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Updated: Aug 19, 2026
Correction of Presbyopia by Monocular Bi-Aspheric Ablation Profile
Published on: September 20, 2024
[The influence of pupil center shift on wavefront-guided laser in situ keratomileusis]
Zheng Wang1, Bin Yang, Xiao-hong Huang
1Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China. gzstwang@pub.guangzhou.gd.cn
Objective:
To evaluate the pupil center shift quantitatively after pupil dilation and to investigate its influence on the outcome of wavefront guided LASIK.
Methods:
Sixty-three eyes in 32 myopic patients with order RMS higher than 0.35 or were divided into groups A and B, and the Zyoptix LASIK was applied to the patients of both groups In group A, pupil center was used as the center of ablation, while in group B the ablation center was adjusted based on the pupil center shift.
Results:
A (0.173 +/- 0.114) mm mean pupil center shift was observed in this study, with the maximum 0.51 mm. At 3 months after the operation, there was no significant difference in visual acuity and refraction power between the two groups. However, the reduction of coma was (0.025 +/- 0.137) microm and (0.097 +/- 0.118) microm in groups A and B respectively (t = 2.131, P = 0.037). The change in spherical aberration was significantly different between the two groups.
Conclusions:
Pupil center shift after dilation is common. Adjustment of ablation center based on the shift may improve the correction of coma.