Researchers recently presented a study describing a “game-changing” surgical procedure—corneal neurotization (CN)—for restoring corneal sensitivity in all stages of neurotrophic keratopathy (NK), regardless of the denervation mechanism. NK results when corneal innervation is disrupted, from any number of ocular or systemic conditions such as herpetic keratitis, chemical injury, corneal surgery, DED, diabetes, intracranial tumors or congenital conditions. The pathologic, degenerative disease can result in ocular surface changes from superficial punctate keratopathy (stage I) and persistent epithelial defect (stage II) to stromal involvement leading to corneal ulcer, keratolysis and perforation (stage III).

The researchers analyzed the two main surgical approaches to NK—direct and indirect CN—in the literature, including ex vivo studies with histopathology of neurotized cornea. They reported that corneal sensitivity improves after both types of CN approaches. “Corneal reinnervation allows the healing of NK in almost the totality of the operated eyes, determining a corresponding improvement of corneal clarity and visual acuity,” they wrote in their paper. “Regeneration of corneal nerve fibers is confirmed by means of either in vivo confocal microscopy or ex vivo histopathology.

“Until recently, NK therapy consisted of only supportive measures focused on lubrication and protection of the ocular surface, whereas surgery was limited to refractory cases to treat corneal complications,” the authors continued. “The recent advent on the market of recombinant human nerve growth factor allowed a paradigm shift in medical therapy.”

They concluded that CN has the potential to restore corneal sensitivity in all disease stages, no matter the cause of disease. CN is still limited to a few research groups, however, largely because of the long surgical time and need for a multidisciplinary team involving maxillofacial/plastic surgeons, the researchers explained. Current issues include identification of the technique of choice, use of autograft or allograft and the timing of CN when performed alone or in combination with other surgeries. However, the authors wrote that “promising results” and more medical advances are coming soon, with an aim toward minimally invasive approaches.

Giannaccare G, Bolognesi G, Pellegrini M, et al. Corneal neurotization: a game-changing surgical procedure for neurotrophic keratopathy. Cornea. April 14, 2021. [Epub ahead of print].