Levobunolol Compared to Dipivefrin in African American Patients with Open Angle Glaucoma

Abstract

ABSTRACT

The prevalence of open angle glaucoma is disproportionately high in the African American population. Information about the effectiveness of anti-glaucoma medications in an exclusively African American population is lacking. We treated both eyes of 38 African American patients who have stable open angle glaucoma with either levobunolol b.i.d. or dipivefrin b.i.d. to evaluate the effectiveness of each drug in lowering intraocular pressure. Patients were treated for six weeks following a two week washout period. We measured intraocular pressure levels after one, three, and six weeks. Each medication produced a statistically significant decrease in intraocular pressure by week one. The mean pre-treatment pressure of 24.4 mmHg in the levobunolol was reduced to 17.0 mmHg by week six. The mean pre-treatment pressure of 25.4 mmHg in the dipivefrin treated group was reduced to 18.2 mmHg by week six. There was not a statistically significant difference in the pre-treatment or the final pressure between the two groups. Both levobunolol and dipivefrin produce a statistically significant decrease in intraocular pressure in African American patients with open angle glaucoma.

Glaucoma is a disproportionately devastating disease in the African American population. Studies in St. Lucia, Barbados, and Baltimore have shown that the prevalence of open angle glaucoma in the West Indian and African American population is between 5 and 12% (1,2,3). This is at least five times as high as the prevalence in the American white population (4). Blindness from glaucoma occurs more frequently and at an earlier age in the African American population (5). Multi-variate analyses of risk factors for glaucoma have indicated that intraocular pressure at initial diagnosis and race have been the two most powerful risk factors for developing eventual visual loss (6).

African Americans have less access to medical care than their white counterparts, and even when care is sought the results of treatment are variable. Responses to surgery, laser, and medical therapy have all been shown to be less favorable in the African American population (7,8,9,10,11). The differential response to medications is not limited to glaucoma or eyedrop medications, but is also seen with systemic hypertension (12). Systemic beta blockers have been found to have greater response in white hypertensive patients than in black hypertensive patients. Beta blockers are the most frequently prescribed anti-glaucoma medications. There have been several studies of beta blocker medications in mixed populations, but the ability of beta blockers to lower intraocular pressure (IOP) in an exclusively African American population has not been looked at as closely. We undertook the present study to determine whether or not two commercially available glaucoma medications, levobunolol (Betagan, Allergan Pharmaceuticals, Inc., Irvine, CA) and dipivefrin (Propine, Allergan Pharmaceuticals, Inc., Irvine, CA), would effectively lower intraocular pressure in an inner city African American population.