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cover story A Leap Forward in Dry Eye Diagnosis and Care New technology helps educate patients about their tear film while also identifying who will benefit from thermal pulsation treatment. By D. Rex Hamilton, MD, MS O ne of the leading causes of dry eye is meiboment warms the eyelids from the inside, immediately mian gland dysfunction (MGD).1 When paradjacent to the meibomian glands, to about 40° C, the tially obstructed, the glands fail to adequately temperature required to liquefy the contents of the secrete healthy, clear lipids onto the ocular sur- obstructed gland.3 The system then applies intermittent gentle pressure to the outer surface of the lids to face, contributing to rapid evaporation of tears and the tear film’s instability. Over time, as patients become more express the softened meibum (Figure 1). The entire process takes 12 minutes for either a unilateral or symptomatic, the ocular surface can become increassimultaneous bilateral treatment. ingly inflamed and irritated, and the meibomian glands become obstructed and begin to atrophy. Recently, we eye care specialists have acquired new diagnostic and therapeutic tools that allow us to image and analyze the lipid layer and treat evaporative dry eye disease (DED) in ways that were not previously possible. Studies have shown a correlation between the thickness of the lipid layer and symptoms of DED.2 Tear film interferometry (LipiView Ocular Surface Interferometer, TearScience) is a noninvasive test for quantifying the lipid layer thickness. It analyzes approximately 1 billion data points in a matter of seconds. In my practice, I use the LipiView and other tests to help me decide which patients are likely to benefit from the LipiFlow thermal pulsation therapy (also Figure 1. LipiFlow thermal pulsation treatment. from TearScience). This unique treat- 44 Advanced Ocular Care May/June 2012 cover story L ipi V iew Testing The LipiView test provides three useful outputs. The first of these is the average interferometric color unit (ICU), a measurement of the interference pattern of light reflected off of the lipid layer (Figure 2). Average ICU is not a static number. Similar to one’s heart rate, it is subject to normal fluctuations, but it plays an important role in evaluation of the tear film. There is a strong correlation between the color on the ICU scale and the lipid layer thickness, measured in nanometers. Second, a frame-by-frame graphical representation shows what is happening to the lipid layer’s thickness between blinks (Figure 2). It is remarkable to see how the interblink lipid layer thickness curves differ from patient to patient. Over time, I believe eye care specialists will learn a great deal more about how to interpret the myriad information provided by the LipiView acquisition. Finally, the system provides a high-resolution video that the patient and clinician can watch on a large, flat-screen display. The video illustrates how the eyelids “grab” the tears and pull them up across the ocular surface, and it helps patients understand the role of ocular lipids. The contrast between the rainbow sheen of tear film with healthy oil levels and the dull gray and white of an eye with MGD is apparent, even to a layperson. LipiView also helps to identify partial blinkers, for whom blinks are inefficient and do not adequately access the tear lake residing on the lower lid. Whether treatment is initiated or not, the LipiView display plays a critical role in the patient’s education about the composition and quality of the tear film, the Figure 2. The LipiView test provides the average interferometric color unit measurement (A) and a frame-by-frame graphical representation of what is happening to the lipid layer’s thickness between blinks (B). “In my practice, LipiView interferometry is just one part of the process of determining whether a patient will benefit from thermal pulsation treatment.” spread of tears over the ocular surface, and the completeness of the blink. It provides something tangible to show patients, which serves to validate the frustrations they have been experiencing from their chronic evaporative DED. Making Treatment Decisions In my practice, LipiView interferometry is just one part of the process of determining whether a patient will benefit from thermal pulsation treatment. I begin with a Standard Patient Evaluation of Eye Dryness (also known as SPEED) questionnaire to elicit the frequency and severity of the patient’s subjective symptoms. This test is scored on a scale of 0 to 28, with 0 representing no symptoms. For any patients who score 8 or more, I recommend a more thorough dry eye evaluation. I prefer for that evaluation to take place during a separate appointment to ensure that the patient has not had any dyes or drops instilled or used any ocular ointments during the preceding 12 hours. During the evaluation, the first step is LipiView interferometry. Higher