Corneal Neurotization in Adults - the University of Toronto Experience
Authors: Georges Nassrallah, Ramez Borbara, Blake Murphy, Asim Ali, Navdeep Nijhawan.
Author Disclosure Block: G. Nassrallah: None. R. Borbara: None. B. Murphy: None. A. Ali: Any direct financial payments including receipt of honoraria; Name of for-profit or not-for-profit organization(s); Santen. Any direct financial payments including receipt of honoraria; Description of relationship(s); Consultant. Funded grants or clinical trials; Name of for-profit or not-for-profit organization(s); Novartis. Funded grants or clinical trials; Description of relationship(s); Grant recipient. N. Nijhawan: None.
Purpose: Corneal neurotization is a recently developed procedure that aims to improve corneal integrity by transferring a donor sensory nerve into the corneoscleral limbus. Several techniques have emerged that vary based on donor nerve selection (supraorbital/supratrochlear vs infraorbital), whether a graft is used or not, and whether an autograft or allograft is used. We report a case series of adult patients that underwent corneal neurotization at our institution.
Study Design: Case series.
Methods: In our approach, a sural nerve graft is harvested and grafted end-to-end to a donor supraorbital and/or supratrochlear nerve that is either ipsilateral or contralateral to the affected eye based on preoperative sensation testing. Adult patients who underwent corneal neurotization at Saint Michael’s Hospital were included in this case series. Their medical charts were reviewed. Demographic factors, history of their disease as well as intraoperative factors and post-operative outcomes were collected.
Results: Seven patients were included in this study. Five were male and two were female. Mean age was
52.5 years (range: 27.7 to 71.3 years). Four patients had complete corneal anesthesia and three had significantly reduced corneal sensation. Six patients had a documented history of neurotrophic corneal ulcers or a history suggestive of recurrent epithelial breakdown. Etiologies were predominantly intracranial neoplasms with resection (5/7), but also included herpetic disease (1/7) and possible trauma (1/7). Mean duration of corneal anesthesia was 12.6 years (range: 1.7 to 20.7 years). Intraoperatively, a mean of 4.3 fascicles were identified in the sural nerve graft (range: 2-10) and these were implanted into a mean of 3 sites around the limbus. Two of seven patients also underwent facial reinnervation surgery. Mean skin-to-skin case time was 276.4 minutes (range: 193 to 367 minutes). No significant intraoperative complications were reported. Only one patient reported ocular discomfort in the first week after surgery and two patients reported leg pain. Of the patients with follow-up past 6 months, 3/4 had some objective improvements in corneal sensation by Cochet-Bonnet Esthesiometer and 3/4 reported some subjective corneal sensation. The average delay before first response by esthesiometry was 7.6 months (n=3) and the average delay before maximal response was 11.2 months (mean improvement of 29.2 mm in central cornea, range: 7.5 mm to 60.0 mm).
Conclusions: Corneal neurotization is a promising procedure for re-establishing corneal sensation in patients with neurotrophic corneal disease. Prospective studies are needed to establish factors that may portend to better outcomes in the adult population.