A case-control study of the association of sickle cell trait and chronic open-angle glaucoma.

Chronic open-angle glaucoma is reported to be more common in blacks than in whites. The reasons for a higher prevalence of this disease in blacks are unclear. Two recent small case series from clinical practice have been published in which secondary open-angle glaucoma was diagnosed in blacks with sickle cell trait who had experienced either traumatic or nontraumatic hyphema. The association of sickle cell trait and chronic open-angle glaucoma has been tested only in a small case-control study of uncontrolled chronic open-angle glaucoma patients undergoing surgery. No significant association was found. However, the higher prevalence of sickle cell trait in blacks compared with whites raises the question of whether the presence of sickle hemoglobin is a risk factor for chronic open-angle glaucoma in the black population. To test for a possible association between this disease and sickle cell trait, we conducted a case-control study in black ophthalmic patients at the University of Pennsylvania and affiliated hospitals between December 1981 and July 1982. Sickle cell trait, as measured by the sickle cell preparation test, was no more prevalent in patients with chronic open-angle glaucoma than in age- and sex-matched ophthalmic clinic controls. It is unlikely that hemoglobin SA is a risk factor for chronic open-angle glaucoma.