SURVEY OF OPHTHALMOLOGY VOLUME 48 • NUMBER 3 • MAY–JUNE 2003 MAJOR REVIEW Primary Open-Angle Glaucoma in Blacks: A Review Lyne Racette, MA, 1 M. Roy Wilson, MD, 2 Linda M. Zangwill, PhD, 1 Robert N. Weinreb, MD, 1 and Pamela A. Sample, PhD 1 1 Glaucoma Center and Visual Function Laboratory, Department of Ophthalmology, University of California at San Diego, La Jolla, California; and 2 Department of Ophthalmology, Creighton University, Omaha, Nebraska, USA Abstract. Glaucoma is one of the leading causes of blindness worldwide. Primary open-angle glaucoma (POAG) is the most prevalent form of glaucoma and has a particularly devastating impact in blacks. In the black American population, POAG prevalence is estimated to be six times as high in certain age groups compared to whites. POAG is more likely to result in irreversible blindness, appears approximately 10 years earlier and progresses more rapidly in blacks than in whites. Racial differences in optic disk parameters have been reported and show that blacks have larger optic disks than whites. This finding is robust and may account for the reported differences in other optic disk parameters. The existence of racial differences in intraocular pressure remains to be demonstrated, as conflicting findings are reported in the literature. Intraocular pressure may actually be underestimated in blacks, perhaps because they have thinner corneas. The prevalence of diabetes and hypertension is higher in blacks than in whites, and although no causal relationship has been established between POAG and each of these systemic diseases, some reports suggest that they often occur together, perhaps through an indirect relationship with intraocular pressure. Compounding the problem, there is evidence that blacks are less responsive to both drug and surgical treatment for POAG. Finally, they often have reduced accessibility to treatment and are less aware of the risks of having POAG. This article provides a comprehensive review of the current knowledge pertaining to POAG in blacks. (Surv Ophthalmol 48:295–313, 2003.  2003 by Elsevier Inc. All rights reserved.) Key words. blacks • intraocular pressure • primary open-angle glaucoma (POAG) • race I. Introduction Glaucoma is one of the leading causes of blind- ness worldwide. 20,30,48,107,124,125,129,134,160,169,170,194,200 Although the number of people affected by the pri- mary glaucomas varies in different reports, it is es- timated that approximately 66.8 million people are affected worldwide. 134 One of the most prevalent forms is primary open-angle glaucoma (POAG), with approximately 33.1 million sufferers around the world. 59,134 In the United States alone, it is estimated that 2.47 million people are affected by POAG, 130,450 of whom have become bilaterally blind. 142 POAG has a serious impact on the quality of life of 295  2003 by Elsevier Inc. 0039-6257/03/$–see front matter All rights reserved. doi:10.1016/S0039-6257(03)00028-6 a large number of people both in the United States and worldwide. 4 Blacks in many areas of the world are dispropor- tionately affected by POAG. Large population-based studies such as the Barbados Eye Study showed that 1 in 11 Afro-Caribbeans over the age of 50 years, and 1 in 6 over the age of 70 years had open-angle glaucoma. 100 Another population-based study was conducted in St. Lucia (West Indies), an island com- posed of a relatively homogeneous black population. Higher prevalence estimates of POAG in blacks 30 years of age and older were reported in St. Lucia, compared to the prevalence estimates reported for