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Objective: To compare the difference of decentration and tilt among 4 kinds of aspherical intraocular lenses (IOLs), and to analyze their objective visual quality. Methods: Prospective non-randomized controlled clinical trial. Age-related cataract patients who planned to undergo phacoemulsification and IOL implantation in the Affiliated Hospital of North Sichuan Medical College from April to June in 2020 were divided into ZCB00 group, SN60WF group, A1-UV group, and AO group according to IOL types. Thirty right eyes and thirty left eyes were selected in each group. Before operation and at 1 day, 1 week and 1 month postoperatively, decentration and tilt values were measured by a new swept-source anterior-segment optical coherence tomography device (CASIA2), and wavefront aberrations, objective scatter index (OSI), modulation transfer function cut off frequency (MTF cut off) and Strehl ratio (SR) were also examined. Values of decentration, tilt and visual quality compared among 4 groups were took from the right eye. One-way analysis of variance was used for inter-group comparison, and repeated measurement one-way analysis of variance was used for intra-group comparison. Data between right eyes and left eyes from all the individuals were compared by independent sample t -test. Results: A total of 181 patients (240 eyes) were enrolled, and 169 patients (224 eyes) completed the follow-up (114 right eyes and 110 left eyes). There were 77 males and 92 females, with an age of (69±9) years. There was no significant difference in gender, age, axial length, decentration and tilt of crystalline lens and IOL power among 4 groups (all P >0.05). At 1 day, 1 week and 1 month postoperatively, there was significant difference in decentration value among 4 groups ( F =7.11, 6.12, 4.66; all P <0.05). For further pairwise comparison, the decentration value of SN60WF group was higher than that of the other 3 groups at 1 day and 1 week postoperatively, and the decentration value of SN60WF group was (0.259±0.101) mm at 1 month postoperatively, which was higher than that of ZCB00 group (0.177±0.099) mm and AO group (0.163±0.122) mm, and the differences were statistically significant (using SNK -q test , both P <0.05). The IOL tilt value in the ZCB00 group, SN60WF group, A1-UV group, and AO group at 1 month postoperatively were (4.806±1.129)°, (5.080±1.309)°, (4.586±1.338)°, (5.112±1.406)°, respectively. No significant difference in tilt value among 4 groups was found at any time after surgery (all P> 0.05). In each group, there was no significant difference in decentration and tilt value at different postoperative time points (all P> 0.05). At 1 month postoperatively, there was no significant difference in decentration and tilt at horizontal and vertical directions respectively among 4 groups (all P> 0.05), and in each group, there was no significant difference in decentration and tilt value between right eyes and left eyes (all P> 0.05), and IOLs tended to tilt towards the inferonasal or inferotemporal direction in both eyes. With 4-mm and 6-mm pupil diameter, there was significant difference in internal ( F =131.32, 85.17) and ocular ( F =46.64, 47.55) spherical aberration among 4 groups (all P <0.01). For further pairwise comparison, the spherical aberration of AO group was higher than that of the other 3 groups, and the difference was statistically significant (using SNK- q test , all P <0.05). There was no significant difference in OSI, MTF cut off and SR among 4 groups (all P >0.05). Conclusions: The four types of IOLs show decentration and tilt in varying degrees after implantation in the capsular bag, but this difference do not lead to clinical significance. Human eyes have tolerance to mild decentration and tilt of aspheric IOLs, showing good visual quality.

Purpose: To investigate the impact of different sizes of steep meridian clear corneal incisions for phacoemul sification on anterior corneal higher-order aberrations., Methods: Medical records of patients who underwent 2.2-mm coaxial micro-incision cataract surgery or 2.75-mm coaxial small-incision cataract surgery were retrospectively reviewed. Only patients with preexisting anterior corneal astigmatism <2.00 diopters (D) and ≥0.50 D who underwent a steep meridian clear corneal incision were included. Primary outcomes were 3rd- to 6th-order anterior corneal higher-order aberrations with an 8-mm pupil. Anterior corneal astigmatism and effective phaco time were evaluated as secondary outcomes. Preoperative and 3-month postoperative outcomes were evaluated., Results: Anterior corneal astigmatism significantly decreased after both procedures; however, there was no significant difference found in surgically induced anterior corneal astigmatism between the two procedures (p=0.146). Although the total higher-order aberrations did not significantly change after both procedures, the group comparison showed a significant difference in surgically induced total higher-order aberrations (a decrease of 0.337 ± 1.156 mm in 2.2-mm coaxial micro-incision cataract surgery and an increase of 0.106 ± 0.521 mm in 2.75-mm coaxial small-incision cataract surgery, p=0.046). Spherical aberrations significantly decreased after 2.2-mm coaxial micro-incision cataract surgery (p=0.001), whereas they did not change significantly after 2.75-mm coaxial small-incision cataract surgery (p=0.564). Coma did not significantly change after either of the procedures. Trefoil did not significantly change after 2.2-mm coaxial micro-incision cataract surgery (p=0.361), whereas it significantly increased after 2.75-mm coaxial small-incision cataract surgery (p<0.001). There was no significant difference shown in effective phaco time between the procedures. A significantly positive correlation was shown between surgically induced anterior corneal astigmatism and coma in 2.75-mm coaxial small-incision cataract surgery (r=0.387, p=0.006). There was no significant correlation found between any surgically induced higher-order aberration changes and effective phaco time., Conclusions: The results showed that 2.2-mm coaxial micro-incision cataract surgery and 2.75-mm coaxial small-incision cataract surgery did not significantly degrade the total higher-order aberrations of the anterior cornea. However, the surgically induced changes in total higher-order aberration showed a significant difference between the two procedures, with a slight reduction after 2.2-mm coaxial micro-incision cataract surgery and a slight increase after 2.75-mm coaxial small-incision cataract surgery. Phaco time and power used during surgery had no impact on corneal aberrations.

