Purpose: To determine whether diabetes and diabetic retinopathy (DR) affect the performance of the Heidelberg Retina Tomograph II (HRT II; Heidelberg Engineering, Heidelberg, Germany) algorithms for glaucoma detection.
Methods: This population-based survey was conducted among Malays in Singapore who were a 40 to 80 years of age. Diabetes was defined as self-report of a physician's diagnosis, use of diabetic medication, or a random blood glucose level ≥11.1 mmol/L. Retinal photographs were graded for DR according to the modified Airlie House classification system. The diagnosis of glaucoma was based on International Society for Geographical and Epidemiologic Ophthalmology criteria. The sensitivity and the false-positive rates were calculated for the Moorfields regression analysis [MRA]; the linear discriminant functions (LDFs) by Mikelberg (Mikelberg-LDF), Burk (Burk-LDF), and Bathija (Bathija-LDF); and the support vector machine (SVM).
Results: A total of 1987 persons without diabetes (including 86 with glaucoma) and 524 with diabetes (including 26 with glaucoma) were analyzed. The presence of diabetes had no influence on both the sensitivities and false-positive rates for all HRT algorithms. In the multivariate analyses adjusting for optic disc size, the presence of DR was significantly associated with the higher false-positive rates for Burk-LDF and Bathija-LDF (P < 0.05), but not with the false-positive rates for MRA, Mikelberg-LDF, and SVM.
Conclusions: Diabetes does not affect the performance of HRT II for diagnosis of glaucoma, but the presence of DR may be a source of false-positive test results.