Dry eyes should not be dismissed as a minor inconvenience and something quickly remedied with over-the-counter eye drops. Dry eye disease is actually an impressively complex condition that significantly affects patients' quality of life. In fact, one study found that the self-reported impact of severe dry eye disease was similar to that of dialysis. You can improve your care of patients with this disease by addressing these five common myths.
Myth 1: Dry Eye Disease Is All About Dryness
Dry eye seems to be a straightforward disease—a physical lack of tears resulting in discomfort that is remedied by lubricants. In reality, dry eye disease is a multifactorial condition that follows a self-perpetuating cycle in which hyperosmolarity plays a central role.
Hyperosmolarity may result from increased evaporation (evaporative dry eye), decreased lacrimal section (aqueous-deficient dry eye), or a combination of both. Hyperosmolarity of the tear film triggers a variety of inflammatory reactions that ultimately lead to corneal damage and decreased tear film quality, thus perpetuating the cycle.
The effects of dry eye disease are not limited to the patient's symptoms; there are ocular consequences as well. An unstable tear film that dissipates too fast negatively impacts visual acuity because the tear film has the greatest optical power of any ocular surface. Fluctuating vision that clears with blinking is characteristic of dry eye disease.
Myth 2: A Feeling of Dryness Is Required for Diagnosis
A common misconception is that symptoms of dryness are necessary to diagnose dry eye disease. Certainly, dryness is a frequent complaint, but patients may experience a foreign body sensation, usually bilaterally. Although itching is typically associated with allergic conjunctivitis, it is often present in patients with dry eye disease. Another counterintuitive symptom may be watery eyes. There are two major systems of tear production: basic and reflexive. When the basal rate of tear production is inadequate, the reflexive tears engage, potentially leading to an overproduction of tears and subsequent epiphora. Burning and redness are two other symptoms often associated with dry eye disease. A small amount of discharge may even be present in dry eye disease, although such discharge is typically connected with conjunctivitis.
Why is there so much variation in patient symptomatology? Research seems to indicate corneal sensitivity itself may actually be altered during the disease process of dry eye. How the cornea perceives pain may change, with the cornea becoming less sensitive the longer the cycle of dry eye continues. This phenomenon may help explain the discrepancy between clinical signs and patient-reported symptoms.
Myth 3: The Diagnosis of Dry Eye Disease Is Straightforward
The clinical diagnosis of dry eye disease is far from simple. No one diagnostic test is considered to be all encompassing. Objective tests, with clearly established cutoffs, have been challenging to develop. To further complicate matters, some patients with pronounced clinical signs, including decreased tear breakup time, corneal staining, and increased tear osmolarity, can be entirely asymptomatic. Conversely, some patients may report severe symptoms with minimal to no clinical signs.
Redness, foreign body sensation, and itching could be symptoms of dry eye disease, but they could also be symptoms of conjunctivitis. Dry eye disease must be included in the differential diagnosis for acute red eye because this chronic condition may have acute flare-ups. Conditions such as dry eye disease, blepharitis, or episcleritis that involve inflammation may have similar symptoms because the ocular surface has only a limited repertoire of responses, regardless of the insult.
Medscape Ophthalmology © 2019 WebMD, LLC
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Cite this: 5 Myths About Dry Eye Disease - Medscape - Apr 17, 2019.