The optic nerve head in normal-tension glaucoma

There is controversy over the definition, appearance, and characteristics of the optic nerve head in normal-tension glaucoma (NTG). Optic disk size is greater in eyes with NTG than in those with primary open-angle glaucoma. However, in an intraindividual bilateral comparison, the eye with the larger optic disk showed neither more marked nor less pronounced glaucomatous optic nerve damage. Optic disk hemorrhage and peripapillary atrophy have been reported to be more frequent in patients with NTG. Nonuse of calcium channel blockers, peripapillary atrophy, and disk hemorrhage were statistically significantly associated with visual field loss progression in NTG. However, there is a possibility that a high IOP may stop disk hemorrhage relatively early. Histopathologic optic nerve head changes correlated with the clinical appearance of the optic nerve head, which is comparable in NTG and primary open-angle glaucoma. However, as novel findings, serum antibodies to retinal proteins and retinal immunoglobulin deposition in the ganglion cells were observed, and the level of serum autoantibodies to optic nerve head glycosaminoglycans was higher in patients with NTG than in patients with primary open-angle glaucoma.