Simple method for accurate alignment in toric phakic and aphakic intraocular lens implantation

Significant Changes of Corneal Astigmatism After Levator Muscle Surgery for Acquired Blepharoptosis

PURPOSE

To investigate the change of corneal astigmatism after the correction of blepharoptosis.

METHODS

This was a single-center retrospective cohort study conducted in Taiwan from 2017 to 2021. The medical records of patients with acquired blepharoptosis who had received levator muscle surgeries were collected. The differences in corneal astigmatism between the measurements before and at least 1 month after surgeries were investigated. Subgroup analysis of various severities of blepharoptosis and different types of corneal astigmatism was performed to determine their impacts on the axial changes after blepharoptosis surgeries.

RESULTS

A total of 120 eyes of 68 patients were enrolled in this study. The mean axial change of corneal astigmatism was 17.4° after blepharoptosis surgeries, and 55 eyes (45.8%) had a change of at least 10°. In the subgroup analysis, the eyes with against-the-rule, with-the-rule, and oblique astigmatism had 42.9%, 68.4%, and 91.7% with an axial change of at least 10° after surgeries, respectively. The averaged axial change of corneal astigmatism after surgeries was 22.7° in eyes with severe blepharoptosis (margin to reflex distance 1 < 1 mm), whereas it was 12.0° in eyes with mild-to-moderate blepharoptosis (margin to reflex distance 1 ≥ 1 mm).

CONCLUSIONS

A high proportion of eyes had a crucial axial change in corneal astigmatism after blepharoptosis surgeries, especially in those with oblique astigmatism and severe blepharoptosis. For blepharoptosis patients needing refractive surgeries or astigmatism correction with toric intraocular lens implantation, a surgical correction of blepharoptosis may be considered beforehand.

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.

Comparison of visual efficacy and patient's satisfaction between two toric IOLs, enhanced for intermediate vision and monofocal

BACKGROUND

To compare the visual efficacy and patient satisfaction between 2 toric IOLs (TIOL), enhanced for intermediate vision or monofocal.

METHODS

A retrospective chart review was performed of 100 eyes from 68 astigmatic patients who underwent cataract surgery with implantation of a Tecnis Eyhance Toric II IOL (Johnson & Johnson Vision, Irvine, CA, USA) (Group 1, 50 eyes) or Tecnis TIOL (Group 2, 50 eyes). The uncorrected distant (UDVA), intermediate (UIVA), and near (UNVA) visual acuities; residual refractive astigmatism; defocus curve; and IOL axis rotation were evaluated at 1 week, 1 month, 2 months, and 3 months postoperatively.

RESULTS

The postoperative UDVA and UNVA refractive astigmatism values of the two groups were better than the preoperative measurements (P < 0.05), but there was no statistical difference between the two groups (P > 0.05). The postoperative UIVA of group 1 (0.18 ± 0.15 logMAR) was significantly better than that of group 2 (0.30 ± 0.25) (P < 0.05). The mean postoperative IOL rotation of group 1 (2.51 ± 0.79°) was lower than that of group 2 (3.02 ± 0.84°) (P < 0.05). Overall satisfaction of group 1 (1.27 ± 0.47) was better than that of group 2 (2.02 ± 0.53) (P < 0.05).

CONCLUSIONS

The Tecnis Eyhance Toric II IOL demonstrated less postoperative IOL rotation and excellent uncorrected intermediate vision compared with the Tecnis TIOL. Near visual acuity and overall satisfaction with the Tecnis Eyhance Toric II IOL were also higher than those with the Tecnis TIOL.

Relation between change of effective lens position and toric IOL rotation after toric IOL implantation

OBJECTIVE

To evaluate the relationship between change of effective lens position (ELP) and toric intraocular lens (IOL) rotation in patients with increasing postoperative refractive astigmatism after successful toric IOL implantation.

METHODS

The subjects include 61 people (61 eyes) with increasing residual astigmatism >0.5 D 3 months after successful toric IOL implantation. Clinical measurements included preoperative, 1-week, and 1-, 2-, and 3-month postoperative visual acuity; refraction; keratometer; anterior and posterior corneal astigmatism; ELP by Scheimpflug camera imaging; and IOL axis by slit-lamp biomicroscopic photograph with pupil dilation.

RESULTS

Residual astigmatism in postoperative month 3 (0.81 ± 0.50 D) is higher than that at postoperative week 1 (0.41 ± 0.38 D; p < 0.05). ELP decreased by 264.44 ± 163.25 μm, and the IOL rotated by 2.91 ± 1.44 degrees from week 1 to month 3 (p < 0.05). The ELP change had a positive correlation with IOL rotation (R2 = 0.383; p = 0.006), and the postoperative refractive astigmatic change had a positive correlation with ELP change (R2 = 0.272; p = 0.027) and IOL rotation (R2 = 0.272; p = 0.0001) from week 1 to month 3.

CONCLUSION

ELP change can influence toric IOL rotation and increase residual astigmatism after toric IOL implantation.

Toric intraocular lens: A literature review

Toric intraocular lenses (IOLs) are universally recommended in cataract cases with preoperative corneal astigmatism ≥1.5 D. An optimal surgical outcome depends on careful patient selection, complete preoperative evaluation, accurate IOL power calculation, precise marking of the axis, meticulous intraoperative approach, and methodical postoperative care. Understanding the importance of posterior corneal astigmatism, surgically induced astigmatism, and effective lens position in IOL power calculation and newer techniques to measure them directly have resulted in better postoperative refractive outcomes. We present a brief overview of toric IOLs along with the preoperative evaluation, IOL power calculation, different marking methods, intraoperative approach, and postoperative outcomes. Functional and anatomical outcomes, including uncorrected visual acuity, residual refractive astigmatism, and postoperative IOL misalignment, which have been reported for both toric IOLs and multifocal toric IOLs, are reviewed.

Comparison of toric intraocular lens alignment between femtosecond laser-assisted capsular marking and digital marking

PURPOSE

To compare the accuracy of toric intraocular lens (IOL) alignment between femtosecond laser-assisted capsular marking and digital marking.

SETTING

Ruhr University Eye Clinic, Bochum, Germany.

DESIGN

Prospective clinical trial.

METHODS

In this study, 28 eyes of 23 patients, who underwent femtosecond laser-assisted cataract surgery with implantation of a toric IOL, were included. Intraoperatively, both femtosecond laser-assisted capsular marking and digital marking were applied simultaneously and compared in every case. The toric IOL was aligned to the capsular markings. Postoperatively, the axis of the capsular markings and toric IOL alignment was examined. Visual acuity and refractive outcomes were evaluated.

