Purpose: To test the hypothesis that cocaine use (abuse and/or dependency) is associated with open-angle glaucoma.
Methods: A case-control study. Potential case patients were identified from the Veterans Health Administration national clinical database using International Classification of Disease, Version 9, Clinical Modification for open-angle glaucoma for fiscal year 2009. Inclusion criteria included consecutive prescriptions for 1 or more topical antiglaucoma medications. Cocaine exposure was identified through International Classification of Disease, Version 9, Clinical Modification codes. The odds of cocaine exposure were compared with the overall outpatient population of national Veterans Health Administration beneficiaries and adjusted for age and other illicit drug use. A nested case-control study was conducted to examine the confounding influence of race.
Results: Age-adjusted odds ratios of cocaine exposure among patients with glaucoma were statistically significant for both men [3.52 (95% confidence interval, CI: 3.21-3.86)] and women [1.87 (95% CI: 1.79-1.96)], and did not change significantly when analyzed according to drug-dependency status. Subset analysis adjusted for age, other illicit drugs, and race remained significant for men [1.45 (95% CI: 1.27-1.66)], but not women. Persons with substance use disorder and glaucoma were nearly 18 years younger than glaucoma patients without a drug exposure history.
Conclusions: This pilot study suggests the use of cocaine and possibly other illicit drugs are predictive of glaucoma. Should the association of substance use disorder (cocaine or cocaine/poly-drug abuse) and open-angle glaucoma be verified, it represents a potentially modifiable risk factor for vision loss.
*Department of General Internal Medicine and Geriatrics, VA Center of Excellence on Implementing Evidence-based Practice, Regenstrief Institute Inc, Indiana University School of Medicine, Indianapolis, IN
†Departments of Ophthalmology and Pathology, University of South Florida, College of Medicine
‡Section of Ophthalmology, James Haley VA Hospital, Tampa, FL
The views expressed in this study are those of the authors and do not necessarily represent the views of the Department of Veterans Affairs. The investigations were performed according to the guidelines of the Declaration of Helsinki; approval of the Investigational Review Board was obtained.
Disclosure: The authors declare no conflict of interest.
Reprints: Dustin D. French, PhD, Department of General Internal Medicine and Geriatrics, Indiana University School of Medicine, VA Medical Center, HSR&D (11H), 1481 West 10th Street, Indianapolis, IN 46202 (e-mail: Dustin.French2@va.gov or Drddfrench@yahoo.com).
Received January 26, 2010
Accepted August 16, 2010