Optic nerve biopsy in the management of progressive optic neuropathy.

Background: In cases of progressive optic neuropathy, diagnostic uncertainty often persists despite extensive work-up. Optic nerve biopsy (ONB) can be considered, especially when visual decline of the affected or fellow eye ensues despite empiric therapy. We aimed to evaluate both diagnostic and therapeutic utilities of ONB based on the long-term experience at a tertiary care institution.

Methods: This was a retrospective chart review of biopsies over 20 years at a single institution involving intrinsic or adherent optic nerve masses. Main outcome measures included the impact of tissue sampling on reaching a diagnosis and on guiding treatment. Secondary measures included vision in the eye of the ONB and the fellow eye.

Results: Fifteen patients with a mean age of 51.7 ± 17.4 years underwent biopsies. At the time of biopsy, visual acuity was no light perception in 8 (53%) eyes, light perception to counting fingers in 5 (33%), and 20/400 or better in 2 (13%). The fellow eye of 7 patients (47%) experienced some degree of sequential vision loss before biopsy. Seven specimens included en bloc biopsy of the nerve, 7 contained the dural sheath (usually with a portion of the optic nerve), and 1 only of the compressive mass. Six patients (40%) had tumors. Six of 8 inflammatory lesions biopsied required further clinical data to arrive at specific diagnoses. In one case, a clinical diagnosis could not be made. No patients experienced further vision loss in the fellow eye at last follow-up (median, 8 months).

Conclusions: In diverse circumstances of progressive optic neuropathy, ONB can be beneficial in establishing the diagnosis. ONB can help direct specific local or systemic treatment, particularly when infectious or inflammatory etiologies are identified. ONB, if considered early in the disease course, can potentially halt or prevent vision loss when the fellow eye is threatened.