Spotlight on corneal neurotization

ABSTRACT

Introduction: Neurotrophic keratopathy (NK) is a degenerative corneal disease originating from a damage to the trigeminal innervation. Corneal neurotization (CN) is a recently introduced surgical procedure consisting of the transfer of normally functioning nerves into the anesthetic cornea. Two main approaches are feasible: i) direct nerve transfer of a healthy nerve branch; ii) interpositional nerve graft coapted to a healthy donor nerve.

Areas Covered: In this review, we present an overview of the current literature on CN for the treatment of NK. We discuss all the surgical approaches with specific advantages and disadvantages for each technique along with the results of published clinical studies in terms of both efficacy and safety.

Expert Opinion: CN is a safe and effective treatment for NK. This procedure has shown the ability to improve corneal sensitivity, epithelial integrity, and visual acuity. Postoperative corneal re-innervation has also been detected by in vivo confocal microscopy. To date, no conclusive data are available about the technique of choice. In our practice, we perform direct nerve transfer techniques in patients with severe NK in order to take advantage of the presumed immediate sprouting from the transferred nerves; in the other cases, we use interpositional sural nerve graft.

KEYWORDS:

• Neurotrophic keratopathy
• corneal neurotization
• neurotrophic keratitis
• corneal nerves
• in vivo confocal microscopy

Article highlights

• Corneal neurotization is a potentially curative surgical procedure in the setting of neurotrophic keratopathy thanks to the action of the neural terminations transferred on the affected cornea.

• Two main surgical approaches have been described: i) direct nerve transfer of a healthy nerve branch; ii) interpositional nerve graft coapted to a healthy donor nerve.

• Both techniques have been shown to be able to restore (at least partially) corneal sensitivity and to promote the healing of neurotrophic keratopathy.

• In vivo confocal microscopy and ex vivo histopathology confirmed the presence of regenerated nerves in the corneal sub-basal nerve plexus.

Acknowledgments

The authors would like to thank Mrs. Anna Marjory Jarabe for preparing the diagrams (Figures 2 and 3).

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Acronym Glossary

NK	=	neurotrophic keratopathy
CN	=	corneal neurotization
MRI	=	magnetic resonance imaging
ANA	=	acellular nerve allograft
IVCM	=	in vivo confocal microscopy
MEG	=	magnetoencephalography

Additional information

Funding

This paper was not funded