Optic disc in glaucoma: Topography and extent of fluorescein filling defects.

The topography and extent of localized areas of hypofluorescence or absolute filling defects of the optic discs of glaucomatous patients correlated positively with the loss of visual field. Filling defects tended to cluster at the inferior and superior poles of the optic disc and were closer to the disc margin than to the center. The location of the defects corresponded with the expected site of visual field loss. There was a positive correlation between the percent area of the filling defects and the degree of visual field loss. These observations support the concept that fluorescein filling defects of the optic disc in glaucoma represent areas of ischemia that are highly correlated with loss of visual field.