Authors: Liu Wenjie, Liu Jiewei, Wang Qi, Wang Jingjing, Jia Zhijie, Wang Bing, Li Xiaorong
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Objective
To investigate the distribution of the spherical aberration in age-related cataractous eyes using the Pentacam HR.
Methods
A cross-sectional study was performed in Shanxi Eye Hospital from December 2014 to December 2015.The preoperative corneal spherical aberration of 1 319 eyes of 1 319 patients with age-related cataract over 40-years-old was analyzed.The mean average keratometry (Km value), and corneal posterior surface Km corneal astigmatism, posterior corneal astigmatism, and corneal thickness were measured with.Pentacam, and the Zernike coefficients of corneal spherical aberration were calculated.A correlation between spherical aberration and corneal parameters was evaluated by Pearson correlation analysis.The proportion of eyes qualifying for spherically neutral or negatively aspheric intraocular lens targeted residual spherical aberration level was evaluated.This study protocol was approved by Ethics Committee of Shanxi Eye Hospital and complied with Declaration of Helsinki.
Results
The average age of all patients was (68.00±11.12) years old with an average spherical aberration (0.34±0.17)μm.The spherical aberration was lower than 0 μm in 22 eyes (1.67%), 0~0.4 μm in 842 eyes (63.84%), and greater than 0.4 μm in 455 eyes (34.50%). There was a weak positive correlation between spherical aberration and age (r=0.398, P<0.001). There were very weak correlations between spherical aberration and corneal Km, posterior corneal surface Km, corneal thickness (r=0.129, P<0.001; r=0.240, P<0.001; r=-0.068, P<0.05). No significant correlations were found between spherical aberration and corneal astigmatism or posterior corneal astigmatism (r=-0.025, P=0.365; r=-0.008, P=0.771). Seven hundred and ten eyes (53.83%) could be qualified for implantation of negatively or neutrally aspheric intraocular lens based on postoperative targets of (0.10±0.05)μm residual spherical aberration.
Conclusions
Corneal spherical aberration in Chinese patients is greater than that in other populations (+ 0.27 μm) in literature and shows individual differences.The appropriate aspheric intraocular lens should be selected according to individual corneal spherical aberration before cataract operation.