An Overview

The cornea is the transparent, outermost part of the eye that serves as a refractive element in the visual pathway. It consists of three major cellular layers: a protective epithelium, stroma made mostly of highly organized collagen, and an endothelium that serves to maintain water balance and transparency. Diseases affecting the cornea are a major cause of blindness worldwide, second only to cataract in overall importance. The epidemiology of corneal blindness is complicated and encompasses a wide variety of infectious and inflammatory eye diseases that cause corneal scarring, which ultimately leads to functional blindness. Corneal transplantation, also known as corneal grafting or Penetrating Keratoplasty (PKP), is a surgical procedure where a damaged or diseased cornea is replaced by donated corneal tissue which has been removed from a recently deceased individual having no known diseases which might affect the viability of the donated tissue. In cases where there have been several graft failures or the risk for keratoplasty is high, synthetic corneas can substitute successfully for donor corneas. Keratoprosthesis is a surgical procedure where a severely damaged or diseased cornea is replaced with an artificial cornea. While conventional cornea transplant uses donor tissue for transplant, an artificial cornea is used in the Keratoprosthesis procedure. Although many keratoprostheses have been developed these keratoprosthesis have the following postoperative complications in order of decreasing prevalence include retroprosthetic membrane (RPM), elevated intraocular pressure/glaucoma, infectious endophthalmitis, sterile vitritis, retinal detachment  focal calcification ,pigmentation and vitreous hemorrhage .Hence there is an increasing need to find a the fabrication of synthetic stromal equivalents with the transparency, biomechanics, and regenerative capacity of human donor corneas

In all these keratoprosthesis a wound healing reaction to implantation weaves new collagen through the porous skirt to integrate the keratoprosthesis with the scleral tissue surround and the keratoprosthesis is held in place. Driven by the health burden from third world corneal blindness, research into improved keratoprostheses continues to advance. No current device supports an epithelium. Cytokine cross talk between the corneal epithelium and stromal fibroblasts (keratocytes) is important in regulating corneal tissue metabolism. If a normal corneal epithelial phenotype can be sustained on a keratoprosthesis, this may protect against tissue necrosis and device extrusion

NCRM is in the process of designing a Hybrid Cornea to replace diseased or damaged corneas or failed human transplants using nanocoated surfaces and synthetic hydrogel materials for replacing the stroma and other components of the diseased cornea so as to restore vision in millions of patients needing a Corneal transplant