Factors influencing 1-year rotational stability of AcrySof Toric intraocular lenses

Effectiveness of prophylactic capsular tension ring implantation during cataract surgery in highly myopic eyes

PURPOSE

To assess the effectiveness of prophylactic capsular tension ring (CTR) implantation during cataract surgery in highly myopic eyes.

SETTING

Eye and Ear, Nose, and Throat Hospital of Fudan University, Shanghai, China.

DESIGN

Prospective cohort study.

METHODS

Consecutive highly myopic patients treated with cataract surgery were recruited and randomized to undergo CTR implantation or not. The outcomes compared between the 2 groups included axial lens position (ALP), intraocular lens (IOL) decentration and tilt, area of anterior capsule opening, severity of anterior capsular opacification (ACO), and posterior capsular opacification (PCO) at 1 year postoperatively.

RESULTS

A total of 55 highly myopic eyes with CTRs implanted and 55 without were included in the analysis. At 1 year postoperatively, no significant differences were detected between the CTR and non-CTR groups for the mean ALP, IOL decentration, or tilt (all P > .05). However, the CTR group had a significantly larger area of anterior capsule opening (23.62 ± 3.30 mm2 vs 21.85 ± 2.30 mm2, P = .003), and less severe ACO (P = .033) and PCO (PCO-3 mm: 0.06 ± 0.13 vs 0.13 ± 0.20, P = .038; PCO-C: 0.15 ± 0.18 vs 0.25 ± 0.26, P = .026) than the non-CTR group. The corrected distance visual acuity, prediction error, and higher-order aberrations did not differ between the 2 groups (all P > .05).

CONCLUSIONS

In highly myopic eyes, although prophylactic CTR implantation can reduce the severity of capsular contraction and opacification, it does not significantly affect postoperative IOL stability or visual outcomes.

Clinical outcomes and rotational stability after implantation of a monofocal toric intraocular lens with textured haptics in normal vs high axial lengths

PURPOSE

To compare the clinical outcomes and rotational stability after implantation of a toric intraocular lens (IOL) with textured haptics in eyes with normal vs high axial lengths (ALs).

SETTING

Nethradhama Superspeciality Eye Hospital, Bangalore, India.

DESIGN

2-arm, retrospective comparative study.

METHODS

This retrospective study included 114 eyes of 114 patients who underwent femtolaser cataract surgery followed by implantation of the HOYA Vivinex Toric monofocal IOL (Model XY1A-SP), of which 62 and 52 eyes belonged to normal (≤23.9 mm) and high (≥24 mm) AL groups, respectively. 1 week and 3 months postoperatively, clinical outcomes and rotational stability of the toric IOL was evaluated.

RESULTS

3 months postoperatively, % eyes achieving refractive astigmatism accuracy within ≤0.50 diopter, was 100% (n = 62) in the normal vs 94% (n = 49) in the high AL group. All eyes that is, 100% (n = 62) in the normal and 96.15% (n = 50) eyes in the high myopia group were <5 degrees of the intended axis. The mean change in postoperative rotation from 1 week to 3 months was 0.28 ± 0.09 degrees in the normal, and 0.30 ± 1.11 degrees in the high AL group ( P = .80). No significant correlation was observed between AL and white-to-white diameter with 1-week postoperative rotation values. No eye required repositioning of toric IOL for significant misalignment.

CONCLUSIONS

No significant differences were observed for clinical outcomes and postoperative rotational stability between eyes with normal and high ALs, suggesting excellent rotational stability of the Vivinex Toric IOL with textured haptics in all eyes, irrespective of the preoperative AL measurements.

Comparison of the effect of capsular bend on the rotational stability between 2 toric intraocular lenses

PURPOSE

To compare the effect of capsular bend on the rotational stability between 2 toric intraocular lenses (IOLs).

SETTING

Eye Hospital of Wenzhou Medical University, Hangzhou, Zhejiang Province, China.

DESIGN

Prospective study.

METHODS

Patients with preexisting astigmatism received AcrySof IQ (SN6AT) or TECNIS (ZCT/ZMT) toric IOL during cataract surgery. CASIA2 was used to record the toric IOL axial orientation and capsular bend index (CBI) at the 1-day, 1-week, 1-month, and 3-month interval postoperatively. The postoperative rotational stability and CBI of both models were compared.

RESULTS

A total of 58 eyes from 58 patients were enrolled in this study. The total misalignment of the TECNIS (ZCT/ZMT) group (6.96 ± 5.10 degrees, 7.41 ± 5.19 degrees, 6.93 ± 5.29 degrees, and 6.86 ± 5. 27 degrees) was significantly higher than that of the AcrySof IQ (SN6AT) group (3.55 ± 2.21 degrees, 4.00 ± 2.74 degrees, 3.72 ± 2.72 degrees, and 3.52 ± 2.50 degrees) at all follow-up intervals ( P < .05). The mean rotation of the TECNIS (ZCT/ZMT) group (2.66 ± 2.18 degrees) was significantly greater than that of the AcrySof IQ (SN6AT) group (1.65 ± 1.47 degrees) from 1 day to 1 week postoperatively ( P < .05). The capsular bend formation in the TECNIS (ZCT/ZMT) group was delayed compared with the AcrySof IQ (SN6AT) group ( P < .05, at the 1-week, 1-month, and 3-month interval). The TECNIS (ZCT/ZMT) group showed fibrosis in the peripheral anterior capsule, leading to its stretching away from the IOL surface, while the AcrySof IQ (SN6AT) group exhibited gentle adherence of the anterior capsule to the IOL surface.

CONCLUSIONS

The AcrySof IQ toric IOL (SN6AT) exhibited greater rotational stability than the TECNIS toric IOL (ZCT/ZMT), which may partially result from the delay in capsular bend formation of TECNIS at the 1-day to 1-week follow-up postoperatively.

Rotational stability of a new hydrophobic acrylic intraocular lens platform

PURPOSE

To evaluate rotational stability for ease of rotation of a new intraocular lens (IOL) platform with 4 haptics in an ex vivo model and compare it with a control single-piece lens with 2 open loops.

SETTING

Intermountain Ocular Research Center, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.

DESIGN

Experimental study.

METHODS

10 human cadaver eyes were prepared as per the Miyake-Apple technique. After injection of the test or control lens, clockwise and counterclockwise rotations were attempted with a hook, with and without an ophthalmic viscosurgical device in place. Ease of rotation was scored as (1) very easy, (2) easy, (3) difficult, and (4) very difficult. Rotation of the entire eye containing test or control IOL was also performed with a multipurpose rotator (2 minutes; 220 revolutions per minute) to evaluate its effect on IOL alignment.

RESULTS

There were statistically significant differences regarding ease of rotation between test and control lenses in all 4 scenarios, with rotation being more difficult with the test lens ( P < .05, Wilcoxon signed-rank test). No change in the alignment of test or control lenses was observed after eye rotation with the multipurpose rotator.

CONCLUSIONS

The new IOL platform showed greater rotational stability than the control lens in this model, owing to design features such as 4 small arcs of contact between the haptics and the bag equator, a bulge at the distal end of each haptic, and arcuate haptics with curvatures oriented toward each other.

Effects of Decentration of Implantable Collamer Lens V4c on Visual Quality With the OPD-Scan III Aberrometer

PURPOSE

This study aimed to analyze the relationship between visual quality and implantable collamer lenses (ICL) decentration.

DESIGN

Prospective treatment evaluation clinical study METHODS: This prospective study included 119 eyes with ICL implantation. Refractive parameters and ocular aberrations were examined pre- and postoperatively. ICL decentration and higher-order aberrations (HOAs) were evaluated using the OPD-Scan III aberrometer.

RESULTS

At the 1-month follow-up, the mean values for decentration were 0.38 ± 0.19 mm (0.02-0.78). Regarding the position of decentration in right and left eyes, 22.8% and 17.7% were located in the superior nasal section, 0% and 6.5% in the inferior nasal section, 50.9% and 53.2% in the superior temporal section, and 26.3% and 22.6% in the inferior temporal section, respectively. The root mean square values of whole-eye total HOAs, coma, and trefoil had significantly increased. Decentration had a significant negative correlation with variation in the pre- and postoperative trefoils of the whole eye.

CONCLUSIONS

ICL decentration had a slightly negative correlation with trefoil and slightly affected visual quality.

Rotational stability and capsular bag performance of a hydrophobic acrylic open-loop single-piece intraocular lens

PURPOSE

To evaluate the rotational stability and capsular bag performance of a blue light-absorbing hydrophobic acrylic open-loop single-piece intraocular lens (IOL) with a blast-finished anchor wing haptic design during the first 6 postoperative months.

METHODS

In this prospective clinical study, patients with age-related cataract and potential postoperative corrected distance visual acuity (CDVA) of 0.2 logMAR or better were included. The patients received a non-toric hydrophobic acrylic single-piece IOL with an axis mark (YST0.00; Nidek Co. Ltd, Japan). Surgeries were video-taped. Retroillumination images were acquired 1 h, 1 week and 6 months postoperatively. Rotational stability was assessed by precise image overlay. At 6 months, Purkinje meter measurements were performed to evaluate tilt and decentration.

RESULTS

In total, 100 eyes of 77 patients were included in the analysis. Mean absolute rotation was 2.1 ± 1.7° (median 1.7, range: 0-7.9) at 6 months (1 h - 6 months postoperatively). IOL rotation was ≤3° and ≤6° in 74 (74%) and 98 (98%) eyes, respectively. Mean absolute IOL rotation from the end of surgery to 6 months was 2.5 ± 2.2° (median 2.3, range: 0-15.6; n = 78). Mean tilt (pupillary axis) and decentration were 4.1 ± 1.9° (median 4.0, range: 0.5-8.2) and 0.35 ± 0.17 mm (median 0.32, range: 0.06-0.91) respectively (n = 84). Postoperatively, 98 (98%) eyes achieved a CDVA of 0.2 logMAR or better, 95 (95%) of ≤0.1 and 81 (81%) of ≤0.0.

