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AIM: To construct an in vitro model of oxygen-glucose deprivation/reperfusion (OGD/R) induced injury to the optic nerve and to study the oxidative damage mechanism of ischemia-reperfusion (I/R) injury in 661W cells and the protective effect of ginsenoside Rg1. METHODS: The 661W cells were treated with different concentrations of Na2S2O4 to establish OGD/R model in vitro. Apoptosis, intracellular reactive oxygen species (ROS) levels and superoxide dismutase (SOD) levels were measured at different time points during the reperfusion injury process. The injury model was pretreated with graded concentrations of ginsenoside Rg1. Real-time polymerase chain reaction (PCR) was used to measure the expression levels of cytochrome C (cyt C)/B-cell lymphoma-2 (Bcl2)/Bcl2 associated protein X (Bax), heme oxygenase-1 (HO-1), caspase9, nuclear factor erythroid 2-related factor 2 (nrf2), kelch-like ECH-associated protein 1 (keap1) and other genes. Western blot was used to detect the expression of nrf2, phosphorylated nrf2 (pnrf2) and keap1 protein levels. RESULTS: Compared to the untreated group, the cell activity of 661W cells treated with Na2S2O4 for 6 and 8h decreased (P<0.01). Additionally, the ROS content increased and SOD levels decreased significantly (P<0.01). In contrast, treatment with ginsenoside Rg1 reversed the cell viability and SOD levels in comparison to the Na2S2O4 treated group (P<0.01). Moreover, Rg1 reduced the levels of caspase3, caspase9, and cytC, while increasing the Bcl2/Bax level. These differences were all statistically significant (P<0.05). Western blot analysis showed no significant difference in the protein expression levels of keap1 and nrf2 with Rg1 treatment, however, Rg1 significantly increased the ratio of pnrf2/nrf2 protein expression compared to the Na2S2O4 treated group (P<0.001). CONCLUSION: The OGD/R process is induced in 661W cells using Na2S2O4. Rg1 inhibits OGD/R-induced oxidative damage and alleviates the extent of apoptosis in 661W cells through the keap1/nrf2 pathway. These results suggest a potential protective effect of Rg1 against retinal I/R injury.
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Purpose: This study aimed to describe and analyze the clinical features of 20 eyes of 15 primary vitreoretinal lymphoma (PVRL) patients. Methods: This was a retrospective case series and a review of the literature. Fifteen PVRL patients (20 affected eyes) referred between February 2011 and December 2019 were recruited, and their medical records were retrospectively reviewed. Results: Among these 15 PVRL patients, seven were men (46.67%), and five had bilateral PVRL (33.33%). The median onset age was 66 ± 9.26 years and six (40%) patients had central nervous system (CNS) involvement, and two of them died of CNS-related complications. The ocular symptoms varied from decreased vision to binocular diplopia. The ocular manifestations were diverse and involved both the anterior and posterior segments, including the vitreous cells, subretinal white-yellow lesions, cotton-wool spots, and ophthalmoplegia. The rate of misdiagnosis and failure to diagnose was 100%, and 30% of them were misdiagnosed as uveitis. We found five cases revealing rare characteristics of this malignancy. Among them, there were two cases with mild hypertensive retinopathy exhibiting cotton-wool spots, one case mimicking age-related macular degeneration (AMD), one case with systemic lupus erythematosus (SLE), and one patient had extraocular muscle involvement. To the best of our knowledge, we reported PVRL exhibiting cotton-wool spots as the main manifestation and coexisting with extraocular myopathy for the first time. Conclusions: PVRL is a rare intraocular malignancy that commonly masquerades as uveitis. As the clinical signs and symptoms are atypical, ophthalmologists must carefully examine patients to avoid misdiagnosis or a failure to diagnose. Cotton-wool spots and extraocular myopathy might be the dominant initial symptoms in PVRL patients, and AMD should be considered a differential diagnosis of PVRL. SLE patients under immunosuppressive treatment could have spontaneous PVRL.