Crohn-related Chronic Relapsing Inflammatory Optic Neuropathy

Because she was stable, and to avoid cumulative toxicity, the cyclophosphamide was discontinued. Specifically, the following were normal or negative: cell-based neuromyelitis optica (NMO) and myelin oligodendrocyte glycoprotein (MOG) antibody assays, complete blood count, calcium, creatine kinase, angiotensin-converting enzyme, complement C3 and C4, cryoglobulins, rheumatoid factor, antinuclear antibody by immunofluorescence, anti-double-stranded DNA, extractable nuclear antigen antibodies-2, extractable nuclear antigen antibodies-4, antineutrophil cytoplasmic antibodies, antiphospholipid antibodies, anticardiolipin antibodies, cyclic citrullinated peptide antibodies, human leukocyte antigen B*51 (B5), syphilis screen, Lyme serology, Bartonella henselae serology, herpes simplex IgG antibodies, Epstein–Barr viral capsid antigen IgG antibodies, cytomegalovirus antigenemia assay. CSF studies were otherwise normal or negative: glucose; cryptococcal antigen; viral PCRs (herpes simplex virus, varicella zoster virus, cytomegalovirus, Epstein-Barr virus); CSF varicella zoster virus IgM; mycobacterial PCR; bacterial, acid-fast bacterial, and fungal cultures; venereal disease research laboratory test; Lyme disease serology; IgG index; oligoclonal band assay; cytology; flow cytometry. The basis for stating that “recurrences of retrobulbar neuritis are not uncommon” is not supported by details or numbers in reports.4 Furthermore, no recurrences were reported in a more recent review.8 Our patient fulfills the criteria for CRION: optic neuritis and at least one relapse; objective evidence for loss of visual function; NMO IgG seronegativity; contrast enhancement of the acutely inflamed optic nerves; response to immunosuppressive treatment and relapse on withdrawal or dose reduction of immunosuppressive treatment.9 Her clinical picture is consistent with the features of CRION.10 NMO and MOG antibody positivity have been found in patients previously diagnosed with CRION11,12 but not in our patient.