RESULTS

Both alignment methods were performed without intraoperative complications in all cases. 25 eyes were included in the final analysis. Misalignment was significantly lower with femtosecond laser-assisted capsular marking than with digital marking (1.71 ± 1.25 degrees vs 2.64 ± 1.70 degrees, P = .016). Deviation from the target axis of the toric IOL was 1.62 ± 1.24 degrees 4 to 6 weeks postoperatively. Postoperative uncorrected distance visual acuity was 0.14 ± 0.13 logMAR, and residual astigmatism was 0.3 ± 0.23 diopter (D) with an astigmatism ≤0.5 D in 93% of eyes.

CONCLUSIONS

Both methods showed excellent results for the alignment of toric IOLs. However, femtosecond laser-assisted capsular marking was significantly more precise than digital marking and showed good refractive results. In addition, capsular marking offers the possibility to avoid parallax error and evaluating postoperative IOL rotation.

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.

[Refractive Results after Implantation of Toric Intraocular Lenses Using the Zeiss Callisto System]

BACKGROUND

For cataract patients with astigmatism, the insertion of a toric intraocular lens is a safe and effective method to achieve emmetropia. The exact alignment of the lens along the calculated axis is essential for effective correction of astigmatism. The purpose of this study is to evaluate our own data using descriptive statistics. The primary focus is on the refractive outcome and thus the verification of the alignment accuracy of toric IOLs with the Zeiss Callisto system.

PATIENTS AND METHODS

The study evaluated a total of 106 eyes of 72 patients who underwent cataract surgery with implantation of a toric intraocular lens at our hospital between January 2019 and December 2020. Preoperative biometry and intraoperative marking of the implantation axis was performed using the Zeiss Callisto system. Postoperative controls were performed after one day, one week and 4 weeks, either at our hospital or by the referring ophthalmologist. For the analysis, only the data of the 4-week control were used.

RESULTS

In 64 eyes (60%), a Zeiss AT Torbi 709 M or MP and in 42 eyes (40%) a PhysIOL Ankoris toric yellow IOL were implanted. In 46 eyes, postoperative uncorrected visual acuity was not recorded. Of the remaining 60 eyes, the mean postoperative uncorrected visual acuity was 0.07 ± 0.12 logMAR. Postoperative uncorrected visual acuity ≥ 1.0 (decimal) was achieved in 48% of the eyes and visual acuity ≥ 0.6 (decimal) in 92%. The postoperative cylinder averaged - 0.65 ± 0.53 D. The cylinder of the target refraction was - 0.45 ± 0.39 D on average. The mean of the absolute value of the postoperative cylinder minus the cylinder of the target refraction was 0.42 ± 0.32 D.

CONCLUSIONS

The Zeiss Callisto system is an effective tool to align toric intraocular lenses.

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.

Efficacy of the Image-Guided Alignment System for a Four-Haptic Hydrophobic Monofocal Toric Intraocular Lens

OBJECTIVE

To compare the difference in performance between the image-guided alignment system and the manual-marking method in the four-haptic hydrophobic monofocal toric intraocular lens (IOL).

METHODS

Medical records of patients who underwent cataract surgery with a four-haptic hydrophobic monofocal toric IOL implantation between May 2020 and April 2021 and with 3-month visit data available were investigated. Toric IOL misalignment, residual astigmatism, and mean prediction errors between the two groups were compared.

RESULTS

This study included 49 eyes of 44 patients (women: 68%; mean age: 67.2±7.0 [range: 47-82] years). Twenty-nine eyes of 26 patients were treated with toric IOL implantation using the image-guided system and 20 eyes of 18 patients were treated using the manual-marking method. No statistical differences were observed regarding the baseline characteristics of the two groups. Three months after the surgery, the misalignment of the toric IOL was significantly lower in the image-guided group (2.18°±0.65°, range: 1.26°-3.95°) than in the manual; marking group (4.72°±0.74°, range: 3.44°-6.21°; P<0.001).

CONCLUSION

In comparison to the manual-marking method, the image-guided system reduced the misalignment of a four-haptic hydrophobic monofocal toric IOL.

Comparing IOLM700 TK, Berdahl and Hardten astigmatism fix calculator and Barrett Rx formula in managing residual astigmatism due to toric intraocular lens misalignment

Purpose:

To compare the accuracy in astigmatism reduction by using IOLM 700 steep total keratometry (TK) axis, Berdahl and Hardten astigmatism fix, and Barrett Rx formula following misaligned toric intraocular lens (IOL).

Methods:

Ten patients with residual refractive astigmatism due to misalignment following toric IOL implantation were included in this retrospective study. They were analyzed at days 4, 7/8, and 10/11 following primary cataract surgery on the platform of Berdahl and Hardten astigmatism fix, Barrett Rx formula, and IOLM 700 to determine the optimum axis of repositioning, and underwent IOL realignment on the steep TK axis of IOLM 700 assisted by the Callisto eye. The final outcome parameters were subjective refraction and orientation of toric IOL assessed 22 ± 1 days following repositioning surgery. These parameters were fed in the Barrett Rx formula and its vector analysis graph was utilized to determine the predicted ideal axis with the least residual astigmatism and the estimated residual astigmatism if the toric IOL was realigned according to the axis suggested by Berdahl and Hardten astigmatism fix and Barrett Rx formula.

Results:

Realigning the toric IOL on IOLM 700 steep TK axis along with the Callisto eye reduces the residual refractive astigmatism significantly (P = 0.003) from 2.00 ± 0.78 D to 0.18 ± 0.12 D (90.5 ± 7.6%) in comparison to the estimated 0.57 ± 0.31 D (68.4 ± 21.9%) by Berdahl and Hardten astigmatism fix and 0.61 ± 0.33 D (66.4 ± 23.5%) by Barrett Rx formula.

Conclusion:

Realigning the misaligned toric IOL on the IOLM 700 steep TK axis gives a better reduction in the residual refractive astigmatism in comparison to Berdahl and Hardten astigmatism fix and Barrett Rx formula.

[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.

Toric intraocular lenses: Expanding indications and preoperative and surgical considerations to improve outcomes

Since the introduction of the first toric intraocular lens (IOLs) in the early 1990s, these lenses have become the preferred choice for surgeons across the globe to correct corneal astigmatism during cataract surgery. These lenses allow patients to enjoy distortion-free distance vision with excellent outcomes. They also have their own set of challenges. Inappropriate keratometry measurement, underestimating the posterior corneal astigmatism, intraoperative IOL misalignment, postoperative rotation of these lenses, and IOL decentration after YAG-laser capsulotomy may result in residual cylindrical errors and poor uncorrected visual acuity resulting in patient dissatisfaction. This review provides a broad overview of a few important considerations, which include appropriate patient selection, precise biometry, understanding the design and science behind these lenses, knowledge of intraoperative surgical technique with emphasis on how to achieve proper alignment manually and with image-recognition devices, and successful management of postoperative complications.

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.

