Assessment of the Safety and Efficacy Study of RGN-259 Ophthalmic Solutions for Neurotrophic Keratopathy : SEER-1

Inclusion Criteria: * Be male or female of any race, at least 18 years of age * Have provided verbal and written informed consent. * Be able and willing to follow instructions, including participation in all study assessments and visits; * Have stage 2 or 3 neurotrophic keratopathy in at least one eye If a female of childbearing potential, have a negative urine pregnancy test at Visit 1 and agree to use an adequate method of birth control throughout the study period. Exclusion Criteria: * Have any clinically significant slit lamp findings at Visit 1 that in the opinion of the investigator may interfere with the study parameters; * Have significant blepharitis, meibomian gland dysfunction (MGD), lid margin inflammation or active ocular allergy that requires treatment * Have a lid function abnormality (ex. Lagophthalmos) which, in the opinion of the investigator, is the primary cause of the persistent epithelial defect; * Be diagnosed with ongoing ocular infection (bacterial, viral or fungal) or active inflammation (e.g. follicular conjunctivitis) not related to NK * Anticipate the use of fluoroquinolone-containing antibiotic eye drops during the study; * Have used contact lenses (excluding therapeutic contact lenses) within 14 days prior to Visit 1 or anticipates use of contact lenses during the study period; * Have an uncontrolled systemic disease that in the opinion of the investigator may interfere with the study parameters; * Anticipate a change in immunosuppressive therapy during the course of the study;