The Differences Of Corneal Astigmatism And Corneal Thickness In Different Populations And Its Quantitative Analysis

OBJECTIVE:The corneal is an important refractive media for human eyes, directly affects people’s visual function. The purpose of this study was to analyze the differences of corneal astigmatism and corneal thickness in different age groups, and to discuss the changes of significance in the clinical.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 statistically analyzed and screened. The corneal curvature was measured by three different instruments, such as Keratometer, IOL Master and Sirius corneal topography. The corneal thickness was measured by two different instruments, such as Sirius corneal topography and A scan of the Ophthalmology. The astigmatism with the rule was ruled that the high refractive power meridian was located in the 90°±30°. The high refractive power meridian of the astigmatism against the rule was located at the level position of plus or minus30°;The else was the oblique astigmatism. The changes of the corneal astigmatism, the corneal astigmatism axial and corneal thickness in different group were analyzed in the study.RESULTS:There were no no statistical differences in the three different measurement results of the corneal astigmatism wich was measured by three different instruments which Include Sirius corneal topography, Keratometer an IOL Master. The two different measurement results of corneal thickness measured by two different instruments which include Sirius corneal topography and A scan had no statistical differences. Corneal refractive power of different groups showed no statistical difference, but the average corneal refractive power of 70 age grou～79p increased than younger group. As the growth of age the astigmatism with the rule gradually reduced, from 85.8% of A Group to 31.0% of F Group; The astigmatism against the rule increased significantly, from 6.7% of A Group to 45.0% of F Group; The oblique astigmatism had no obvious change before the age of 40, the proportion of oblique astigmatism increased obvious at the C group, and tended to be stable after the age of 40. After the age of 60, the proportion of different types of astigmatism among all age groups tended to be stable. The corneal thickness turned to be thinner at the E group and was stable after the age of 60.CONCLUSIONS:The different measurement methods of the corneal astigmatism and the corneal thickness by different instruments were consistent. As the growth of age, the proportion of the astigmatism with the rule gradually reduced. The proportion of the astigmatism against the rule increased significantly. The oblique astigmatism had no obvious change before the age of 40.The proportion of oblique astigmatism increased obviously at the C group and tended to be stable after then. After the age of 60, the proportion of different types of astigmatism in the all groups tended to be stable. For young cataract patients, the corneal astigmatism should be drawn attention when Astigmatism type intraocular lens were implanted. The instability of astigmatism axial also made the treatment effect of myopic with astigmatism by implanting TICL uncertain in the future. After the age of 60, the corneal thickness turned to be thinner in the E group and kept stable after the age of 60. After the age of 60, the corneal thickness might change, so the safety boundaries of the corneal refractive surgery needed to be redefined probably for avoiding the corneal lesions which occurred after corneal refractive surgery with age.