Patient Expectation, Satisfaction and Clinical Outcomes with a New Multifocal Intraocular Lens

Purpose

To report patient expectations, visual performance and satisfaction with AcrySof IQ PanOptix multifocal intraocular lens in a heterogeneous patient group. Additionally, determine if identifiable pre-operative characteristics can predict post-operative satisfaction.

Methods

Data were prospectively collected for 67 consecutive patients (134 eyes) who underwent bilateral Panoptix implantation in a private ophthalmology clinic. A pre-operative questionnaire was completed regarding vision satisfaction, visual phenomena and expectations. Routine clinical parameters were collected 1 month and follow-up questionnaire administered 3 months post-operatively.

Results

Post-operative unaided distance vision was 20/20 (0.01 ± 0.10) and binocular near vision 20/25^-2 (N5; 0.14 ± 0.06). Patients satisfied with vision increased from 6% (n=4) unaided and 48% (n=32) aided pre-operatively to 94% (n=63) unaided post-operatively (p<0.001). There was marked increase in frequency of halo from 14% (n=9) to 69% (n=46; p<0.001) but no corresponding increase in how bothersome this symptom was (p=0.193) nor the frequency of other visual phenomena. Worse post-operative vision and fluctuating vision were associated with lower post-operative satisfaction. There was no difference in satisfaction or residual astigmatism in those implanted with toric lenses. A total of 96% (n=64) of patients were spectacle-free at 3-months and would recommend this procedure to others.

Conclusion

This study supports the trend towards increased patient expectations of multifocal intraocular lenses, matched by excellent visual outcomes and satisfaction. Visual phenomena may be less troubling with new multifocal lenses than previously reported. A pre-operative questionnaire may be a useful education tool but could not isolate pre-operative characteristics that predict post-operative satisfaction.

Clinical outcomes, predictability and rotational stability following implantation of Eyecryl toric versus TECNIS toric intraocular lenses-A comparative study

PURPOSE

To compare the visual outcomes, predictability and rotational stability following implantation of Eyecryl toric versus TECNIS toric intraocular lenses.

METHODS

This retrospective study included 100 eyes of 78 eligible patients who underwent phacoemulsification followed by implantation of either Eyecryl Toric IOL or TECNIS Toric IOL (n = 50 eyes in each group), using an intraoperative image-guided marker less system. All toric IOL implantations were performed under balanced salt solution. At 2 weeks, 3 months and 6 months, uncorrected (UDVA) and corrected distance visual acuity (CDVA), spherical equivalent refraction, residual astigmatism, and rotational stability of the toric IOL was evaluated and compared. Rotational stability was assessed using ray tracing.

RESULTS

Mean age of the participants was 67.8 ± 9.26 years in Eyecryl toric group and 64 ± 11 years in TECNIS toric group. The mean pre-op corneal astigmatism was 1.75 ± 0.62 D and 2.00 ± 0.71 D in the Eyecryl and TECNIS group, respectively (p = 0.07). At 2 weeks and at 6 months post-op, there was no statistically significant difference between the UDVA, CDVA, and residual astigmatism between the two groups (p < 0.05). Mean post-operative toric IOL rotation was 3.94 ± 2.27 degrees in the Eyecryl Toric group, and 4.44 ± 2.77 degrees, in the TECNIS Toric group, respectively, the difference was not statistically significant (p = 0.32). One IOL in the Eyecryl group and two IOLs in the TECNIS group required re-positioning for significant post-op rotation at 1 week post-op.

CONCLUSION

At 6 months, both Eyecryl toric and TECNIS toric IOLs showed comparable post-operative outcomes in terms of UDVA, CDVA, residual astigmatism and rotational stability.

Evaluation of Intraocular Lens Rotational Stability in a Multicenter Clinical Trial

Purpose

To evaluate the postoperative rotational stability of two prototype intraocular lens (IOL) designs (subsequently termed version 1 and version 2).

Patients and Methods

A prospective, multicenter, randomized, paired-eye, 6-month study evaluated the version 1 and version 2 IOLs. Results were compared with a control IOL (TECNIS^® toric 1-piece monofocal IOL) evaluated in a separate, similarly designed study. Participants aged ≥22 years and scheduled to undergo bilateral cataract extraction were randomly assigned 1:1 to receive the version 1 or version 2 IOL in the first operative eye; the alternate test IOL was then implanted in the second operative eye.

Results

Mean absolute IOL rotation at postoperative week 1 was the primary effectiveness end point. Additional end points included the percentage of eyes with postoperative IOL rotation >5°/>10°, direction of lens rotation, surgeon-reported ease of IOL handling during implantation, and safety. At postoperative week 1, mean (±standard deviation) absolute IOL rotation was significantly lower for both version 1 and version 2 versus control (0.88° [±0.94] and 0.71° [±0.69] vs 2.24° [±3.21], respectively; both P < 0.001). For both study lenses, absolute rotation was <5° for all eyes at postoperative week 1, and no cases of rotation >10° were observed at any postoperative time point. From postoperative week 1 onward, version 2 had a statistically significant clockwise bias in the direction of rotation (P = 0.03); similar findings were observed for version 1. Surgeons reported acceptable ease of IOL handling during implantation for both version 1 and version 2. No device-related adverse events were reported.

Conclusion

Both the version 1 and version 2 IOLs, each with frosted, squared haptics, demonstrated improved postoperative rotational stability compared with a control lens without frosted haptics. Because version 2 had the same overall geometry as the current TECNIS toric IOL, this design was selected for commercialization.

Trial Registration

German Clinical Trials Register, DRKS00015287.

Clinical outcomes and rotational stability following implantation of Eyecryl toric intraocular lens - Results of a 12-months prospective study

Purpose:

To evaluate the clinical performance and rotational stability after implantation of Eyecryl Toric monofocal IOL following cataract surgery.

Methods:

Patients undergoing phacoemulsification for age-related cataract and satisfying the eligibility criteria were implanted with Eyecryl Toric IOL. All implantations were done under balanced salt solution. A marker-less system Callisto Eye (Carl Zeiss Meditec, Germany) was used to guide the intra-operative alignment of the toric IOL.

Results:

A total of 50 eyes from 39 patients with mean age of 68.2 ± 8.7 years were included in the study. At 12 months, 82% (41) eyes had cumulative UDVA of 20/20 or better. Post-op SE refraction accuracy was within ± 0.50 D for 94% (n = 47) eyes and refractive cylinder accuracy was within ≤0.50 D in 98% (n = 49) eyes. Average post-op rotation at 1 year was 4.06 ± 2.15 degrees. Eighty-four percent of eyes were within 5 degrees and 16% were within 6-10 degrees of intended axis. Two eyes required IOL re-positioning due to significant rotation of the toric IOL (>10 degrees), identified within the 1^st week after surgery.

