Optic Nerve and Optic Nerve Sheath Biopsy Indications and Outcomes.

Background: This study describes the clinical presentation, diagnostic yield, and outcomes of patients who have undergone optic nerve or nerve sheath biopsies.

Methods: A total of 72 patients undergoing an optic nerve or optic nerve sheath biopsy at Mayo Clinic, Rochester, MN; Jacksonville, FL; or Scottsdale, AZ were included. Patients were identified by searching the pathology database between January 1, 2000, and December 31, 2023. Charts were reviewed to confirm the site of biopsy and review the patient's presentation, clinical course, and indication for biopsy. The main outcome measure was the diagnostic yield.

Results: Of the 72 patients included, 32 underwent optic nerve and 40 optic nerve sheath biopsies. The median age at biopsy was 34 years (range, 1-81 years), and 44 patients (61%) were female. The median preoperative visual acuity was no light perception (NLP) (range, 20/20 to NLP). Prebiopsy optic disc appearance was pallor in 32 (44%), edema in 18 (25%), normal in 11 (15%), and edema with pallor in 5 (7%) patients. Surgical approach was by orbitotomy in 43 (60%), craniotomy in 25 (35%), and trans-nasal in 4 (5%) patients. A definitive diagnosis was achieved on 48 biopsies of 72 patients with an unexplained optic neuropathy, thus giving a diagnostic yield of 67%, higher in optic nerve biopsies (81%) compared with nerve sheath biopsies (55%). The most common diagnoses were meningioma in 23 (32%), glioma in 9 (13%), and sarcoidosis in 6 (8%) patients. For all patients, postbiopsy complications occurred in 11 patients (18%), including strabismus in 5 (7%) patients and acute unexpected vision loss in 4 (6%) patients. The patients in this cohort were followed for a median of 3.3 years, and visual acuity at most recent visit was NLP (range, 20/20 to NLP).

Conclusions: Based on our study, the diagnostic yield of optic nerve and optic nerve sheath biopsies was 67%. The potential diagnostic benefits of an optic nerve and optic nerve sheath biopsies may be offset by the possible permanent postsurgical complications.