ICU scores indicate a thicker lipid layer, and thinner measures of the lipid layer indicate a Figure 3. The Meibomian Gland Evaluator. May/June 2012 Advanced Ocular Care 45 cover story 80% of our cases, there has been an objective improvement in the 1-month posttreatment ICU score, and about 70% of patients experience a reduction in symptoms. One reason why improvements appear to last longer than was originally anticipated is that heating from the posterior lid surface combined with the 12-minute pressure profile does a better job than expected at flushing out stagnant or purulent material that may have been sitting within the gland structures for months or even years. Most of our patients who have used LipiFlow have tried multiple other treatments, from warm compresses to punctal plugs, cyclospoFigure 4. Clinical trial results with LipiFlow: meibomian gland function rine, steroids, and tetracyclines. Initially, espe1 month after treatment. cially in a tertiary care center like the Jules Stein Eye Institute, we are treating patients with deficiency and suggest obstructive MGD. quite advanced MGD. I do not believe, however, that My next diagnostic step is the use of the Meibomian one should consider LipiFlow a “last resort” treatment. Gland Evaluator (TearScience). This is a simple tool Obstructive MGD is a chronic disease similar to glaufor applying standardized pressure to the meibomian coma, and it may not be reversible. Intervening earlier glands (Figure 3) to evaluate the presence or absence of in the process may help position the patient for better lipid secretion, as well as its quality, from 15 glands on long-term success. the lower lid. If four or fewer of these glands are secreting clear lipids, that is a sign of obstructive MGD.4 CONCLUSION I also perform lissamine green staining and fluoresWe are still learning the best way to position the cein tear breakup time (TBUT) as part of the analysis treatment device on different types of eyes, how to for DED. By using this comprehensive evaluation, I am harvest and interpret the rich trove of data LipiView looking for consistency in the results. For example, if gathers about the tear film, and how to identify the the patient is more symptomatic in the eye that has best predictors of success. Based on our experience a short TBUT, ICU of 25, and few functioning glands, I thus far, I am very excited about the new opportunibelieve he or she is an excellent candidate for LipiFlow ties that LipiView and LipiFlow present for our patients and will likely benefit from the treatment. If the glands with DED. n are mostly functioning well and the patient has an D. Rex Hamilton, MD, MS, is an associate ICU of 85, I may decide not to treat with Lipiflow and clinical professor of ophthalmology and direcinstead use an alternative therapy. tor of the UCLA Laser Refractive Center at the UCLA Jules Stein Eye Institute. He has received RESULTS of LipiFlow treatment honoraria from TearScience for educational In a controlled, prospective clinical trial, there was lectures. He may be reached at (310) 825-2737; a mean improvement from baseline to 1 month after treatment with LipiFlow in the meibomian gland score, [email protected]. TBUT, and the SPEED and Ocular Surface Disease 1. Nichols KK, Foulks GN, Bron AJ, et al. The international workshop on meibomian gland dysfunction: execuIndex (known as OSDI) questionnaires.5 The patients tive summary. Invest Ophthalmol Vis Sci. 2011;52(4):1922-1929. assigned to treatment with LipiFlow had a significantly 2. Blackie CA, Solomon JD, Scaffidi RC, et al. The relationship between dry eye symptoms and lipid layer thickness. Cornea. 2009;28:789-794. greater improvement in the number of meibomian 3. Bron AJ, Tiffany JM, Gouveia SM, et al. Functional aspects of the tear film lipid layer. Exp Eye Res. glands secreting clear liquid compared with control 2004;78(3):347-360. 4. Korb DR, Blackie CA. Meibomian gland diagnostic expressibility: correlation with dry eye symptoms and patients who were treated with warm compress gland location. Cornea. 2008;27(10):1142-1147. therapy (Figure 4). Nine-month results have been pub- 5. Greiner JV. A single LipiFlow thermal pulsation system treatment improves meibomian gland function and dry eye symptoms for 9 months. Curr Eye Res. 2012;37(4):272-278. lished,5 and investigators have recently reported 1- and reduces 6. Grenier JV. Improvement in meibomian gland dysfunction and dry eye persists 2 years after single treatment 6,7 2-year results at major meetings. with thermal pulsation system. Presented at: The ASCRS-ASOA Symposium & Congress; April 19-23, 2012; Chicago, Il. My colleagues and I have seen very similar results in 7. Herzig S. Effect of thermal pulsation treatment on subjective and objective measures of dry eye. Presented at: our first few months of nonstudy treatments. In 75% to The ASCRS-ASOA Symposium & Congress; April 19-23, 2012; Chicago, Il. 46 Advanced Ocular Care May/June 2012