Conclusion:

Eyecryl toric IOL demonstrated the ability to achieve a significant reduction in astigmatism, improved UDVA outcomes, high levels of spectacle independence, low rates of intra-operative injector related complications and good rotational stability at 12 months post-op.

Time-efficiency assessment of guided toric IOL cataract surgery: a pilot study

PURPOSE

To compare the time spent on toric intraocular lens (IOL) implantation during cataract surgery using a manual-marking versus a digital image-guided system (the Verion) for toric IOL alignment.

SETTINGS

All procedures were performed at the Instituto Oftalmológico Quirónsalud ophthalmology clinic (A Coruña, Spain).

DESIGN

We designed an experimental and longitudinal (1-month follow-up) study.

METHODS

A total of 98 eyes of 65 participants (68.2 ± 12.2 years) were divided into two groups: 49 eyes operated with toric IOL alignment using a manual-marking technique (manual group) and another 49 eyes operated using image-guided marking (Verion group). The primary variable for comparison between both groups was cataract surgery time. Other outcomes such as toric IOL misalignment, spherical equivalent (SE), astigmatism, uncorrected distance visual acuity (UDVA), and corrected distance visual acuity (CDVA) were also measured.

RESULTS

The total cataract surgery time was 2:09 minutes shorter (p  < 0.001) with the Verion system (12:12 ± 2:20) compared to the surgical procedure performed using manual marking (15:27 ± 3:04). One month after surgery, there were no statistical differences in terms of toric IOL misalignment between the Verion (3.38° ± 2.95°) and the manual group (4.66° ± 3.95°). No statistical differences were observed between groups for refractive and visual outcomes either (p ≥ 0.05).

CONCLUSIONS

The cataract surgery time was reduced when the procedure was assisted using the Verion system to align the IOL compared to manual marking, maintaining the same efficacy in terms of toric IOL misalignment, residual refraction, and visual acuity.

Femtosecond laser-assisted arcuate keratotomy at the time of cataract surgery for the management of preexisting astigmatism

PURPOSE

To evaluate the outcomes of femtosecond laser-assisted arcuate keratotomy combined with cataract surgery in eyes with low-to-moderate corneal astigmatism.

SETTING

Eyes of York Private Practice Ophthalmology Clinic, York, Pennsylvania, USA.

DESIGN

Retrospective case series.

METHODS

This retrospective analysis included case records of patients with preexisting corneal astigmatism ranging from 0.5 to 2.0 diopter (D). Study parameters included corneal astigmatism, refractive astigmatism, and uncorrected (UDVA) and corrected (CDVA) distance visual acuities. The results, which were analyzed at 3 months postoperatively, included frequency distribution histograms, vector analysis, and single-angle polar plots.

RESULTS

The study comprised case records of 189 eyes of 143 patients (56 men and 87 women). The postoperative refractive astigmatism was reduced significantly compared with preoperative corneal astigmatism to 0.14 D ± 0.23 (SD) from 0.92 ± 0.34 D (P < .001). One hundred eighty-one eyes (95.8%) demonstrated postoperative refractive astigmatism of 0.5 D or less. The mean surgically induced change along the preoperative steep axis was -0.59 ± 0.56 D, and the change along the orthogonal axis was 0.01 ± 0.35 D. Postoperatively, 171 eyes (90.5%) had astigmatism angle of error of 15 degrees or less. The postoperative mean UDVA and CDVA were 0.09 ± 0.16 logarithm of the minimum angle of resolution (logMAR) and 0.02 ± 0.05 logMAR, respectively. One hundred seventy eyes (90%) had a postoperative UDVA of 20/30 or better. The results demonstrated stability at 12 months postoperatively. No intraoperative or postoperative arcuate keratotomy-related events were observed.

CONCLUSION

The results suggest that femtosecond laser-assisted arcuate keratotomy represents a safe and effective method for astigmatism correction at the time of cataract surgery with demonstrated stability of correction for at least 1 year postoperatively.

Comparison of the Orientation of the Corneal Steep Meridian Determined by Image-Guided System and Manual Method in the Same Eye

Purpose

To evaluate the difference between the preoperative marking methods for toric intraocular lens (IOL) implantations using an image-guided system (IGS) and the manual marking method in the same eye.

Patients and Methods

In this retrospective case series, 82 patients (101 eyes) who underwent cataract surgery using both manual and IGS (VERION, Alcon  Laboratories) marking were enrolled. First, preoperative reference marks were placed at 6 o’clock and 3 or 9 o’clock position under slit-lamp biomicroscope in the outpatient department using the manual method. Using the reference unit of IGS, the ocular surface data were captured and overlaid. The difference was then measured (preoperative axis misalignment). In the operating room, the orientation of the steep meridian of the manual method was determined based on this reference mark under the surgical microscope. Just before surgery, the digital degree gauge of IGS was overlaid on the ocular surface, and the difference was then measured (total axis misalignment). We calculated the intraoperative axis misalignment by subtracting preoperative axis misalignment from the total axis misalignment.

Results

Mean absolute preoperative, intraoperative, and total axis misalignment values were 3.87±3.95 degrees, 5.46±4.42 degrees, and 4.98±4.49 degrees, respectively. In preoperative, intraoperative, and total misalignment, the ratios of 10 degrees or greater were 10 (14.7%), 12 (17.6%), and 20 (19.8%) eyes, respectively.

Conclusion

The manual method that determines the fixed position of the toric intraocular lens (IOL) may cause large misalignment compared with the IGS, suggesting that using manual method could sometimes result in a large misalignment of toric IOL implantation.

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Spontaneous rotation of a toric implantable collamer lens related to abnormal ciliary body morphology: a case report

BACKGROUND

This is a case of spontaneous toric implantable collamer lens (TICL) rotation that occurred twice in the left eye of a patient.

CASE PRESENTATION

A 24-year-old gentleman received TICL implantation for treatment of myopic astigmatism encountered with spontaneous rotation of approximately 90° from its original position. TICL reposition procedure was performed with visual outcome of 20/16. Surprisingly, a re-rotation of TICL occurred. The patient underwent a replacement of non-toric ICL with a larger size after careful re-evaluation with final visual outcome of 20/20. A short and small ciliary process with shallow ciliary sulcus and posteriorly positioned ciliary body was found by Ultrasound Biomicroscopy (UBM).

CONCLUSIONS

The unique morphology of the ciliary body may have a potential association with the vault and instability of implanted ICL. Careful examination of the ciliary body morphology is essential in preoperative evaluation.

Rotational slit-beam marking: an advanced manual corneal astigmatic marking method for toric intraocular lens implantation

PURPOSE

To evaluate the accuracy of an advanced manual corneal astigmatic marking method for toric intraocular lens (IOL) implantation.

