Research has shown that dry eye syndrome is largely due to inflammation. Therefore, "soft" corticosteroids such as loteprednol etabonate ophthalmic suspension 0.5% (Lotemax, Bausch & Lomb) or fluorometholone ophthalmic suspension 0.1% (FML, Allergan), or cyclosporine ophthalmic emulsion 0.05% (Restasis, Allergan), may be effective.
The syndrome, also known as keratoconjunctivitis sicca, is one of the most under-diagnosed conditions in ophthalmology and can puzzle specialists because some patients present with a mild form but complain of frequent symptoms, and yet other patients have symptoms of dry eye on the cornea but do not experience any symptoms of discomfort.
Statistics reveal that the prevalence of dry eye syndrome is up to 7.8% of women and 4.7% of men over age 50 years. The significant impact on quality of life for these patients makes dry eye an important disease to manage.
Dry eye syndrome has many etiologies. It can occur as part of the natural aging process (especially during menopause) or as a side effect of numerous medications including antihistamines, antidepressants, and certain drugs treating blood pressure and Parkinson's disease. Also, it can be due to ambient temperatures that are too high or too low, as well as insufficient blinking. And dry eye can be experienced in common activities such as reading, driving, computer work, and television-watching. It also can be seen in systemic diseases such as lupus, rheumatoid arthritis, rosacea, and Sjögren's syndrome.
As mosaic-like are the causes of dry eye, so are the therapeutic strategies. Treatment usually is based on the quality and quantity of tears, patient complaints, and the health status of the cornea.
"The big development in dry eye over the past decade has been the realization that a large part of it is due to inflammation," said Stephen C. Pflugfelder MD, professor of ophthalmology, Baylor College of Medicine, Houston. "The inflammation is due to the stress of dry eye, which is probably initiated on the epithelial cells, but then there is recruitment of bone marrow cells, such as T lymphocytes, into the conjunctiva, and these cells amplify the inflammatory process. So it is really more of a stress response to the dryness."
According to Dr. Pflugfelder, loteprednol etabonate ophthalmic suspension 0.5% (Lotemax, Bausch & Lomb) is one of the several different corticosteroids that can be used to treat dry eye effectively and the inflammation it causes in the eye. Loteprednol 0.5% and fluorometholone ophthalmic suspension 0.1% (FML, Allergan) are considered "soft" corticosteroids and are two products that Dr. Pflugfelder said he likes to use.
Loteprednol 0.5% is designed as a site-active corticosteroid that undergoes a relatively rapid metabolism, he said.
This characteristic improves its safety profile, reducing the risk of an increase in IOP, and makes it a good candidate for inflammatory ocular conditions.
"The drug works by inhibiting cytokine and chemokine production, as well as inhibiting the metalloproteinase production," he said. "It also may turn off some vascular adhesion molecules, the production of prostaglandin mediators and lipid mediators of inflammation so readily seen in dry eye."