Objective Retinal neovascularization or retinopathy is a proliferative disorder of the retinal capillaries and is the primary cause of blindness. Some studies have shown that oxidative stress plays an important role in hyperoxia-induced retinal neovascularization. Previous reports have indicated that hydrogen has a therapeutic, antioxidant activity by selectively reducing hydroxyl radicals. This study examined the therapeutic effect of hydrogen saline on retinopathy in an established mouse model of hyperoxia-induced retinopathy.

Methods Mouse pups were exposed to 75% O2 from postnatal day 7 (P7) to P12. Hydrogen saline was administered by intraperitoneal injection (5 ml/kg) daily for 5 days. At P17, the pups were decapitated, and retinal neovascularization was assessed using fluorescence imaging and histopathological examination. VEGF expression was evaluated using real time PCR and fluorescence immunohistochemistry. Oxidative stress was quantified based on the malondialdehyde level.

Results Hydrogen saline decreased retinal neovascularization, reduced the mRNA and protein expression of VEGF, and suppressed the MDA levels.
Conclusions Hydrogen saline may be a potential treatment for hyperoxia-induced retinopathy that acts via the inhibition of oxidative stress and the reduction of VEGF expression.