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Dry Eye Disease in Ocular Surgery
BY GEORGE M. SALIB, M.D., M.S.

Dry eye disease and its symptoms are among the most common reasons patients seek an ophthalmologist, and it is said to affect between 4.3 and 9.1 million people in the United States alone.1-3 This figure is probably grossly underestimated, as the number of patients coming in complaining of sandy, burning or watery eyes on a daily basis is staggering. This widely prevalent disease has an enormous impact on the quality of life of people who suffer from it, prohibiting them from enjoying such pleasures as reading, watching a movie or enjoying an air-conditioned room.

Predisposing factors include: increasing age, hormonal factors (such as in post-menopausal women), allergy, desiccating or windy environments, medications (e.g., anthistamines, antihypertensives, antidepressants), ocular surgery, preservatives in topical medications and autoimmune disorders.

Presented below is a case involving a prominent factor that can lead to dry eye: LASIK.

Case History

A 34-year-old male with myopic astigmatism presented at the clinic interested in having refractive surgery. He was an athletic man who participated in triathlons, so wearing glasses or contact lenses was impractical. Additionally, he was not able to tolerate his contact lenses for any extended period of time, as they would feel dry and irritating after a while. His examination revealed mild to moderate dry eye disease with Schirmer scores of 7 mm and 8 mm/5 minutes. He had mild corneal staining but otherwise had a normal exam.

In order to optimize his ocular surface prior to having LASIK, the patient was placed on cyclosporine (Restasis, Allergan) b.i.d. and Refresh tears (Allergan) q.i.d. and asked to return in 1 month. He was also asked not to wear his soft contact lenses. His Schirmer scores were repeated on his return visit and were found to be 14 mm and
12 mm/5 minutes. He had rare corneal staining in either eye and he reported his eyes feeling less dry.

He then underwent successful bilateral LASIK. He was placed on antibiotic and steroid drops q.i.d. and was asked to use carboxymethylcellulose (Refresh Plus, Allergan) tears every hour immediately postop. He also resumed his use of topical cyclosporine on the third postop day and continued for 3 months. He had an excellent postop course, with his uncorrected visual acuity equal to 20/20 and 20/15 for his right and left eyes, respectively. He also had only minimal corneal staining during his first postop week, which progressively improved thereafter. Furthermore, he was able to resume his athletic pursuits unencumbered by the use of glasses or contact lenses.

Discussion of Patient

Dry eye disease (keratoconjunctivitis sicca) is a disorder of the preocular tear film that results in damage to the ocular surface.1,4,5 Most busy practitioners will often overlook the fact that the ocular surface is truly being damaged. This is a situation that in many cases needs more than the quick fix that artificial tears provide.

In this case, the patient achieved excellent postop refractive results despite being a less-than-ideal candidate for LASIK, given his dry eye disease. A study that we recently published with Marguerite McDonald, M.D., examined the effect of topical cyclosporine vs. unpreserved artificial tears in patients who were undergoing LASIK.6

Forty-two eyes of 21 patients were divided into one of these two treatment groups randomly, although both groups were allowed to supplement their drop usage with tears as needed. They had an extensive preop workup for dry eyes and for LASIK and were started on their study drug
1 month prior to surgery. They then had their baseline studies repeated and underwent LASIK.

The study drug was stopped for 48 hours after surgery to allow time for the corneal flaps to heal, and then it was resumed for 3 months postop. It was shown that the mean refractive spherical equivalent in eyes treated with topical cyclosporine was significantly closer to the intended target at 3 and 6 months after LASIK, than in eyes treated with artificial tears alone. This study also showed that a greater percentage of cyclosporine-treated eyes were within ±0.5 D of the refractive target 3 months after surgery than the artificial tears group. Both the artificial tears and topical cyclosporine groups had significant increases in their Schirmer wetting scores, but the topical cyclosporine group had increases at a majority of tested time periods, while the artificial tear group was statistically significant at only one tested time period.

For patients with dry eyes who are interested in refractive surgery, it would be best to proactively optimize their ocular surface prior to undergoing surgery. For mild to moderate dry eye patients, I recommend starting the patients on artificial tears as well as topical cyclosporine a full month preop and then continuing for at least 3 months postop. For moderate to severe dry eye patients, one may want to start this therapy 3 months preop and continue for 6 months postop.

In advising patients, one needs to emphasize the chronic nature of dry eye disease and that the process of undoing the damage and increasing tear production might take a few months. Despite this, 71% of patients experienced the effects of topical cyclosporine within 3 weeks of beginning treatment.7

We have come a long way in terms of the treatment of dry eye disease. Once, our only option was to lubricate the eyes palliatively with artificial tears. Now we have the option to help restore the eye back to a healthier state and help dry eye sufferers produce their own tears again, effectively dealing a strong blow to one of the most common presenting complaints in today's ophthalmology practice.

George Salib, M.D., M.S., is a corneal, external disease and refractive surgery specialist in private practice in Los Angeles, Calif.

References

1. Foulks GN. Dry eye—part I—understanding the epidemiology and pathogenesis. Highlights Ophthalmol. 2003;31:20-26.

2. Schaumberg DA, Sullivan DA, Buring JE, Dana MR. Prevalence of dry eye syndrome among US women. Am J Ophthalmol. 2003;136:318-326.

3. Schein OD, Munoz B, Tielsch JM, Bandeen-Roche K, West S. Prevalence of dry eye among the elderly. Am J Ophthalmol. 1997;124:723-728.

4. Pflugfelder SC. Antiinflammatory therapy for dry eye. Am J Ophthalmol. 2004;137:337-342.

5. Stern ME, Beuerman RW, Fox RI, Gao J, Mircheff AK, Pflugfelder SC. The pathology of dry eye: the interaction between the ocular surface and lacrimal glands. Cornea. 1998;17:584-589.

6. Salib GM, McDonald MB, Smolek M. Safety and efficacy of cyclosporine 0.05% drops versus unpreserved artificial tears in dry-eye patients having laser in situ keratomileusis. J Cataract Refract Surg. 2006;32:772-778.

7. Infomedics, Inc. RESTASIS Experience Program REP Survey Results. July 31, 2004.