Abstract
Abstract: :
Purpose: To examine the effect of posture change on the central corneal refractive power and corneal aberrations. Methods: The Keratron topographer (OPTICON) improved to measure under the supine position was used to measure corneal refractive power and aberrations. Nine healthy volunteers (aged 20–28 years; mean 21.9±2.8) that were free of ocular pathology took part in this study. The first was measured in the sitting and the others immediately, 10, 20 and 30 minutes after the supine position. Results: In central corneal refractive power a significant difference was not found through the experimental procedure. The mean total higher order aberration in the sitting and the posture change were 0.419±0.120 µm and 0.500±0.157µm, respectively (p < 0.05). Corneal aberration showed a statistically significant decrease with time after posture change. After the posture change from the sitting to the supine position, the increase in total higher order aberration may cause slightly change of ocular structure distorted by intraocular pressure or gravitational influence. Conclusions: These results suggest that the increase in higher order aberration from the sitting to the supine position causes limit the improvements in visual performance after customized refractive surgery based on wavefront measurement.
Keywords: optical properties • refraction • topography