ObjectiveTo evaluate the safety and efficacy of the intravitreal methotrexate treatment in patients with primary vitreoretinal lymphoma (PVRL). MethodsRetrospective non-comparative interventional case series. Fourteen patients (26 eyes) with biopsy-proven PVRL were included in the study. All patients received examination of Snellen chart visual acuity, fundus color photography and optical coherence tomography (OCT). Among the 24 eyes with recordable visual acuity, 17 eyes has initial visual acuity≥0.1 (0.45±0.20) and 7 eyes with initial visual acuity ranged from light perception to hand movement. The vitreous opacities and (or) subretinal yellowish-white lesions and retinal pigment epitheliumuplift were observed in all eyes. All eyes were treated with intravitreal methotrexate (4000 μg/ml, 0.1 ml) injections according to a induction-consolidation-maintenance regimen. For 26 treated eyes, each received an average of (11.5±6.3) injections. Twenty eyes had finished theintraocular chemotherapy, while 6 eyes had not. Eight of 20 eyes were clinically confirmed free of tumor cells by diagnostic vitrectomy, 12 eyes were still with tumor cell involvement.The follow-up was ranged from 2 to 48 months, the mean time was 18 months. The examination of BCVA, fundus color photography and OCT were performed. No tumor cell was defined as clinical remission. Visual acuity was scored as improved or declined obviously (improved or declined 2 lines) or mild improved or declined (changed within 2 lines). ResultsTwenty eyes achieved clinical remission after (3.5±3.6) injections, 12 eyes of 20 eyes with tumor cell involvement before chemotherapy achieved clinical remission after (5.8±3.0) injections. The mean visual acuity of seventeen eyes with initial visual acuity 0.1 in induction phase and at the end of treatment were 0.36±0.23 and 0.56±0.20, respectively. Compared with before treatment, the visual acuity was mild declined in induction phase (t=1.541, P>0.05), but mild improved at the end of treatment (t=2.639, P<0.05). The visual acuity at the end of treatment in 7 eyes with initial visual acuity<0.1 was ranged from no light perception to 0.1. Of 14 patients, 2 patients have been fatal because of brain lesions progression at 42 and 48 months after diagnosis of primary central nervous system lymphoma. No ocular recurrence was noted during the follow-up in 20 eyes who finished intraocular chemotherapy. ConclusionsPVRL patients can achieve clinical remission after (3.5±3.6) injections by intravitreal chemotherapy of methotrexate, and the visual acuity improved mildly. No ocular recurrence was found during follow-up.