Inclusion Criteria:  Male or female between 18 and 80 years old Stage 2 (persistent epithelial lesion : LEP) or stage 3 (corneal ulcer) trophic ulcer affecting only one eye. Patient whose contralateral eye is affected by stage 1 neurotrophic keratitis may also be included Two or more weeks old LEP or corneal ulcer refractory to one or more conventional nonsurgical therapies Absence of objective evidence of improvement of the epithelial ulceration or corneal ulcer within 2 weeks prior to study inclusion Failure of amniotic membrane treatment of the trophic ulcer: failure by absence of healing a few day after overlay treatment or 15 days after inlay grafting Patient able to understand French language Informed and consenting patient Patient affiliated to a social security system or beneficiary of such a system  Exclusion Criteria:  Pregnant or breastfeeding patient or without contraception for non-menopausal women Active infectious ulcer Preperforating ulcer or ulcer that has reached the posterior 1/3 of the storm Allergy to Oxybuprocaine or Tetracaine eye drops, to ester type local anesthetics and to fluorescein Current contact lens wear, including scleral lenses NSAID eye drops and any drops containing preservatives Antibiotic, anti-viral, anti-parasitic eye drops Patients with identified causes of the ulcer for which medical treatment without preservatives or other healing treatment is beneficial Ocular surgery for other pathology than the trophic ulcer in the 3 months preceding the inclusion in the study Ophthalmologic pathology requiring daily eye drops Monophtalmic patients Persons deprived of liberty by a judicial or administrative decision Adults who are subject to a legal protection measure or who are unable to express their consent