Efficacy and safety of intravitreal methotrexate for vitreo-retinal lymphoma - 20 years of experience.

Vitreo-retinal lymphoma (VRL) is the most common intraocular lymphoma and is highly associated with central nervous system (CNS) lymphoma (CNSL), both posing a therapeutic challenge. We investigated patients' characteristics, efficacy and safety of intravitreal methotrexate (MTX) injections and their outcomes over 20 years. The records of 129 patients diagnosed between 1997 and 2018 were retrospectively reviewed. Lymphoma involved both the CNS and vitreo-retina (49%), solely the CNS (37%) or solely the vitreo-retina (14%). In all, 45·5% of the patients with CNSL either presented with VRL or developed it after a mean (±SE) of 85·7 (7·3) months. In all, 66·0% of the patients diagnosed with VRL either presented with CNSL or developed it after a mean (±SE) 42·6 (7·6) months. The 81 patients with VRL (134 eyes) received a mean (±SD) of 19 (7) injections; however, only 5 (4) injections were needed to reach complete remission. Local recurrence occurred in two of the 81 patients. Overall, 80·2% of eyes had an initial moderate-severe visual loss, and >50% of them improved. Reversible keratopathy was the most prevalent side-effect. A total of 18·5% developed intraocular pressure (IOP) elevation due to angle neovascularisation after 16 injections, which could be reversed with prompt intravitreal injection of bevacizumab. Intravitreal MTX injections are a safe and effective treatment for VRL. Fewer injections (15) may offer similar results with fewer side-effects.