What are the optic changes associated with Interferon (IFN) therapy?

From the Guidelines

Interferon (IFN) therapy can cause various optic changes, and patients should undergo regular ophthalmologic examinations to monitor for potential toxicities, such as uveitis, iritis, and episcleritis, which can occur in approximately 1% of patients receiving IFN therapy 1.

Key Considerations

• The median onset of immune-related ocular toxicities is 5 weeks, but can range from 1 to 72 weeks, and presenting symptoms may include blurred vision, change in color vision, photophobia, distortion, scotomas, visual field changes, double vision, tenderness, pain with eye movement, eyelid swelling, proptosis, redness, and/or dryness 1.
• Ocular toxicities are considered uncommon and less complex in their management compared with other immune-related toxicities, and a variety of ocular events have been reported with IFN therapy, including uveitis, iritis, episcleritis, and blepharitis 1.
• The principal mechanism of ocular toxicity is inflammatory, and often the IFN therapy can be safely continued as most presenting grades are mild and manageable with topical corticosteroids 1.

Management

• Typical management of ocular toxicities includes topical corticosteroids, often with the addition of cycloplegic agents, and in rare cases, systemic steroids 1.
• Any visual compromise (vision < 20/40) should prompt urgent ophthalmology referral to assess the need for more specific interventions, and in case of recurrent events or a grade 4 presentation (vision 20/200 or worse), permanent discontinuation of IFN therapy is advised 1.
• Infliximab may be considered for severe and treatment-refractory cases, although this is based on case reports only 1.

From the Research

Optic Changes with Interferon (IFN) Therapy

• There is evidence to suggest that type 1 interferon therapy can be associated with the development of autoimmune diseases, including optic neuritis 2.
• A case study reported a 60-year-old woman who developed type 1 diabetes mellitus and anti-aquaporin-4 antibody positive optic neuritis during type 1 interferon therapy for chronic hepatitis C 2.
• The study suggests that type 1 interferons may lead to the onset of autoimmune diseases by inducing disease-specific autoantibodies 2.

Treatment of Optic Neuritis

• Corticosteroids are commonly used to treat optic neuritis, but there is no conclusive evidence of benefit in terms of recovery to normal visual acuity, visual field, or contrast sensitivity with either intravenous or oral corticosteroids at the doses evaluated in trials 3, 4, 5.
• A randomized clinical trial found that bioequivalent doses of oral corticosteroids may be used as an alternative to intravenous corticosteroids to treat acute optic neuritis 4.
• The use of steroids in traumatic and ischemic optic neuropathies is highly controversial, and the evidence for the efficacy of treatment with steroids is insufficient to show that there is significant benefit 6.

Key Findings

• The risk ratio of normal visual acuity with intravenous corticosteroids compared with placebo was 1.06 (95% confidence interval 0.89 to 1.27) at six months and 1.06 (95% confidence interval 0.92 to 1.22) at one year 3.
• The risk ratio of normal contrast sensitivity for the same comparison was 1.10 (95% confidence interval 0.92 to 1.32) at six months follow-up 3.
• There is no significant difference in the recovery of vision between intravenous and oral corticosteroid treatment groups at 1 month or 6 months 4.