Article

An evidence-based approach to DED

With its updated definition of dry eye, TFOS DEWS II helps practices accurately diagnose and treat the disease.

Patients commonly schedule exams due to dry eye disease (DED). Many times, however, they are not aware that their symptoms of burning, watering, foreign body sensation, and even intermittent blurred vision are due to DED, but they know they are uncomfortable and seek our expertise.

The understanding of dry eye as a disease of the tear film has changed over the years, much in part due to the efforts of the Tear Film and Ocular Surface Society (TFOS). This non-profit organization founded by the Sullivan family is dedicated to raising awareness, increasing research and treatments, and providing evidence-based reports classifying DED and its management. With the TFOS Dry Eye Workshop II (DEWS II), once again we have an evidence-based encyclopedia on DED to aid in our diagnosis and treatment.

TFOS DEWS II consisted of 150 members from 23 countries working together over two years to develop this 397-page report. This is a summary of the practical findings that you can apply to every patient encounter.

DED redefined

The TFOS DEWS II report was recently published in the Ocular Surface Journal. It featured a new definition of dry eye: “a multifactorial disease of the ocular surface characterized by a loss of homeostasis of the tear film, and accompanied by ocular symptoms, in which tear film instability and hyperosmolarity, ocular surface inflammation and damage, and neurosensory abnormalities play etiological roles.”

Here’s a practical application of this definition:

  • A disease of the ocular surface. Dry eye is a chronic and progressive disease of the tear film, and it demands the same attention as other diseases of the eye. Failure to treat adequately not only leads to discomfort but also compromised vision and ocular surface damage. When working with patients, be their advocate, ask questions about dry eye symptoms that may go missed, such as intermittent blurred vision with prolonged periods of reading, computer use, or television viewing, watering, and ocular itching. The staff members should bring these symptoms to the eye-care provider’s attention prior to the patient exam.
  • Loss of homeostasis. Failure to treat leads to loss of homeostasis and hyperosmolarity as well as inflammation. The good news is with new treatments, including topical medications, OTC products, and in-office procedures such as LipiFlow (TearScience) and intense pulsed light, the eyecare provider can restore homeostasis and improve ocular surface health.
  • Sequelae of symptoms and ocular surface damage. Imagine working for a primary-care provider and routinely screening patients for hypertension but the doctor fails to treat the positive readings. This would result in a plethora of cardiovascular risks to the patient. The same is true for dry eye — if not treated correctly, it could have lasting effects on the ocular surface, including conjunctival hyperemia, meibomian gland keratinization, down-regulation of corneal nerves, and corneal and conjunctival damage as seen with vital dye testing, all of which negatively impact the patient’s vision.

Classification of DED

Classification systems, like the one provided in the TFOS DEWS II report, help to simplify a complex, multifactorial disease like dry eye. Let’s decode the new classification:

  • No signs/no symptoms – Believe it or not, dry eye is NOT omnipresent, and normal patients do exist.
  • Clinical signs/symptoms – These DED patients will be subtyped as predominantly aqueous deficient or predominantly evaporative deficient by further testing often performed by the ophthalmic professional, including tear osmolarity (TearLab) meibography, lipid layer thickness (LipiView [TearScience]), and InflammaDry (Quidel).
  • Clinical signs/no symptoms – You may miss this patient during the work up. The eye-care provider will see much of the dry eye during the routine slit lamp exam.
  • Symptoms/no clinical signs – These challenging patients have seen many providers without relief, mostly because they have a central nervous system disorder causing overactive nerve function resulting in pain.

DED diagnosis

This could be the most important element for ophthalmic technicians/professionals. By collecting information — and in the correct order — you can influence the doctor’s clinical decision making regarding treatment.

TFOS DEWS II provides a series of triaging questions to aid DED diagnosis. Many syndromes masquerade as DED. The answers to these questions allow for easy differentiation:

  • How severe is the eye discomfort?
  • Do you have mouth dryness?
  • How long have your symptoms lasted, and was there any triggering event?
  • Are the symptoms much worse in one eye than the other?
  • Do the eyes itch?
  • Are they swollen or crusty, or has there been any discharge?
  • Do you wear contact lenses?
  • Have you been diagnosed with any general health conditions (including recent respiratory infections)?

In addition, we must assess potential dry eye risk factors. These should be captured during the comprehensive history-taking and should be noted as associated signs and symptoms in the HPI. Risk factors include:

  • Medications. Common medications that contribute to DED include antihistamines, antihypertensives, antipsychotic and anti-depression medications, chemotherapeutic agents, neuroleptics (Parkinson’s), decongestants, and hormone replacement therapy.
  • Systemic disease. Diabetes, thyroid disease, Rheumatoid arthritis, lupus, dermatological conditions (rosacea), and inflammatory bowel diseases like irritable bowel and Crohn’s all are pro-inflammatory systemic diseases that increase a patient’s likelihood for having DED.
  • Social history. Social risk factors include smoking, environment, digital device use, and alcohol consumption.

Due to evidence-based studies, TFOS DEWS II recommends the new five-item Dry Eye Questionnaire (DEQ-5) and Ocular Surface Disease Index (OSDI) questionnaire, which are designed to determine symptoms consistent with DED. Understand how to score the questionnaire and what the score means.

Also, diagnostic tests and the order of the tests is key — some need to be performed on different days. This is a great conversation to have with your staff to determine what tests the providers use for their diagnosis and how best to administer them. TFOS DEWS II recommends one of the following to make a DED diagnosis:

  1. Tear break-up time (TBUT). Preferably done without fluorescein dye, which is more disruptive to the tear film. Non-invasive techniques are recommended. Anything <10 seconds is consistent with dry eye.
  2. Tear osmolarity. The TearLab Osmolarity system is the only commercially available point-of-care test. A reading of >308 mOsm/L or an 8 mOsm/L difference between eyes is considered inclusive for dry eye. Perform this test after the non-invasive TBUT or prior to the fluorescein dye TBUT. If a patient administered drops within two hours of their visit, consider saving the test for another visit and explain to the provider and patient not to administer drops prior to their exam because it will negate the results.
  3. Corneal and conjunctival staining with vital dye. Use both lissamine green and fluorescein.

You play an important role in patient care. Observation and Communication are critical to accurate diagnosis for patient. For example, if during pre-testing it is obvious that the patient is light sensitive or blinking often, this is important to share with the ECP. Also, if artificial tears are needed to improve pre-testing, the ECP should know this. Even subtle findings, such as vision fluctuating on blink during VA check, helps the provider better understand the tear film instability and its impact on the patient’s ocular surface health.

Conclusion

TFOS DEWS II is a complex document that provides the clinician with the tools to best diagnose and treat patients. Understanding how to apply during every patient encounter will improve the early diagnosis for patients and improve their overall quality of life.

Don’t forget the burden DED has on the patient. Reports from Nichols, et al in June 2016 Investigative Ophthalmology & Visual Science show slowed reading rates, decreased work productivity, and lower quality of life. If we take the time to listen, we can have a rewarding impact on a dry eye patient’s life. OP