Nonarteritic anterior ischemic optic neuropathy. A case-control study of potential risk factors
D. M. Jacobson, R. A. Vierkant and E. A. Belongia
Department of Neurology, Marshfield Clinic, Wis., USA.
OBJECTIVE: To determine the influence of certain potential risk factors on
the occurrence of nonarteritic anterior ischemic optic neuropathy. DESIGN:
Case-control using 2 independent control groups, one involving a
geographically defined population and the other involving patients who
underwent a routine comprehensive medical evaluation. SETTING:
Multispecialty clinic in a rural setting providing primary, secondary, and
tertiary care for residents of central and northern Wisconsin and the Upper
Peninsula of Michigan. PATIENTS: Fifty-one patients older than 45 years
with first ever acute nonarteritic anterior ischemic optic neuropathy. MAIN
OUTCOME MEASURES: Potential risk factors defined using standardized
definitions abstracted from the medical records, including diabetes,
hypertension, hypercholesterolemia, coronary artery disease, tobacco use,
chronic obstructive pulmonary disease, body mass index, hematocrit, and
white blood cell count. METHODS: Conditional logistic regression analyses,
first using a univariate analysis and then employing a multivariate
analysis using a forward selection process. RESULTS: The geographically
defined case-control multivariate analysis revealed that diabetes (odds
ratio = 2.7, 95% confidence interval = 1.2-6.3, P = .02) and body mass
index (odds ratio = 1.07, 95% confidence interval = 1.00-1.14, P = .08)
were associated with case status. The comprehensive case-control
multivariate analysis revealed that only diabetes (odds ratio = 5.0, 95%
confidence interval = 1.4-17.3, P = .01) was a significant risk factor. The
attributable risk estimation for diabetes was 0.21 and 0.27 for the
geographically defined and comprehensive controls, respectively.
CONCLUSIONS: Diabetes seems to be a major risk factor for the development
of nonarteritic anterior ischemic optic neuropathy. The low attributable
risk estimation suggests that factors other than diabetes are important in
the development of nonarteritic anterior ischemic optic neuropathy or in
predisposing individuals to it.
