Axon numbers and landmarks of trigeminal donor nerves for corneal neurotization

Abstract

PurposeCorneal anesthesia leads to chronic corneal injury. This anatomical study characterizes the donor nerve branches of the supratrochlear and supraorbital nerves used for corneal neurotization.MethodsIn 13 non-embalmed cadavers, the supratrochlear and supraorbital nerves were dissected and distances to anatomical landmarks measured. Cross-sections of supratrochlear and supraorbital donor nerves were harvested and histomorphometrically analyzed to assess the number of myelinated axons.ResultsThe donor axon counts were 3146 ± 1069.9 for the supratrochlear and 1882 ± 903 for the supraorbital nerve distal to the supraorbital notch. The supratrochlear nerve was dissected on the medial upper eyelid 2 cm lateral to the facial midline and the branch of the supraorbital nerve 1 cm medial to the mid-pupillary line.ConclusionThe supraorbital and supratrochlear branches of the trigeminal nerve are potent donor nerves for corneal neurotization in the treatment of neuropathic keratopathy and can be reliably dissected using anatomical landmarks.

Histomorphometry of the Sural Nerve for Use as a CFNG in Facial Reanimation Procedures

“…Through dissection of non-embalmed cadavers, they found that the mean donor axon counts were 3146 ± 1069.9 for the supratrochlear nerve and 1882 ± 903 for the supraorbital nerve. Consequently, the supratrochlear and supraorbital nerves, both sensory nerves, can be considered potent donor nerves for ocular neuropathologies [54].…”

Corneal Neurotization—Indications, Surgical Techniques and Outcomes

“…Domoshek et al compared the distal supraorbital to the supratrochlear nerve, indicating that the former contains approximately 1000 more axons than the latter (3146 ± 1069 versus 1882 ± 903), which is an important consideration in direct reinnervation techniques [ 76 ]. If the supraorbital nerve is approached very proximally, just above the orbital rim, it contains yet more axons, suggesting that connecting the nerve (or coaptation) to a nerve graft should be done as proximal as possible to maximize the axonal load [ 77 ]. The same study by Domoshek et al reported that the sural nerve, harvested as a conduit graft, contained 3176 ± 1524.5 myelinated nerve fibres.…”