Breakthroughs in Corneal Healing Lead to New Options for Rare Eye Conditions

Advancements in corneal healing research are paving the way for innovative treatments for rare eye diseases, which are known to be a leading cause of irreversible blindness across Europe. A dedicated research team, RESTORE VISION, has identified seven uncommon ocular conditions that primarily affect the cornea and overall ocular surface.

Among the conditions being studied is aniridia, a genetic disorder that occurs in approximately one in 80,000 individuals and is characterized by the partial or complete absence of the iris. This condition typically arises from mutations in the PAX6 gene, which plays a crucial role in eye development during pregnancy. Aniridia can lead to significant complications including photophobia, glare sensitivity, and increased risks of cataracts, glaucoma, and corneal abnormalities.

Despite the challenges posed by aniridia, current medical strategies primarily focus on managing symptoms rather than offering a cure. Early intervention is emphasized, particularly through visual stimulation in childhood. Later treatments may include specialized lenses to mitigate light sensitivity and, in specific cases, surgical implantation of artificial irises.

In addition to aniridia, the RESTORE VISION project is investigating several other rare eye diseases. These include neurotrophic keratopathy, ocular cicatricial pemphigoid (an autoimmune disorder affecting mucous membranes), ectrodactyly-ectodermal dysplasia-clefting (EEC) syndrome, graft-versus-host disease (GVHD), limbal stem cell deficiency (LSCD), and corneal neovascularization, which involves abnormal blood vessel growth in the cornea, leading to inflammation and potential vision loss.

Recent studies from the Ocular Neurobiology Laboratory have shed light on critical aspects of corneal nerve function. Research published in Acta Ophthalmologica has delineated two distinct populations of cold-sensitive trigeminal neurons that innervate the cornea. These neurons, classified by their levels of baseline activity, are essential for sensing temperature changes on the corneal surface and may influence tear production and blinking reflexes.

Understanding the functional dynamics of these neurons is vital, especially concerning diseases that impair corneal sensitivity, such as neurotrophic keratopathy. Insights gained from this research may guide the development of novel treatments aimed at restoring nerve function in patients affected by rare eye conditions.

Moreover, the laboratory has pioneered an innovative technique to study nerve regeneration within the cornea. By employing lasers to create precise, controlled lesions in the corneal nerve fibers of adult mice, researchers can observe the healing process. Their findings indicate that in mice deficient in the SARM1 protein--which is linked to post-injury nerve degeneration--nerve deterioration occurs more slowly, although this may also hinder their regenerative capabilities.

This research model holds promise for understanding the recovery process of nerves after injury, which could be instrumental in developing therapies for rare diseases that disrupt corneal innervation.

The RESTORE VISION project is advancing towards practical applications, with ongoing efforts to formulate new drug therapies and repurpose existing medications for the treatment of rare ocular diseases. Clinical documents are being prepared for submission to ethics committees and regulatory bodies, marking a significant step toward initiating patient treatments with RESTORE VISION therapies.

The Institute for Neurosciences at UMH-CSIC is expected to play a pivotal role in evaluating topical treatments aimed at corneal regeneration. Research efforts will focus on pinpointing therapeutic targets within cells, followed by preclinical trials before proceeding to clinical trials. Once these treatments receive validation, the consortium will develop clinical protocols and legislative recommendations to facilitate expedited access to these medical advancements.