Patients with MFCPU and optic neuropathy seen in Ocular Immunology at Wilmer Eye Institute from 1984 through 2005 were studied and clinic characteristics described. The diagnosis of MFCPU was based on the characteristic clinical appearance.^1,2 Optic neuropathy was diagnosed in eyes with optic disc edema or pallor greater than cupping in patients with an afferent pupillary defect (APD), decreased visual acuity, and either dyschromatopsia or a visual field defect consistent with an optic neuropathy. The study was performed with the approval of the Johns Hopkins University Institutional Review Board.

Eight patients with optic neuropathy were identified (Table). Median age at presentation was 45 years. Six patients were women and 7 were Caucasian. Three patients had bilateral optic neuropathy, resulting in 11 affected eyes. All patients had an APD and 7 patients had dyschromatopsia (no data available for Patient 1). Visual field data were available for 7 patients (see Table). Median disease duration was zero months (range: 0 to >10 years). Despite the variable disease duration at presentation to our clinic, all patients had their optic neuropathy diagnosed either at the time of MFCPU diagnosis or early in the disease course. Four patients were receiving prednisone for MFCPU either prior to or at presentation.

Six patients had available follow-up (median follow-up duration = 37 months). All 6 were treated with prednisone 60mg daily with improvement in acuity and color vision, and resolution of optic nerve edema (if present). However, all 6 patients became corticosteroid-dependent and developed recurrences of optic neuropathy when the prednisone was discontinued. In each case of recurrence, treatment was reinstituted with control of the inflammation and at least partial visual recovery. Five patients required immunosuppressive drugs for their optic neuropathy because the prednisone could not be tapered to ≤10 mg daily without disease recurrence. None of these patients had recurrences of optic neuropathy after immunosuppressive agents were instituted (P = 0.02).

MFCPU is a chronic inflammatory disease that frequently results in ocular complications and loss of visual acuity over time.^1–5 Although uncommon, we found 8 patients with optic neuropathy complicating MFCPU in our original cohort (12% of patients; 8% of eyes).³ A review of the literature found reports that described optic nerve edema^2,5 and pallor^1,4 as complications of MFCPU, but information on other findings consistent optic neuropathy, such as presence of an APD, visual field defects, and dyschromatopsia, were lacking in these reports. It is possible that optic neuropathy is an underreported complication of MFCPU, as to our knowledge, this represents the first series reported in the literature.

During follow-up, the optic neuropathy appeared responsive to but dependent on corticosteroid therapy. Although reinstitution of treatment typically resulted in improvement of the optic neuropathy, the visual recovery after recurrent bouts of inflammation often was not complete. The course of optic neuropathy observed in our patients appears typical to that found in patients with inflammatory optic neuropathy not associated with demyelinating disease.^6,7 Corticosteroid-dependent optic neuropathy may require immunosuppressive drugs in order to taper the corticosteroids to doses that decrease the likelihood of corticosteroid-related side effects.⁶ The 5 patients that required immunosuppressive drugs had no recurrences of optic nerve inflammation while receiving immunosuppressive drugs, suggesting that this may be the optimal approach to treating these patients.