The Real Cause and Extent of Evaporative Dry Eye
Eighty-Six percent (86%) of patients with symptoms of Dry Eye have Meibomian Gland Dysfunctions or MGD1. This large pool of patients, currently suffering pain and discomfort, may benefit from an entirely new approach to treatment.
Responding to an unmet need
The very real suffering of patients, who present with dry eye symptoms, has been a continual frustration for physicians and patients for years. With limited tools to treat the cause, often patients experienced mild, short-term, and inconsistent relief.
As research has uncovered the origins of evaporative dry eye, traditional treatment approaches have limitations in efficacy2. By incorporating this new information into treatment protocols, ophthalmic professionals have the opportunity to improve clinical outcomes and patient satisfaction in their practices.
The types of Dry Eye
There are two predominant forms of Dry Eye. Evaporative, due to lipid deficiency, is the most prevalent, affecting 86% of sufferers1.
Evaporative Dry Eye (86% of patients with dry eye symptoms)
Occurs when the aqueous evaporates at a faster rate than normal due to an inadequate protective lipid (oil) layer on the surface of the tear film. This is a manifestation of reduced lipid excretion from the oil-producing meibomian glands found within the eyelids.
Aqueous Deficient Dry Eye
Occurs when tear aqueous generation from the lacrimal gland is insufficient to keep the eyes moist.
The two forms have been difficult to distinguish, since tools to assist physicians in differentiating dry eye etiology have not been available. Instead of determining etiology and initiating effective treatment, physicians have treated patients based on the level of symptom severity.
Using traditional treatment approaches, there has been little physician incentive to depart from this course and identify the lipid deficient etiology.
Difficulty in diagnosis
Dry eye often accompanies other primary ocular ailments. In its moderate-to-severe stages, dry eye is found more commonly in referral-based corneal practices. When dry eye patients present symptoms, many may have already self-medicated with artificial tears, taken medications for some time or stopped wearing contact lenses in an effort to improve them. But they may not have received specific physician directed treatment for dry eye.
Accurate diagnosis is difficult, since common evaporative dry eye symptoms can mimic the same symptoms as those of other ailments. For instance, itching may be due to allergy or dry eye, while both ocular fatigue and contact lens intolerance can have many causes, including dry eye. Compounding this is the fact that dry eye symptoms do not always correlate well with clinical signs. A patient can experience the classic symptoms of dry eye – tiredness, burning, redness, stinging – and yet show no evidence of conjunctival or corneal involvement. In fact, the eye may appear completely normal.
It is also possible for a patient to manifest any or all signs of dry eye, such as corneal or conjunctival staining, or thin tear meniscus, and still report being normal, without any symptoms. This can occur when a patient has lived with evaporative dry eye for an extended period of time and experienced a loss of corneal sensation.
This puzzle is one reason it has been difficult to establish either a universally accepted definition, or a gold standard test, for dry eye. Instead, identification depends on a physician’s ability to evaluate evidence and determine diagnosis, disease severity and treatment – utilizing available tests designed to assess the ocular status and patient history. These tests have known limitations.
Frequently reported symptoms that lead physicians to suspect dry eye include dryness, discomfort, irritation, foreign body sensation, grittiness, pain, tearing, contact lens intolerance, and sensitivity to light. Additional symptoms that are less frequently reported include: ocular fatigue, mucus discharge, transient blurring, and any symptom that worsens as the day passes, or occurs during prolonged computer usage.