Author reply

Abstract

We are pleased to respond to the question from Drs. Sommer and Tielsch regarding the Barbados Family Study,1Leske M.C. Nemesure B. He Q. et al.Patterns of open-angle glaucoma in the Barbados Family Study.Ophthalmology. 2001; 108: 1015-1022Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar which is similar to their earlier query after another publication.2Sommer A. Tielsch J.M. Risk factors for open-angle glaucoma the Barbados Eye Study.Arch Ophthalmol. 1996; 114 ([letter]): 235Crossref PubMed Scopus (19) Google Scholar, 3Leske M.C. Connell A.M.S. Wu S.Y. et al.Risk factors for open-angle glaucoma. The Barbados Eye Study.Arch Ophthalmol. 1995; 113: 918-924Crossref PubMed Scopus (564) Google Scholar In essence, they ask if our data confirm their hypothesis of a biphasic relationship between hypertension and open-angle glaucoma (OAG). This hypothesis was based on age-specific odds ratios in the Baltimore Eye Study which, although not statistically significant, suggested a possible deleterious relationship between elevated blood pressure and OAG mainly in persons 80 years of age or older.4Tielsch J.M. Katz J. Sommer A. et al.Hypertension, perfusion pressure, and primary open-angle glaucoma. A population-based assessment.Arch Ophthalmol. 1995; 113: 216-221Crossref PubMed Scopus (562) Google Scholar Although these odds ratios were race-adjusted, other relevant (and unaccounted for) variables could have influenced the results, thus leading to difficulties in interpretation. The population-based Barbados Eye Study did not confirm the hypothesized relationships with hypertension, although it included a larger number of cases.3Leske M.C. Connell A.M.S. Wu S.Y. et al.Risk factors for open-angle glaucoma. The Barbados Eye Study.Arch Ophthalmol. 1995; 113: 918-924Crossref PubMed Scopus (564) Google Scholar, 5Leske M.C. Wu S.Y. Risk factors for open-angle glaucoma the Barbados Eye Study.Arch Ophthalmol. 1996; 114 ([letter]): 235Crossref Scopus (1) Google Scholar Similarly, no age trends were observed in the longitudinal data from the Barbados Incidence Study.6Leske M.C. Wu S.Y. Nemesure B. et al.Incident open-angle glaucoma and blood pressure.Arch Ophthalmol. 2002; (in press)Google Scholar Our current family study,1Leske M.C. Nemesure B. He Q. et al.Patterns of open-angle glaucoma in the Barbados Family Study.Ophthalmology. 2001; 108: 1015-1022Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar although not population based, again showed no consistent patterns by age. The letter also mentions our perfusion pressure results. In 1983, we reported the association of OAG with low intraocular pressure and blood pressure relationships in the Framingham Study,7Leske M.C. Podgor M.J. Intraocular pressure, cardiovascular risk variables, and visual field defects.Am J Epidemiol. 1983; 18: 280-287Google Scholar a finding corroborated in our subsequent studies in Barbados, West Indies, and Long Island, New York,1Leske M.C. Nemesure B. He Q. et al.Patterns of open-angle glaucoma in the Barbados Family Study.Ophthalmology. 2001; 108: 1015-1022Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar, 3Leske M.C. Connell A.M.S. Wu S.Y. et al.Risk factors for open-angle glaucoma. The Barbados Eye Study.Arch Ophthalmol. 1995; 113: 918-924Crossref PubMed Scopus (564) Google Scholar, 6Leske M.C. Wu S.Y. Nemesure B. et al.Incident open-angle glaucoma and blood pressure.Arch Ophthalmol. 2002; (in press)Google Scholar, 8Leske M.C. Warheit-Roberts L. Wu S.Y. et al.Open-angle glaucoma and ocular hypertension. The Long Island Glaucoma Case-control Study.Ophthalmol Epidemiol. 1996; 3: 85-96Crossref PubMed Scopus (65) Google Scholar as well as in the Baltimore study.4Tielsch J.M. Katz J. Sommer A. et al.Hypertension, perfusion pressure, and primary open-angle glaucoma. A population-based assessment.Arch Ophthalmol. 1995; 113: 216-221Crossref PubMed Scopus (562) Google Scholar Associations with low perfusion pressure need careful interpretation, because they could be affected by low blood pressure, high intraocular pressure, or related treatment. Further data and discussion of these issues appear in our publication, “Incident Open-Angle Glaucoma And Blood Pressure,6Leske M.C. Wu S.Y. Nemesure B. et al.Incident open-angle glaucoma and blood pressure.Arch Ophthalmol. 2002; (in press)Google Scholar” in which persons with systemic hypertension at baseline had half the relative risk of OAG as nonhypertensive subjects. We hope that this article will also be of interest to our colleagues. We thank Drs. Sommer and Tielsch for their thoughtful comments and their continued consideration of our work.