DIAGNOSTIC ACCURACY EVALUATION OF VISUAL ACUITY AND FUNDUS AUTOFLUORESCENCE MACULAR GEOGRAPHIC ATROPHY AREA FOR THE DISCRIMINATION OF STARGARDT GROUPS.

Abstract

To evaluate diagnostic accuracy of visual acuity and fundus autofluorescence (FAF) macular geographic atrophy (GA) area for the discrimination of autosomal recessive Stargardt groups. Subjects aged <50 years old with confirmed molecular diagnoses were classified to Groups 1, 2, or 3 according to a full-field electroretinogram reference standard. Diagnostic accuracy of visual acuity and the FAF macular GA area was assessed with generalized estimating equations, receiver operating characteristic curve area under the curve, and support vector machines. Ten eyes were classified as Group 1 and 7 as Group 2. The mean log minimum angle resolution (Snellen equivalent) was 0.64 (20/87) for group 1 and 0.96 (20/182) for group 2. Mean FAF macular GA area was 0.96 mm for Group 1 and 3.23 mm for Group 2. The generalized estimating equation analysis showed an 8.3% increase in odds of Group 2 classification with each 0.1-unit increase in log minimum angle resolution and a 24% increase with each 1-mm increase in FAF macular GA area. Multivariate generalized estimating equation analysis showed that only the FAF macular GA area was significant. Area under the curve was 0.79 for log minimum angle resolution and 0.89 for FAF macular GA area. The support vector machine classification accuracy was 71% for log minimum angle resolution and 82% for FAF macular GA area. Visual acuity and FAF macular GA area had good independent accuracy for the discrimination of groups 1 and 2, indicating that they may serve as useful diagnostic parameters.