Effect of IKERVIS® Eye Drops Once Daily on the Quality of Vision in Dry Eye Disease Patients With Severe Keratitis

Inclusion Criteria: * Patient eligibility is determined according to the following criteria: 1. In the opinion of the investigator, the patient is capable of understanding and complying with protocol requirements. 2. The patient signs and dates a written, informed consent form and any required privacy authorization prior to the initiation of any study procedures 3. Male or female patient is aged 18 years or above. 4. DED patients with persistent severe keratitis at the Screening and Baseline Visits defined as the following: • CFS score of 3, 4 or 5 on the modified Oxford scale 5. Patient must be willing and able to undergo and return for scheduled study-related examinations. 6. The same eye (eligible eye) should fulfill all the above criteria. Exclusion Criteria: * Patients with history of ocular trauma or ocular infection (viral, bacterial, fungal, protozoal) within 90 days before the Screening Visit and any ocular diseases other than dry eye disease requiring topical ocular treatment during the course of the study.