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Objective:To investigate the influence of angle Kappa on total high-order aberration (HOA) before and after small incision lenticule extraction (SMILE).Methods:An observational case series study was conducted.Right eyes of 98 patients with myopia and myopic astigmatism who underwent SMILE surgery at Tianjin Eye Hospital from April 2015 to May 2016 were selected.Uncorrected visual acuity (UCVA), spherical diopter and cylindrical diopter under cycloplegic condition were examined before the surgery and at l and 3 months postoperatively.The chord distance of angle Kappa was measured by Pentacam topography.Wavefront aberrations were measured by WaveScan aberrometer.Pre- and postoperative UCVA, refractive status and each HOA were analyzed.The relationship between angle Kappa and each HOA was analyzed by Pearson correlation.This study adhered to the Declaration of Helsinki.The study protocol was approved by an Ethics Committee of Tianjin Eye Hospital (No.TJYYLL-2017-17). Written informed consent was obtained from each subject.Results:The preoperative, postoperative 1-month and postoperative 3-month UCVA (LogMAR) were 0.06±0.23, -0.03±0.07 and -0.05±0.07, respectively, showing a statistically significant difference ( F=779.330, P<0.001). There were statistically significant differences in spherical diopter, cylinder diopter and spherical equivalent (SE) between before and after operation ( F=1 107.811, 127.786, 1 191.266; all at P<0.001), and the postoperative spherical diopter, cylinder diopter and SE were significantly lower than those before surgery (all at P<0.001). At 6-mm pupil diameter, significant differences were found between postoperative total HOA, spherical aberration, coma, the third-order aberration (S3), fourth-order aberration (S4), fifth-order aberration (S5) and sixth-order aberration (S6) and the preoperative values ( F=75.915, 78.231, 66.186, 64.521, 97.161, 36.623, 28.852; all at P<0.001). The postoperative 1- and 3-month total HOA, spherical aberration, coma, S3, S4, S5 and S6 were significantly increased in comparison with those before surgery (all at P<0.05). There was a positive correlation between angle Kappa and total HOA, coma and S3 at 1 and 3 months after surgery (total HOA: r=0.357, 0.363; both at P<0.001.coma: r=0.310, 0.341; both at P<0.01.S3∶ r=0.343, 0.371; both at P<0.01). Significant differences were found in preoperative, postoperative 1-month and 3-month total HOA, coma and S3 between groups with different angle Kappa ( Fgroup=3.363, 4.277, 4.029; all at P<0.05). The postoperative total HOA, coma and S3 of the larger angle Kappa group were greater than those of the smaller angle Kappa group, with statistically significant differences between them (all at P<0.05). Conclusions:A larger angle Kappa may induce HOAs in SMILE surgery.
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Objective:To study the pupillary centroid shift of myopia and characteristics of pupil diameter change from scotopic to photopic condition.Methods:A case series study was carried out, 140 eyes of 70 myopia patients from September to November 2016 in Tianjin Eye Hospital were enrolled.The pupillary centroid shift and pupil diameter parameters were measured by visual quality analyzer from scotopic (0.017 lx) to photopic (10.400 lx) condition.This study followed the Declaration of Helsinki.Results:Under the scotopic and photopic conditions, the pupil diameter was positively correlated between the bilateral eyes (scotopic: rs=0.85, P<0.001; photopic: r=0.85, P<0.001), and the pupil diameter variation from scotopic to photopic condition was positively correlated between the bilateral eyes ( r=0.75, P<0.001). The pupil diameter in scotopic and photopic conditions, and the change of pupil diameter in the right eyes were significantly higher than those in the left eyes (all at P<0.05). The pupillary centroid shift was within 0.2 mm in the left eyes of 94.2% (66/70) subjects and in the right eyes of 97.1%(68/70) subjects.The pupillary centroid shift of all subjects was within 0.3 mm.From scotopic to photopic condition, the pupil centroid was mainly shift to the nasal superior direction.There was no significant correlation between pupil diameter and age or gender.There was no significant correlation between pupillary centroid shift and age, diopter or pupil diameter. Conclusions:The binocular pupillary centroid shift are symmetrical from scotopic to photopic condition in myopic eyes, and the pupil centroid mainly shift to nasal superior direction.
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In recent years,corneal refractive surgery continues to develop with becoming to be one of the most prevalent utilizations of correction of many patients and brings about better visual quality for ametropic patients.Meanwhile,some patients are subjected to optical complications,and poor night vision is one of the most serious problems which are complained by sufferers after refractive surgery,such as glare,halo and reduce of contrast sensitivity,and the affective factors include age,pupil diameter,high order aberation,scattering,pre-estimated diopter,corneal healing,individual sensitivity to surgery,which are supposed to attract the attention of the majority of clinicians and researchers,at the same time.Ophthalmic clinical doctors and researchers only fully understand the mechanism of the above factors and explore the corresponding measures in order to purposefully treat these complications.In addition,ophthalmologists should be aware of the interaction of these factors and their relationship with individual sensitivity and explore the impact of postoperative visual impairment and the way to avoid them in clinical practice inorder to improve the visual quality by controlling the postoperative optical complications.