Therapeutic Potential of Dimethyl Sulfoxide via Subconjunctival Injection in a Diabetic Retinopathy Rat Model.

Background/aim: Diabetic retinopathy (DR), a complication of diabetes, causes damage to retinal blood vessels and can lead to vision impairment. Persistent high blood glucose levels contribute to this damage, and despite ongoing research, effective treatment options for DR remain limited. Dimethyl sulfoxide (DMSO) has shown anti-inflammatory and antioxidant properties in both in vivo and in vitro studies; however, its potential as an anti-inflammatory agent in the context of DR has not yet been explored. This study aimed to assess the effects of subconjunctival injection of DMSO on the progression of DR.

Materials and methods: DR was induced in rats using intraperitoneal injections of streptozotocin (55 mg/kg), confirmed by measuring blood glucose levels and electroretinography (ERG). The rats were divided into five groups: a normal control group (CON), a DR control group receiving PBS injections (DMSO 0), and three DR groups receiving different concentrations of DMSO (98%, 50%, and 10%). Retinal function was evaluated using ERG at weeks 10 and 14, and histological analysis at week 16.

Results: The DMSO 50 group had significantly higher B-wave amplitude in ERG compared to the DMSO 0 group (p<0.05). Flicker response amplitudes were also significantly greater in the DMSO 50 and DMSO 10 groups compared to DMSO 0 (p<0.05). Histological examination revealed thinner retinal layers in the DMSO 0 group compared to the CON group, while the DMSO-treated groups showed improved retinal thickness.

Conclusion: Subconjunctival injection of 50% DMSO appears to improve retinal function in a rat model of DR.