According to a report published early online in Ophthalmology, interferon alpha might rarely be linked with anterior ischemic optic neuropathy (AION).

This finding is based on a review of case reports from the literature and from spontaneous reporting systems (National Registry of Drug-Induced Ocular Side Effects, WHO and FDA),

The following findings were reported:

• 36 case reports of AION are described in association with interferon alfa therapy

• The average age of subjects was 54.5 years; 26 were male and 10 were female

• The median duration of therapy to onset of AION was 4.5 months, with 50% of subjects having some form of permanent vision loss

• Anterior ischemic optic neuropathy was bilateral in 67% of subjects

• There are 3 positive rechallenge case reports.

The authors stress that clinicians should be made aware of this possible adverse effect, particularly the finding that 50% of the subjects from this case series had some form of permanent vision loss, and stop the interferon as soon as possible if visual symptoms are reported by the patient.