Long-term management of dry eye

The incidence of dry eye has been increasing for more than a decade and will continue to do so as the percentage of the population over the age of 50 increases. The impact will be felt on patient quality of life as well as in financial costs directly and indirectly attributable to dry eye, making it all the more urgent for clinicians to become adept at managing this condition.

Population-based epidemiology studies of dry eye have been conducted in various parts of the world, including the United States, Australia, and Asia. Findings show that at-risk populations, in addition to individuals over 50, include females, Hispanics, and Asians, according to Penny Asbell, MD, FACS, MBA, professor of ophthalmology, Mount Sinai School of Medicine, New York.

"But we see it in men as well, so don't ignore the possibility that when some of your male patients might be complaining of irritation and uncomfortable eyes, they might be suffering from dry eye," she added.

Dr. Asbell was one of several experts reviewing strategies for individualizing care of patients with dry eye syndrome at a breakfast continuing education symposium held Saturday at the Embassy Suites New Orleans Convention Center.

Studies have also identified a number of suspected risk factors for dry eye, including hormonal factors such as postmenopausal estrogen therapy and sex steroid deficiency. Dietary risk factors include vitamin A deficiency and a diet low in omega-3 or with a low omega-3:omega-6 ratio. Other possible risks stem from refractive surgery, radiation therapy, bone marrow transplant, hepatitis C, and certain systemic medications, such as antihistamines, Dr. Asbell said.

Dysfunctional tear syndrome can have many causes, such as aqueous tear deficiency, lipid deficiency, mucin deficiency, exposure keratopathy, neurotrophic keratopathy, or environmental precipitants. Successful management depends on identifying the primary and contributing causes through the use of various diagnostic tools, said Anthony J. Aldave, MD.

Another critical component of disease management is categorizing the severity. This can be done with the Ocular Surface Disease Questionnaire or by following severity levels outlined by a Delphi panel that studied dysfunctional tear syndrome and issued treatment recommendations, said Dr. Aldave, associate professor of ophthalmology at the Jules Stein Eye Institute, University of California in Los Angeles.

Adhering to a treatment algorithm recommended by the experts can aid in selection of an appropriate treatment strategy and the evaluation of that strategy, he added.

Clinicians have a host of therapies to choose from, with emerging options that may soon join the ranks of established strategies. Approaches include tear supplements, tear retention, tear stimulation, biological tear substitutes, anti-inflammatory therapy, essential fatty acids, and environmental strategies, according to Clark L. Springs, MD, assistant professor of cornea, cataract, and refractive surgery at Indiana University School of Medicine, Indianapolis.

Tear supplements are widely used and ideally should be preservative-free, contain potassium and bicarbonate, include a polymeric solution to increase retention time, and have neutral to slightly alkaline pH, Dr. Springs said. He suggested that clinicians guide patients in the selection of a tear supplement, since many people opt for the least expensive brand and are unaware that these products may contain ingredients that potentially could be toxic to the ocular surface.

Occlusive therapy also is an option, often applied through lacrimal plugs, either temporary or permanent. Tear stimulation with secretagogues is currently under investigation. These agents increase mucin secretion, aqueous secretion, or both. Other approaches that may be tried include biological tear substitutes, such as serum or salivary gland transplantation.

Anti-inflammatory therapy with cyclosporine A (Restasis, Allergan) has been shown to improve the symptoms of dry eye, Dr. Springs said, and other agents are undergoing clinical trials. Corticosteroids are effective but may have more side effects, while androgen and estrogen derivatives are under investigation. Tetracyclines are used in patients with severe symptoms, although there are concerns about dosage, safety, and duration of treatment.

This array of new and investigational therapies indicates that advances are being made in treating dry eye.

"We've come a long way," Dr. Springs said. "Twelve years ago in 1995 when we last looked at dry eye in a comprehensive fashion, we were hydrating and lubricating the eye. We're still doing that, but we're now doing that in much more controlled and educated ways with lubricating eye drops that have improved polymers and recognizing the importance of osmolarity as well as inflammation."

A tear substitute is often the first-line therapy for dry eye, but to obtain results it should be adequate to the ocular surface needs, suggested Maurizio Rolando, MD, associate professor in the department of neurosciences, ophthalmology, and genetics at the University of Genoa, Italy. The tear substitute should adhere to the epithelium for a significant period of time so that corrective interventions can heal the damaged surface, he explained.

It is also important to treat all of the conditions present during dry eye together in order to break the vicious cycle, Dr. Rolando said. The components of treatment are to increase tear volume, improve tear film stability, improve mucus conditions, improve corneal epithelium, reduce evaporation, treat the lids, control inflammation, and supplement growth factors.

He also recommended that therapy be adapted to eye conditions as they change and advised against excessive treatment that could lead to toxicity.

Communication with patients is also important. Clinicians should explain the disease and treatment approaches and teach patients about prevention measures.