Vorinostat: A Potent Agent to Prevent and Treat Laser-induced Corneal Haze

PURPOSE: This study investigated the efficacy and safety of vorinostat, a deacetylase (HDAC) inhibitor, in the treatment of laser-induced corneal haze following photorefractive keratectomy (PRK) in rabbits in vivo and transforming growth factor beta 1 (TGF beta 1) -induced corneal fibrosis in vitro. METHODS: Corneal haze in rabbits was produced with -9.00 diopters (D) PRK. Fibrosis in cultured human and rabbit corneal fibroblasts was activated with TGF beta 1. Vorinostat (25 mu m) was topically applied once for 5 minutes on rabbit cornea immediately after PRK for in vivo studies. Vorinostat (0 to 25 mu m) was given to human/rabbit corneal fibroblasts for 5 minutes or 48 hours for in vitro studies. Slit-lamp microscopy, TUNEL assay, and trypan blue were used to determined vorinostat toxicity, whereas real-time polymerase chain reaction, immunocytochemistry, and immunoblotting were used to measure its efficacy. RESULTS: Single 5-minute vorinostat (25 mu m) topical application on the cornea following PRK significantly reduced corneal haze (P<.008) and fibrotic marker proteins (alpha-smooth muscle actin and f-actin; P<.001) without showing redness, swelling, or inflammation in rabbit eyes in vivo screened 4 weeks after PRK. Vorinostat reduced TGF beta 1-induced fibrosis in human and rabbit corneas in vitro in a dose-dependent manner without altering cellular viability, phenotype, or proliferation. CONCLUSIONS: Vorinostat is non-cytotoxic and safe for the eye and has potential to prevent laser-induced corneal haze in patients undergoing PRK for high myopia. [J Refract Surg. 2012;28(4):285-290.] doi:10.3928/1081597X-20120210-01