The classical thinking in categorizing dry eye patients according to the underlying etiology suggests that patients may be suffering either because of a lack of quality in their tears or a decreased number of tears. More recently, though, we have come to appreciate dry eye as a continuum, and while evaporative or aqueous deficient elements may predominate in an individual, many patients have a mixed mechanism of factors contributing to their dry eye.
We also know that up to 86% of dry eye disease is caused by meibomian gland dysfunction, or MGD. Fostered both by a greater ability to detect MGD and a heightened awareness to look for it, we are finding MGD in populations that we used to not think about, including men and younger women (especially computer users), and teenagers. There is indeed a strong link between MGD and dry eye, because MGD decreases both the quality and quantity of the tear film—and both of those things can trigger hyperosmolarity that causes inflammation.
A clinical suspicion of abnormal meibomian glands, however, may be incomplete without a baseline with which to compare. In a recent interview for Dry Eye Coach, noted dry eye expert Scott Schachter, OD, pointed out to me that MGD is best appreciated in the context of serial meibography. If a patient in his practice scores higher than a 7 on a SPEED questionnaire, they begin the dry eye workup that includes imaging—he uses both Meibox and Keratograph in his clinic. After treatment has commenced for about a month, they repeat the imaging to see if there is any change—and what they learn on repeat imaging is important both for making treatment decisions and for educating the patient.
For treatment, Dr. Schachter offers patients an anti-inflammatory drop for topical application. Especially in individuals who report heavy use of digital devices or computers, he also prescribes blink exercises: getting patients to squeeze their eyes tight for about 10 or 15 seconds about 4 or 5 times a day to help draw the meibum out. Where appropriate, he instructs them to use warm compresses at home. Because compliance with that recommendation is often incomplete, Dr. Schachter offers patients access to thermal pulsation treatment with the LipiFlow system in the clinic. A single treatment with LipiFlow is believed to be effective for at least a year, and recent studies suggest the effect can last 3 or 4 years. Already, we are getting a glimpse of a holistic approach to treating dry eye and MGD, which many think of simply as a local disease entity.
According to Dr. Schachter, there may also be a role for systemic approaches to complement topical therapy. While topical therapy addresses inflammation at the ocular surface, inflammatory mediators relevant to the system may still be active. Encouraging patients to eat a balanced diet and to exercise is certainly one aspect of this approach, but nutraceutical supplementation may also be beneficial.
Studies show that patients taking a nutraceutical product called HydroEye (Science Based Health) demonstrated improvement in signs and symptoms of dry eye after 2 months of use. In the study, OSDI scores were reduced and patients using nutraceutical supplementation experienced improvements in corneal smoothness. Among the growing body of literature supporting a role for HydroEye in dry patients are studies showing improvements in contact wear comfort after 6 months of use. The bottom line is that the concept of nutritional supplementation improving the health of the ocular surface is not merely anecdotal; it is based in science.
Given that dry eye is a multifactorial disease with many causes and triggers, it makes sense that we offer treatments that work on various pathophysiologic factors. Writing a script for an anti-inflammatory drop may be insufficient in some cases; however, most dry eye patients also have an underlying element of MGD that might require direct treatment with thermal pulsation, or, at a minimum, warm compresses. But consideration should also be given to the long-term, where nutraceutical supplementation might be helpful, especially in those patients who do not already follow a healthy diet and lifestyle.