Therapeutic targets in dry eye syndrome

Dry eye is a multifactorial disease of the tears and the ocular surface that manifests with a wide variety of signs and symptoms. It is prevalent in about 33% of the population worldwide. Due to the importance of the pathology, new tests, drugs and technologies have been developed to assist the diagnosis, management and follow-up of the disease. Current available therapies try to alleviate symptoms and to reduce signs in order to restore the ocular surface. Depending on the etiology of the pathology it is possible to use lubricants, secretagogues, biological tear substitutes or antiinflammatory drugs, either independently or combined. Nowadays, the therapies under clinical trial are devoted to stimulating tear components (e.g., diquafosol, a P2Y receptor agonist), or mucin secretion (e.g., rebamipide, an amino acid analogue of quinolinone). Others include gefarnate, a water-insoluble terpene fatty acid that contributes to restoring mucins on the ocular surface, or cevimeline, an oral cholinergic agonist that reduces the symptoms associated with dry eye. Other potential compounds described in patents are in a lower phase of drug development. These compounds come from different families of therapies, and among others, can be found in the form of steroidal and nonsteroidal antiinflammatory agents, vitamins A and D, neurotransmitters and neuropeptides.