What Can You Do About Dry Eye? A New Treatment May Help
BY LEO SEMES, OD, FAAO
The spectrum of dry eye problems seems endless. Dry eye diagnosis has remained enigmatic since Schirmer introduced his eponymous test for dry eye 100 years ago. We have learned from anatomy and physiology that a number of factors may cause dry dry eye. But even knowing its clinical etiology may give us little hope for developing a treatment strategy.
Dry Eye Etiology and Treatment
Research over the early part of the 21st century suggests an inflammatory etiology for dry eye. While we can't overlook lacrimal gland infiltration in Sjögren's Syndrome patients, hyperosmolarity of keratoconjunctivitis sicca (KCS) patients or lid disease contributions to ocular surface deficiencies, we can't deny the importance of inflammatory components in dry eye diagnosis.
Dry eye treatments 50 to 70 years ago included steroids, but current methods for controlling dry eye inflammation have taken on a new look. Recent research suggests that chronic inflammation and irritation may result in reduced tear quality and quantity with resulting dry eye symptoms.
Unfortunately, our clinical measures can't detect inflammatory contributions, but they do reflect the outcomes: epithelial staining, reduced tear break-up times and conjunctival injection, to name a few. Typical palliative treatments include tear supplements, tear conservation methods and environmental adjustments. Unfortunately, these measures are also often inadequate.
According to one sample poll, 20 percent of contact lens wearers attribute dry eye symptoms to their lenses and many former wearers (54 percent) cite dry eyes as their reason for discontinuance. Manufacturers have gone to great lengths to find alternatives to exacerbating preservatives such as benzalkonium chloride. Some tear supplements now contain transient preservatives that turn into water upon instillation.
The Latest Treatment Option
Newest on the horizon is the immunomodulator cyclosporine ophthalmic emulsion 0.05%, which Allergan markets as Restasis. Allergan formulates Restasis with an emulsion vehicle. That may sound familiar because a cousin of Restasis, Refresh Endura (Allergan), has a similar constituency. The emulsion prolongs contact time with the ocular surface, allowing extended release of the active ingredient.
Restasis has undergone both animal and human clinical trials for more than a decade. The landmark trial examined more than 1,200 patients to determine Restasis's safety and efficacy as well as to compare concentrations. This study enrolled patients who had moderate to severe disease. The results demonstrated a clear treatment benefit with the 0.05% concentration (vs. 0.1% or vehicle). Statistically significant improve ments occurred for tear production (Schirmer II) and vital dye staining as well as for subjective improvement in vision quality. Patients could use concomitant tear supplements during the trial, and their resulting frequency of application decreased by roughly one third.
Restasis is indicated to increase tear production when the presumed etiology is suppressed tear production secondary to ocular inflammation associated with KCS. Dosing is twice daily, approximately 12 hours apart. Restasis is available in single-use 0.9ml vials that contain 0.4ml of medication. Restasis is not indicated for patients under the age of 16 years.
The only cloud in Restasis' silver lining exists because cyclosporine is an immunomodulator, so it may take six months before patients experience its intended full effect. You and your patients should persist and be patient.
Dr. Semes is an associate professor at the University of Alabama at Birmingham School of Optometry.