ABSTRACT
Objective To assess the effects of femtosecond laser-assisted anterior capsulotomy versus manual continuous curvilinear capsulorhexis on intraocular lens (IOL) centration by measuring and comparing shape,size and positional parameters.Methods Eighty cases (80 eyes) with age-related cataract from March 2015 to July 2016 in our hospital were collected.Forty patients (40 eyes) in the femtosecond group underwent femtosecond laser anterior capsulotomy and 40 patients (40 eyes) in the annular group were treated with annular continuous capsulorhexis.At postoperative 1 week,1 month,1 year,the slit lamp digital photography and Pentacam anterior segment analyzer were used to collect the anterior segment images,and the parameters include horizontal and vertical diameter,roundness,package and partial centre of IOL were analyzed by image analysis software image-pro-plus 6.0.Using repeated measurement of variance analysis,Fisher exact probability,and Generalized estimation equations (GEE),the differences between parameters of the groups and IOL decentration predictor were analyzed.Results The vertical diameter,roundness,maximum distance,minimum distance,package and horizontal deviation were statistically significant between the femtosecond group and the annular group at 1 week and 1 month after operation (all P ＜ 0.05),and there was no significant difference in horizontal diameter and vertical deviation between two groups (all P ＞ 0.05).At 1 year after operation,the maximum distance,minimum distance,package and horizontal deviation between two groups were statistically significant (all P ＜ 0.05).There was no significant difference in vertical and horizontal diameter,roundness,and vertical deviation between two groups (all P ＞ 0.05).There was no patient with horizontal shift ＞ 0.4 mm in the femtosecond group at 1 week,1 month and 1 year;The ratio of cases with horizontal shift ＞0.4 mm and ＜0.4 mm in the annular group at 1 week,1 month and 1 year were 2/38,4/36,8/32,respectively.There was significant difference in the horizontal shift ＞ 0.4 nun between the two groups after 1 year(P ＜ 0.05).In the univariate generalized estimating equation model,the capsulorhexis type was a significant predictor of horizontal shift.Of all the capsulorhexis parameters,the difference of inclusion degree was statistically significant (P =0.001).There was negative correlation between the horizontal shift and package at different time points in the femtosecond group at 1 week,1 month and 1 year (r =-0.89,P ＜ 0.05;r =-0.72,P ＜ 0.05;r =-0.58,P ＜ 0.05);There was negative correlation between the horizontal shift and package at different time points in the annular group at 1 week(r =-0.68,P ＜ 0.05),but no correlation at 1 month and 1 year (r=-0.41,P＞0.05;r=-0.33,P＞0.05).Conclusion The anterior capsule made by femtosecond laser anterior capsulotomy is more round,centered and accurate,pocket IOL position is more stabled and neutral.