CONCLUSIONS

This hydrophobic acrylic single-piece IOL showed an excellent rotational stability and capsular bag position with low tilt and decentration values.

Rotational stability of monofocal and diffractive multifocal toric intraocular lens with identical design and material: a propensity score based prospective comparative study

PURPOSE

To compare the rotational stability of a monofocal and a diffractive multifocal toric intraocular lens(IOLs) with identical design and material.

METHODS

This prospective study enrolled patients who underwent plate-haptic toric IOL (AT TORBI 709 M and AT LISA 909 M) implantation. Propensity score matching (PSM) was performed to balance baseline factors. Follow-up examinations were conducted at 1 h, 1 day, 3 days, 1 week, 2 weeks, 1 month, and 3 months postoperatively. A linear mixed model of repeated measures was used to investigate the changes in IOL rotation over time. A 2-week timeframe was utilized to assess differences in IOL rotation between the two groups.

RESULT

After PSM, a total of 126 eyes were selected from each group for further analysis. Postoperatively, the time course of IOL rotation change in the two groups remained consistent, with the greatest rotation occurring between 1 h and 1 day postoperatively. At the 2-week postoperative mark, the monofocal toric IOL exhibited a higher degree of rotation compared to the multifocal toric IOL (5.40 ± 7.77° vs. 3.53 ± 3.54°, P = 0.015). In lens thickness(LT) ≥ 4.5 mm and white-to-white distance(WTW) ≥ 11.6 mm subgroups, the monofocal toric IOL rotated greater than the multifocal toric IOL (P = 0.026 and P = 0.011, respectively).

CONCLUSION

The diffractive multifocal toric IOL exhibits superior rotational stability compared to the monofocal toric IOL, especially in subgroups LT ≥ 4.5 mm and WTW ≥ 11.6 mm. Moreover, the time course of IOL rotation change is consistent for both, with the maximum rotation occurring between 1 h and 1 day postoperatively.

Insights into the rotational stability of toric intraocular lens implantation: diagnostic approaches, influencing factors and intervention strategies

Toric intraocular lenses (IOLs) have been developed to enhance visual acuity impaired by cataracts and correct corneal astigmatism. However, residual astigmatism caused by postoperative rotation of the toric IOL is an important factor affecting visual quality after implantation. To decrease the rotation of the toric IOL, significant advancements have been made in understanding the characteristics of toric IOL rotation, the factors influencing its postoperative rotation, as well as the development of various measurement techniques and interventions to address this issue. It has been established that factors such as the patient's preoperative refractive status, biological parameters, surgical techniques, postoperative care, and long-term management significantly impact the rotational stability of the toric IOL. Clinicians should adopt a personalized approach that considers these factors to minimize the risk of toric IOL rotation and ensure optimal outcomes for each patient. This article reviews the influence of various factors on toric IOL rotational stability. It discusses new challenges that may be encountered to reduce and intervene with rotation after toric IOL implantation in the foreseeable future.

Effect of Decentration, Rotation, and Tilt on Objective Optical Quality of Plate Haptic Toric Intraocular Lenses in the Early Postoperative Period

Purpose

This study aimed to determine the influence of decentration, rotation, and tilt on objective optical quality of plate haptic toric intraocular lenses (tIOLs).

Methods

The area ratio of modulation transfer function (MTF), strehl ratio of point spread function (PSF), and higher order aberrations (HOAs) for 3 mm and 5 mm pupil diameter (PD) were evaluated at postoperative 1 month. The retroillumination images pictured by OPD-scan III were used to quantify the degree of decentration and rotation, whereas the tIOL tilt was directly obtained by the tilt aberration. Patients were separated into two subgroups based on tIOL misalignment cutoff values.

Results

There were 29 eyes (24 patients) in the study. The decentration of more than 0.25 mm did not substantially differ from those less than or equal to 0.25 mm. PSF of 3 mm PD and MTF, intraocular HOAs, and trefoil aberration for 3 mm and 5 mm PD significantly deteriorated with a rotation of more than 3 degrees, whereas only intraocular HOAs for 5 mm PD and coma for 3 mm and 5 mm PD were significantly severe with a tilt of more than 0.1 µm and 0.25 µm in corresponding PD. Furthermore, tIOL rotation and tilt were highly correlated with intraocular trefoil aberration and coma, respectively.

Conclusions

The decentration of the monofocal bitoric IOLs is more tolerant to optical quality degradation after 1 month of surgery but more sensitive to intraocular trefoil aberration caused by rotation and coma aberration induced by tilt.

Translational Relevance

As far as we know, this is the first study to investigate the relationship between the plate haptic bitoric IOL misalignment and objective optical quality measured by OPD-scan III in the real world, which may provide reference information for IOL selection to improve surgical outcomes.

Influence of Nd:YAG laser capsulotomy on toric intraocular lens rotation and change in cylinder power

PURPOSE

To investigate toric monofocal intraocular lens (TIOL) rotation and associated changes in cylinder power caused by Nd:YAG laser capsulotomy performed due to posterior capsule opacification (PCO).

SETTING

Ekol Eye Hospital, Izmir, Turkey.

DESIGN

Prospective case series.

METHODS

41 eyes of 20 women and 21 men were included in the study. Before and 1 month after Nd:YAG laser capsulotomy, TIOL tilt and decentration were determined with Scheimpflug camera, and TIOL axial rotation and the change in cylinder power induced by this rotation were measured by ray tracing aberrometry. The time interval between cataract surgery and Nd:YAG laser capsulotomy was noted.

RESULTS

Rotational misalignment of the TIOL was measured as 4.65 ± 2.75 degrees (range 0 to 11 degrees) before vs 6.97 ± 2.92 degrees (range 0 to 13 degrees) after capsulotomy, and absolute rotation was 2.75 ± 1.94 degrees (range 0 to 7 degrees, P = .028). Before and after Nd:YAG laser capsulotomy, cylinder power was 0.24 ± 0.70 diopter (D) (range 0.00 to 0.63 D) vs 0.56 ± 0.77 D (range 0.02 to 0.91 D), respectively, with an absolute change in cylinder power of 0.34 ± 0.22 D (range 0.01 to 0.90 D, P = .001). After capsulotomy, there was a significant decrease in IOL tilt in the horizontal and vertical planes and an increase in decentration ( P < .05). Time interval (33.02 ± 12.9 months) and IOL horizontal decentration were independent factors affecting IOL rotation after capsulotomy ( P < .05).

CONCLUSIONS

Nd:YAG laser capsulotomy may cause TIOL rotation as well as tilt and decentration, resulting in a change in the TIOL's corrective effect on corneal astigmatism. Although this change was clinically insignificant, it may be beneficial to consider that TIOL rotational misalignment may occur in patients undergoing early capsulotomy.

Refractive surgical correction and treatment of keratoconus

Keratoconus is an ectatic corneal disorder that causes severe vision loss. Surgical options allow us to correct, partially or totally, the induced refractive error. Intracorneal ring segments (ICRS) implantation represents a minimally invasive surgical option that improves visual acuity, with a high success rate and a low overall complication rate. Corneal allogenic ICRS consists of ring segments derived from allogenic eye bank-processed donor corneas. Selective topography-guided transepithelial photorefractive or phototherapeutic keratectomy combined with CXL is another way in selected cases to improve spectacles corrected distance visual acuity. The microphotoablative remodeling of the central corneal profile is generally planned by optimizing the optical zones and minimizing tissue consumption. Phakic intraocular lens (PIOL) implant is considered in patients with stable disease and acceptable anatomical requirements. The two types of pIOLs, depending on their implantation inside the eye, are anterior chamber-pIOLs, which fixate to the anterior surface of the iris by using a polymethomethacrolate claw at the two haptics, and posterior chamber-pIOLs. In patients with both cataracts and keratoconus, the correct IOL power is difficult to obtain due to the irregular corneal shape and K values. Toric IOL is recommended, but carefully judging the topography and the possible need of subsequent keratoplasties.

Repositioning Rates of Toric IOLs Implanted in Cataract Surgery Patients: A Retrospective Chart Review

Purpose

To determine the incidence of postoperative repositioning of toric intraocular lenses (IOLs) due to clinically significant rotation.

Patients and Methods

This study included consecutive cataract patients with pre-existing astigmatism who had undergone cataract surgery with toric IOL implantation by a single experienced surgeon. Case records of patients who were recommended to undergo toric IOL repositioning surgery due to clinically significant postoperative IOL rotation from the implanted axis were identified. The need for a secondary intervention to manage residual astigmatism was based upon postoperative residual astigmatic error ≥0.75 D, the patient's qualitative dissatisfaction with the level of postoperative distance vision, dilated post-op examination, and confirmation of the significant potential for astigmatism reduction.

Results

Case records of 993 eyes implanted with AcrySof toric (N = 362), Tecnis Toric I (N = 53), Tecnis Toric II (N = 308), or enVista Toric IOLs (N = 270) were included. Postoperative toric IOL repositioning was recommended in 16 eyes (1.6%). The repositioning rate was highest in the eyes implanted with Tecnis Toric I (5.7%), followed by AcrySof Toric (2.2%), enVista Toric IOLs (1.1%), and Tecnis Toric II (0.6%).

