Photographic Documentation of the Loss of Medullated Nerve Fibers of the Retina in Uncontrolled Primary Open Angle Glaucoma

Abstract

We report the first case of retinal myelin loss associated with uncontrolled primary open angle glaucoma (POAG). The clinical features, visual fields, and serial disc photos documenting the changes are described. The literature regarding this phenomenon in other forms of optic neuropathy and the specific implications in glaucoma patients are discussed. A 75-year-old black man with POAG had medullated nerve fibers of the retina bilaterally abutting the optic discs inferonasally. Optic disc appearance and visual fields were stable over 6 years. The patient was then lost to follow-up for 2 years and returned with elevated intraocular pressures (IOPs), visual acuity and field loss, progressive optic disc damage, peripapillary atrophy, and disappearance of retinal myelin on the left greater than the right. Retinal myelin loss occurred in areas of nerve fiber layer dropout. Loss of medullated nerve fibers in the retina occurs secondary to anterograde axonal degeneration as a nonspecific response to any form of optic atrophy. The apparent paucity of glaucoma patients with retinal myelin may be due to late referral rather than any inherent protective effect of retinal myelin against elevated IOP.