Corneal Neurotization Via Sural Nerve Transfer or Cadaveric Nerve Graft for Neurotrophic Keratopathy

Corneal anesthesia, which can lead to visually devastating outcomes from ulceration, perforation, and scarring, can be recalcitrant to both medical and surgical treatment[1-3]. Neurotization is a revolutionary technique reported to restore corneal sensation in neurotrophic keratopathy[4-6]. Prior techniques described include direct neurotization with contralateral supraorbital and supratrochlear nerves accessed via a bicoronal incision of the scalp over the forehead[5]; nerve grafting with contralateral supratrochlear nerves accessed via a medial upper eyelid incision[6]; and sural nerve grafting to contralateral supratrochlear nerves accessed via a transverse incision over the medial upper eyelid[4]. Despite the challenges associated with these techniques (needing to subcutaneously tunnel the nerve graft over the nasal bridge or requiring a large bicoronal incision), these techniques all demonstrated efficacy in direct neurotization to improve corneal sensation in these patients.

The investigators aim to assess the efficacy of this innovative surgical technique involving coaptation of the sural nerve or cadaveric nerve allograft to an intact sensory branch of the trigeminal nerve to restore corneal sensation. The investigators have previously described the anatomic feasibility of using the infraorbital nerve using a cadaveric model, of which the results were presented at the American Society of Ophthalmic Plastic and Reconstructive Society Fall meeting in 2017. Utilization of the infraorbital nerve provides advantages over existing techniques due to ease of access via a cosmetically favorable incision, large caliber with increased ability to create a perineural window, relatively short and direct tunnel with possibly more rapid neurotization, and absence of complex surrounding anatomical structures. Others have previously describe success using the contralateral and ipsilateral supraorbital nerve and supratrochlear nerve.