Retinal Pigment Epithelium Undulations in Primary Vitreoretinal Lymphoma: An Under-Recognised OCT Biomarker.

To determine the significance of retinal pigment epithelium (RPE) undulations in primary vitreoretinal lymphoma (PVRL) and evaluate the association of RPE undulations, intraretinal infiltration, and sub-RPE/subretinal lesions with severity indicators, including partial regression, subsequent central nervous system (CNS) involvement, and recurrence. It is a multicentred, retrospective observational study which included 134 biopsy-proven PVRL eyes from Asian and American populations. Regression analysis was used to determine the association between various OCT biomarkers of PVRL and disease severity indicators. A total of 134 eyes from 77 patients with biopsy-confirmed PVRL were included. The median age of the patients was 67 years (range 59-71), and the sex distribution was 72 females (54%) and 62 males (46%). On OCT, 35 (26%) eyes showed RPE undulations, which were more common in Asians (61%) than in the American population (16%). In addition, 67 (50%) eyes exhibited sub-RPE/subretinal hyperreflective lesions, and 45 (34%) eyes had intraretinal lesions. Multivariate regression analysis showed an association between RPE undulations and partial regression odds ratio (OR) of 4.032 (95% CI: 1.518-10.71), (p = 0.005), and likelihood ratio of 8.418, and intraretinal lesions were associated with CNS involvement OR of 2.597 (95% CI: 1.14-5.876), (p = 0.01), and likelihood ratio of 5.26. RPE undulation is more common in Asians than in the American population. It is a marker of disease severity associated with partial regression of the disease, whereas intraretinal lesions are associated with an increased risk of subsequent CNS involvement.