Causes
There are many things that may contribute to the onset of dry eye, including:
- Lipid Anomaly
- Tear Deficiency
- Mucin Anomaly
- Allergic/Toxic
- Blinking Problems
- Primary Epitheliopathies
Other causes may include deficiencies in the sensory nervous system, motor nervous system, or target organs such as the lacrimal gland.
Environmental factors such as wind, pollution, sun, and dry air inside homes or offices affect the eyes, but especially in a patient with dry eyes. Patients usually do not produce enough natural tears to offset these and other environmental irritants.
Systemic autoimmune disease sufferers, such as those with sjogren’s disease, most often have problems with dry eyes. Patients with tear deficiency due to sjogren’s or other factors have compromised corneas and conjunctivae. When there is a tear deficiency, “T” cells are activated, cytokines are released on the ocular surfaces, and this disrupts the corneal lacrimal reflex. Resulting chronic irritation causes progression of the disease.
Clinically dry eye can be present in varying degrees. Mild disease is associated with superficial punctuate epithelial erosions on the cornea and conjunctiva. Severe disease may show filamentary keratopathy and severe puntate epithelial erosions. Untreated, dry eye may lead to sterile ulcerative ‘melting’ or even bacterial keratitis.
