Dry eye is estimated to affect 25% of those who visit a general ophthalmology clinic. The disorder has a significant effect on quality of life. In this article, one ophthalmologist reviews how to evaluate patients presenting with dry eye complaints and how to manage the condition.
About one in four people who come to a general ophthalmology clinic have dry eye symptoms, she said, adding that the quality of life impairment associated with dry eye is similar to that seen in patients with moderate-to-severe angina.
"A healthy tear film has many important functions because it provides optical clarity, refractive power, comfort, protection, and a trophic environment for the corneal epithelium," said Dr. Akpek, associate professor of ophthalmology and director, ocular surface diseases and dry eye clinic, Wilmer Eye Institute, Johns Hopkins University, Baltimore. "Therefore, it is not surprising that patients with dry eye and a dysfunctional tear film can suffer with significant symptoms, including problems with vision."
"Meibomian gland dysfunction results in excessive tear film evaporation as a result of reduced tear lipid content, and it is an important problem to identify because affected patients may experience severe ocular burning that can make them more miserable than even a patient with Sjögren's syndrome-associated dry eye," she said.
Rule out other causes
During the examination, the ophthalmologist also should rule out other possible contributing causes, including lagophthalmos, floppy eyelid syndrome, medication use, corneal anesthesia, systemic diseases (e.g., Graves' disease, rheumatoid arthritis), and other ocular surface diseases, such as allergic keratoconjunctivitis and contact lens-related allergy in particular.
"The examination also should include a good review of systems and medical history to identify associated dermatologic (e.g., psoriasis, rosacea) and systemic (e.g., thyroid problems, rheumatologic diseases) diseases because they are common in patients with dry eye," Dr. Akpek said.
Although no single accepted method to diagnose dry eye syndrome exists, Dr. Akpek said that, generally, she will evaluate the tear film break-up time (TFBUT) to evaluate tear film stability, do fluorescein and lissamine green staining to assess the health of the corneal and conjunctival epithelium, and perform a Schirmer test to measure tear production.
"Although I like to use rose bengal, it is pretty irritating to the ocular surface, and I have found lissamine green performs as well as a vital stain. The Schirmer test is controversial, but I believe it is helpful for identifying patients who may have underlying rheumatoid arthritis or Sjögren's syndrome," she said.
If an autoimmune disease is suspected, a blood workup also should be undertaken. In a significant proportion of patients with Sjögren's syndrome, however, the anti-Ro (SS-A), anti-La (SS-B), and ANA results will be negative, Dr. Akpek cautioned.
"Don't hesitate to order a minor salivary gland biopsy if your index of suspicion remains," she said.
Dry eye treatment requires replenishment of tears and control of ocular surface inflammation. Artificial tears are the first step in managing dry eye syndrome, but if the patient needs to instill the drops more than four times a day, then a preservative-free formulation is recommended to minimize goblet cell toxicity. Ointment formulations also can be used for lubrication but should be reserved for bedtime use because of their potential to cause blurring.
"Inserts are only rarely recommended because of their associated discomfort," Dr. Akpek said.