Objective:To explore the clinical efficacy of cenegermin in the treatment of neurotrophic keratitis (NK).Methods:An observational case series study was adopted.Twenty-two patients (26 eyes) with moderate and severe NK diagnosed in Xi'an No.1 Hospital from June to November 2021 were collected and locally treated with cenegermin eye drop.After the corneal epithelium of the affected eye healed, the treatment ended.Relevant index data of patients before and after treatment were obtained through eye examination.The main indicators were the fiber length of corneal sensation measured by Cochet-Bonnet aesthesiometer, the morphological and quantitative indexes of corneal nerves by in vivo confocal microscopy, including the density of corneal nerve fibers and the number of nerve bifurcation points, and tear meniscus height measured by Keratograph Ocular Surface Analyzer.The secondary indicators were best corrected visual acuity (BCVA) and adverse reactions.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Xi'an No.1 Hospital (No.2021-11). Written informed consent was obtained from each subject. Results:The average treatment duration of patients receiving cenegermin was (4.42±1.86) weeks.After treatment, the corneal epithelial defect of moderate and severe patients healed completely.After treatment, the fiber length of sensation of corneal epithelial defect area and superior defect area were improved, the differences were statistically significant ( Z=-2.45, -3.22; both at P<0.05). There was no significant difference in corneal sensation in inferior, nasal and temporal of corneal epithelial defect area between before and after treatment ( Z=-1.89, -0.31, -1.86; all at P>0.05). After treatment, the average corneal nerve fiber density and the number of corneal nerve fiber bifurcation points in the affected eyes were significantly increased ( Z=-3.95, -3.48; both at P<0.01). There was no significant difference in the tear meniscus height between before and after treatment ( Z=-1.58, P=0.11). After treatment, the BCVA (LogMAR) of patients was 0.22(0.10, 0.40), which was higher than 0.52(0.30, 0.70) at baseline, and the difference was statistically significant ( Z=-3.63, P<0.01). During the treatment of cenegermin eye drops, transient pain occurred in 3 eyes, and intraocular pressure increased in 1 eye, which all returned to normal after symptomatic treatment. Conclusions:Topical application of cenegermin can repair corneal nerve morphology and function in patients with NK.