The differences of corneal astigmatism in different populations and its quantitative analysis

Objective: To analyze the differences of corneal astigmatism in different age groups. Methods: The clinical data of the patients from the outpatient Department of Ophthalmology of the Tengzhou Central People’s Hospital from April 2014 to June 2014 was screened and statistically analyzed. The corneal curvature was measured by three different instruments: Keratometer, IOL Master and Sirius corneal topography. The changes of the corneal astig- matism in different groups were evalutaed in the study. Results: Corneal astigmatism of different groups showed no statistical difference and the average corneal astigmatism of 70~79 age group were higher than younger groups. As the age grew, the with-the-rule astigmatism gradually reduced from 85.8% ( A Group) to 31.0% (F Group). The against-the-rule astigmatism increased from 6.7% ( A Group ) to 45.0% (F Group). Conclusion: The proportion of the with-the-rule astigmatism gradually reduced with the growth of age. The proportion of the against-the-rule astigmatism increased significantly. The oblique astigmatism had no obvious change before the age of 40. The proportion of oblique astigmatism increased obviously at the 40~49 group and tended to be stable. After the age of 60, the proportion of different types of astigmatism tended to be stable. Keywords: With-the-rule astigmatism; against-the-rule astigmatism; oblique astigmatism.