Response time and safety profile of pulsed oral methotrexate therapy in idiopathic retinal periphlebitis.
PURPOSE: To evaluate the response time and safety profile of low-dose oral methotrexate pulsed therapy in idiopathic retinal periphlebitis (Eales' disease). METHODS: A tertiary care center-based prospective interventional study, based on visual acuity grading, was undertaken. Twenty-one consecutive patients with idiopathic retinal periphlebitis were administered 12.5 mg methotrexate as a single oral dose, once per week for 12 weeks (cumulative dose = 150 mg). Each patient was assessed for change in visual acuity grades. Time of first therapeutic response was also noted. Drug safety was monitored by laboratory tests that included twice-weekly white blood cells and differential counts, twice-weekly platelet counts, and monthly liver function tests. RESULTS: Twenty-one eyes were assessed. Mean follow-up period was 6 months. All showed improvement in visual acuity grades. An excellent visual outcome (6/6 or better) was achieved in 18 (69%) eyes. Time of first therapeutic response varied from 2 to 6 weeks with a majority of eyes (80%) showing response by 4 weeks (median = 3 weeks). All the side effects of methotrexate were mild or moderate in severity and rapidly reversible on dose reduction or discontinuation. No patient had any constitutional symptoms severe enough to necessitate cessation of therapy. CONCLUSIONS: Low dose oral methotrexate pulse therapy (at a dose of 12.5 mg/week) is clinically effective within 4 weeks, and is associated with an acceptable safety profile.