dry eye dx and tx
Systemic Medications for Severe Inflammatory Dry Eye
In the past decade, the introduction of anti-inflammatory drops, gel-forming tear substitutes, new punctal plug designs and a new appreciation for the importance of omega-3 essential fatty acideour ability to effectively treat ocular surface disease acids has enhanced our ability to effectively treat ocular surface disease. There's never been a time when we've had so many options for patient care.
But there are times when we need more than drops. In cases of severe inflammatory dry eye, it may benefit patients to add an oral medication.
When Drops Aren't Enough
Sj�gren's syndrome is characterized by dry eye and xerostomia (dry mouth). Findings that confirm the diagnosis include lymphocytic infiltration, apoptosis, alteration of neurogenic control of secretory function and clinical dryness. Laboratory findings that demonstrate an autoimmune process include the presence of a positive autoantibody to SS-A antigen or a confirmatory lip biopsy.
Sj�gren's may present as an isolated finding, but it's often associated with systemic autoimmune diseases such as systemic lupus, rheumatoid arthritis and polymiositis. All of these features confirm the inflammatory nature of this disease.
The impairment of neural control may result from the production of autoantibodies that interfere with muscarinic type 3 acetylcholine receptors. Secretory dysfunction in Sj�gren's syndrome may occur in the absence of glandular destruction.
Practitioners have used oral pilocarpine (Salagen) to treat severe dry eye for years. It's available in 5mg and 7.5mg tablets taken every eight hours. Papas et al (2004) conducted an 11-center, 256-patient, placebo-controlled study to evaluate the safety and efficacy of oral pilocarpine (20mg to 30mg daily) for relief of Sj�gren's-related dry mouth and dry eye. At 12 weeks the pilocarpine group demonstrated statistically significant improvement in global assessment of dry eye relief in six of eight related symptoms.
Aragona et al (2006) evaluated the effect of oral pilocarpine therapy on the conjunctival epithelium of patients who had Sj�gren's syndrome over a period of two months. They noted a statistically significant reduction of burning, foreign body sensation and ocular dryness over time. Goblet cell density increased 850 percent over a two-month period. Increase in tear volume was not statistically significant. They concluded that oral pilocarpine improved signs and symptoms, but these changes were independent of tear secretion.
Cevimeline hydrochloride (Evoxac) is a muscarinic receptor agonist that has recently gained popularity in treating Sj�gren's syndrome. In a multicenter study, Petrone et al (2002) found that Sj�gren's syndrome patients who took three 30mg doses of Evoxac experienced substantial improvement in the rate of saliva production and tear flow when compared to placebo. A 15mg dose afforded less improvement than the 30mg dose. The number of adverse events in patients receiving the active drug didn't differ significantly from those in the placebo group.
Educate about Side Effects
The more common side effects of cevimeline and pilocarpine include increased sweating, urinary frequency, flushing, diarrhea and chills. Avoid prescribing these mediations in patients who are taking anticholinergic medications as they will essentially negate each other. One other side effect you should know about is�tearing.
Dr. Townsend practices in Canyon, Texas and is an adjunct faculty member at UHCO. E-mail him at email@example.com.
For references, please visit www.clspectrum.com/references.asp and click on document #138.