabetic retinopathy. Some microaneurysms may not cause thickening and/or other factors may contribute to retinal thickening in diabetic retinopathy. The results may have implications on how to apply laser treatment optimally in diabetic retinopathy.
This PDF is available to Subscribers Only