Interferon Associated Retinopathy in a Patient with Relapsing Remitting Multiple Sclerosis

Background: Interferon beta-1a is used in the treatment of relapsing remitting multiple sclerosis (RRMS). Although visual side effects associated with disease modifying therapies have been reported, there are a limited number of reports on interferon-beta associated retinopathy.

Objectives: To report a case of interferon beta-1a associated retinopathy.

Methods:  Observational case report.

Results:  A 30-year-old Caucasian woman diagnosed with relapsing remitting MS in 2013, presented to our MS Center. She was first started on glatiramer acetate 40 mg three times per week but due to the interval progression in magnetic resonance imaging (MRI) of the brain, she was switched to subcutaneous interferon beta-1a in 2014. She has been on interferon beta-1a 44 mcg subcutaneously three times per week since then. Over the next following 18 months, the patient was clinically stable without any change in MRI scans of the brain and spinal cord.  However, six months after initiation of subcutaneous interferon beta-1a, she developed scotoma in her left eye, not associated with any other neurological symptoms. The scotoma is peripheral, small and does not interfere with her vision. Currently, her visual acuity is 20/20 bilaterally, visual fields and funduscopic examination are within normal limits. The scotoma has not subsided since then. Optical coherence tomography (OCT) showed pigmented epithelium detachment in her left eye. The diagnosis of interferon-beta 1a retinopathy is retained due to the exclusion of other etiologies.

Conclusions:  Interferon beta-1a is frequently used in the management of patients with relapsing remitting multiple sclerosis. Although interferon beta-1a associated retinopathy is rare and likely benign, the clinician should be aware of this complication.