Title of Article: Corneal neurotization for neurotrophic keratopathy: Review of surgical techniques and outcomes
What are the key takeaway points from this article?
Neurotrophic keratopathy (NK) is a rare neurodegenerative disease caused by a dysfunction in corneal innervation that can lead to corneal epithelial defects, corneal hypoesthesia and importantly, significant visual impairment. Corneal nerves are critical to maintaining ocular surface homeostasis, including wound healing, reflex blinking, epithelial proliferation, and the secretion of important growth factors. Historically, treatment options for NK were limited to supportive care, due to an inability to restore corneal nerves and important growth factors.
Corneal neurotization (CN) is a surgical procedure to restore corneal innervation by directly transferring a donor sensory nerve or indirectly using an interpositional nerve graft, such as a healthy supraorbital or supratrochlear nerve. The graft is used as a link to reinnervate and restore sensation to the cornea. This relatively new surgical technique is a promising treatment for NK. This review sought to synthesize the existing literature on CN to elucidate the technical considerations, outcomes, and limitations of this procedure.
The authors found that studies using endoscopic and minimally invasive direct transfers permitted smaller incisions and faster healing. The studies evaluated found objective improvement of sensation over 3-8 months up to 2.8 years post direct transfer and the majority showed overall improvements in corneal neovascularization and opacity. The small number of cases in the literature, however, was noted as a limitation to these conclusions. Rare adverse outcomes included the development of a subgaleal hematoma, neuroma, or scaring at the incision site.
In terms of the indirect approach, the studies examined showed subjective improvement of sensation as early as 1 month, up to 6-9 months post-op. Additionally, it was found that processed nerve allografts demonstrated a similar time frame of sensation return compared to autografts. Ultimately, this review found that both direct and indirect corneal neurotization methods showed promising rates of recovery and that selection of surgical technique should be individualized based on the patient’s needs and surgeon’s experience. However, the authors acknowledged that more studies are needed to understand the longer-term outcomes of corneal neurotization.
Publication Date: February 2021
Liu, C. Y., Arteaga, A. C., Fung, S. E., Cortina, M. S., Leyngold, I. M., & Aakalu, V. K. (2021). Corneal neurotization for neurotrophic keratopathy: Review of surgical techniques and outcomes. The ocular surface, 20, 163–172. https://doi.org/10.1016/j.jtos.2021.02.010
Summary By: Natalie Mezey