Eyeworld

EW CORNEA 68 by Ellen Stodola EyeWorld Staff Writer Dry eye disease: History and diagnosis September 2014 The first in a three-part series explores the history of dry eye disease, as well as signs and tools to diagnose it W hen dealing with dry eye disease, it is im- portant to recognize the clinical signs and know how to distin- guish the types of the disease and other associated conditions. Vincent P. de Luise, MD, FACS, assistant professor of ophthalmolo- gy, Yale University School of Medi- cine, and adjunct clinical assistant professor of ophthalmology, Weill Cornell Medical College, New York; and Henry Perry, MD, Ophthalmic Consultants of Long Island, Rock- ville Centre, N.Y., commented on the history and clinical diagnosis of dry eye disease. It is imperative that the physi- cian asks patients to articulate their symptoms to pursue a diagnostic exam and testing. Dr. de Luise said that relevant symptoms include blurry vision, a burning or irritating feeling, foreign body sensation, and photophobia. Itching implies some degree of allergy. He added that tak- ing a good history from the patient helps in identifying and tailoring a treatment plan. Clinical signs There are two major types of dry eye, Dr. de Luise said: aqueous de- ficient dry eye disease (ADED) and evaporative dry eye disease (EDED). In terms of distinguishing between dry eye, posterior blepharitis, and meibomian gland dysfunction (MGD), it might be better to question how to segregate these two main forms of dry eye. To do this, Dr. de Luise said there are important details to consider. Patients with ADED are "typically women, in their peri- menopausal years, have normal lid margins and normal meibomian gland secretions, have decreased tear film menisci, and usually have elevated tear film osmolarity," he said. Meanwhile, those with EDED tend to be older "with a slight male preponderance, cheesy or inspissat- ed meibomian gland secretions, and debris in the tear film even if the tear film height is normal." Dr. Perry said that it is some- times hard to distinguish ADED from EDED because of the ubiquity of blepharitis, MGD, and dry eye in the population. "In terms of distinguishing dry eye from blepharitis, blepharitis patients usually present with their most significant symptoms in the morning, as opposed to the dry eye patients who seem to be getting worse with the passage of time," he said. Schirmer's test "The Schirmer's test was developed around 1905, and it's been our mainstay until the last decade," Dr. Perry said. "In the last decade, we've had a potpourri of tests that we've added." There are variations of the Schirmer's test including doing the test with or without an anesthetic or doing it in combination with nasal stimulation, he said. Dr. de Luise said that the Schirmer's test with anesthetic has some predictive value in the diag- nosis of aqueous deficient dry eye. "However, for the Schirmer's test with anesthetic to be performed properly and to minimize false neg- atives, the observer must first blot out the anesthetic after it is placed, wait 1 minute before placing the Schirmer's test strip in the conjunc- tival cul-de-sac, and then wait the standard 5 minutes to obtain the result," he said. Vital dyes Dr. Perry said there are essentially three types of dyes that are used. Fluorescein is not a vital dye "but it is a dye that helps pick up abnor- malities mainly in the cornea where the epithelium has been damaged from some cause." The "vital" dyes are rose bengal and lissamine green, and Dr. Perry said they are both sen- sitive to changes in the conjunctiva. "They're the gold standard for mak- ing the diagnosis of ocular surface disease," he said. Of these three dyes, Dr. Perry said that he uses lissamine green more than any other dye "because of its sensitivity and the fact that it doesn't cause any burning." He add- ed that it usually fades quickly. Rose bengal is also sensitive, but patients sometimes complain of burning or discomfort. Tear meniscus evaluation Tear meniscus can be measured with special equipment or by a surgeon through a slit lamp. For many years, there wasn't equipment to deter- mine the size of the tear meniscus, Dr. Perry said. "A clear look at the tear menis- cus with the slit lamp is accurate in more than 90% of patients." "The evaluation of the tear meniscus and tear film breakup time (TBUT) remain the most crucial and essential observations for the diag- nosis of DED and do not need any expensive equipment," Dr. de Luise said. When evaluating the tear film meniscus, there should be an assessment of its quantity, mor- phology, quality, and asymmetry between the eyes. TBUT "There's always a controversy in terms of tear breakup time because it's an average of a couple of times related to the blinking with fluores- cein, and anything quicker than 5 to 10 seconds is considered to be ab- normal," Dr. Perry said, adding that breakup times that are significant are usually almost instantaneous. Anterior blepharitis Expressed secretions in patient with MGD or posterior blepharitis Source (all): Henry Perry, MD Combination of anterior and posterior blepharitis Posterior blepharitis

• Cover