The present study investigated the effects of triamcinolone acetonide (TA) on retinal vessel-related factors and retinal vascular leakage in the retina of oxygen-induced retinopathy (OIR) rats.

Sprague-Dawley rats used for OIR were exposed to hyperoxia from postnatal day 2 to day 14, then returned to normoxia from day 15 to day 30 and compared with control rats. On postnatal day 16, 2 µl of TA (4 mg/kg) was injected into the vitreous of the right eye in control and OIR rats. The Evans blue method was used for evaluating vascular leakage and RT-PCR was performed for confirmation of mRNA expression.

In OIR rats exposed to hyperoxia, retinal vascular permeability increased when returned to normoxia. After intravitreal injection of TA, vascular permeability was decreased in OIR rats, but no changes were found in control rats. In OIR rats, mRNAs of HIF-1α, VEGF, SDF-1 and ICAM-1 were more expressed and down-regulated after intravitreal injection of TA. Occludin mRNA level was decreased in the hypoxic condition and up-regulated after TA treatment.

The present study suggests the ability of TA to inhibit retinal vascular leakage in OIR rats and a possibility that TA controls expression of the HIF-1, VEGF, SDF-1, ICAM-1 and Occludin, which may protect retinal vascular destruction from hypoxic conditions; further studies are necessary to confirm changes in protein levels.