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55 EW CORNEA October 2014 right patients, they can be useful in mild to severe dry eye cases. Punctal plugs are often suggest- ed for later stages of dry eye, but they could also be helpful for those patients who may not want to use artificial tears 4 to 5 times a da . In severe cases, upper and lower plugs may be a helpful part of the treat- ment regimen. The negative aspect, Dr. Latkany said, is sometimes patients are misdiagnosed and a surgeon will have to remove the plugs. However, they are easily re- movable and can sometimes be used for diagnostic purposes to identify a patient's condition based on the response to the punctal plugs. What tool would you choose? Dr. McCulley said the tool he would be most likely to choose in diag- nosing dry eye is a bottle of vital stain, either lissamine green or rose bengal. Fluorescein staining is not adequate when observing a patient, he said. The conjunctiva is first to show evidence of dryness before the cornea, and to pick that up best, you need a vital stain. Although there are a number of tests that can help diagnose dry eye, he would not choose them over the vital stain at this point. Dr. McCulley believes the tear osmolar- ity test has potential as an endpoint in assessing therapy. He added that the MMP-9 test may be helpful; however, it is important to clarify if this test is specific for d y eye or if it is simply a marker for inflammation Dr. Latkany said that at this time, he would recommend contact- ing an ocular surface specialist, who is one of the most valuable resources in diagnosing dry eye. EW Editors' note: Dr. McCulley has financial interests with Alcon (Fort Worth, Texas), Allergan (Irvine, Calif.), and Bausch + Lomb (Bridgewater, N.J.). Dr. Latkany has no financial interests related to this article. Contact information Latkany: relief@dryeyedoctor.com McCulley: james.mcculley@utsouthwestern.edu by Ellen Stodola EyeWorld Staff Writer However, the reality is that in many patients, these conditions seem to overlap. He said the ques- tion to answer for a patient who has aqueous deficient d y eye is whether MGD is contributing to that dry eye with excessive evaporation or if the MGD changes simply represent a reaction of the meibomian glands to inflammation associated with aqueous deficient d y eye. Where do punctal plugs fit in "Punctal plugs are not frontline," Dr. McCulley said. He starts the patient with artificial tears. If replacing the tears and obtaining a normal sur- face does not deal with the disease process, he adds cyclosporine as an anti-inflammato y. After that, Dr. McCulley adds punctal plugs. His last resort would be to consider moisture chambers. Dr. Latkany thinks punctal plugs are a good addition to the treatment regimen for different levels of dry eye disease. Companies offering punctal plugs include Beaver-Visitec International (Waltham, Mass.); FCI Ophthalmics (Pembroke, Mass.); Lacrimedics (DuPont, Wash.); Medennium (Irvine, Calif.); and Oasis Medical (Glendora, Calif.). These plugs should not be used for all patients, he said, but for the look at that do not require any ex- pensive alternative machines to help you differentiate evaporative and aqueous deficient d y eye." Dr. McCulley said in a research study setting, he uses fluoroph - tometry to measure tear volume, tear flo , and turnover. He also uses evaporometry to measure the evap- orative rate of aqueous tear loss. Dr. McCulley noted that this technology is not practical for clinical use in the office because not only is it expe - sive, but it takes time to perform and requires special technical expertise. Distinguishing Dr. McCulley said he uses a slit lamp to attempt to distinguish meibo- mian gland dysfunction (MGD) or posterior blepharitis from aqueous deficient d y eye. There are two approaches to diagnosing MGD. "One is slit lamp assessment of the meibomian glands and their secretions," he said. "Another is anatomical where the physician does infrared photography to determine attenuation of mei- bomian glands." Physicians accept both approaches. When looking through a slit lamp, Dr. McCulley said it is important to determine if there is a qualitative or quantitative alteration in meibomian secretions. Tests and techniques physicians can utilize to aid in diagnosis T here are a number of tech- nologies and techniques available to diagnose and evaluate dry eye. Robert Latkany, MD, New York, and James McCulley, MD, Univer- sity of Texas Southwestern Medical Center, Dallas, discussed the options available to diagnose and differenti- ate the types of dry eye. What's available? Dr. Latkany said there are a number of tests, including tear testing by Advanced Tear Diagnostics (Birmingham, Ala.), TearLab (San Diego) osmolarity technology, and Rapid Pathogen Screening (RPS, Sarasota, Fla.). The TearLab technol- ogy is gaining ground, however, he said there are still varied results with this testing. "I think there is a place for osmolarity levels, but I think we need more precise measurements." The kits from RPS check for ma- trix metalloproteinase 9 (MMP-9), and this is a simple way of gathering information on the inflammato y enzymes found in the tear film. D . Latkany said the question remains of how a positive reading would change the therapy for a patient. Dr. Latkany does not use any tests in his office currentl . "As of now, the best method of diagnos- ing dry eye remains a good clinical history with a good slit lamp exam," he said. Looking at how a patient blinks, how often he or she blinks, eyelid opening, and other factors that can be gathered without testing are important, as long as you know what you are looking at, he said. Dr. McCulley said that for diagnosis of dry eye, he primarily uses patient history and vital staining of the ocular surface. Differentiating aqueous deficient and e aporative dry eye When it comes to differentiating between aqueous deficient d y eye and evaporative dry eye, this can be a challenging task for a physician. A slit lamp exam should be able to help with this, Dr. Latkany said. "There are so many things you can Evaluating and diagnosing dry eye Lissamine green staining of the conjunctiva in a patient with mild dry eye. Lissamine green is a valuable vital dye to use because it is sensitive and highlights even early devitalization of conjunctival epithelium. Source: Vincent P. de Luise, MD This is the second in a three-part series on dry eye. See page 68 of the September issue for the first part The last part is slated for November.