Abstract
Purpose: :
To comparatively analyze the repeatability and accuracy of different methods in measuring corneal refraction and astigmatism in order to precisely determine the target of toric intraocular lens.
Methods: :
The medical records of Two hundred fifty-four eyes of 194 persons were retrospectively reviewed to compare corneal refraction, degree of astigmatism, and steep axis of astigmatism measured with autorefraction, IOL Master, and topography. The repeatability coefficiency andthe difference between the estimated spherical equivalents and the actual spherical equivalents(SEs) after cataract surgery were compared to evaluate the accuracy of each measurement. Mismatching of the degree and the axis of the astigmatism was also analyzed between those methods.
Results: :
The average corneal refraction was significantly highest in topography, followed by IOL Master, and autorefraction in order. Mean astigmatism was significantly higher measured with IOL master than the others. The inter-measurement difference in the axis of steep astigmatism was less than 6.00 degrees between those groups that had more than 1.5D astigmatism. The repeatability of coefficient of corneal refraction was lowest with autorefraction, followed by IOL Master, and topography in order and the estimated SEs was mostaccurate with IOLMaster and autorefraction followed by topography.
Conclusions: :
Combined measurement using autorefraction and IOL Master seemed to be efficient way to precisely estimate the power calculation of the toric IOL in the patients with more than 1.5D of astigmatism.
Keywords: cataract • topography