Clinical Characteristics and Outcomes of Primary Vitreoretinal Lymphoma in Northern Thailand

OBJECTIVE This study aims to describe clinical characteristics and outcomes after treatment of primary vitreoretinal lymphoma (PVRL). METHODS Fifteen patients with a proven diagnosis of PVRL by histology, cytology and/or flow cytometry were analyzed. RESULTS The median age of the 15 patients was 59 years (range 41-71). Median follow-up time was 37 months (IQR 22.5-80) (range 4-106). Ophthalmic presentations of 25 eyes included vitritis (72%), chorioretinal infiltrations (60%), and retinal vasculitis (20%). Bilateral involvement was observed in 10 patients at presentation and in 4 patients during follow up. Ten patients (67%) developed brain involvement after ocular presentation with a median time of 22.5 months (range 2-84). Treatment modalities were included: 1) isolated intravitreal (IVT) methotrexate (6/15 patients; 40%) with a median number of injections of 4 (IQR 1,6) (range 1-16) 2) combined with IVT metho-trexate and/or rituximab and systemic chemotherapy and/or radiation (8/15; 53%) with a median of 6 injections (IQR 1,11) (range 1-16) and 3) systemic chemotherapy alone (1/15; 7%). Whole brain radiotherapy (WBRT) was performed in 10 of 15 patients (67%). Among the 6 patients who received isolated IVT methotrexate, 3 patients had complete remission (3/6; 50%), one died at 96 months after treatment, and one was lost to follow up after a single injection. Nine of 15 patients who received systemic chemotherapy with or without IVT chemotherapy and/or WBRT had complete remission (8/9; 89%). CONCLUSIONS Vitritis and chorioretinal infiltrations were the main ocular presentations of PVRL. Two-thirds of the patients developed brain involvement which resolved after treatment. Systemic chemotherapy tends to provide a higher rate of complete remission compared to local therapy alone.