Conclusion

This real-world analysis of eyes implanted with toric IOLs revealed that the rate of surgical IOL repositioning due to clinically significant IOL rotation was lower than 2% for enVista and Tecnis Toric II IOLs. When needed and with appropriate planning, toric IOL repositioning can be very successful.

Visual and Refractive Outcomes After Bilateral Implantation of a Biconvex Aspheric Toric Monofocal Intraocular with a Double C-Loop Haptic Design

Purpose

To show the visual and refractive outcomes in cataract patients with corneal astigmatism when bilaterally implanted with a biconvex aspheric toric monofocal intraocular lens (IOL) with a double C-loop haptic-design.

Methods

Forty-seven cataract patients (94 eyes) with corneal astigmatism (≥0.75D) were implanted with the monofocal PODEYE toric IOL and assessed for 4-6 months post-surgery. Measurements included monocular and binocular uncorrected-distance visual acuity (UDVA) and corrected-distance visual acuity (CDVA), under both photopic and mesopic lighting conditions. Refraction, photopic and mesopic contrast sensitivity (with and without glare), and rotational stability were also recorded at the last postoperative visit.

Results

At 4-6 months, 78.2% and 98.9% of eyes were within ±0.50D and ±1.00D of the target refraction, respectively. The mean spherical equivalent and refractive cylinder values were 0.09±0.35D and -0.36±0.35D, respectively. 76.5% and 98.8% of eyes presented a postoperative refractive cylinder of ≤0.50D and ≤1.00D, respectively. 91.5% and 100% of patients had a binocular UDVA and CDVA of ≥20/25, respectively. The mean binocular UDVA and CDVA were 0.02±0.08 and -0.02±0.07 logMAR, respectively. Under mesopic conditions, 78.7% and 83.0% of patients presented a binocular UDVA and CDVA ≥20/32, respectively. The mean binocular UDVA and CDVA were 0.15±0.11 and 0.12±0.11 logMAR, respectively. The patients showed good contrast sensitivity under photopic and mesopic conditions. The mean absolute IOL rotation was 1.22±2.21 degrees with 97.87% of eyes having a rotation of <10 degrees.

Conclusion

This study shows good visual and refractive outcomes for the PODEYE toric IOL when implanted bilaterally in cataract patients with corneal astigmatism.

Relationship between anterior capsule opening and direction of intraocular lens decentration

PURPOSE

To compare intraocular lens (IOL) decentration between patients in whom the continuous curvilinear capsulorhexis (CCC) completely covers the IOL optic and those in whom it incompletely covers the IOL optic and determine how an incompletely covered CCC affects the IOL position.

SETTING

Tertiary hospital in Japan.

DESIGN

Single-center retrospective study.

METHODS

57 eyes of 57 patients (mean age 70.8 ± 6.2 years) that underwent phacoemulsification and IOL (SN60WF) implantation in the bag between April 2010 and April 2015 were included in this study. The patients were classified based on whether the CCC completely (CC group) or incompletely (NCC group) covered the IOL optic using an anterior eye segment analysis system (EAS-1000). The IOL decentration of the groups was analyzed using EAS-1000 at 1 week, 1 month, 3 months, and 6 months postoperatively and compared. The relationship between the NCC location and the IOL direction at 3 months postoperatively was analyzed.

RESULTS

The NCC group (25 eyes) had a significantly higher amount of IOL decentration than the CC group (32 eyes) at 1 week, 1 month, 3 months, and 6 months postoperatively ( P < .05). There was a correlation between the direction of IOL decentration and the NCC location, and IOL decentration in the NCC group occurred in the opposite direction to the NCC area.

CONCLUSIONS

An anterior capsule opening that completely covers the IOL optic is important to control IOL decentration.

Visual performance and rotational stability of a multifocal toric intraocular lens in myopic eyes

OBJECTIVE

This study aimed to evaluate the visual performance and rotational stability of the multifocal toric intraocular lens in myopes.

METHODS

This prospective, observational study included patients with an axial length of ≥24.5 mm and regular corneal astigmatism of >1 diopter who underwent phacoemulsification cataract surgery and implantation of a multifocal toric intraocular lens (AT LISA toric 909M). The visual acuity, defocus curves, residual astigmatism, rotational stability, higher-order aberrations (HOAs), modulation transfer function (MTF), spectacle dependence and patient satisfaction were evaluated 3 months after surgery.

RESULTS

Forty-three eyes from 30 patients were enrolled in this study. Postoperatively, uncorrected distance and near visual acuities (logMAR) were 0.09 ± 0.08 (standard deviation, SD) and 0.14 ± 0.08, respectively. The defocus curve analysis provided a bimodal curve showing two peaks of maximum vision at 0.0 D and at -3.0 D defocus level. The multifocal toric intraocular lens showed excellent rotational stability; the mean rotation was 4.02 ± 2.49 (SD) degrees at 3 months postoperatively. Refractive predictability was excellent with a mean spherical equivalent of 0.19 ± 0.37 (SD) diopters (D) and a mean refractive cylinder of -0.34 ± 0.39 (SD) D.

CONCLUSIONS

The diffractive multifocal toric intraocular lens, AT LISA toric 909M, provided effective distance and near visual acuities in myopic eyes. It was a predictable and effective device with good rotational stability for the correction of preexisting astigmatism during cataract surgery. In this study, more than 80% of patients achieved spectacle independence.

Extensive misalignment of plate-haptic rotationally asymmetric multifocal toric intraocular lens

PURPOSE

Plate-haptic rotationally asymmetric multifocal toric intraocular lenses (IOL) (Lentis Comfort Toric) occasionally rotate extensively after surgery. We conducted the current study to investigate the incidence of extensive misalignment of this IOL and its association with clinical parameters.

STUDY DESIGN

Retrospective case series.

SUBJECTS AND METHODS

Data were collected from patients who had undergone phacoemulsification and implantation of a plate-haptic multifocal toric IOL.

RESULTS

Among 332 eyes, extensive misalignment of toric IOLs ≥ 45º occurred in 3.3% (11 eyes). The amount of misalignment in eyes with extensive misalignment was 81.6 ± 22.9º, while in those without extensive misalignment, it was 3.0 ± 2.7º. The eyes with extensive misalignment showed significantly greater axial length (p < 0.001), larger corneal diameter (p = 0.034), and flatter corneas (p = 0.044) than those without extensive misalignment. Repositioning surgery to correct toric IOL misorientation was conducted in 9 eyes between 7 and 28 days after cataract surgery. In 2 eyes, repositioning surgery was carried out twice.

CONCLUSIONS

In majority of cases plate-haptic multifocal toric IOLs showed satisfactory rotational stability, but extensive misalignment ≥ 45º occurred in 3.3% of cases.

Effectiveness of toric IOL and capsular tension ring suturing technique for rotational stability in eyes with long axial length

OBJECTIVE

To evaluate the efficacy of the toric intraocular lens (IOL) and capsular tension ring (CTR) suturing technique in eyes with long axial length (AL) with a high risk of toric IOL rotation.

METHODS

This is a retrospective observational case series. The data files of patients who underwent a one-piece acrylic toric IOL (Tecnis Toric IOL and Acrysof IQ Toric IOL) implantation with the toric IOL and CTR suturing technique for cataract and astigmatism or toric IOL repositioning were analyzed. Inclusion criteria were a regular total corneal astigmatism of ≥ 1.5 D and an AL of ≥ 26.0 mm. Preoperative and postoperative astigmatism, uncorrected distance visual acuity (UDVA), IOL rotation, intraoperative, and postoperative complications were evaluated.

RESULTS

A total of 30 eyes of 29 patients were included in this study. The mean AL was 27.82 ± 1.53 mm (range, 26.08-31.07). UDVA revealed a statistically significant improvement from 0.84 ± 0.20 logMAR preoperatively to 0.04 ± 0.06 logMAR postoperatively (p < 0.001). The mean preoperative corneal astigmatism was 3.08 ± 1.01 D reduced to the postoperative residual astigmatism of 0.59 ± 0.32 D which was found also statistically significant (p < 0.001). Only 2 eyes (6.2%) had postoperative toric IOL rotation of 5° and 10°, respectively. The mean degree of postoperative rotation was 0.50 ± 2.01.

CONCLUSION

This technique provided excellent rotational stability even in eyes with longer AL and did not require additional intervention.

Stereopsis after bilateral implantation of Toric intraocular lenses in high myopic cataract patients with astigmatism

Purpose

To evaluate near, intermediate, distance visual acuity and stereopsis after bilateral implantation of Toric intraocular lenses (IOLs) in high myopic patients with astigmatism.

Methods

Bilateral Toric or non-Toric IOL implantation (n ​= ​40 eyes each) was performed on high myopic cataract eyes with astigmatism. Best-corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UCIVA), uncorrected near visual acuity (UCNVA), residual refractive astigmatism (RRA), and near, intermediate, and distance stereoacuity were measured postoperatively at 7 days, 1 month, and 3 months.

Results

The three-month postoperative BCDVA, UCIVA, and UCNVA of the Toric group were 0.08 ​± ​0.07, 0.30 ​± ​0.11, and 0.23 ​± ​0.14 LogMAR. All improved over the preoperative assessments (P ​< ​0.05). The RRA, UCIVA, and UCNVA were significantly better in the Toric group than the non-Toric group at all follow-up examinations (all P ​< ​0.05). At 3 months, the median near and intermediate stereoacuity of the Toric group were 100 (range 40 - 400) and 120 (range 50 - 400) arcsec, which were better than the non-Toric group (both P ​< ​0.05). Fine near stereopsis ≥100 arcsec was present in 65% of the Toric patients, and 50% had good intermediate stereopsis of ≥100 arcsec. However among non-Toric patients, only 15% and 5% achieved fine near and intermediate stereopsis. The postoperative BCDVA and best-corrected distance stereoacuity were similar in the two groups (P ​> ​0.05).

