Eyeworld Supplements

EW NOV 2013 - Supported by TearLab, TearScience, Nicox, and PRN

This is a supplement to EyeWorld Magazine.

Issue link: https://supplements.eyeworld.org/i/203232

Contents of this Issue


Page 1 of 7

2 Advanced tear film testing: Improving diagnosis and patient treatment Using advanced diagnostics to overcome clinical challenges in ocular surface disease by Christopher E. Starr, MD A ccurately diagnosing ocular surface diseases is not as easy as previously thought. Ocular surface patients typically present with a multitude of issues. They can have aqueous deficient dry eye and evaporative dry eye, meibomian gland dysfunction (MGD), and/or anterior blepharitis. Additionally, their eyes can be red and irritated due to infection or allergy. Other conditions, such as conjunctivochalasis, preservative toxicity, basement membrane dystrophy, eyelid malpositions, and a whole host of others, blur the picture and often co-exist. Unfortunately, our traditional diagnostic techniques are largely subjective, highly variable, often unreliable, and poorly reproducible. These techniques include Schirmer's test, tear breakup time, corneal and conjunctival staining, tear meniscus height, lid expression, and symptom questionnaires. Basing our diagnoses of ocular surface diseases on traditional signs and symptoms is more difficult than many of us care to admit. It has been known for years that there is a very poor correlation between subjective symptoms and the objective signs of ocular surface diseases. Therefore, it is difficult for us, as doctors, to make an accurate diagnosis in the absence of signs, and it's also difficult for patients to accept an offered treatment in the absence of any significant symptoms. Additionally, it is challenging to monitor the efficacy of our treatments based on these subjective and variable endpoints. Until recently, there hasn't been any single gold standard diagnostic test for accurately establishing dry eye disease. Diagnostic tests are often evaluated based on their positive predictive value (PPV), which is the proportion of positive tests that are true positives. Following are the PPVs of some commonly used diagnostic tools: • Schirmer's: 31% • Tear breakup time: 25% • Staining: 31% • Tear meniscus height: 33% Tear osmolarity testing We have been aware of the utility of tear osmolarity testing for many years, but it has always been outside the reach of the average practitioner. It has a PPV of 87% and could become the new gold standard for dry eye diagnosis; it certainly has in my practice. The American Academy of Oph- thalmology agrees, stating in its most recent Preferred Practice Patterns publication that tear osmolarity is a more sensitive method of diagnosing and grading the severity of dry eye than staining, tear breakup time, Schirmer's testing, and meibomian gland grading. Additionally, according to the 2007 Dry Eye Workshop Study (DEWS), in order to meet the new definition of dry eye disease, patients must have tear hyperosmolarity, and it is well known that osmolarity is linearly related to dry eye severity. Meibomian gland dysfunction There are several current challenges in the diagnosis and treatment of MGD. Aqueous and evaporative dry eye often overlap and coexist. It is common to see patients with low Schirmer's scores and rapid tear breakup times. Additionally, hyperosmolarity is present in both forms and doesn't distinguish between them. It is important to differentiate between them clinically because treatment should ideally be tailored based on whether the condition is predominantly evaporative, aqueous, or both. It is reported that up to half of MGD can be "non-obvious MGD," in which there are very subtle signs and no overwhelming continued from page 1 When attendees were asked whether they regularly consult with and adhere to the Delphi/DEWS guidelines for treating aqueous deficient dry eye and meibomian gland disease, 10% said yes before the symposium, and 36% said yes after the symposium. Additionally, attending the symposium improved attendees' confidence level in a dry eye treatment protocol, with 43% saying they had very high/ high confidence before the symposium, and 67% indicating very high/high confidence after the symposium. Similar results were observed for attendees' confidence in a red eye treatment protocol, with 32% saying they had very high/high confidence levels before the symposium and 57% saying they had very high/high confidence levels after the symposium. Results from pre-registrant survey In the pre-registrant survey, attendees were asked how significant of an impact they believed that dry eye and blepharitis have on outcomes after cataract and refractive surgery. Forty-one percent said they have a very significant impact, 52% said they have a significant impact, and 7% said they have little impact. When asked about the average percentage of patients presenting for their preop consult with sufficient ocular surface dysfunction to require some treatment beyond artificial tears, attendees said that 30% of cataract patients and 25% of laser vision correction patients required treatment beyond artificial tears. Attendees were also asked about patients who present with ocular surface disease issues. Of these, attendees believe that 27% have aqueous deficiency/evapo- rative dry eye, 30% have meibomian gland disease, and 43% have both. Moving forward Unique diagnostic point-of-service tools are now able to assess key information in the tear film. These tests allow clinicians to confidently diagnose and monitor challenging ocular surface diseases. These tools include measurement of lipid layer thickness using interferometry and OCT/topography assessment of tear breakup time, lid parallel conjunctival folds (LIPCOF), and tear meniscus height. These point-of-care tests can improve outcomes in a costeffective manner. Dr. Donnenfeld is in practice at Ophthalmic Consultants of Long Island and is clinical professor of ophthalmology, New York University Medical Center. He can be contacted at ericdonnenfeld@gmail.com.

Articles in this issue

Links on this page

Archives of this issue

view archives of Eyeworld Supplements - EW NOV 2013 - Supported by TearLab, TearScience, Nicox, and PRN