|
 |
 |
|
The Difference of Corneal Astigmatism between IOLMaster and Automated Keratometry Influenced by Topographic Patterns 1. Jong-Suk Song, MD, PhD Department of Ophthalmology, Korea University College of Medicine, Seoul, South Korea Purpose: To compare the corneal astigmatism obtained from the IOLMaster and automated keratometer and to evaluate the association between these differences and corneal topographic patterns. Methods: We obtained corneal astigmatic values with the IOLMaster and automated keratometer from 312 eyes having no previous ocular surgery. A total of 312 eyes were divided into three groups according to the difference of astigmatic values between the IOLMaster and automated keratometer. (Difference (d) = astigmatic value of IOLMaster – astigmatic value of automated keratometer). Group 1 was defined as d<-0.25 diopters (D), group 2 was -0.25 D≤d≤0.25 D, and group 3 was d>0.25 D. The topographic map was grouped into the following patterns: round, oval, symmetric bow tie, asymmetric bow tie, and irregular pattern. Distributions of topographic patterns according to group and astigmatic values by topographic patterns were evaluated. Results: The asymmetric bow tie pattern was the most common topographic pattern (34.6%), followed by symmetric bow tie (20.5%), round (18.9%), irregular (16.3%), and oval (9.6%) pattern. The asymmetric bow tie pattern was the most common topographic pattern in group 1 and group 2 (36.1%, and 50.0%, respectively); however, in group 3, the symmetric bow tie pattern was the most common type (32.8%). The distribution of topographic patterns by groups was significantly different (Pearson's chi-square test, p=0.015). Conclusion: The difference of corneal astigmatism between the IOLMaster and automated keratometer may depend on the pattern of corneal topography. |
 |