This is a parallel randomized controlled trial for the treatment of dry eye disease. The main objective is to investigate the efficacy and safety of the use of insulin eye drops in the control of moderate-severe dry eye disease. Topical insulin drops will be compared to the current gold standard treatment, cyclosporin and placebo (artificial tears).

Patients will be recruited in Madrid. Patients with dry eye disease and no topical treatment other than artificial tears will be identified through the Ophthalmology clinic. They will be directly referred to a physician who is participating in this study.

Inclusion Criteria:

• Patients older than 18 years
• Dry eye disease diagnosis
• Treatment with artificial tears or hyaluronic acid gels for at least 3 months
• Signed informed consent by the patient
• Staining equal to or greater than Oxford II

Exclusion Criteria:

• Under 18 years old
• Corneal staining under Oxford II
• Treatment for dry eye disease other than artificial tears or hyaluronic acid gels
• Severe dry eye disease that requires immediate treatment
• Eye surgery in the last 6 months
• Other concomitant corneal pathology, eyelid malpositions, nasolacrimal drainage abnormalities, blinking alterations
• Contact lenses
• Other treatment besides artificial tears or hyaluronic acid gels
• Visual acuity less than 0.1
• Allergy or intolerance to any of the components included in the study
• Modifications in systemic immunosuppressive treatment
• Pregnancy or lactation
• Women of childbearing age who do not use a highly effective contraceptive method
• History of alcohol or drug abuse
• Participation in another clinical trial in the last 30 days
• Systemic pathology (cardiopulmonary pathology, connective tissue disorders, neurological or psychiatric pathology) or baseline situation of the patient that does not allow the examination (such as mental or psychomotor retardation)