Managing Concomitant Eye Disease

November 9, 2007

Glaucoma and dry eye is the number one comorbidity in America's older population, and with this age group making up an ever greater proportion of the entire population not only in the United States but in many other parts of the world, clinicians may need to alter their approach to either disease when both are present.

Glaucoma and dry eye is the number one comorbidity in America's older population. With this age group making up an ever greater proportion of the entire population, not only in theUnited States but in many other parts of the world, clinicians may need to alter their approach toeither disease when both are present.

Both dry eye and glaucoma are associated with increased age, are chronic conditions, and impact theocular surface directly or indirectly. Dry eye syndrome is present in approximately 10% to 12% ofadults, although prevalence estimates vary widely, and occurs in about 15% of persons aged 65 orolder. On the other hand, the prevalence of glaucoma is generally considered to be less than 5%.While no published data exist on the prevalence of comorbid glaucoma and dry eye, one clinician foundthat at her clinic, 10% of patients with dry eye also had glaucoma. Esen K. Akpek, MD, associateprofessor of ophthalmology at the Wilmer Eye Institute, reviewed the records of 220 patients withaqueous tear deficiency over a 2-year period and found that 20 of 191 individuals over age 40 alsohad glaucoma.

The demographic changes in store in the next several decades will have a significant impact on bothdiseases and their combined effect, but lifestyle changes will also influence prevalence, Dr. Akpeksaid. Computer use, contact lens wear, and the popularity of refractive surgery among aging babyboomers will contribute to the development of conditions affecting the ocular surface, while theheightened awareness and expectations for high-quality vision in this group are likely to send moreof them to the ophthalmologist's office to seek treatment.

However, addressing the growing challenge of dry eye and comorbidity can be complicated, Dr. Apkeksaid. "In order for us to be able to study the epidemiology of a disease, we need to have a consensuson the definition of the disease. This is particularly challenging in the case of the dry eyecondition because there is no single diagnostic test, and more importantly there is a lack ofcorrelation between clinical tests and patient signs and symptoms."

Dr. Akpek was one of a panel of clinicians who discussed management of concomitant eye diseasesduring a continuing education symposium held at the Sheraton New Orleans Hotel Friday evening.When older patients come for an appointment for any reason, clinicians should always consider thepossibility that glaucoma is present and should perform structure and function tests, said Ronald L.Gross, MD, professor of ophthalmology and Clifton R. McMichael chair in ophthalmology, Cullen EyeInstitute, Baylor College of Medicine, Houston. But they should also consider the likelihood of dryeye in this same patient population, Dr. Gross continued. He advised clinicians to listen closely topatients' descriptions of their symptoms, look for clinical signs, and ask about tear use and othercommon indicators of dry eye.

When both conditions are present, the treatment approach should be to minimize the impact of glaucomatherapy on the ocular surface and ensure adequate dry eye therapy, Dr. Gross recommended.A Delphi panel made up of experts from around the world has released recommendations forclassification and treatment of dry eye and also suggested that it be called dysfunctional tearsyndrome (DTS) as a means of emphasizing the complexity of the condition, said Peter J. McDonnell,MD, William Holland Wilmer professor of ophthalmology and chairman, department of ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore.

The challenges the panel addressed included how to grade disease severity and how to factor in liddisease, tear deficiency, and other factors. The panel recommended that DTS be stratified by thepresence or absence of lid disease, that there be four severity levels for DTS without lid margindisease with corresponding treatment strategies, and that inflammation should be controlled beforeproceeding to punctual occlusion.

These recommendations should be useful as ophthalmologists face the coming increase in patients withDTS and glaucoma. "Even as ophthalmologists we occasionally have to think in terms of holisticmedicine and treating the patient as a whole, and this coexistence of dry eye and glaucoma is oneexample of where we need to focus on multiple factors," Dr. McDonnell said.Following on the work of the Delphi panel, another group also recently released evidence-based dryeye treatment recommendations. The Dry Eye WorkShop (DEWS2) considered dry eye as a summation of oneor more tear deficiencies and proposed a severity-based treatment algorithm based on the Delphipanel's conclusions, said Stephen C. Pflugfelder, MD, professor, James and Margaret Elkins chair inophthalmology, Baylor College of Medicine, Houston.

He added that dry eye in glaucoma patients can be exacerbated by chronic glaucoma eyedrop use, andglaucoma surgeries can alter tear distribution. For example, a bleb or shunt may result in poor tearspread. Management strategies may include limiting benzalkonium chloride exposure, considering oralcarbonic anhydrase inhibitors for short-term control of elevated IOP, and followingthe severity-based treatment recommendations for dry eye.

It is also critical to minimize the number of medications used in glaucoma patients with dry eye byselecting the most effective medication to achieve the target pressure, said Steven T. Simmons, MD,associate clinical professor of ophthalmology at Albany Medical Center, Albany, NY, and a clinicianin private practice. But besides efficacy, tolerability, safety and compliance are critical."Glaucoma is a team sport, and you have to work even harder with these patients who have dry eye tosucceed in your goals," Dr. Simmons said.

Surgical therapy may be necessary in some patients with glaucoma and dry eye. Laser trabeculoplastycan be very helpful, but it is important to properly prepare patients for surgery by startingcyclosporine therapy at least three months prior to the procedure and controlling blepharitis.Clinicians should not undertreat either glaucoma or dry eye but must strive to limit tolerabilityissues with both medical and surgical therapy in order to improve treatment outcomes, Dr. Simmonsadded.

This continuing medical education activity was jointly sponsored by the New York Eye and EarInfirmary and cme², a wholly owned subsidiary of Advanstar Communications Inc., publisher ofOphthalmology Times, and was supported through an unrestricted educational grant fromAllergan.