METHODS

From 52 patients, 52 eyes with cataracts and corneal astigmatism were included. The target axis of the toric IOL was marked with the new manual marking method preoperatively and with the Zeiss CALLISTO Eye image-guided system intraoperatively. For the manual method, a slit-lamp with a minimum rotation angle of 5 degrees was used and rotated to the meridian of the toric IOL and incision axes. The relative rotational and vertical deviation of the IOL and incision axes were measured using the digital marker as a reference.

RESULTS

There was no significant difference between the manually marked IOL axis (100.9° ± 65.62°) and the digital mark (100.8° ± 65.76°; P = 0.771). The absolute values of the relative rotational and vertical deviations of the manually marked IOL axis were small, at 2.03° ± 1.44° and 0.46 ± 0.43 mm, respectively. There was no significant difference between the manually marked corneal incision and the digital meridian (P = 0.179). Then, patients were classified into three groups based on the type of astigmatism they had. There was no significant difference in mean absolute deviation among the groups (P = 0.112). The manual incision mark had a relative rotational deviation of 1.65° ± 1.44°. The vertical misalignment of the manually marked incision axis was 0.27 ± 0.30 mm.

CONCLUSION

Rotational slit-beam marking could be an effective and convenient marking method for toric IOL implantation. This method could be a potential alternative in underdeveloped areas where digital image-guided systems are not available.

Optical tolerance to rotation of trifocal toric intraocular lenses as a function of the cylinder power

BACKGROUND

The aim was to assess the impact of 5- and 10-degree rotations in the optical quality of a trifocal toric intraocular lens with different amounts of cylinder.

METHODS

Two Physiol Toric intraocular lenses with 1.5 and 3.0 D of cylinder were analysed in three different positions: centred, 5 and 10 degrees rotated. The optical quality of the intraocular lenses was evaluated with the PMTF optical bench through specific perpendicular targets. The analysis was performed by the through-focus modulation transfer function curves and the modulation transfer function corresponding to distance vision (0 D of vergence).

RESULTS

For a centred situation, the through-focus modulation transfer function curves of both intraocular lenses showed the classical three peaks corresponding to the powers of the two principal meridians of the intraocular lenses. When 5 and 10 degrees of rotation were induced, the three peaks were attenuated in both cases. The case with the intraocular lens with 3.0 D of cylinder and 10 degrees of rotation showed the worst optical quality and a significant loss of trifocality. The modulation transfer function values obtained for distance vision also showed the worst optical quality for the intraocular lens with 3.0 D of cylinder and 10 degrees of rotation.

CONCLUSION

Rotations over 5 degrees decreased the optical quality of trifocal toric intraocular lenses, being this reduction moderate from 5 to 10 degrees for low levels of cylinder (≤1.5 D). For mid-high levels of cylinder (≥3.0 D), rotations over 5 degrees cause a significant loss of optical quality at all object distances.

Management of Cataract in Patients with Irregular Astigmatism with Regular Central Component by Phacoemulsification Combined with Toric Intraocular Lens Implantation

Purpose

To evaluate visual acuity (VA) and refractive status in patients with cataract and irregular astigmatism with a regular central component after phacoemulsification with implantation of a toric intraocular lens (IOL).

Methods

Patients with cataract associated with irregular astigmatism with a regular central component were enrolled. All patients underwent phacoemulsification and toric IOL implantation. Postoperative visual acuity, residual astigmatism, toric IOL rotation, higher-order aberration, and objective and subjective visual quality were measured 3 months after surgery.

Results

Twenty-three eyes were included in the study. The logMAR corrected and uncorrected distance visual acuity values were decreased at 3 months postoperatively (p  <  0.005). The preoperative average corneal astigmatism and postoperative residual astigmatism were 1.15–6.97 D (1.99 ± 1.26 D) and 0–2.75 D (0.65 ± 0.57 D), respectively. The average IOL rotation was 3.17 ± 2.01°. Some objective indicators of visual quality, including the modulation transfer function (p  <  0.05), Strehl ratio (p  <  0.005), 100% VA (p  <  0.005), 20% VA (p  <  0.005), and 9% VA (p  <  0.005), were significantly higher than the corresponding preoperative values. The objective scatter index (p  <  0.005) was significantly lower than that before surgery. The postoperative VF-14 scale score was 83.99 ± 14.58.

Conclusion

Toric IOL implantation has a good corrective effect on certain specific types of corneal irregular astigmatism with cataract. This effect can be attributed to its ability to correct the regular component of irregular astigmatism. The indications for toric IOL implantation could be expanded to some extent, thereby bringing benefit to more patients.

Astigmatic Outcomes of Single, Non-Paired Intrastromal Limbal Relaxing Incisions During Femtosecond Laser-Assisted Cataract Surgery Based on a Custom Nomogram

Purpose

To determine astigmatic changes of intrastromal limbal-relaxing incisions (LRIs) performed during femtosecond laser-assisted cataract surgery (FLACS).

Design

Retrospective case series.

Patients and Methods

Patients undergoing FLACS with adjunctive astigmatism management with intrastromal LRIs were included. All eyes had preoperative corneal cylinder (Kcyl) ≥0.20 D on ocular biometry. An intrastromal LRI nomogram of single, non-paired LRIs placed at the 9 mm optical zone was used. Keratometry was measured preoperatively, and postoperatively at 1 week, 1 month, and 3 months (POM3). Alpins astigmatism analysis was used to calculate target-induced astigmatism (TIA, equivalent to preoperative Kcyl), surgically induced astigmatism (SIA), difference vectors (DV), and correction indices (CI). Secondary analysis included multivariable binary logistic regression to determine clinical factors associated with corrections >125% (CI > 1.25).

Results

A total of 154 eyes (125 patients) were studied. Mean preoperative Kcyl was 0.87±0.42 D (SD), which did not significantly differ from POM3 Kcyl (0.87±0.51 D, p=0.470). Only the against-the-rule (ATR) subgroup demonstrated a small but significant reduction in Kcyl from preoperative (0.96±0.51D) to POM3 (0.89±0.55D, p=0.032). Sixteen eyes (10.4%) had Kcyl ≤0.5 D preoperatively, compared to 46 eyes (29.9%) at POM3 (p<0.0001). Mean SIA was 0.80±0.52 D. Mean DV was 0.85±0.47. Mean CI was 0.79. Fifty-one eyes (33%) had astigmatism correction >125%. On multivariable regression analysis, ATR astigmatism class (p=0.026) and lower arc lengths (30º) (p=0.005) were associated with correction >125%. Lower preoperative corneal astigmatism was inversely correlated with CI (p<0.001).

Conclusion

Although intrastromal LRIs can be conveniently performed during FLACS and appear safe, only patients with ATR astigmatism demonstrated a significant reduction in corneal astigmatism 3-months postoperatively under the current nomogram. Areas for future refinements to the nomogram were identified.

