Baltimore—Dry eye syndrome is very common—about one quarter of the patients who present to ophthalmology clinics complain of dry eye symptoms. The decrease in the quality of life is comparable to that in patients with severe angina, which underscores the importance of proper diagnosis and management, according to Esen Akpek, MD.
"Healthy tear film is essential for optimal vision, because about 80% of the refractive power of the eye is provided by the anterior surface of the cornea and the pre-corneal tear film, which lubricates the ocular surface and serves as a barrier against environmental insults," Dr. Akpek explained at the Current Concepts in Ophthalmology meeting in Baltimore.
"Altered composition of the mucins, proteins, and lipids in the tear film is characteristic of dry eye syndrome. The balance between the immunosuppressive cytokines and their antagonists is disrupted, the protease activity is increased, and there is an increase in the tear film osmolarity. This all leads to ocular surface damage. The tight junctions between the corneal epithelial cells are disrupted, making the patient more prone to ocular infection as well as substantial decreases in vision," he continued.
Differential diagnosis The differential diagnosis of dry eye syndrome includes any corneal or systemic diseases that can cause dry eye symptoms, such as lagophthalmos, floppy eyelid syndrome, Graves' disease, intake of certain medicines including antihistamines and tricyclic antidepressants, corneal anesthesia from shingles, ocular allergy, etc.
"A quick visual inspection of the patients should be performed to uncover any systemic disease. The patient's hands, face, and skin should be examined." Dr. Akpek provided an example of a patient who presented with a corneal ulcer that would not heal. The patient complained of severe dry eye, dry mouth, and joint pain. A systemic workup led to a diagnosis of Sj�n's syndrome and appropriate treatment that resulted in healing of the corneal ulcer.
"There is no one accepted method to diagnose dry eye syndrome. However, multiple tests can be performed to detect various deficiencies of the ocular tear film. There are various stains available to assess the health of the ocular surface in vivo such as fluorescein staining, rose bengal, and lissamine green staining. The tear film break-up time is a test that measures the time between the blink and the development of a dry spot on the pre-corneal tear film. The Schirmer test measures tear volume using filter paper strips. Impression cytology performed under topical anesthesia provides a good assessment of the ocular surface health, according to Dr. Akpek.
"Treatment of dry eye syndrome is difficult and should be tailored to individual patients based on the severity and the type of the dry eye disease. The first line of therapy is artificial tears, which lubricate and provide temporary symptom relief but do not change the outcome of the disease. The artificial tears are available in different viscosities. One factor for consideration is that the preservatives in the tears can affect the health of the ocular surface. Preservative-free artificial tears are preferred," Dr. Akpek said.
In addition, ointments, which last longer than tears, can be used. Inserts are also available, but these can cause substantial discomfort. Punctual plugs and cauterization are other options, but Dr. Akpek does not recommend their utilization until the ocular surface inflammation is controlled, because the pooling of tear film containing harmful cytokines can cause surface breakdown.