What is Dry Eye Syndrome?
- Dry eye syndrome (DES) is a disorder of the tear film due to tear deficiency or excessive evaporation, which causes damage to the interpalpebral ocular surface and is associated with symptoms of ocular discomfort;
- It is a multifactorial disease with a neurological component;
- DES is one of the more common complaints to eye care professionals;
- DES is a chronic and typically progressive condition;
- With symptoms from discomfort to burning and blurred vision, this condition decreases the quality of life and may lead to severe complications (e.g. corneal damage).
TRPM8 and DES
- Tear secretion is regulated through a neural reflex initiated by trigeminal primary afferent neurons innervating the corneal epithelium;
- DES may be caused by a dysfunction in the tear secreting glands themselves or in the neuronal circuit regulating these glands;
- Furthermore, DES itself may modify the properties of corneal afferents and affect their ability to regulate secretion;
- Converging pre-clinical and clinical evidence suggest that TRPM8 agonists will improve symptoms (e.g. discomfort) and clinical signs (i.e. tear deficiency)
by stimulating this reflex arc and can be applied on the upper eyelid rather than directly on the cornea.
DES affects 5-30% of the population over 50:
- Over 20 million patients in US and hundreds of million worldwide;
- Current treatment options are mainly targeting inflammatory pathways with limited effectiveness and severe side effects;
- Current drugs only with topical ocular delivery (inconvenient, unpleasant).
Well tolerated and effective treatments improving both clinical signs (tear production/quality, integrity of the ocular surface) and symptoms are needed.