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Ocular surface interferometer can assist in dry eye disease treatment
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Conventional dry eye disease therapy is centered on the use of aqueous eye drops to replace the tears presumed to be deficient in individuals with the disease.
Despite this established mode of therapy, dry eye disease remains a puzzling condition, difficult to diagnose and treat effectively. Patients often resign themselves to a lifetime of bothersome symptoms, punctuated with temporary relief achieved only by flooding their eyes with artificial tears. Physicians have struggled to adequately meet the needs of their patients, relying on trial and error to find the best tear replacement solution for each patient.
Fortunately, the last few years have brought a paradigm shift in the understanding of the mechanisms by which dry eye disease arises. Indeed, the contribution of the meibomian glands to normal tear composition has become a much more prominent consideration when treating patients with dry eye disease.
The LipiView (TearScience) is a device that allows the visualization of the tear film of patients with suspected dry eye disease. The test is noninvasive and takes less than 5 minutes, and the tear film image obtained clearly shows if lipid deficiency underlies the patient’s dry eye symptoms.
A report from the March 2011 MGD Workshop conducted by the Tear Film Ophthalmic Society provided much needed evidence in favor of lipid deficiency secondary to meibomian gland dysfunction as a cause of dry eye disease. It stated: “[Meibomian gland dysfunction] is an important, underestimated condition and is very likely the most frequent cause of dry eye disease.”
SPEED questionnaire
In response to this paradigm shift, TearScience has developed a triage-to-treatment system, which consists of a three-step approach — symptoms, oils, glands — to diagnosing and treating dry eye disease, with specific focus on identifying lipid deficiency when it underlies dry eye disease. The first step in the system, the Standard Patient Evaluation of Eye Dryness (SPEED) questionnaire, involves symptom assessment.
I initially implemented the SPEED questionnaire in my practice with skepticism. At the time, I had little awareness of the true prevalence of dry eye disease among my patient population and questioned the necessity of an additional step in the patient management process. However, within 1 week of using the questionnaire on all patients passing through the practice doors, my colleagues and I noticed that a large proportion had dry eye complaints that would otherwise have been missed.
In light of this revelation, we started assessing all patients as they came into the practice by first performing a SPEED questionnaire. Patients scoring 9 or higher were progressed to stage 2 of the management pathway, the Lipi-View Ocular Surface Interferometer, to identify any problems with tear film dynamics.
Once the tear film has been assessed with the LipiView, these patients undergo meibomian gland assessment using a device called a meibomian gland evaluator. This device applies standardized pressure to the lid margin to identify and grade meibomian gland function and to provide a quality score for tear lipid secretion. Patients found to have lipid-deficient dry eye disease after these tests are recommended for therapy with the LipiFlow Thermal Pulsation System. Treatment with this system involves the local application of heat and pressure to gently open and evacuate blocked meibomian glands. This provides an opportunity to reset and possibly restore normal lipid contribution to the tear film. As standard, the restoration of natural gland function achieved with LipiFlow treatment lasts between 9 and 15 months, although more research is required to specify an exact duration of gland function and symptom relief.
Practice use
We have now set up an optometrist-led dry eye clinic within our practice. Our dedicated optometrist is well trained in not only conducting the test, but more importantly in explaining the findings to patients so they really understand why they are experiencing the symptoms they have and how we can work together to improve those symptoms. I have found that having a trained specialist — optometrist or technician — specifically dedicated to dry eye disease diagnosis and care is crucial to the success of the LipiFlow program in any practice wishing to improve management of dry eye disease patients.
We are now increasing the number of dry eye disease diagnosis and treatment procedures every day. We regularly see patients who have achieved symptom relief and are much less reliant on daily therapies (eg, wetting drops, ointments) after failing to respond to years of conventional aqueous-based therapy.
The etiology-based decision pathway captured by the SPEED, LipiView and meibomian gland evaluation system allows us to determine the level of severity of lipid deficiency when present and to more confidently diagnose aqueous-deficient dry eye disease in patients who have normal LipiView and meibomian gland evaluation results. Patients who are lipid deficient receive therapy for lipid deficiency rather than for aqueous deficiency, so they experience improved treatment outcomes and higher levels of satisfaction.
Implementation of the TearScience system in our practice has produced results similar to those found in previous research. Studies conducted by TearScience in which the etiology-based decision pathway was used in approximately 285,000 patients (0.5 million patient visits per year) revealed that around 40% of all patients who visited an ophthalmic practice had dry eye disease. Furthermore, up to 70% of those with dry eye disease reported that they actually attended clinic with a complaint unrelated to dry eye. This highlights the benefit of patient screening with the SPEED questionnaire if the majority of patients who require dry eye disease treatment are to be accurately identified.
One system, many uses
In our practice, we have found that the LipiFlow system is not only useful in identifying and treating primary dry eye disease, but also in reducing the risk of dry eye disease after LASIK and PRK. Now, prior to surgery, all LASIK and PRK patients are provided a SPEED questionnaire followed by the LipiView test if the questionnaire results indicate dry eye disease. I find that identifying the presence and type of dry eye disease helps with patient counseling. It is also invaluable in reassuring the patient that if dry eye disease does occur after surgery, we are equipped with an effective treatment method. I find it much easier to manage dry eye disease patients who are prepared and informed prior to surgery than those who do not understand the dry eye disease risk associated with laser surgery and inevitably become distressed if symptoms arise after surgery. In pre-procedure laser eye surgery patients, I also like to assess the presence of dry eye disease to determine if a slightly different type of surgery will be more beneficial for them.
I have found that the SPEED, Lipi-View, meibomian gland evaluation pathway is also very useful for ensuring that a patient’s postoperative visual clarity is maximized. If a patient has a poor-quality tear film that remains undetected and uncorrected, their vision will not be optimized, no matter how accurate the laser correction achieved. If I can detect a poor-quality tear film before surgery, I can treat it with the LipiFlow to potentially prevent it from compromising the final visual outcome.
Future
Overall, the SPEED, LipiView, meibomian gland evaluation pathway makes a very useful addition to any ophthalmic practice. Simply implementing use of the SPEED questionnaire soon reveals the sheer volume of patients who have dry eye complaints but never mention them. The SPEED questionnaire, meibomian gland evaluator, LipiView and LipiFlow are revolutionary devices that reflect a shift in the way dry eye disease is perceived and managed by ophthalmic professionals. Not only do these devices assist disease identification and symptomatic relief, but they also get to the root cause of dry eye disease in most patients — meibomian gland dysfunction — thereby helping to achieve the long-lasting treatment that every dry eye disease patient desires.