Long-Term Follow-Up Of Two Different Techniques Of Corneal Neurotization For Neurotrophic Keratopathy - A Multicenter In Vivo Confocal Microscopy Study

Corneal neurotization (CN) has been recently introduced as a potentially curative surgical procedure in the setting of neurotrophic keratopathy (NK). Two main surgical approaches have been described: the first involves the transposition of the contralateral or ipsilateral supraorbital/supratrochlear nerves to the anaesthetic cornea (direct corneal neurotization [DCN]). The second involves the interposition of a nerve graft between the supraorbital and/or supratrochlear nerves and the affected cornea (indirect corneal neurotization [ICN]). Our purpose is to report esthesiometric and structural data on neurotized corneas after a follow-up of more than two years correlating those data with the specific surgical approach used (DCN vs ICN).

Our study is a spontaneous, cross-sectional, multicentric study (ASST Santi Paolo e Carlo Hospital, University of Milan; S.Orsola-Malpighi Hospital, University of Bologna; Santa Maria alle Scotte Hospital, University of Siena, Italy, Ospedali Privati Forlì, Villa Igea

In this paper, we reviewed the cohort of patients who received CN from November 2014 to October 2023 in 3 Italian tertiary cornea centers. We selected patients with a follow-up of at least two years and performed centrally in vivo confocal microscopy (IVCM), in order to study the central sub-basal nerve plexus of the cornea, electrophysiological tests of the nerve terminations and clinical assessment of the ocular surface and cornea including corneal esthesiometry. Clinical findings will be correlated in the attempt of identifying possible sources of long-term stability of results. 

We followed for a mean period of 3.7±1.4 years (range 2.3 to 9 years) a cohort of 25 neurotized patients with anesthetic cornea at baseline (mean corneal sensibility 3 mm). Corneal sensitivity after at least two years of follow-up post-neurotization was 25±18 mm; persistent epithelial defects were present in 3 patients despite treatments.

Sub-basal plexus was clearly detectable with IVCM in 15 patients. Non-statistically significant structural or esthesiometric differences were found between the two different surgical techniques (direct versus indirect CN). Electrophysiological and IVCM data will be provided.

As previously demonstrated, independently from the specific surgical approach, CN is a surgical technique capable of restoring corneal sensitivity and ocular surface homeostasis in several patients. However careful follow-up in a corneal tertiary center is needed to promptly manage possible complications (the most frequent being PED recurrence) with appropriate treatments.