Vitreoretinal lymphoma: Central nervous system lymphoma risk with unilateral or bilateral ocular tumour. A multicentre collaboration

Objectives To investigate the risk of developing central nervous system (CNS) lymphoma in patients with vitreoretinal lymphoma (VRL) presenting with unilateral versus (vs.) bilateral ocular involvement. Methods Retrospective, multicentre cohort study from January 1, 1984 to December 31, 2020. Results There were 218 eyes of 127 patients with isolated VRL of the confirmed or presumed diffuse large B-cell subtype in the absence of known CNS or systemic lymphoma. Overall, mean patient age at presentation was 67 years (median 68, range 22-93 years), with 52 (40%) male, and 118 (90%) Caucasian. By univariate Cox regression analysis, two factors were predictive of decreased risk for development of CNS lymphoma, including initial presentation with unilateral VRL (versus bilateral VRL) (HR 0.5 [0.2-0.9], p = 0.02) and use of systemic chemotherapy for initial treatment of isolated ocular disease (HR 0.2 [0.1-0.6], p = 0.002). Both factors remained significant on multivariate and competing risk analyses. Progression from unilateral to bilateral VRL, patient age at presentation, and ocular structures involved (vitreous, subretinal space, subretinal pigment epithelial space) were not significantly associated with CNS lymphoma risk. Conclusion Initial presentation with unilateral VRL and treatment of isolated VRL with systemic chemotherapy were associated with lower risk of developing CNS lymphoma. Further study is required to determine whether select patients with isolated VRL might benefit from systemic chemotherapy in the prevention of CNS lymphoma.