Verion digital marking versus smartphone-assisted manual marking and isolated manual marking in toric intraocular lens implantation

Purpose

To compare the accuracy of isolated manual marking and smartphone-assisted manual marking with the Verion image-guided system for toric intraocular lens (IOL) implantation.

Methods

In this prospective observational study, 42 eyes of 36 patients planned for phacoemulsification with toric IOL implantation with corneal astigmatism >1D as measured on Lenstar LS 900 optical biometer were included. Patients were preoperatively registered and photographed on the Verion image-guided system. In the operating room, the patient's eye was manually marked at the 6 o' clock limbus (Manual axis-90°) on slit-lamp in sitting position. Next, using the smartphone android app-iToric Patwardhan, the exact mark axis was confirmed (Smartphone axis). Following this, the patient was taken on the operation table where the mark axis was confirmed with Verion digital overlay on an external screen (Verion axis). The absolute angular deviation of manual axis from Verion was compared with the absolute angular deviation of the smartphone axis from Verion as the primary outcome measure.

Results

The mean absolute angular deviation between the smartphone axis and the Verion axis was 2.62°, which was significantly lower (P < 0.05) than that between the manual axis and Verion axis (4.60°). Moreover, the intraclass correlation coefficient between the smartphone axis and Verion axis was 0.88 indicating a strong agreement between the two.

Conclusion

Smartphone-assisted manual marking significantly improves the accuracy of manual marking alone when comparing with the Verion Digital Marker system for toric IOL implantation.

Posture-related ocular cyclotorsion during cataract surgery with an ocular registration system

Ocular cyclotorsion when a patient changes from seated to supine position in cataract surgery and factors predicting the amount of cyclotorsion were investigated using VERION system. Variables analyzed were age, gender, preoperative visual acuity, axial length, laterality of eyes, operative duration, and the direction and degree of cyclotorsion. The mean cyclotorsion of 107 eyes of 93 cataract patients was 0.98 ± 4.85 degrees (median, 1 degree; range, -11 to 12 degrees), and the median absolute value was 4 degrees (mean, 4.05 ± 2.82 degrees; range, 0 to 12 degrees). Cyclotorsion was ≥3 degrees in 68 (63.6%) eyes. Excyclotorsion occurred more frequently than incyclotorsion (50.5% vs. 43.0%). There was no cyclotorsion in seven (6.5%). Multiple regression analysis showed that gender was a significant predictive factor for the absolute value of cyclotorsion (β = 1.06, P = 0.041); however, the other variables had no effect on cyclotorsion. The absolute value of cyclotorsion was significantly larger in female than in male patients [median, 4 degrees and 3 degrees, respectively; mean, 4.66 ± 3.02 degrees and 3.44 ± 2.52 degrees, respectively (P = 0.039)]. In conclusion, cataract patients had significant posture-related ocular cyclotorsion. The amount of cyclotorsion was larger for female than male patients.

Evaluation of postoperative toric intraocular lens alignment with anterior segment optical coherence tomography

We describe the use of a simple tool to evaluate the postoperative alignment of toric intraocular lenses (IOLs). The entire anterior segment is scanned using anterior segment optical coherence tomography and analyzed with an internal dedicated tool. A topographic map is displayed along with an anterior segment image, including a linear axis marker centered on the corneal apex. The marker can be rotated until it is aligned with the line connecting the IOL marking dots, precisely reproducing the IOL astigmatic axis, which is measured in angle degrees. The value of the IOL astigmatic axis is compared with the value of the astigmatic axis shown in real time on the same screen in the topographic map. Evaluating the alignment of a toric IOL axis simultaneously with the topographic astigmatic axis eliminates the potential errors that result from head tilting and strictly correlates with the astigmatic correction achieved.

Image-guided system versus manual marking for toric intraocular lens alignment in cataract surgery

PURPOSE

To compare the accuracy of toric intraocular lens (IOL) alignment using the Verion Image-Guided System versus a conventional manual ink-marking procedure.

SETTING

University Eye Clinic Maastricht, Maastricht, the Netherlands.

DESIGN

Prospective randomized clinical trial.

METHODS

Eyes with regular corneal astigmatism of at least 1.25 diopters (D) that required cataract surgery and toric IOL implantation (Acrysof SN6AT3-T9) were randomly assigned to the image-guided group or the manual-marking group. The primary outcome was the alignment of the toric IOL based on preoperative images and images taken immediately after surgery. Secondary outcome measures were residual astigmatism, uncorrected distance visual acuity (UDVA), and complications.

RESULTS

The study enrolled 36 eyes (24 patients). The mean toric IOL misalignment was significantly less in the image-guided group than in the manual group 1 hour (1.3 degrees ± 1.6 [SD] versus 2.8 ± 1.8 degrees; P = .02) and 3 months (1.7 ± 1.5 degrees versus 3.1 ± 2.1 degrees; P < .05) postoperatively. The mean residual refractive cylinder was -0.36 ± 0.32 D and -0.47 ± 0.28 D in the image-guided group and manual group, respectively (P > .05). The mean UDVA was 0.03 ± 0.10 logarithm of minimum angle of resolution (logMAR) and 0.04 ± 0.09 logMAR, respectively (both P > .05). No intraoperative complications occurred during any surgery.

CONCLUSION

The IOL misalignment was significantly less with digital marking than with manual marking; this did not result in a better UDVA or lower residual refractive astigmatism.

Visual quality and patient satisfaction with a trifocal intraocular lens and its new toric version

PURPOSE

To assess and compare the visual quality and subjective outcomes of a trifocal spherical intraocular lens (IOL) and its new toric version.

SETTING

Clínica Rementería, Madrid, Spain.

DESIGN

Prospective case series.

METHODS

Patients had bilateral implantation of the AcrySof IQ PanOptix spherical or toric IOL. Three months postoperatively, monocular and the binocular uncorrected and corrected distance, intermediate, and near visual acuities; binocular defocus curves; and binocular contrast sensitivity function (CSF) were assessed. Patient satisfaction was evaluated with the Catquest 9SF questionnaire.

RESULTS

The study comprised 250 eyes (166 with spherical IOL; 84 with toric IOL) of 125 patients. Both groups had good monocular visual acuity at all distances with no statistically significant differences between groups. The mean monocular uncorrected acuity in the spherical group was 0.06 logarithm of the minimum angle of resolution (logMAR) ± 0.07 (SD), 0.20 ± 0.10 logMAR, and 0.05 ± 0.07 logMAR for far, intermediate, and near, respectively, and in the toric group, 0.07 ± 0.10 logMAR, 0.23 ± 0.20 logMAR, and 0.07 ± 0.12 logMAR, respectively. Defocus curves showed a visual acuity of 0.1 logMAR or better between -2.5 diopters (D) and +0.5 D with no differences between groups. The CSF values were within normal ranges with both IOLs. The questionnaire showed high rates of patient satisfaction with no differences between groups.

