Influence of Diabetes Mellitus on the Morphometric Analysis of the Optic Nerve Head

ABSTRACT

To evaluate the influence of diabetes mellitus (DM)on the optic nerve head topographic parameters, each group of 101 patients with open-angle glaucoma (OAG)and 91 control subjects was divided into two subgroups according to the presence or absence of DM.We compared the optic nerve head topographic parameters among groups using Topographic Scanning System (TopSSTM software version 2.2, LDT, Inc., U.S.A.);53 nonglaucomatous eyes without DM (normal group), 38 nonglaucomatous eyes with DM, 67 OAG eyes without DM, and 34 OAG eyes with DM. In the group with OAG without DM, mean contour depth, cup shape, neuroretinal rim area (NRRA), NRRA/disc area were significantly smaller but, effective area and cup/disc area were signifcantly larger than normal group (p<0.05, Student t-test).In nonglaucomatous group, the presence of diabetes showed statistically significant decrease in mean contour depth, cup shape, NRRA, NRRA/disc area ratio (p<0.05).It also showed increase in effective area and cup/disc ratio (p<0.05).These changes were similar to those reported for glaucomatous optic nerve damage.In the group with OAG, the presence of diabetes did not show statistically significant differences in the optic nerve head topographic parameters. In this study, we tried to measure the diabetic changes of the optic nerve head quantitatively using the confocal scanning laser ophthalmoscope (TopSSTM). These results suggest that the diabetic changes should be considered in the evaluation of the optic nerve head parameters for the screening or early diagnosis of open-angle glaucoma when using TopSSTM.