Abstract
Abstract: :
Purpose:Because the shape of crystalline lens changes in response to accommodation, ocular higher-order aberrations are considered to vary concomitantly. To investigate the effect of accommodation on higher-order aberrations in the whole eye, we measured wavefront aberration with accommodation sequentially. Methods:Seven normal eyes were measured. Wavefront aberrations were measured 4 frames per second during a trial with a Hartmann-Shack wavefront aberrometer (Wavefront Analyzer, Topcon). One trial took seven seconds. At first, a fixation target was located at the far point of each subject for one second. Then the target quickly moved toward the subject with three diopters and stayed at the place during the rest of the trial. Wavefront aberrations up to sixth order were analyzed in 4 mm and 6 mm circle in the center of the pupil. Temporary changes of spherical power, astigmatism, spherical aberration, and coma were analyzed. Results:For all eyes, the sign of the coefficient of the fourth order spherical aberration varied toward minus direction (wavefront delays in the center) in both 4 mm and 6 mm pupil. Temporary changes of the spherical aberration in 6 mm pupil were well correlated with that of spherical power (r=0.57, p<0.01), while those in 4 mm pupil moderately correlated (r=0.36, p<0.01). Other aberrations and the total higher-order aberration didn't change. Conclusion:It was confirmed that spherical aberration changed concomitantly with the change of spherical power during accommodation. We speculate that accommodation introduces the change of lens shape to increase the power of the lens especially in the central pupillary area.
Keywords: 500 optical properties • 542 refraction • 304 accommodation