Facilitation of Corneal Re-epithelialization After Photorefractive Keratectomy

Overview

Photorefractive keratectomy (PRK) or surface ablation is one of the most commonly used surgical procedures to correct refractive errors, which was proved to be safe and effective. In PRK, the corneal epithelium is removed by various techniques such as diluted alcohol, manual debridement, brush, or excimer laser, before the refractive excimer laser ablation of the corneal stroma. Compared to laser in situ keratomileusis (LASIK), the two main drawbacks for PRK are slower visual recovery and discomfort in the immediate postoperative period, due to the epithelial removal. Corneal healing is a complex process involving cellular interaction and reaction with various molecules (proteases, growth factors, and epithelial and stromal cytokines). Enhanced corneal re-epithelialization may reduce the risk for corneal infection and stromal scarring or melting. Over the past few years, a new type of matrix therapy by ReGeneraTing Agent (RGTA) has provided encouraging results, accelerating the healing of chronic skin ulcers in diabetes or vascular origin. RGTAs mimic the action of heparin sulfate molecules, breaking the negative repair-destruction cycle occurring in chronic lesions and inhibit proteolytic enzymes in vitro. In the domain of ophthalmology, RGTA has been reported to show encouraging results in the treatment of corneal ulcer and dystrophies of various etiologies. The Cacicol20 is an RGTA that binds to matrix proteins to protect them from proteolysis; the extracellular matrix microenvironment protection improves the production of signals and growth factors needed for tissue healing. It is supplied as a sterile single-dose solution of alpha 1-6 poly-carboxymethyl glucose sulfate described and synthesized as in US Patent Number 6689741, with dextran T40 and 0.9% sodium chloride as excipients. It contains no component of animal or biological origin, and penetrates into the cornea without crossing Descemet´s membrane (no intraocular penetration). The Cacicol20 has been reported to be effective in treatment of neurotrophic ulcers and persistent epithelial defects which were unresponsive to the common treatment approaches. Therefore, we expect that the Cacicol20 may facilitate the corneal re-epithelialization after PRK.