Conclusions

In bilateral high myopic cataract patients with astigmatism, Toric IOLs not only improved UCIVA, UCNVA, and RRA, but also enhanced near and intermediate stereopsis acuity.

Rotational stability and clinical outcomes after implantation of a new monofocal toric intraocular lens with double C-loop design

PURPOSE

To investigate rotational stability and visual outcomes of patients unilaterally or bilaterally implanted with a new monofocal toric intraocular lens (IOL).

SETTING

Ophthalmology service, clinique Beausoleil, avenue de Lodève, Montpellier.

DESIGN

Single-center retrospective study.

METHODS

This study included patients who underwent routine cataract surgery with the PODEYE toric (BVI/PhysIOL SA, Liège, Belgium) IOL using the ZEISS CALLISTO eye®. Biometry and keratometry data, refractive outcomes, rotational stability, and astigmatism correction were recorded. IOL rotation was evaluated using an image analysis technique. Postoperative assessments were performed at 1 week, 1 month, and 4 to 6 months after surgery.

RESULTS

Clinical outcomes of 102 patients (136 eyes) were analyzed. Patients had a mean age of 74 years. Of the included eyes, 25% had an axial length greater than 24.5mm. Median postoperative IOL rotation from baseline (surgery) was 2̊. With the exception of one outlier (15̊ rotation), IOL rotation was ≤ 6̊ (1 month) and ≤ 10̊ (4-6 months) in 100% of the eyes. No surgical IOL re-positioning was required. Median postoperative corrected distance visual acuity was -0.08 logMAR, and median postoperative subjective cylinder was between 0.25 and 0.50 D.

CONCLUSION

The PODEYE toric IOL showed high rotational stability, allowing for correction of corneal astigmatism during cataract surgery.

Building prediction models of clinically significant intraocular lens tilt and decentration for age-related cataract

PURPOSE

To explore the risk factors and construct nomogram models to predict the risks of clinically significant intraocular lens (IOL) tilt and decentration after cataract surgery in patients with age-related cataract.

SETTING

Zhongshan Ophthalmic Center, Guangzhou, China.

DESIGN

Prospective cohort study.

METHODS

207 patients (207 eyes) who underwent phacoemulsification combined with IOL implantation were enrolled in the study. Casia2 was used to measure the tilt and decentration of crystalline lenses and IOLs before and 3 months after surgery. Univariate and multivariate logistic regression analyses were used to determine the risk factors of clinically significant IOL tilt and decentration, and nomogram prediction models were constructed according to the results of the multivariate logistic regression analysis.

RESULTS

Two hundred and seven patients were included in analysis. 24 eyes (11.59%) and 16 eyes (7.73%) had clinically significant IOL tilt and decentration at 3 months after cataract surgery. Multivariate logistic regression analysis revealed that preoperative crystalline lens tilt and decentration were the risk factors for clinically significant IOL tilt (odds ratio [OR], 3.519, P < .001) and decentration (OR, 410.22, P = .001), respectively. Axial length was another association factor for clinically significant IOL decentration (OR, 2.155, P = .019). The risk models demonstrated good calibrations and discriminations for the predictions of clinically significant IOL tilt (receiver operating characteristic [ROC] area = 0.833, cutoff value = 6.5) and decentration (ROC area = 0.757, cutoff value = 0.08).

CONCLUSIONS

The good performances of our models suggested that they may be useful risk prediction tools for postoperative IOL tilt and decentration. The measurement of preoperative crystalline lens tilt and decentration should be one of the routine examinations before cataract surgery, especially for toric and multifocal IOLs.

Rotational stability of plate-haptic toric intraocular lenses in Asian eyes: risk period for intraocular lens rotation and its influencing factors

PURPOSE

To investigate the rotational stability of plate-haptic toric intraocular lenses (IOLs) during 3-month follow-up.

SETTING

Eye and ENT Hospital of Fudan University, Shanghai, China.

DESIGN

Prospective observational study.

METHODS

Patients with cataracts implanted with AT TORBI 709M toric IOLs were enrolled and followed at 1 hour, 1 day, 3 days, 1 week, 2 weeks, 1 month, and 3 months postoperatively. A linear mixed model of repeated measures was applied to investigate the time course of absolute IOL rotation change. The 2-week overall IOL rotation was analyzed in the age, sex, axial length (AL), lens thickness (LT), preexisting astigmatism, and white-to-white subgroups.

RESULTS

A total of 328 eyes of 258 patients were included. The rotation from the end of surgery to 1 hour and 1 day to 3 days was significantly smaller compared with the rotation from 1 hour to 1 day but more than that at other time intervals in the overall group. 2 weeks postoperatively, the mean uncorrected distance visual acuity and remaining positive cylinder were 0.19 ± 0.22 logMAR and 0.60 ± 0.44 diopters, respectively. Significant between-group differences in 2-week overall rotation were found in the age, AL, and LT subgroups.

CONCLUSIONS

Maximum rotation occurred within 1 hour to 1 day postoperatively, and the first 3 days postoperatively was a high-risk period for the plate-haptic toric IOL rotation. Surgeons should make the patients aware of this.

Optimal Timing of Repositioning Surgery for a Plate-Haptic Toric Intraocular Lens: A Multicenter Retrospective Study

PURPOSE

To evaluate risk factors for significant rotation and determine optimal timing for repositioning surgery following a plate-haptic toric intraocular lens (IOL) implantation.

METHODS

This retrospective study enrolled patients who underwent the plate-haptic toric IOL implantation at seven hospitals in Shanghai. IOL rotation and residual astigmatism were compared before and after repositioning surgery. Risk factors for significant IOL rotation after cataract surgery were identified by stepwise multiple linear regression analysis. Spearman's and linear regression analyses were performed to identify factors associated with IOL rotation after repositioning. The receiver operator characteristic (ROC) curve was used to analyze the optimal timing for repositioning surgery.

RESULTS

Among 2,745 eyes implanted with the toric IOL, 46 eyes (1.68%) of 45 patients underwent repositioning surgery. Axial length and lens thickness were significantly associated with IOL rotation before repositioning. After repositioning surgery, IOL rotation and residual astigmatism were significantly reduced (all P < .001). IOL rotation after repositioning was negatively associated with the timing of repositioning surgery (all P < .001). The ROC curve showed that the optimal cut-off for the timing of repositioning surgery was 15 days or greater.

CONCLUSIONS

The prevalence of repositioning surgery after the plate-haptic toric IOL implantation was 1.68%, and the optimal timing for repositioning surgery was recommended to be 2 to 3 weeks after cataract surgery. [J Refract Surg. 2023;39(2):120-126.].

Effect of capsular bend on the rotational stability of toric intraocular lens

PURPOSE

To assess the effect of capsular bend and axial length on the rotational stability of toric IOL.

METHODS

The prospective study included patients with preexisting astigmatism that were implanted with Acrysof IQ Toric IOL. According to the pre‑operative axial length, all patients were divided into 2 groups: high myopia (AL ≥ 26 mm) group, and emmetropia or low to moderate myopia group (AL <26 mm). High-speed Swept-source Optical Coherence Tomography (SS-OCT) radial scanning was performed after pupil dilation to obtain the toric IOL axial orientation and capsular bending index (CBI) at 1-day, 1-week, 1-month and 3-month intervals postoperatively. The correlation between the rotation of toric intraocular lens and the axial length or CBI was subsequently analyzed.

RESULTS

68 eyes of 57 patients were included in the research. The rotation of toric IOL within the high myopia group was greater than the control group (P = 0.001, 1month postoperative). Capsular contact with the IOL was delayed in highly myopic eyes, although the results were not statistically significant (P = 0.094, 1-month postoperatively). There was a positive correlation between the degree of rotation and axial length at the interval found between 1-week and 1-month after the operation (r = 0.333, P = 0.005). There was a significant negative correlation between the IOL rotational speed and CBI (P < 0.001). The regression equation was Y = -0.441*X + 1.712 (R2 = 0.323, P < 0.001).

CONCLUSION

There was a significant negative correlation between the IOL rotation speed and the CBI, while the influence of the axial length and capsular bending mainly occurred between one week and one month after the operation.

Single-cell RNA sequencing: Inhibited Notch2 signalling underlying the increased lens fibre cells differentiation in high myopia

High myopia is the leading cause of blindness worldwide. It promotes the overgrowth of lens, which is an important component of ocular refractive system, and increases the risks of lens surgery. While postnatal growth of lens is based on the addition of lens fibre cells (LFCs) supplemented by proliferation and differentiation of lens epithelial cells (LECs), it remains unknown how these cellular processes change in highly myopic eyes and what signalling pathways may be involved. Single-cell RNA sequencing was performed and a total of 50,375 single cells isolated from the lens epithelium of mouse highly myopic and control eyes were analysed to uncover their underlying transcriptome atlas. The proportion of LFCs was significantly higher in highly myopic eyes. Meanwhile, Notch2 signalling was inhibited during lineage differentiation trajectory towards LFCs, while Notch2 predominant LEC cluster was significantly reduced in highly myopic eyes. In consistence, Notch2 was the top down-regulated gene identified in highly myopic lens epithelium. Further validation experiments confirmed NOTCH2 downregulation in the lens epithelium of human and mouse highly myopic eyes. In addition, NOTCH2 knockdown in primary human and mouse LECs resulted in enhanced differentiation towards LFCs accompanied by up-regulation of MAF and CDKN1C. These findings indicated an essential role of NOTCH2 inhibition in lens overgrowth of highly myopic eyes, suggesting a therapeutic target for future interventions.