CONCLUSIONS

The visual outcomes with the 2 IOLs were similar. With optimum implantation and alignment, the trifocal toric IOL seems to provide visual quality and patient satisfaction that is equivalent to that with the nontoric version with the same platform.

Evaluation of an intraoperative toric intraocular lens alignment system using an image-guided system

PURPOSE

To evaluate an intraoperative toric intraocular lens (IOL) alignment system using a dedicated operating microscope with an image-guided system without preoperative corneal marking.

SETTING

Vienna Institute for Research in Ocular Surgery, Department of Ophthalmology, Hanusch Hospital, Vienna, Austria.

DESIGN

Prospective case series.

METHODS

In this prospective study, a new operating microscope system was used for cataract surgery (toric IOL alignment system of the OPMI Lumera 700 microscope and CALLISTO eye software). This system allows toric IOL alignment by matching limbal vessels from a preoperative photograph with the live image of the microscope. The preoperative photograph was taken with IOLMaster 500, which included a "Reference Image Attachment" system (red-free image), and this was used to track and follow the eye during surgery. After surgery, rotational alignment was assessed and compared with the preoperative axis calculation. At 1 hour postoperatively, a retroilluminaton photograph was taken, and then rotational alignment was compared with the preoperative axis calculation to see the rotational stability.

RESULTS

Fifty eyes of 50 patients were included. The feasibility of the intraoperative marking was high. Deviation between the postoperative (at the end of surgery in the operating room) and aimed IOL axes was 0.52 degrees ± 0.56 (SD). The deviation between 1 hour postoperatively and the aimed IOL axes was 5.10 ± 4.45 degrees.

CONCLUSION

Intraoperative toric IOL alignment using an image-guided system was an accurate and fast procedure resulting in precise toric IOL alignment, and the system simplified the positioning of toric IOLs. There was a slight rotation of IOLs shortly after surgery (within the first hour).

Early Postoperative Rotational stability and its related factors of a single-piece acrylic toric intraocular lens

Purpose

In the present study, we aimed to evaluate the early postoperative rotational stability of TECNIS toric intraocular lens (IOL) and analyse its correlation with preoperative and intraoperative parameters.

Methods

A total of 102 eyes from 87 cataract patients who underwent implantation of TECNIS toric IOL during July 2016 to November 2017 were enrolled in this retrospective study. Preoperative parameters including corneal astigmatism, axial length (AL), lens thickness (LT), anterior chamber depth (ACD) and sulcus-to-sulcus (STS), were determined. The area of capsulorhexis was measured with Rhinoceros 5.0 software. The follow-up examinations including the residual astigmatism (RAS) and postoperative toric IOL axis, were performed at 1 month and 3 months after surgery.

Results

RAS was −0.84 ± 0.88 D at 1 month and −0.81 ± 0.89 D at 3 months after surgery. The rotation of toric IOL at 3 months was 4.83 ± 3.65°. The Pearson’s r of ACD, horizontal and vertical STS, and toric IOL target axis was 0.011, 0.039, 0.045 and 0.082. The toric IOL rotation was positively correlated with the area of capsulorhexis (r = 0.522, P = 0.0003), LT (r = 0.288, P = 0.003) and AL (r = 0.259, P = 0.009). As for the area of capsulorhexis, the regressive equation was: y = 0.682 × −13.105, demonstrating that the diameter of capsulorhexis should be controlled within 5.8 mm to maintain the toric IOL rotation within 5.0°.

Conclusions

TECNIS toric IOLs possessed great early postoperative rotational stability. The area of capsulorhexis, AL and LT were positively correlated with postoperative rotational stability. A capsulorhexis within 5.8 mm had an important significance in improving rotational stability.

Femtosecond laser-assisted capsulotomy with capsular marks for toric IOL alignment: Comparison of tensile strength with standard femtosecond laser capsulotomy

PURPOSE

To compare the capsulotomy rim strength with capsular marks (CMs) to the rim strength without CMs in porcine eyes, and to demonstrate the practicality of CMs for intraoperative toric intraocular lens (IOL) alignment.

SETTING

LENSAR facility, Orlando, Florida, USA.

DESIGN

Laboratory study.

METHODS

The biomechanical strength of the capsulotomy with CMs was tested under two different load orientations (orthogonal to or in-line with CMs). Thirty-six porcine eyes were randomly assigned to three treatment cohorts: (1) standard capsulotomy with no CMs, (2) capsulotomy with CMs for in-line tensile testing and (3) capsulotomy with CMs for orthogonal tensile testing. Study parameters were capsulotomy break force and maximum extensibility. The ease of using CMs for toric IOL alignment was also evaluated.

RESULTS

There was no significant difference between the mean break force for standard capsulotomy (180.57 mN ± 22 [SD]), capsulotomy with CMs with orthogonal load (178.04 ± 20 mN, P = 1.000), and with in-line load (181.05 ± 15 mN, P = 1.000). Likewise, the mean extensibility at the break point for standard capsulotomy (6.47 ± 0.33 mm) was equivalent to the mean extensibility with CMs with orthogonal load (6.49 ± 0.45 mm, P = 1.000) and with in-line load (6.3 ± 0.47 mm, P = .960). In the implanted eyes, toric IOLs were found to be easily aligned with the CMs.

CONCLUSION

The femtosecond laser capsulotomies with CMs were equivalent in tensile strength and extensibility to standard femtosecond laser capsulotomies and showed high potential for effective alignment of toric IOLs.

Novel method for preventing cyclorotation in Ziemer Femto LDV Z8 femtosecond laser-assisted cataract surgery with Verion image-guided system

Purpose

To investigate the feasibility of a new method involving the use of the Verion image-guided system in preventing cyclorotation during femtosecond laser-assisted cataract surgery (FLACS).

Patients

Our preliminary data included details of 24 consecutive patients. All patients underwent cataract surgery at Universal Eye Center, Zhong-Li, Taiwan, between December 2016 and January 2017.

Methods

We developed a technique to use the Verion image-guided system in FLACS and evaluated whether this new technique is compatible with Femto LDV Z8. The Verion image-guided system was used to prevent misalignments. The only additional step in this technique is using a marking tool to place ink on the corneal limbus (at 3 and 9 o’clock positions) guided by the Verion digital marker system. Remaining procedures could be performed using the touchscreen of Femto LDV Z8 to calibrate the horizontal reference axis.

Results

This study included 24 patients who underwent cataract surgery. The technique used could effectively neutralize misalignments at an average of 8.08° and 2.66° in clockwise and counterclockwise directions, respectively.

Conclusion

This technique combines the advantages of iris fingerprinting technology and mobile features of Femto LDV Z8, has fewer transfer steps, improves centration of the eyes, and, most importantly, can prevent misalignments through cyclotorsion or docking procedures. Furthermore, this method can improve the accuracy of arcuate incisions and toric intraocular lens alignment in astigmatism correction.

