Optic cup deepening spatially correlated with optic nerve damage in focal normal-pressure glaucoma

To evaluate whether deepening of the optic cup in patients with focal normal-pressure glaucoma is correlated with the location of most marked loss of neuroretinal rim and visual field.

Using morphometric evaluation of color stereo optic disc photographs of 102 eyes of 65 patients with focal normal-pressure glaucoma, the superior half of the optic disc was compared with the inferior half.

In eyes in which the optic cup was deepest in the inferior half of the disc, the most pronounced rim loss was located inferiorly significantly more often than superiorly, and the most marked visual field loss was located superiorly significantly more often than inferiorly. In eyes in which the optic cup was deepest in the superior half of the disc, the most pronounced rim loss was located superiorly significantly more often than inferiorly, and the most marked visual field loss was located inferiorly significantly more often than superiorly. Correspondingly, in eyes in which the most marked rim loss was located inferiorly, the deepest optic cup part was located inferiorly significantly more often than superiorly, and vice versa.

In focal normal-pressure glaucoma, location of the most marked deepening of the optic cup is spatially correlated with the location of most pronounced neuroretinal rim loss and visual field damage. Because high-pressure glaucoma is typically associated with optic cup deepening and vascular optic nerve damage is associated with optic cup flattening, the spatial correlation between focal optic nerve damage and focal cup deepening may suggest the presence of a pathogenetic aspect in both high-pressure glaucoma and focal normal-pressure glaucoma.