Cataract surgery in Keratoconus revisited - An update on preoperative and intraoperative considerations and postoperative outcomes

PURPOSE

This review aims to evaluate and simplify the recent literature on preoperative surgical planning, intraoperative considerations, postoperative surprises, and their management in patients with keratoconus undergoing cataract surgery.

METHODS

A review of the literature was done to analyze all the pertinent articles on Keratoconus and cataract surgery.

RESULTS

The surgical planning of cataracts in eyes with keratoconus needs a multifaceted approach. Preoperatively, techniques such as cross-linking or the use of intra-corneal rings help stabilize the progression. Unreliable biometric measurements are a significant problem in keratoconus patients, especially in an advanced stage of the disease. It is better to consider actual K readings if the K value is less than 55D but for a K value, more than 55D using standard K values will prevent postoperative refractive surprises. For calculation of K values, an elevation-based device like pentacam gives better repeatability in mild to moderate cases whereas for advanced keratoconus none of the keratometers is reliable. Recently, the Kane keratoconus formula performed better in all stages of disease whereas previous studies showed good results with SRK/T formula is a mild and moderate disease. Monofocal intraocular lenses are a better choice in these patients. Toric lenses can be used in mild and stable keratoconus. Intraoperatively, the use of a customized RGP lens can overcome the challenge of image distortion and loss of visual perspective. Despite taking necessary measures, postoperative refractive surprise can occur and can be managed with IOL exchange or Secondary IOLs.

CONCLUSION

There is a spectrum of challenges in managing cataracts in keratoconus which makes thorough preoperative planning important for good surgical outcomes. Despite the measures, there might be post-operative surprises and the patients need to be informed regarding the same.

Cataract surgery considerations in patients with prior history of keratoconus and ectasia

PURPOSE OF REVIEW

Preoperative workup for cataract surgery in patients with keratoconus poses certain challenges, particularly in patients with moderate-to-severe disease. This review aims to outline the appropriate preoperative, intraoperative, and postoperative considerations and provides an algorithm to help guide the workup prior to surgery.

RECENT FINDINGS

A new system for keratoconus progression and staging has been proposed and additional studies comparing intraocular lens (IOL) formulas calculations and biometry devices have been conducted.

SUMMARY

Patients with severe keratoconus have unpredictable results and have an increased risk of a hyperopic refraction postoperatively. Although studies have compared IOL calculation formulas, there is no consensus on management. Clinical considerations and an approach to the workup are presented; however, additional studies are required to determine the most appropriate management of cataracts in severe keratoconus.

Cataract surgery in patients with underlying keratoconus: focused review

An underlying diagnosis of keratoconus (KC) can complicate cataract surgery. In this study, the results of a focused review of the literature pertaining to cataract surgery in patients with KC are detailed. Topics essential for the appropriate management of this patient population are discussed. First, the individual and shared epidemiology and pathophysiology of cataract and KC are reviewed. Then, the theory and approach to intraocular lens power calculation are discussed, highlighting particularities and pitfalls of this exercise when performed in patients with KC. Finally, several special-although not uncommon-management scenarios and questions are addressed, such as surgical planning in cases where corneal stabilization or tissue replacement interventions are also necessitated.

A Case Exhibiting Late, Postoperative, Toric Intraocular Lens Rotation

Purpose: We present a case of spontaneous toric intraocular lens (IOL) rotation in the late postoperative period (after 10 months).Case summary: A 44-year-old male underwent phacoemulsification and placement of an IOL (AcrySof IQ Toric, Alcon Laboratories Inc., Fort Worth, FL, USA) in the right eye. The preoperative best corrected visual acuities (BCVAs) were 0.2 in the right eye and 0.3 in the left eye, and the corneal astigmatisms -2.25 × 175° and -2.25 × 178°. Ten months later, the astigmatic IOL axis was 85° (the initial [correct] value). The BCVA after surgery was 1.0. At 11 months postoperatively, the patient presented with a sudden decrease in visual acuity in the right eye. The IOL had rotated 50° clockwise; we decided to reposition it. A capsular tension ring had been placed during surgery. The IOL was re-aligned but rotated again 1 week later. We replaced the IOL with a monofocal non-toric IOL (enVista MX60, Bausch & Lomb, Rochester, NY, USA).Conclusions: Severe toric IOL rotation is a late postoperative complication.

Comparison of visual outcomes of a diffractive trifocal intraocular lens and a refractive bifocal intraocular lens in eyes with axial myopia: a prospective cohort study

Background

To assess and compare the efficacy, safety, accuracy, predictability and visual quality of a diffractive trifocal intraocular lens (IOL) and a refractive rotationally asymmetric bifocal IOL in eyes with axial myopia.

Methods

This prospective cohort study enrolled patients with implantation of the diffractive trifocal IOL or the refractive bifocal IOL. Eyes were divided into four groups according to the IOL implanted and axial length. Manifest refraction, uncorrected and corrected visual acuity at far, intermediate and near distances, prediction error of spherical equivalent (SE), contrast sensitivity and aberrations were evaluated three months after surgery.

Results

In total, 80 eyes of 80 patients were included: 20 eyes in each group. Three months postoperatively, the corrected distance visual acuity of two trifocal groups were significantly better than the axial myopia bifocal group (P = 0.007 and 0.043). There was no significant difference of postoperative SE (P = 0.478), but the SE predictability of the trifocal IOL was better, whether in axial myopia groups (P = 0.015) or in control groups (P = 0.027). The contrast sensitivity was similar among four groups. The total aberration, higher order aberration and trefoil aberration of bifocal groups were significantly higher (all P < 0.001).

Conclusions

The diffractive trifocal IOL and the refractive bifocal IOL both provided good efficacy, accuracy, predictability and safety for eyes with axial myopia. By contrast, the trifocal IOL had a better performance in corrected distance visual acuity and visual quality.

Trial registration

The study was retrospectively registered and posted on clinicaltrials.gov at 12/02/2020 (NCT04265846).

An Experimental Laboratory Study Using the Miyake-Apple Posterior View Technique to Investigate the Dynamics Between Capsular Bags and Different IOL Models

PURPOSE

To evaluate the dynamics between capsular bags and different intraocular lens (IOL) models in human cadaver eyes using the Miyake-Apple posterior view technique.

METHODS

In an in vitro laboratory study, human cadaver eyes were prepared according to the Miyake-Apple posterior view technique. Five IOLs from each of the six groups (Avansee 1P [Simonvision], Avansee 3P [Simonvision], CT Lucia [Carl Zeiss Meditec], Acrysof [Alcon Laboratories, Inc], RayOne [Rayner], and CT Asphina [Carl Zeiss Meditec]) were implanted into capsular bags with different diameters. The empty capsular bag diameter and capsular bag diameter with an IOL in it were evaluated based on the Miyake-Apple view pictures. Posterior capsule striae were observed and compared between groups. The arc of contact between IOLs and the capsular equator was noted. Correlations between the empty capsular bag diameter and the capsular bag diameter with IOL, as well as between the empty capsular bag diameter and the arc of contact, were examined. With the Avansee 3P as a reference, the area deviation of the haptics of IOL models with looped haptics was compared.

RESULTS

The capsular bag diameter with IOL inside and the arc of contact were proportional to the empty capsular bag diameter. The RayOne, Avansee 3P, and CT Lucia showed a longer arc of contact. Posterior capsule striae were observed in the Avansee 1P (1, 20%), Avansee 3P (5, 100%), Acrysof (1, 20%), and RayOne (2, 40%). Areas of deviation were 0.38 mm² (Avansee 1P), 0.24 mm² (CT Lucia), 0.34 mm² (Acrysof), and 0.31 mm² (RayOne), respectively.

CONCLUSIONS

Different IOL models showed varied characteristics in terms of capsular bag fitting and arc of contact. Understanding these dynamics is critical to optimizing postoperative outcomes. [J Refract Surg. 2022;38(10):654-660.].

Deviation from the planned axis of three toric intraocular lenses

In this study, we retrospectively evaluated the deviation from the planned axis of 3 Toric intraocular lenses (TIOL). Included in the study 190 eyes, operated by two surgeons using two different manual marking techniques. The patients were implanted with either AcrySof IQ Toric SN6AT (Alcon) (n = 90), POD FT (PhysIOL) (n = 50), or TECNIS Symfony Toric (J&J) (n = 50). At least 1 month postoperatively, the IOL was photographed, and the axis was measured using a designed software. The difference between the planned and actual axis was defined as axis deviation. The effect of IOL type, astigmatism direction, and marking techniques on the average degree and direction of the IOL deviation were evaluated and compared. There was no significant difference in the average deviation between the IOLs (TECNIS Symfony: 4.03° ± 4.34, POD FT: 3.52° ± 3.38, and SN6AT: 4.24° ± 4.10), and its direction (55.8%, 39.0%, and 56.6% clockwise (CW) deviation, respectively). With the rule, astigmatism had significantly more CW deviation compared with against the rule and oblique astigmatism (64.3%, 43.8%, and 41.7%, respectively, P = 0.027), but the average deviation was similar. The marking techniques did not influence the degree or direction of the deviation.

Toric intraocular lenses: Evidence‐based use

Uncorrected refractive astigmatism degrades visual acuity. Spherical intraocular lenses (IOLs) leave astigmatic errors resident in the cornea manifest in refractive astigmatism. Toric IOLs, correcting for this corneal astigmatism, contribute to spectacle‐free vision in the pseudophakic eye. This review provides information to assist surgeons in a rational choice of eyes suitable for toric IOL implantation, methods of IOL cylinder power calculation, surgical techniques for toric IOLs and management of complications. With appropriate application of this information, correction of visually detrimental astigmatism can be achieved routinely.

