Eye drops provide relief for the symptoms of mild dry eye, but are not adequate for more severe cases. Research into the underlying cause offers hope for a different approach. An article from the Baylor College of Medicine reports evidence that dry eye should be regarded as an inflammatory disease. The tear film of patients with dry eye contains elevated levels of pro-inflammatory cytokines, chemokines, matrix metalloproteinases, and T cells. In addition, the gold standard for diagnosis is a change in the quality as well as quantity of tears. In dry eye syndrome, the tears have abnormally high concentrations of electrolytes (salts). This is thought to be part of a vicious cycle of inflammation: damaged tear ducts produce inadequate tears, which stimulate the production of more inflammatory molecules.
Sjogren's syndrome produces some of the worst cases of dry eye. This autoimmune condition is characterized by dry eye, dry mouth, vasculitis (inflammation of the blood vessels), and neurological problems. Other inflammatory disorders, such as rosacea, include eye symptoms.
These observations suggest that anti-inflammatory eye drops may be the definitive treatment for dry eye. There are several brands on the market:
1. Restasis. This contains cyclosporine, the well known immune suppressive drug for organ transplant recipients. It is also used for other diseases related to inflammation, including psoriasis, rheumatoid arthritis, and ulcerative colitis. It was approved by the U.S. Food and Drug Administration for use in eye drops in 2002.
2. Inflamase. This contains prednisolone, which is a corticosteroid widely used for inflammation.
3. Fluorometholone Ophthalmic Suspension. This is a “soft steroid” which has a lower risk of raising intraocular pressure and causing glaucoma, compared to prednisolone.
4. Alrex. This contains loteprednol etabonate, another “soft steroid”.
Reference 1 also reports that tetracyclines have anti-inflammatory properties as well as their antibiotic properties, and may be useful for dry eye. Doxycycline is a semi-synthetic tetracycline which was in clinical trials as a dry eye treatment at the time the Baylor article was written.
Anti-inflammatory and immune suppressive drugs in general have serious risks of infection. All eye drop manufacturers urge caution in handling their products to prevent infection. This is even more important when the eye drops are supposed to decrease inflammation.
Check with your eye doctor for the latest results.
References:
1. De Paiva CS et al, “Ratinale for anti-inflammatory therapy in dry eye syndrome”, Arq Bras Oftalmol. 2008; 71 (6 Supl): 89-95.
2. Cyclosporine eye drops (Restasis):
http://www.restasis.com/default.htm?x=Restasis
3. Prednisolone eye drops (Inflamase):
http://www.agingeye.net/cataract/inflamase.pdf
4. Loteprednol eye drops (Alrex):
http://www.rxlist.com/alrex-drug.htm
5. Fluorometholone eye drops:
http://www.agingeye.net/cataract/fml.pdf
Linda Fugate is a scientist and writer in Austin, Texas. She has a Ph.D. in Physics and an M.S. in Macromolecular Science and Engineering. Her background includes academic and industrial research in materials science. She currently writes song lyrics and health articles.