Understanding Pre-Disposing Factors for Dry Eye Disease
By: Paul M. Karpecki, OD, FAAO
Director of Education – PECAA
One of the keys to the diagnosis of dry eye disease is to know the predisposing factors for it. This is one of the most important steps in developing a successful ocular surface disease protocol. There are a number of reasons why this is critical to making a diagnosis and that begins with the fact that if you based your decision on treating dry eye disease solely on symptoms, research shows you would only be correct about 60% of the time. For this reason, predisposing factors combined with key findings become paramount to a proper diagnosis and thus eventual treatment.
Signs do not equal Symptoms.
In most conditions we face as optometrists, symptoms are paramount. For example the key to success in managing allergic conjunctivitis is a patient who returns or responds to treatment with the absence of itching, redness and swelling. But in dry eye disease many of the patients with symptoms of dryness, grittiness, burning or stinging may not actually have dry eyes. A treatment that targets dry eye would likely not alleviate symptoms. The result would be a patient having to return with the same symptoms, often more frustrated than the first examination. They may even seek out another doctor. For example, a patient with dryness, fluctuating vision, gritty, burning eyes -especially late in the day or while on a computer, may actually have convergence insufficiency, vertical disparity or other eye alignment issues. This patient would receive a much greater response from visual training and/or prism in their spectacles than dry eye therapy. Other non-dry eye disease causes of similar symptoms include anterior blepharitis, contact lens solution issues such as corneal infiltrates, mild allergic conjunctivitis, map dot fingerprint dystrophy, recurrent corneal erosion, pingueculitis, giant papillary conjunctivitis, Salzmann’s nodular degeneration, conjunctivochalasis and many others. In some circumstances you may get mild resolution of the symptoms with dry eye therapies but in many cases, it will never fully treat the disease.
At the other end of the spectrum, some of the worse cases of dry eye disease will present with little to no symptoms. The patient with severe dry eye that has resulted in no symptoms (other than perhaps blurred vision from the advanced ocular surface disease findings) is often due to a neurotrophic cornea. These include patients with Sjogrens’ Syndrome, diabetes and severe dry eye, post viral infections, herpes zoster, post chemotherapy or radiation treatment and even long-standing disease. Unfortunately many are overlooked, frustrated and seeking doctors who understand ocular surface disease management. A recent Harris Interactive study showed that only 29% of patients with dry eye disease felt their optometrist provided adequate care and knowledge of their disease.
It was once said that a proper diagnosis is the most important step to treatment. So if symptoms are not reliable, how might we make the proper diagnosis?
One key is to look at advanced testing like osmolarity, meibography, meibomian gland expression, blink analysis etc. But many doctors just starting out may not have access to these technologies and so another very important determinant is to look at the number of predisposing factors a patient may have. This in itself may not be 100% accurate to a true dry eye disease diagnosis but when combined with the testing mentioned above often helps confirm the disease. So it is worth knowing the predisposing or contributing factors.
Key predisposing factors include:
• Female gender
• Hormone replacement therapy
• Systemic antihistamine use
• Lack of healthy essential fatty acid intake (e.g. omega-3 fatty acids)
• Connective tissue disorders
• Refractive surgery
• Androgen deficiency
• Contact lens use
• Certain medications including certain antidepressants, diuretics, beta-blockers, isotretinoin
• Low humidity environments
• Cigarette smoking
A patient with a significant number of these predisposing factors may point the clinician to having a heightened suspicion for dry eye disease. Then implementing and understanding dry eye diagnostics can point to the cause and true diagnosis. As one example, I recall using osmolarity testing when it was first approved and had a series of patients with consistently normal osmolarity measurements. I’d look at the patient and ask them about their symptoms and they described their eyes as dry, gritty, burning with fluctuating vision that worsened late in the day and especially while reading or spending significant time on a computer. An expert in the field of binocular vision and eye alignment enlightened me and actually visited my clinic to help with these patients. He discovered that 9 of 10 patients that day had eye alignment issues and he was able to resolve all of their symptoms with appropriate binocular vision management. I had a whole new respect for the accuracy of these advanced testing options like TearLab osmolarity and a humbling experience to what I thought was my advanced clinical knowledge in the field of dry eye disease. Since that time I’ve uncovered many other insights that have changed how we run the ocular surface disease clinic to achieving highly successful outcomes in some of the most advanced OSD referrals.
Dry eye is one of the most complex conditions to manage. By understanding the predisposing factors, realizing that signs and symptoms may not align, and learning about new diagnostic technologies will aid clinicians to make the right diagnosis. From there an appropriate treatment is much more likely, resulting in successfully managed ocular surface disease patients.