Long-term outcomes of cataract surgery with toric intraocular lens implantation by the type of preoperative astigmatism

Surgical outcomes of toric intraocular lens (IOL) implantation for 8 years after surgery were analyzed. Data were retrospectively collected in 176 eyes of 176 patients before and 1 month, 1, 3, 5, and 8 years after phacoemulsification and implantation of a toric IOL. Preoperative corneal and postoperative manifest astigmatism was analyzed by converting to power vector notations; horizontal/vertical (J₀) and oblique (J₄₅) astigmatism components. Toric IOL implantation significantly reduced pre-existing astigmatism by decreasing J₀ in eyes with preoperative with-the-rule (WTR) astigmatism, increasing J₀ in eyes with against-the-rule (ATR) astigmatism, and correcting J₄₅ in eyes with oblique astigmatism. After surgery, the eyes with preoperative ATR astigmatism showed a significant ATR astigmatic shift, and J₀ at 5 and 8 years was significantly smaller than that at 1 month postoperatively. Uncorrected distance visual acuity was also significantly worse at 5 and 8 years than at 1 month postoperatively. In eyes with WTR and oblique astigmatism, the effects of toric IOLs on astigmatism and visual acuity were sustained for 8 years. The long-term astigmatism-correcting effects did not differ among the models of toric IOL used in this study, SN6AT3–8 (Alcon Laboratories). In eyes with preoperative ATR astigmatism, astigmatism-correcting effects of toric IOLs decreased at 5 years and later postoperatively, indicating that overcorrection may be considered at the time of cataract surgery. In eyes with WTR and oblique astigmatism, the effects of toric IOLs were maintained throughout the 8-year follow-up period.

Evaluation of Intraocular Lens Tilt and Decentration in Congenital Ectopia Lentis by the Pentacam Scheimpflug System

Purpose

The purpose of this study was to quantify the characteristics of the tilt and decentration of the IOL after trans-scleral suture fixation surgery in congenital ectopia lentis (CEL) patients.

Methods

The clinical characteristics of 70 CEL patients at Zhongshan Ophthalmic Center in China were retrospectively analyzed. The tilt and decentration of intraocular lens (IOL) were measured by using a Pentacam and compared between different axial length (AL) subgroups. The correlation between IOL tilt, decentration, and ocular characteristics was investigated using Spearman's correlation analysis.

Results

The postoperative IOL position of CEL patients was mainly located nasally inferiorly. The average tilt of the IOL in CEL patients was less than 7° (for temporal: 2.21 ± 1.53°, for nasal: −1.84 ± 2.04°, for superior: 2.22 ± 2.18°, and for inferior: −1.70 ± 1.62°), and the average decentration of the IOL in CEL patients was larger than 0.4 mm (for temporal: 0.49 ± 0.38 mm, for nasal: −0.69 ± 0.46 mm, for superior: 0.72 ± 0.58 mm, and for inferior: −0.68 ± 0.54 mm). The decentration of CEL patients in the AL ≥ 26 subgroup was greater than those with AL < 24 mm and AL 24 to 26 mm subgroups (for superior: 0.72 ± 0.28 mm vs. 0.46 ± 0.25 mm and 0.48 ± 0.22 mm, all P < 0.05; for inferior: -0.94 ± 0.56 mm vs. −0.44 ± 0.26 mm and -0.44 ± 0.46 mm, all P < 0.05). IOL decentration was positively correlated with AL (for superior: r = 0.44, P=0.019; for inferior: r = 0.54, P=0.006). IOL tilt was positively correlated with AL on the superior side (r = 0.38, P=0.041).

Conclusions

The extent of IOL decentration after trans-scleral suture fixation was great in CEL patients, and the IOL decentration in CEL patients was significantly associated with AL.

Comparison of Anterior Capsule Polishing on the Rate of Neodymium: YAG Laser Capsulotomy After Two Multifocal Intraocular Lens Implantation

Purpose

To compare the impact of anterior capsule polishing (ACP) during cataract surgery on the rate of neodymium: YAG (Nd: YAG) laser capsulotomy in pseudophakic eyes with two multifocal intraocular lenses (MIOLs).

Methods

Data were collected on patients who underwent cataract surgery and implanted segmental refractive MIOLs (SBL-3, Lenstec) or diffracted MIOLs (AT LISA tri 839MP, Carl Zeiss Meditec). The participants were divided into ACP and non-ACP groups based on whether the anterior capsule was polished. The primary outcome measure was whether Nd: YAG capsulotomy was performed during the 3 years follow-up. We used Kaplan–Meier survival curves to determine the time from IOL implantation to Nd: YAG laser capsulotomy.

Results

ACP and non-ACP groups comprised 70 and 60 eyes, respectively. One year postoperatively, 7.14% of ACP group eyes and 8.33% of non-ACP group required Nd: YAG laser capsulotomy (P &gt; 0.99). After 2 years, it was 24.29 and 18.33%, respectively (P = 0.52), while after 3 years, it reached 30.0 and 28.33% (P = 0.85). No distinct difference existed in the probability of using Nd: YAG laser in both groups evaluated using Kaplan-Meier survival curves (P = 0.81). Patients with diffractive MIOLs (AT LISA tri 839MP) implantation were more likely to require Nd: YAG laser capsulotomy (P &lt; 0.01).

Conclusion

Polishing the anterior capsule had no remarkable effect on reducing the rate of Nd: YAG laser capsulotomy following phacoemulsification in MIOLs. Patients with diffractive MIOLs implantation had a high probability of requiring Nd: YAG laser capsulotomy.

Impact of Material and Lens Design on Repositioning Surgery of Toric Intraocular Lenses: A Single-Arm Meta-Analysis

Aim

To analyze the pooled incidence rate in repositioning surgery by considering different materials and designs.

Methods

All published studies investigating the repositioning surgery of toric intraocular lenses (IOLs) before September 1, 2020, were searched and evaluated. The R3.5.2 software was used to extract the data, and a single arm meta-analysis was performed.

Results

19 cases from 18 published studies articles were included in the meta-analysis. The pooled incidence rate in repositioning surgery was 2% (I² = 53%, P_{heterogeneity}<0.01). Plate and silicone IOLs had significantly higher incidence rates (6% for each) than loop (2%) and hydrophobic acrylate (2%). Incidence rates of Acrysof, Staar, TECNIS, PhysIOL SA, T-flex 623T, and Microsil 6116TU groups were 1% (95% CI [1%–2%]), 6% (95% CI [4%–9%]), 3% (95% CI [2%–4%]), 1.40% (1/71), 3.03% (1/33), and 4.76% (1/21), respectively.

Conclusions

The pooled incidence rate of repositioning surgery in IOLs was 2%. Materials and designs would be risk factors for the rotational stability of the toric IOLs. Pooled incidence rates of the hydrophobic acrylate and loop group were lower than those of the silicone and plate group. Product identity is the main driver of heterogeneity.

Clinical Characteristics and Early Visual Outcomes of Highly Myopic Cataract Eyes: The Shanghai High Myopia Study

Purpose: To report ocular characteristics and early visual outcomes of highly myopic cataract eyes, and to analyze the risk factors of low vision. Methods: A total of 2,027 eyes of 1,400 cataract patients with axial length (AL) ≥ 26 mm undergoing cataract surgery in Eye & ENT Hospital of Fudan University, who were registered in the Shanghai High Myopia Study, were analyzed. Routine pre-operative ophthalmic examinations were performed and macular scan of optical coherence tomography (OCT) were obtained. Macular complications, central foveal thickness (CFT) and subfoveal choroidal thickness (SFCT) were evaluated from OCT images. Ocular and surgical history and perioperative complications were also recorded. Uncorrected and best-corrected visual acuity (UCVA/BCVA) 1 month post-operatively and its influencing factors were evaluated. Results: The average AL of all involved eyes was 29.52 ± 2.26 mm, and 39.7% of which were with an AL > 30 mm and 26.4% of which were with a corneal astigmatism more than 1.5 D. Nuclear cataract accounted for the largest proportion (70.6%). The rate of overall macular complications was 27.6%. Postoperative UCVA and BCVA were 0.70 ± 0.46 and 0.25 ± 0.32 logMAR, respectively. BCVA improved significantly after surgery (vs. P < 0.001) and affected by the elongation of AL (P < 0.001) and thinning of CFT and SFCT (both P < 0.001). The risk factors of post-operative low vision (BCVA < 20/66) were macular atrophy, lamellar macular hole, high corneal astigmatism, long AL, thin SFCT and junior surgeons, odds ratios ranging from 1.54 to 54.87 (all P < 0.05). Conclusion: Cataract surgery could improve the VA of highly myopic eyes. Eye with macular complications, higher corneal astigmatism, longer AL, thinner SFCT, and who was treated by a junior surgeon, may have a high risk of low vision after surgery.

Evaluation of Decentration, Tilt and Angular Orientation of Toric Intraocular Lens

Purpose

The aim of this study was to develop software for the universal objective evaluation of factors influencing intraocular correction of astigmatism, such as decentration, tilt, axial position and angular orientation the toric intraocular lens (IOL).

Patients and Methods

Software was developed using the MS Visual Studio environment. The analysis was presented using images of 67 eyes with an implanted IOLs of the SN6ATx model series. Decentration and angular position of the lens were obtained from images of the anterior segment of the eye, using a Visucam unit. Tilt was measured on tomographic images from OCT Avanti (in meridian of highest tilt and perpendicular meridian) and preoperative biometry parameters of eye (axial length, anterior chamber depth – ACD, ocular lens thickness – LT, limbus diameter and mean keratometry value) including postoperative anterior chamber depth (pACD) were measured using Lenstar LS900.

