Rare Eye Disease Aniridia Linked to Progressive Nerve Damage and Loss of Corneal Sensitivity, Clinical Study Finds

A study by Universidad Miguel Hernández reveals that aniridia causes progressive corneal nerve damage, reducing the eye's ability to protect and repair itself.

By: AXL Media

Published: Feb 27, 2026, 4:06 AM EST

Source: The information in this article was sourced from Universidad Miguel Hernández de Elche

Beyond the Iris: The Neurobiological Impact of Aniridia

Congenital aniridia is a rare genetic disorder primarily caused by mutations in the PAX6 gene, which is essential for ocular development. While the most striking symptom is the partial or total absence of the iris, the disease's impact on the eye's internal health is far more pervasive. A new clinical study published in the journal Cornea has demonstrated for the first time that aniridia does not just alter the anatomy of the eye; it progressively degrades the function of the corneal sensory nerves. This finding is critical because these nerves are responsible for both protecting the eye from external stimuli and maintaining the health of the corneal tissue itself.

A Comparative Study Across Generations

Led by Professor Mª Carmen Acosta and in collaboration with aniridia specialist Dr. Nora Szentmáry from Semmelweis University, the research team assembled a unique cohort of both pediatric and adult patients. Using a specialized device called the i-Onion—developed from a patent held by the research group—the team measured corneal sensitivity to mechanical pulses of air and cold stimuli. They also assessed reflex tearing by using CO₂ microstimulation to trigger the eye's natural defensive response. By comparing these results against healthy individuals, the team was able to map how nerve function evolves as patients age.

The Discovery of Progressive Deterioration

The study’s findings revealed a distinct shift in nerve performance over time. In childhood, patients with aniridia exhibited corneal sensitivity levels remarkably similar to those of healthy peers. However, adult patients showed a significant decrease in sensitivity, requiring much stronger stimuli to perceive contact or cold. "The most relevant finding is that the deterioration is not static, but progressive," Professor Acosta noted. This suggests that the remaining nerves in adult patients are not only fewer in number but are also failing to transmit sensory information effectively as the disease advances.