Don’t be Fooled by Dry Eye’s Many Imitators: Part 2
Last month, we talked about the numerous conditions that can mimic dry eye, and in so doing, often escape diagnosis. Many of these conditions have similar symptoms and may even overlap with simultaneous dry eye, which contributes to the difficulty in detecting them. But while some are relatively rare, many are common, and there is a good chance that more than one of these conditions eventually will walk into your Dry Eye Center of Excellence.
In addition to recurrent corneal erosions, mucus fishing syndrome, and exposure keratitis due to nocturnal lagophthalmos, which were described last month, other dry eye imposters include:
Giant Papillary Conjunctivitis (GPC). This condition is relatively common, and very often associated with contact lens wear and with prosthetic wear. Consequently, any patient who presents with dry eye symptoms and wears contact lenses should be evaluated for GPC. And, don’t let a definitive dry eye diagnosis fool you: many patients with GPC may also have dry eye. The patient may complain of red, itchy, swollen eyes, light sensitivity, discharge, and vision disruptions. Those who have examined their own palpebral conjunctivae may even complain of large bumps on the inside of the eyelids. The patient may say that when putting in a fresh pair of contact lenses, they experience an “ahhh!” moment. Often, though not always, there is a history of improper contact lens use, such as wearing daily contacts overnight, or wearing them past their expiration date. For example, wearing two-week disposable lenses for three weeks or longer.
Treatment: Instruct the patient to dispose of their contact lenses earlier than the manufacturer’s recommendation. A two-week disposable lens should be disposed of at seven to 10 days. Ideally, especially for more severe cases, it may be advisable to switch the patient to daily disposables. Dual action anti-allergy eye drops (with antihistamine and mast-cell stabilizing properties) should be used twice a day. Patients should be advised to wait five minutes after instilling the drop in the morning to insert contact lenses, but they can instill the second drop after the contacts are removed at night, without waiting. In addition, patients should be counseled about proper care and use of disposable lenses. In the most severe cases, it may be advisable to transition patients from daily disposables to gas permeable lenses.
Floppy Eyelid Syndrome (FES). This often-under-diagnosed condition is found most often in middle aged males who are overweight and has been associated with sleep apnea. FES is characterized by chronic inflammation to the cornea and conjunctiva. A simple diagnostic technique is a test for excessively easy eversion, particularly with increased horizontal laxity and redundancy of the lid. Patients with FES typically report symptoms including burning, stinging, and irritation, and they may describe a feeling that the eyelid is extremely elastic, or report spontaneous eyelid eversion, particularly during sleep. Another common manifestation is chronic conjunctivitis that does not respond well to topical or steroid treatment.
Treatment: Ocular lubrication and temporary antihistamines can provide relief, and an eye shield worn while sleeping may help prevent spontaneous eversion. However, as the condition advances, eyelid tightening surgery may become necessary.
Salzmann's Nodular Degeneration (SND). Patients with this uncommon, progressive, degenerative condition often report symptoms much like those of dry eye, including a feeling of foreign bodies in the eye, occasional blurred vision, and grittiness. The condition is characterized by the formation–usually in both eyes–of gray-white to bluish nodules measuring 1 to 3 millimeters anterior to Bowman’s layer of the cornea. If often co-exists with Meibomian gland disease, which is thought to be a causative factor. Complicating efforts to differentiate it from dry eye, SND patient demographics also are very similar: Caucasian women account for up to 90 percent of all cases, and symptoms typically begin in the mid- to late-50s. Diagnosis can often be made with a slit lamp exam, which reveals the nodules.
Treatment: Artificial tears, particularly those with greater viscosity and longer retention time, can help alleviate mild symptoms. Treatment for the Meibomian gland disease is helpful in preventing the nodules from continuing to form and/or enlarge. For patients whose symptoms are more advanced, such as a chronic foreign body sensation, topical corticosteroids and non-steroidal anti-inflammatory drugs may provide relief. However, in some cases of advanced disease, in which nodules cause visual disturbances or discomfort by altering the tear film, surgery may be necessary to remove the nodules.
Conjunctivochalasis. In our practice, conjunctivochalasis patients often are referred to us as dry eye patients with advanced disease. In patients with this relatively common condition, the Tenon’s fascia has loosened or may even be missing, and the conjunctiva folds in on itself. One of the most prevalent symptoms is a foreign-body sensation, and patients often are able to describe exactly where the feeling or their pain originates. The condition occurs most often in patients over age 50, and those with a history of dry eye, previous eye surgery, or a history of conjunctival chemosis such those that occur with repeated attacks of allergic conjunctivitis. There also is evidence of a correlation between conjunctiveochalasis and autoimmune thyroid disease.
Treatment: Corticosteroids may be effective in many patients. In some, however, surgery to remove the loose or redundant conjunctiva will be necessary. Some surgeons use amniotic membrane tissue over the open area to accelerate healing, while others simply remove an ellipse or crescent of the excessive conjunctiva and close with bipolar cautery or dissolvable sutures.
Allergic Conjunctivitis. This most common of eye complaints is a condition in which reaction to airborne allergens such as pollen or mold causes inflammation of the conjunctiva and cornea. Typically, it occurs in patients known to have hay fever or a history of allergic reactions. Symptoms include burning, itching, redness, and watery eyes. Diagnosis often can be made through observation. Scraping of the conjunctival tissue, which reveals the presence of eosinophils, indicating allergic reaction, is another option.
Treatment: For minor cases, encouraging the patient to reduce exposure to allergens by keeping windows closed while sleeping and driving, or keeping household dust to a minimum with air purifiers, can ease symptoms. Over-the-counter antihistamine drops may also provide temporary relief. For more advanced or bothersome cases, prescription drops (see those listed above under GPC), including short courses of topical steroids, usually help. The more bothersome cases should have airborne allergen skin testing, which is now commonly performed in ophthalmology practices. Very severely affected patients may have to change clothes, shower and wash their hair when entering the home.
Marguerite McDonald, MD, FACS, with OCLI on Long Island, NY, is clinical professor of Ophthalmology at NYU Langone Medical Center, NY, and clinical professor of Ophthalmology at Tulane University Health Sciences Center, New Orleans, Louisiana.