The Diagnostic Methodology Report enables almost any doctor, at any level of expertise, to effectively diagnose, grade and treat dry eye patients.1 For example, most doctors use a basic patient history to initiate the diagnostic workup. This report prompts clinicians to delve deeper into the history-taking process, and ask patients about the presence of dry mouth, duration of symptoms and severity of discomfort, as well as whether they have specific triggers or notice vision improvement upon blink.
If any of the aforementioned questions lead the clinician to a potential dry eye disease (DED) diagnosis, the Diagnostic Methodology Report directs us to evaluate associated risk factors. These include smoking, certain medications, contact lens wear, etc.
Based on a combination of history and risk factors, the eye care provider can then perform a series of tests to assess symptoms and signs. For symptoms, a validated questionnaire—such as the DEQ-5—was recommended to confirm DED symptoms. Questionnaire scoring enables the clinician to monitor progress in follow-up examinations. A positive result on the screening questionnaire (score > 6) prompts additional testing for tear film homeostasis. The recommendations for additional dry eye tests are:
- Tear film break-up time
- Ocular surface staining
The committee recommended non-invasive tear film break-up time testing because of its specificity.2-4 This would include technologies such as the Keratograph 5M (Oculus), CA-800 (Topcon), the Tear Film Analyzer (Visiometrics) and placido disc imaging. If doctors do not have access to these technologies, more invasive testing (i.e., fluorescein staining) is a potential option.
Osmolarity testing—while one of the most specific tests for DED—requires proper technique. The patient should be seated, chin tilted upward, with his or her eyes directed to the ceiling. The technician should not pull the eyelid down or away, but rather take a sample from just above the lower eyelid tear meniscus, while avoiding contact with the globe (which could precipitate reflex tearing). A positive test result is greater than or equal to 308mOsm/L, or an interocular difference greater than 8mOsmol/L.5
The third option is ocular surface staining, such as fluorescein or lissamine green. In the case of fluorescein, it can be an accurate indicator of late-stage disease. Thus, it’s often best to pair this approach with one of the more sensitive tests outlined above.
Based on these results, we can determine the presence of dry eye disease. The next step—which we’ll cover in next week’s pearl—is to determine whether you are dealing with aqueous- deficient dry eye, evaporative dry eye or both.
1. Wolffsohn JS, Arita R, Chalmers R, et al. TFOS DEWS II Diagnostic Methodology report. Ocul Surf. 2017 Jul;15(3):539-74.
2. Gumus K, Crockett CH, Rao K, et al. Noninvasive assessment of tear stability with the tear stability analysis system in tear dysfunction patients. Invest Ophthalmol Vis Sci 2011;52:456-61.
3. Best NDL, Wolffsohn JS. Clinical evaluation of the Oculus keratograph. Cont Lens Anterior Eye. 2012;35:171e4.
4. Hong J, Sun X, Wei A, et al. Assessment of tear film stability in dry eye with a newly developed keratograph. Cornea. 2013 May;32(5):716-21.
5. Sullivan B. Challenges in using signs and symptoms to evaluate new biomarkers of dry eye disease. Ocul Surf 2014;12:2-9.