Physiology of Corneal Innervation
Lawrence F. Borges, M.D.

Dr Borges | Research Lab

Research Summary

The cornea is the most densely innervated tissue in the mammalian organism. Axons from the trigeminal ganglion and sympathetic ganglion terminate in delicate endings among the epithelial cells of the cornea. While some of the corneal nerves subserve corneal sensation, the role played by most of the remaining nerve fibers is unknown. Dr. Borges' laboratory is studying the function of the nerves within the corneal epithelium and devising strategies for treating the clinical problems that occur when the cornea loses its normal innervation.

The health of the corneal epithelium is dependent upon a normal innervation. Denervation of the cornea causes a degenerative change in the corneal epithelium that is called "neuroparalytic keratitis. This change is an inflammation within the corneal epithelium that is associated with the corneal epithelium losing its firm attachment to its basement membrane. Epithelial defects and a loss of corneal clarity lead to impaired vision. This condition is important clinically to the neurosurgeon who may denervate the cornea inadvertently in the treatment of trigeminal neuralgia or in the removal of skull base tumors.

Dr. Borges' laboratory has been applying the techniques of neural transplantation to better understand and treat the problem of neuroparalytic keratitis. They have developed a model of corneal denervation in the rat. Denervated rat corneas develop severe keratitis by day 7 after lesioning. This degeneration can be prevented by transplanting fetal trigeminal ganglion grafts into the anterior chamber of the eye. Currently they are determining the length of time that these grafts can support the denervated cornea and the neural substrate within the graft that subserves corneal health.