Eyeworld

EW CORNEA 92 September 2015 by Michelle Dalton EyeWorld Contributing Writer "IgE should be a great marker for allergic eye disease, but we need to validate those tests," Dr. Holland said. Bottom line "Clinicians still need to take a good clinical history and perform a thor- ough clinical slit lamp evaluation before devising a treatment plan for their dry eye patients," Dr. de Luise said. "In aggregate, history, exam, and diagnostic testing can bring us closer to the correct diagnosis, which will then lead to the correct treatment strategy." The more tests a clinician has in the armamentarium, however, the more the field is recognizing that disease progression occurs. Common to many other ocular disorders, the more progressed a patient's dry eye, the more difficult to treat. "We have older patients who didn't have their ocular surface disease diagnosed until late in the disease course, and the result is poor quality of vision and unhappy pa- tients," Dr. Holland said. "The more advanced the disease, the more dif- ficult it will be to treat and improve. We have been diagnosing ocular surface disease the same way for decades. It is time we use these new technologies to make us better and more efficient clinicians," he said. Eventually, Dr. Holland thinks clinicians will have the ability to get a variety of diagnostics run from 1 or 2 tear samples, and that may become a reality within the next few years. "Researchers are working on it now," he said. "These types of tests will be less expensive, be faster be- cause it's one sample, and will give us a lot more data." EW Editors' note: Dr. de Luise has no financial interests related to this article. Dr. Holland has financial interests with TearLab, TearScience, and Rapid Pathogen Screening. Contact information de Luise: vdeluisemd@gmail.com Holland: Eholland@holprovision.com He thinks the "whole field" of meibomography is "going to be very valuable." The LipiView system (TearScience, Morrisville, N.C.) uses tear interferometry to visualize and measure the thickness of the tear film lipid layer. "Explaining MGD to patients is difficult and doesn't always resonate, but when patients see an image of their truncated glands or completely obliterated glands, they start to understand why treatment is important," Dr. Holland said. Dr. de Luise said "the astute cli- nician will notice on slit lamp eval- uation if the meibomian glands are abnormal, cheesy, stuck, closed, or inspissated." Once the abnormality is confirmed and clinicians use the LipiFlow to help express the glands, "there's benefit there," he said. "The LipiView is more likely to be abnormal when you have a lipid phase abnormality than when you have an aqueous phase abnormality. A lipid phase abnormality usually confers evidence of evaporative dry eye. There is value to the TearScience test to distinguish evaporative from aqueous phase dry eye, but the slit lamp evaluation would have likely uncovered an abnormal tear film or if the TBUT was low," Dr. de Luise said. Other potential tools For patients with more severe dry eye or Sjögren's syndrome, there is the Sjo series panel of immunolog- ical markers designed to diagnose Sjögren's, Dr. de Luise said. Dr. Holland thinks the serum test for Sjögren's evaluates the biomarkers that present earlier in the disease process and may allow diagnosis earlier in the disease course. Allergic eye disease is another important ocular surface disease that may benefit from newer diagnostics. Birmingham, Ala.-based Advanced Tear Diagnostics' TearScan "provides real-time point-of-care quantitative results for lactoferrin and IgE tear diagnostic tests," the company said. Edward Holland, MD, director of cornea services, Cincinnati Eye Institute, and professor of ophthal- mology, University of Cincinnati, Ohio, agrees and said it is difficult to diagnose because there are different types of dry eye. Each type of dry eye has a specific treatment regimen. He believes that point-of-service testing helps clinicians diagnose dry eye and distinguish between aque- ous tear deficiency and meibomian gland dysfunction. Newer diagnostics Dr. Holland recommends practices "empower technicians to use these new point-of-service tests" to help improve clinician efficiency, and thinks the Tear Osmolarity System (TearLab, San Diego) is the "best initial screening test to diagnosis whether there's dry eye present or not. Having data available to the cli- nician before he or she sees the pa- tient is extremely valuable in terms of improving our ability to diagnose and efficiently see patients," he said. The threshold for a dry eye diagnosis is 308 mOsm/L on the TearLab system, but "you need a clinical diagnosis as well as a num- ber," Dr. de Luise said. "The number alone can be difficult to interpret, and can sometimes be asymmetric between eyes. In some cases, the os- molarity value can be in the normal range and the patient is clinically dry, or the value can be somewhat abnormal and the patient is clinical- ly OK." The InflammaDry (Rapid Pathogen Screening, Sarasota, Fla.) detects elevated levels of matrix metalloproteinase-9 and "it has value if you are using it in the con- text of patient history and clinical slit lamp examination, but alone these tests can be difficult to inter- pret," Dr. de Luise said. The InflammaDry can help diagnose patients "with an inflam- matory mediator in the cornea and be more specific to aqueous tear deficiency, but I don't use that as the first screen," Dr. Holland said. In the future, clinicians may have a single test to quantify and distinguish the various types of dry eye, but for now, newer diagnostic tools are helping to confirm the disease D ry eye disease remains largely a clinical diagno- sis, but there are now a number of diagnostic tools clinicians can use to help narrow the diagnosis. However, no one single test has yet emerged as the de facto standard, experts said. "All of the currently marketed tests have some value when used to confirm a clinical diagnosis of dry eye disease," said Vincent P. de Luise, MD, assistant clinical professor of ophthalmology, Yale University School of Medicine, New Haven, Conn. "However, one should evaluate the sensitivity, specificity, and predictive value of a positive result and a negative result to assess the clinical value of each test. Understanding the role of dry eye diagnostic testing becomes as much a statistical discussion as it is a clinical one." This may be why the single most important factor remains subjective patient complaints and patient history, he said, adding that clinicians should continue to per- form tear film and lid margin eval- uation, tear breakup time (TBUT), vital dye staining, and even Schirm- er's testing, along with subjective questionnaires. "A decision needs to be made early on as to whether the patient has aqueous phase deficiency, evap- orative disease, or a combination of both as the cause of their dry eyes," Dr. de Luise said. "The problem is that currently none of the diagnos- tic tests is able to tell us which type of dry eye a patient has or if there's another disease involved (such as meibomian gland or goblet cell dysfunction)." Diagnosing dry eye disease Device focus

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