Anisometropia: Prevalence, Demographic Associations, Pattern and Physiologic Determinants in a Nigerian Community

Abstract

Anisometropia is the difference in the magnitude of ametropia between the two eyes. This anomaly causes unpleasant ocular symptoms; can alter binocularity; and impair vision. Under-corrected anisometropia and lack of optical considerations in correction is a common cause of spectacle intolerance. This was to determine the prevalence, demographic association pattern and physiologic determinants in Imo State, Nigeria in order to provide a base line data for comparison between countries. Results show that twenty-one percent and 9.4% of study and control groups respectively had anisometropia mostly in the 60-69 age group in both males and females of the population Eighteen percent and 4.3% of study and control groups respectively had presenting vision < 6/18 in the right eye while 15.2% and 5.0% of study and control groups respectively had presenting vision at 6m <6/18 in the left eye. The magnitude of anisometropia less than2.0D(<2.0D)was 89.6% and 96.2% of study and control groups respectively. There was a statistically significant difference between the two groups. Hyperopic anisometropia was more common. The ametropia was higher in the right eye in majority of subjects in the study group and in the left eye for the control group. A higher prevalence was noted among the rural dwellers and the contributory factors were environmental influences, poor nutrition and irrational use of quines as first-line drugs for malaria. Anisometropia is common. The difference in magnitude of anisometropia between the groups was statistically significant. There is need for optical considerations in correction of anisometropia to reduce the burden from spectacle intolerance. To achieve the targets of VISION 2020 we recommend periodic vision screening& appropriate intervention; and visual health education on safe environmental practices especially for people living in low-income resource economies like ours.

Keywords: Anisometropia, Ametropia, Visual impairment, Spectacle intolerance

JOURNAL OF HEALTH AND VISUAL SCIENCES (2013) VOL. 15 (1): 16 - 22