An 8-week Follow-up to Evaluate the Renewal of Corneal Nerves Structure and Function in Patients With Neurotrophic Keratopathy Treated With Recombinant Human Nerve Growth Factor (rhNGF) Eyedrops

Inclusion Criteria: * Patients with documented moderate or severe neurotrophic keratopathy based on a recent new classification of NK, refractory to conventional non surgical treatments. The diagnosis was made on medical and ophthalmological history, slit lamp examination, aesthesiometry, in vivo confocal microscopy. * Decreased corneal sensitivity on the area of corneal defect and on superior, inferior, nasal and temporal quadrants (≤ 4 cm using the Cochet-Bonnet aesthesiometer) * Patients who satisfy all Informed Consent requirements. The patient and/or his/her legal representative must read, sign and date the Informed Consent document before any study-related procedures are performed * Patients with ability to understand and perform the treatment. Exclusion Criteria: * active infective keratitis or inflammation not related to NK in the affected eye. * presence of corneal dystrophies. * presence of glaucoma. * Any other ocular disease requiring topical ocular treatment during the course of the study treatment period. * History of any ocular surgery (including laser or refractive surgical procedures) within the three months before study enrolment. (An exception to the preceding statement will be allowed if the ocular surgery is considered to be the cause of the stage 2 or 3 NK). * patients with known hypersensitivity to one of the components of the study or procedural medications (e.g. anaesthetic drops, fluorescein). * Females currently pregnant