A Novel Approach to Measuring Binocular Visual Fields in Glaucoma.

PRCIS Combined average visual field index is a simple, novel tool for binocular visual field which agrees with the existing binocular integrated visual field model, as well as patient reported activity limitation in glaucoma. PURPOSE To determine the correlation between novel models of binocular visual field with the existing integrated visual field (IVF) and glaucoma activity limitation. MATERIALS AND METHODS Integrated visual fields were calculated from the monocular visual fields of 58 patients with primary glaucoma and the novel binocular visual field models termed binocular summation visual field index (BiSumVFI) and combined average visual field index (CaVFI) were derived from the visual field indices (VFI) of both fields. Glaucoma activity limitation (GAL-9) questionnaire was administered to the patients. The relationship between IVF and the two newer models of binocular fields were determined and the correlation of IVF, BiSumVFI and CaVFI with GAL-9 was estimated. RESULTS A very strong correlation was seen between IVF and BiSumVFI (r=-0.913, P<0.001, CI: -0.958 to -0.821) and also between IVF and CaVFI (r=-0.896, P<0.001, CI: -0.947 to -0.802). Linear regression analysis showed a significant R2 of 0.902 (P<0.001) to predict IVF from BiSumVFI and R2 of 0.847 (P<0.001) to predict IVF from CaVFI. IVF, BiSumVFI and CaVFI correlated moderately and significantly with Glaucoma activity limitation with correlation coefficients of 0.481, -0.499 and -0.505 respectively. CONCLUSION The binocular summation visual field index and combined average visual field index models of binocular visual field are good predictors of integrated visual field in glaucoma. They correlate well with the existing integrated visual field model in estimating patients' perception of activity limitation in glaucoma.