Results

Applying the software methodology to the evaluation of individual toric IOL parameters, the following results were obtained: mean decentration 0.25 ± 0.17 mm which was observed in 61.19% of eyes, mean misalignment to the planned axis equal to 3.8 ± 3.6 degrees, mean highest inclination equal to 3.7 ± 1.2 degrees and mean difference of pACD and ACD was equal to 1.46 ± 0.31 mm. There was only a weak nonsignificant correlation between preoperative ACD versus decentration and tilt of IOL or a weak significant correlation between preoperative LT and both decentration and misalignment of IOL.

Conclusion

The use of the presented methodology for determining the positional parameters of the toric IOL provided comparable results with the results of recent studies. Software design can be considered as a suitable alternative to previously published techniques, with the significant advantage of the possibility of using universal input images, their graphical editing and especially the possibility of comprehensive analysis of all parameters.

[The impact of the position of toric intraocular lenses on the functional outcomes of phaco surgery]

The article reviews data on the impact of the position (orientation) of toric intraocular lenses on the functional outcomes of cataract phacoemulsification surgery, discusses the algorithm of astigmatism correction with intraocular lenses including preoperative determination of the size and position of main meridians, calculation of lens parameters, marking of corneal meridians, intraoperative positioning, as well as rotation and/or repositioning of the lens when necessary.

Rotational stability of Toric intraocular lenses

BACKGROUND

A prospective study to evaluate the rotational stability of toric intraocular lenses (IOLs).

METHODS

A prospective study of 30 eyes in 29 patients. All patients with regular astigmatism of range 0.75-4 D were included in the study. Exclusion criteria included irregular corneal astigmatism, post-refractive surgery and corneal dystrophies. All patients underwent uncomplicated phacoemulsification cataract surgery by the same surgeon. Three eyes with corneal astigmatism of 0.75-1.5 D were implanted with the AcrySof SA60T3 IOL, eight eyes with astigmatism between 1.5 and 2.0 D received the SA60T4 IOL and eight eyes with astigmatism between 2.0 and 2.50 D received the SA60T5 and rest with astigmatism of 2.5 D and higher received SA60T6 and above models. Main outcome measure was the post-operative position of the lens, assessed at day 1, 1 week, 1 month and 6 months, using toric marker and the slit lamp.

RESULTS

There was no significant rotation of IOL observed during a follow-up period of 6 months. Overall, the post-operative rotation was within 5° in 95% of cases. There was no trend for either clockwise or anti-clockwise rotation. However, IOL rotation happens mostly within the first month of surgery, and if it is significant, it requires early repositioning.

CONCLUSION

Toric IOLs are very effective and consistent in correcting astigmatism during the cataract surgery. Once placed to its position, toric IOLs demonstrate rotational stability in the capsular bag.

The Effect of Toric Intraocular Lens Implantation in Irregular Corneal Steep and Flat Meridian

Purpose

To evaluate the effect of toric intraocular lens implantation in cataract patients with irregular corneal steep and flat meridian.

Methods

Data of 112 eyes of 78 patients who underwent toric intraocular lens implantation were analyzed retrospectively. Steep meridian deviations (not 180°) and steep and flat meridian deviations (not 90°) were classified as 0, 1–9, 10–19, 20–29, 30–39, and over 30°. Meridian deviation was measured with a sagittal map of a rotating Scheimpflug camera (Pentacam®: Oculus, Wetzlar, Germany) using PicPickTools (NGWIN, Seoul, Korea).

Results

Residual astigmatism (D) of 0 (0.51 ± 0.13, 0.55 ± 0.15) and 1–9 (0.61 ± 0.16, 0.66 ± 0.19) groups were significantly lower than that of 10–19 (0.92 ± 0.24, 0.90 ± 0.28), 20–29 (0.10 ± 0.32, 1.01 ± 0.35), and over 30° groups (1.12 ± 0.37, 1.14 ± 0.40) both in steep meridian deviations and horizontal and vertical meridian deviations at 6 months (P < 0.05). Postoperative mean UCVA (logMAR) of 0 (0.09 ± 0.04, 0.09 ± 0.05) (logMAR) and 1–9 (0.10 ± 0.04, 0.11 ± 0.08) groups was significantly improved compared to that of 10–19 (0.14 ± 0.05, 0.17 ± 0.10), 20–29 (0.18 ± 0.08, 0.21 ± 0.10), and over 30° groups (0.20 ± 0.09, 0.22 ± 0.11) both in steep meridian deviations and horizontal and vertical meridian deviations at 6 months (P < 0.05).

Conclusions

Correction of astigmatism with toric intraocular lens implantation is not accurate in corneas with steep meridian deviations and steep and flat meridian deviations of more than 10°. Therefore, care should be taken when we perform toric intraocular lens implantation in patients with irregular corneal meridian.

Rotational Stability of a New Hydrophobic Acrylic IOL With Modified C-loop Haptics

PURPOSE

To assess rotational stability, axial stability, decentration, and tilt of the Rayner RAO800C single-piece hydrophobic acrylic intraocular lens (IOL) (Rayner Intraocular Lenses Ltd) from end of surgery to 4 to 7 months postoperatively.

METHODS

Surgeries were performed at the Department of Ophthalmology at the Medical University of Vienna. A total of 130 eyes of 68 patients received an aspheric hydrophobic Rayner RAO0800C IOL. IOLs were randomly implanted to the 0 ± 10, 45 ± 10, 90 ± 10, or 135 ± 10 degree axis. Baseline measurement was performed with the patient still supine on the operating table. Axis alignment after 1 hour, 1 week, 1 month, and 4 months was evaluated by retroillumination pictures. Postoperative IOL decentration, tilt, and aqueous depth at 4 months were assessed using an anterior segment swept-source optical coherence tomography.

RESULTS

Absolute median IOL rotation from end of surgery to 4 months was 2.4 degrees (range: 0.0 to 85.0 degrees). Median IOL rotation from end of surgery to 1 hour, 1 hour to 1 week, 1 week to 1 month, and 1 month to 4 months was 1.6 (range: 0.0 to 86.2), 1.1 (range: 0.0 to 28.8), 0.6 (range: 0.0 to 5.2), and 0.7 (range: 0.0 to 2.6) degrees. Respective proportions of IOLs rotating more than 5, 10, and 20 degrees from end of surgery to 4 months were 23.9%, 11.0%, and 6.4%. Horizontal and vertical decentration at 4 months was -0.09 ± 0.14 and 0.09 ± 0.14 mm, respectively. Horizontal and vertical tilt at 4 months was -4.78 ± 1.36 and -1.58 ± 1.10 degrees, respectively. A posterior axial shift of 0.052 ± 0.055 mm was observed from 1 week to 4 months.

CONCLUSIONS

Although median IOL rotation appeared to be low, a significant proportion of IOLs rotated postoperatively. Decentration and tilt values were generally low. A minimal posterior optic shift was observed after 1 week. [J Refract Surg. 2021;37(2):112-118.].

Toric intraocular lens implantation - atypical cases

Objective: To describe the results of toric intraocular lens (IOL) implantation in three atypical cases (four eyes) with cataract and corneal astigmatism: one with bilateral keratoconus, one with pellucid marginal degeneration and one with buphthalmos due to congenital glaucoma.

Methods: Three patients (four eyes) with corneal astigmatism (one with bilateral keratoconus, one with pellucid marginal degeneration and one with buphthalmos due to congenital glaucoma) underwent cataract surgery by standard phacoemulsification and the implantation of toric IOLs in the capsular bag. The presence of corneal astigmatism was identified by automated keratometry and confirmed by Scheimpflug-based corneal tomography. The toric IOL implanted in all cases was a single-piece AcrySof Toric IOL (Alcon Laboratories, Inc.). Postoperative visual acuity, the reduction in the refractive astigmatism, the spherical equivalent (SE) and the rotational stability of the toric IOL were recorded for all the patients.

Results: Visual acuity increased and the refractive astigmatism decreased in all cases. In Case 1, the right eye achieved a postoperative uncorrected visual acuity (UCVA) of 20/ 20, a decrease in the refractive astigmatism from -3 DCyl to -0.75 DCyl and a spherical equivalent (SE) of -0.25. The left eye presented with a best-corrected visual acuity (BCVA) of 20/ 20, a decrease in the refractive astigmatism from -1.50 DCyl to -1.25 DCyl and a SE of -0.25. In Case 2, the postoperative UCVA was 20/ 20, with a decrease in the refractive astigmatism from -5.5 DCyl to -1 DCyl and a SE for the right eye of 0.00 D. In Case 3, the postoperative BCVA was 20/ 20, with a decrease in the refractive astigmatism from -4.75 DCyl to -1.50 DCyl and a SE of +1.25. No misalignment of the axis of the toric IOL was observed in any patient at subsequent follow-ups. The postoperative visual acuity was satisfactory for all the patients.

Conclusions: Toric intraocular lenses can be an effective option for implantation in patients with cataract and corneal astigmatism in atypical situations such as mild to moderate keratoconus, pellucid marginal degeneration and buphthalmos due to congenital glaucoma. Predicting the refractive outcome is difficult in atypical cases and the surgeon should have accuracy and consistency in the preoperative measurements, for achieving satisfactory postoperative results.

Rotational stability of toric intraocular lenses with a newly modified capsular tension ring

PURPOSE

To determine whether a newly modified capsular tension ring (CTR) is effective at preventing toric intraocular lens (TIOL) rotation and misalignment.

SETTING

John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

DESIGN

Experimental study.

