Abstract
Purpose: :
Astigmatism is a commonly encountered refractive error. Theories suggesting the development of astigmatism include genetics, visual feedback, and environmental or mechanical forces such as eyelid pressure, eye rubbing, and extraocular muscle tension. However, the etiology of astigmatism remains unknown. To date, there have been no studies to determine if sleeping position has any correlation with astigmatism development. Our study aims to examine the mechanical forces applied to the globe by various sleeping positions and the development of astigmatism.
Methods: :
Patients presenting to the Joint Warfighter Refractive Surgery Center for their preoperative evaluation were surveyed regarding their sleeping habits. The amount and axis of cylinder from the preoperative manifest refraction was compared among six groups which were divided according to sleeping position. A total of 109 patients returned surveys.
Results: :
The mean cylinder power for each group was compared using a one-way ANOVA test. There was no statistically significant difference among the means of any of the groups. The mean cylinder axis was also compared among the groups and did not show any statistical difference.
Keywords: astigmatism • topography • clinical (human) or epidemiologic studies: risk factor assessment