Background: To compare the postoperative optical quality in eyes with customized selection and random selection of aspheric intraocular lens (IOL) implantation., Methods: A prospective, nonrandomized study was implemented in adult cataract patients who underwent unilateral phacoemulsification with aspheric IOL implantation. Patients were allocated into two treatment groups: a customized group and a control group. In the customized group, the aspheric IOL selection was based on the corneal spherical aberration to enable the postoperative target ocular spherical aberration closest to zero; in the control group, the aspheric IOLs were chosen using a random strategy. Primary outcome measurements included the following objective optical quality assessments: higher-order aberrations obtained by a Hartmann-shack aberrometer at 4 mm and 6 mm pupil diameters; objective scatter index (OSI), modulation transfer function (MTF) cut-off, Strehl ratio (SR) and a simulated contrast visual acuity-optical quality analysis system value (OV) obtained by a double-pass system with a 4-mm aperture. Subjective visual acuity was measured as secondary outcome. All the patients were followed up for 3 months., Results: Eighty-four patients in the customized group and 78 patients in the control group were evaluated. There was no significant difference in postoperative visual acuity between the two groups (P > 0.05). Significantly less ocular higher-order aberrations were shown in the customized group (P < 0.05). No significant difference was shown in OSI, MTF cut-off, SR and OV between the two groups (P > 0.05)., Conclusions: Although customized selection of aspheric IOL implantation showed less postoperative ocular aberrations, it performed similarly to random selection of aspheric IOL implantation in terms of postoperative visual acuity, simulated contrast visual acuity, intraocular scatter, modulation transfer function and Strehl ratio., Trial Registration: Retrospectively registered on 07/06/2019. Registration number: ChiCTR1900024356 .

Objective: To systematically compare the effects of Toric intraocular lens (IOL) implantation and corneal incisional procedures on the correction of astigmatism during cataract surgery. Methods: A peer-reviewed literature search was implemented in MEDLINE, EMBASE, EBSCO, ScienceDirect, Trip Database, Ovid, and the Chinese databases including CNKI and Wanfang Data. The inclusion criteria were randomized controlled trials (RCTs) that compared the Toric IOL implantation and the corneal incisional procedures to correct low and moderate astigmatism during cataract surgery. The mean difference ( MD ) and the relative risk were respectively used to describe the effect sizes of continuous data and nominal data with a confidence interval ( CI ) of 95%. The random effects model was applied to pool the data including postoperative uncorrected visual acuity, residual astigmatism and surgical complications by Review Manager 5.3. Results: A total of 12 RCTs were included in this study, including 330 eyes implanted with Toric IOLs and 336 eyes with non-Toric IOLs combined with corneal incisional procedures to correct astigmatism. According to the types of corneal incisions, the included RCTs were divided into three groups: limbal relaxing incision group, opposite clear corneal incision group, and astigmatic keratotomy group. Meta-analysis showed that postoperative logarithm of the minimum angle of resolution uncorrected visual acuity was significantly better in eyes implanted with Toric IOLs than those with corneal incisional procedures ( MD , -0.05; 95% CI , -0.08 to -0.02; P< 0.01), and the residual astigmatism was significantly lower in eyes implanted with Toric IOLs ( MD , -0.33 D; 95% CI , -0.48 to -0.18 D; P< 0.01). There was no significant difference in the risk of surgical complications between the Toric IOL implantation and the corneal incision correction for astigmatism (relative risk, 0.45; 95% CI , 0.07 to 2.95; P= 0.40). Conclusions: The current evidence suggests that Toric IOL implantation is more effective in correcting astigmatism than corneal incisional procedures during cataract surgery and shows better postoperative visual acuity. However, they are similar in the risk of postoperative complications. (Chin J Ophthalmol, 2019, 55: 522-530) .