METHODS

Ten human cadaver eyes were used to test the ease or difficulty of TIOL rotation in the capsular bag under 3 experimental conditions: a TIOL alone, a TIOL with a standard CTR, or a TIOL with a newly modified CTR with indentations in a sinusoidal pattern. Scores for the ease of IOL rotation were compared by using the nonparametric Friedman analysis of variance test. In addition, both anterior and posterior Miyake-Apple views were filmed to observe the rotational stability of TIOLs in the capsular bag under the 3 test conditions.

RESULTS

In the ten eyes of five patients, the rotational stability improved with a standard CTR, but further improvement was statistically observed (P < .05) with the newly modified CTR under all test conditions. This was true for both IOLs used (AcrySof and TECNIS toric IOLs), with or without ophthalmic viscosurgical device, and for either clockwise or counterclockwise rotations.

CONCLUSIONS

A newly designed CTR prototype represents a new technology for improving the rotational stability of a TIOL in the capsular bag. Under all test conditions, the prototype performed significantly better than a standard CTR. The results support the use of this new CTR design to improve the accuracy and refractive success of TIOLs.

Characteristics and factors associated with intraocular lens tilt and decentration after cataract surgery

PURPOSE

To analyze the characteristics and factors associated with intraocular lens (IOL) tilt and decentration after uneventful phacoemulsification with IOL implantation.

SETTING

Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.

DESIGN

Cross-sectional study.

METHODS

All patients underwent a general ophthalmologic examination and anterior segment photography. IOL tilt and decentration were measured with a second-generation anterior segment optical coherence tomography (Casia2). Univariate and multivariate regression analyses were performed to assess the association between IOL tilt and decentration with ocular biometric and systemic parameters, and the visual acuity.

RESULTS

A total of 196 eyes of 196 patients were enrolled in this study. IOLs showed a mean tilt of 4.8 degrees toward the inferotemporal direction, and the mean decentration was 0.21 mm. Both eyes presented a mirror symmetry relationship. Twenty-two eyes (11.22%) had a tilt greater than 7 degrees, and 21 eyes (10.72%) had a decentration more than 0.4 mm. Multivariate regression analysis showed previous pars plana vitrectomy (PPV) and short axial length (AL) were associated with greater IOL tilt (P = .014 and P < .001). In addition, long AL, thicker lens, and less capsulorhexis-IOL overlap were positively correlated with decentration (P < .001, P = .029, and P = .026). Corrected distance visual acuity did not directly correlate with IOL tilt and decentration (P = .417 and P = .550).

CONCLUSIONS

PPV history and short AL were associated with greater IOL tilt, whereas longer AL, thicker lens, and overlarge capsulorhexis contribute to greater decentration. Implantation of toric and multifocal IOLs in these patients should be cautious.

Anterior capsule coverage and rotational stability of an acrylic toric intraocular lens

PURPOSE

To investigate factors related to the rotational stability of an acrylic toric intraocular lens (IOL).

SETTING

Four ophthalmic surgical sites in Japan.

DESIGN

Prospective case series.

METHODS

The study included 120 eyes of 120 patients undergoing phacoemulsification and implantation of a toric IOL (AcrySof IQ, Alcon Laboratories, Inc.). At 1 hour postoperatively, the area of continuous curvilinear capsulorhexis (CCC) was measured, and the state of anterior capsule coverage on the IOL optic (total on or partial on) was recorded. The toric IOL axis orientation was assessed at the end of surgery and at 1 hour, 1 week, 1 month, and 6 months postoperatively. Multiple regression analysis was performed to explore any clinical factors relevant to IOL rotation from the end of surgery to 6 months postoperatively. The explanatory variables included age, anterior chamber depth preoperatively, axial length, type of corneal astigmatism (with-the-rule, against-the-rule, or oblique astigmatism), area of CCC, state of anterior capsule overlap on IOL optic (total coverage vs partial coverage), and surgical sites (surgeons).

RESULTS

The multiple regression analysis in 110 eyes of 110 patients indicated that anterior capsule overlap on the IOL optic was the only variable associated with IOL rotation at 6 months postoperatively (P = .0482). The mean absolute rotation at 6 months was 1.96 ± 1.81 degrees in the total on group and 3.79 ± 3.12 degrees in the partial on group (P = .0004).

CONCLUSIONS

Rotational stability of a single-piece, acrylic toric IOL was better in eyes with total anterior capsule coverage than that in those with partial anterior capsule coverage on the IOL optic.

Comparison of the rotational stability between plate-haptic toric and C-loop haptic toric IOLs in myopic eyes

PURPOSE

To compare the rotational stability of a plate-haptic toric intraocular lens (IOL) vs a C-loop haptic toric IOL in myopic cataract eyes.

SETTING

Eye and Ear, Nose, and Throat Hospital of Fudan University, China.

DESIGN

Prospective, randomized, controlled study.

METHODS

Cataract eyes with axial length (AL) more than 24.5 mm were randomly assigned to receive implantation of a C-loop haptic toric IOL (AcrySof Toric IOL) (Group A) or a plate-haptic toric IOL (AT TORBI 709M IOL) (Group B). IOL rotation, residual astigmatism, visual acuity, and higher-order aberrations (HOAs) evaluated with OPD-Scan III aberrometer were compared at 3 months postoperatively.

RESULTS

In total, 62 eyes of 62 patients were eligible for analysis: 31 in Group A and 31 in Group B. The mean rotation of toric IOLs was greater in Group A than that in Group B (8.00 ± 3.60 degrees vs 4.42 ± 3.24 degrees, respectively, P < .001), especially when IOLs were vertically placed. IOL rotation was positively correlated with AL in Group A, whereas no such correlations were found in Group B. Residual astigmatism in Group A was greater than that in Group B (-0.76 ± 0.30 diopter [D] vs -0.51 ± 0.29 D, respectively, P = .001). Fewer eyes achieved residual astigmatism of 0.50 D or less in Group A than in Group B (38.71% vs 64.52%). Group A had worse postoperative uncorrected visual acuity and higher total HOAs and coma for a 6.0 mm pupil than Group B, whereas postoperative corrected visual acuity was not different between the 2 groups.

CONCLUSIONS

The plate-haptic toric IOL might be a better choice for myopic cataract eyes with corneal astigmatism because of reduced postoperative rotation.

Characteristics and Risk Factors of Intraocular Lens Tilt and Decentration of Phacoemulsification After Pars Plana Vitrectomy

Purpose

The purpose of this study was to investigate the characteristics and risk factors of intraocular lens (IOL) tilt and decentration of phacoemulsification after pars plana vitrectomy (PPV) using swept-source optical coherence tomography (SS-OCT).

Methods

One hundred four eyes with prior PPV and 104 eyes without PPV undergoing uneventful cataract surgery were enrolled in this study. IOL tilt and decentration were measured by SS-OCT (CASIA2) 3 months postoperatively.

Results

The mean IOL tilt and decentration were greater in the PPV group (5.36 ± 2.50 degrees and 0.27 ± 0.17 mm, respectively) than in the non-PPV group (4.54 ± 1.46 degrees, P = 0.005; 0.19 ± 0.12 mm, P < 0.001, respectively). Multiple logistic regression showed that silicone oil (SO) tamponade (odds ratio [OR] = 5.659, P = 0.021) and hydrophilic IOL (OR = 5.309, P = 0.022) were associated with IOL tilt over 7 degrees, and diabetes mellitus (DM; OR = 5.544, P = 0.033) was associated with IOL decentration over 0.4 mm. Duration of SO tamponade was positively correlated with IOL tilt (P = 0.014) and decentration (P < 0.001). The internal total higher-order aberration, coma, trefoil, and secondary astigmatism in the PPV group were higher than in the non-PPV group, and positively correlated with IOL tilt (P < 0.05).

Conclusions

Patients with prior vitrectomy had greater IOL tilt and decentration than the non-PPV group. Longer duration of SO tamponade, hydrophilic IOL, as well as DM were the risk factors of greater IOL tilt and decentration in patients with prior PPV.

Translational Relevance

Optically sophisticated designed IOLs should be used cautiously in vitrectomized eyes.

Evaluation of the White-to-White Distance in 39,986 Chinese Cataractous Eyes

Purpose

To investigate the distribution of white-to-white (WTW) distance and its associations with other biometric parameters in Chinese cataractous eyes.

Methods

Data on 39,986 eyes from 23,627 Chinese cataract patients were analyzed. Ocular biometric parameters, including WTW distance, corneal curvature, anterior chamber depth (ACD), lens thickness (LT), central corneal thickness (CCT), and axial length (AL), were obtained using the ZEISS IOLMaster 700.

Results

The mean age of patients was 63.7 ± 12.4 years, and 57.61% were female. The mean WTW distance was 11.69 ± 0.46 mm. The WTW distance was larger in male patients than in female patients for all age groups (all P < 0.001). The WTW distance was positively correlated with corneal curvature and ACD and negatively correlated with age, LT, and CCT (all P < 0.001). Multivariable analysis revealed that a larger WTW distance was associated with younger age; male gender; larger corneal curvature, ACD, and LT; and thinner CCT (all P < 0.001). Notably, the association between WTW distance and AL was not linear. As the AL increased, the WTW distance initially increased, reached a peak in the group with ALs of 24.5 to 26 mm, and then slowly decreased. However, all of the myopic eyes (AL > 24.5 mm) still had larger WTWs than the normal and short eyes (AL ≤ 24.5 mm).

Conclusions

In Chinese cataractous eyes, the WTW distance was larger in younger male patients with flatter corneas, deeper anterior chambers, thicker lenses, and thinner central corneas. The association between WTW distance and AL was not linear, and WTW distance was the largest in eyes with ALs of 24.5 to 26 mm.