Analysis of Corneal Astigmatism and Asphericity before Phacoemulsification

Objective To investigate the distribution of corneal astigmatism and Q-value in the senile cataract patients before phacoemulsification(PHACO).Methods 101 eyes of 85 senile cataract patients in our department were studied.Corneal curvature,astigmatism,astigmatic axis and corneal Q-value were examined by OrbscanⅡeye segment analysis system before PHACO.Statistical software package SPSS 11.5 was used to analyze statistically.Results ①The mean of corneal curvature before PHACO was(44.71±2.1) D,normal distribution.②Astigmatism before PHACO was(1.02±0.82) D,non-normal distribution,of which there were 40 eyes with astigmatism ≥1.0 D,accounted for 40%;30 eyes with the rule astigmatism,accounted for 30%;53 eyes with against rule astigmatism,accounted for 52%;18 eyes with oblique astigmatism,accounted for 18%.③The mean of corneal Q-value before PHACO was(-0.10±0.27),normal distribution.There was negative relationship between the corneal Q-value and corneal curvature before surgery(r = -0.51,P=0.000),there was no relationship between the corneal Q-value and astigmatism power before surgery(r=-0.11,P=0.29).Conclution ①The corneal astigmatism of senile patients is against the rule in majority,about 40% patients need to correct astigmatism.②The corneal Q-value of senile patients is negative in majority,normal distribution,and it has negative correlation with corneal curvature and no correlation with astigmatism.