An investigator-initiated single-center, randomized, double-blind, placebo-controlled clinical study .The main purpose is to evaluate the effectiveness of ZKY001 eye drops in treating corneal epithelial defects caused by neurotrophic keratitis in patients.

Inclusion Criteria:

• 18 years ≤ aged ≤ 80 years； Consistent with the diagnosis of neurotrophic keratitis caused by diabetes or the herpes simplex virus； Patients with Stage 2 or Stage 3 neurotrophic keratitis，involving only one eye； PED or corneal ulceration of at least 2 weeks' duration refractory to one or more conventional non-surgical treatments for neurotrophic keratitis (e.g., preservative-free artificial tears, gels or ointments; discontinuation of preserved topical drops； medications that can decrease corneal sensitivity; therapeutic contact lenses and Cenegermin eye drops)； Signed informed consent forms。

Exclusion Criteria:

• Patients with Stage 2 or 3 NK affecting both eyes； Any active ocular infection (bacterial, viral, fungal or protozoal) or active ocular inflammation not related to NK in the affected eye； Any other ocular disease requiring topical ocular treatment in the affected eye during the study treatment period； Patients with severe vision loss in the affected eye with no potential for visual improvement in the opinion of the Investigator because of the study treatment； Schirmer's test without anesthesia ≤ 3 mm/ 5 minutes in the affected eye； Patients with severe blepharitis and/or severe meibomian gland disease in the affected eye； History of laser surgical procedures in the affected eye within the 3 months before study enrollment，history of any ocular surgery (except retinal laser photocoagulation) in the affected eye within the 1 month before study enrollment. No ocular surgery (except retinal laser photocoagulation) will be performed on the affected eye during the study period； Prior surgical procedure(s) for the treatment of NK (e.g., complete tarsorrhaphy, conjunctival flap, etc.) in the affected eye except for amniotic membrane transplantation could only be enrolled 2 weeks after the membrane had disappeared within the area of the PED or corneal ulcer or at least 6 weeks after the date of the amniotic membrane transplantation procedure； Use of therapeutic contact lenses or contact lens wear for refractive correction during the study treatment periods in the eye with NK； Anticipated need for obliteration lacrimal punctum during the study treatment period. Patients with obliteration lacrimal punctum or lacrimal plugs inserted prior to the study were eligible for enrollment if the obliteration lacrimal punctum was maintained during the study； Evidence of corneal ulceration involving the posterior third of the corneal stroma, corneal melting or perforation in the affected eye； Presence or history of any ocular or systemic disorder or condition that may hinder the efficacy of the study treatment or its evaluation, could possibly have interfered with the interpretation of study results, or could have been judged by the Investigator to be incompatible with the study visit schedule or conduct (e.g., progressive or degenerative corneal or retinal conditions, uveitis, optic neuritis, poorly controlled diabetes, autoimmune disease, systemic infection, neoplastic diseases)； Any need for or anticipated change in the dose of systemic medications known to impair the function of the trigeminal nerve (e.g., neuroleptics, antipsychotic and antihistamine drugs). These treatments were allowed during the study if initiated prior to 30 days before study enrollment on condition that treatment remains stable throughout the course of the study treatment period； Known hypersensitivity to one of the components of the study or procedural medications (e.g., fluorescein)； History of drug, medication or alcohol abuse or addiction； Participation in another clinical study at the same time as the present study；