Comparison of incidence of repositioning surgery to correct misalignment with three toric intraocular lenses

PURPOSE

To compare the incidence of re-orientating surgery to improve misalignment of three models of acrylic toric intraocular lenses: AcrySof toric intraocular lens (Alcon Laboratories, Inc.), TECNIS toric intraocular lens (Johnson & Johnson Vision, Inc.) and HOYA 355 toric intraocular lens (HOYA).

METHODS

In this retrospective, multicenter case series, medical charts were reviewed for collecting data on realignment surgery of toric intraocular lenses at 10 ophthalmic surgical sites in Japan.

RESULTS

Over all, intraocular lens repositioning surgery was conducted in 89 of 9430 eyes (0.944%) at an average of 10.5 ± 9.7 days after the initial cataract surgery. The incidence was 0.213% (11/5155), 1.797% (62/3451) and 1.942% (16/824) with AcrySof, TECNIS and HOYA toric intraocular lenses, respectively. The incidence was significantly lower with AcrySof than with other two brands of toric intraocular lenses (p < 0.0001). In those eyes which underwent reorientation surgery, the amount of misalignment was 26.4 ± 21.9°, 29.7 ± 15.4° and 28.1 ± 20.7° with AcrySof, TECNIS and HOYA toric intraocular lenses, respectively; there was no significant difference among groups (p = 0.821). The repositioning surgery significantly reduced misalignment in all three groups.

CONCLUSION

The rotational stability was considerably different among toric intraocular lenses of different manufacturers. The incidence of repositioning surgery was significantly lower with AcrySof than with TECNIS and HOYA toric intraocular lenses.

Image-guided lens extraction surgery: a systematic review

A systematic review of the recent literature regarding the current image-guided systems used for cataract surgery or refractive lens exchange was performed based on the PubMed and Google Scholar databases in March 2018. Literature review returned 21 eligible studies. These studies compared image-guided systems with other keratometric devices regarding their accuracy, repeatability and reproducibility in measurement of keratometric values, astigmatism magnitude and axis, as well as in IOL power calculation. Additionally, the image-guided systems were compared with conventional manual ink-marking techniques for the alignment of toric IOLs. In conclusion, image-guided systems seem to be an accurate and reliable technology with measurements of high repeatability and reproducibility regarding the keratometry and IOL power calculation, but not yet interchangeable with the current established and validated keratometric devices. However, they are superior over the conventional manual ink-marking techniques for toric IOL alignment.

Differences in visual quality with orientation of a rotationally asymmetric bifocal intraocular lens design

PURPOSE

To evaluate visual and perceptual performance for different orientations of a rotationally asymmetric bifocal intraocular lens (IOL) (M-Plus) simulated optically using a simultaneous vision simulator.

SETTING

Instituto de Optica, Madrid, Spain.

DESIGN

Prospective observational study.

METHODS

Perceptual quality and decimal high-contrast visual acuity (HCVA) was measured under cycloplegia for 8 orientations of the asymmetric bifocal IOL phase pattern at far, intermediate, and near distances simulated with a simultaneous vision simulator using face images and tumbling E targets. The preferred orientation at each distance was calculated as the centroid of the data for 8 orientations. The visual Strehl value was calculated using the subjects' ocular aberrations and multifocal pattern at each orientation. Optical predictions were obtained by implementing a differential visual Strehl values-based ideal observer model.

RESULTS

The study comprised 20 subjects (aged 21 to 62 years). Horizontal orientation (near segment at 0 or 180 degrees ± 45 [SD]) was preferred by 14 subjects and by 13 subjects at far and near distances, respectively; 8 subjects showed strong orientation preferences. The mean difference in preferred orientation between far and near was 27 ± 22 degrees. No significant differences in HCVA were observed. Optical predictions correlated strongly and significantly with measurements (far r = 0.71, near r = 0.62; P < .0001). The mean difference between measurement and simulation in the preferred orientation was 28 ± 29 degrees at far and 36 ± 28 degrees at near.

CONCLUSIONS

The perception varied for different orientations of an asymmetric bifocal IOL design tested using a simultaneous vision simulator. Optimum orientation was driven by interactions of the design with the eye's optical aberrations.

FINANCIAL DISCLOSURE

None of the authors has a financial or proprietary interest in any material or method mentioned.

[Refractive outcomes and precision in toric intraocular lens alignment using an automated alignment system]

PURPOSE

To compare precision in toric intraocular lens (TIOL) alignment and refractive outcomes between an intraoperative automated digital marker system and the conventional manual-ink marking.

MATERIALS AND METHODS

Prospective single center study including consecutive patients undergoing uneventful cataract surgery with corneal astigmatism greater than 1 diopter. Total corneal astigmatism was measured using a placido-dual Scheimpflug system (GalileiG4^®, Ziemer). Acrysof^® SN6AT (Alcon) TIOL's were implanted, and patients were divided into 2 groups, the digital group (Verion^®, Alcon) and the ink-marking group (Pendular marker, AMO). Mean error in TIOL axis, visual acuity and residual astigmatism were analyzed at 3 days, one month and 6 months after surgery.

RESULTS

In total, 45 eyes of 30 patients were included (n=25 digital group, n=20 ink-marking group). The mean preoperative total corneal astigmatism was 1.71±0.53 diopters. At one month, there was a significantly lower mean average error in TIOL axis in the digital group compared to the ink-marking group (2.6±2.3° and 6.4±2.8° respectively, P=0.009). At 6months, these results remained statistically significant. Mean residual astigmatism was 0.7±0.4 diopters at one month, without significant difference between the two groups (P=0.9). The rate of misalignment less than or equal to 5° was 86 % (n=25) in the digital group and 63 % (n=20) in the ink-marking group (P=0.05).

CONCLUSION

Intraoperative digital marker system is associated with better TIOL alignment accuracy and better reproducibility than the manual ink-marking method.

Optimizing outcomes with toric intraocular lenses

Toric intraocular lenses (IOLs) are the procedure of choice to correct corneal astigmatism of 1 D or more in cases undergoing cataract surgery. Comprehensive literature search was performed in MEDLINE using “toric intraocular lenses,” “astigmatism,” and “cataract surgery” as keywords. The outcomes after toric IOL implantation are influenced by numerous factors, right from the preoperative case selection and investigations to accurate intraoperative alignment and postoperative care. Enhanced accuracy of keratometry estimation may be achieved by taking multiple measurements and employing at least two separate devices based on different principles. The importance of posterior corneal curvature is increasingly being recognized in various studies, and newer investigative modalities that account for both the anterior and posterior corneal power are becoming the standard of care. An ideal IOL power calculation formula should take into account the surgically induced astigmatism, the posterior corneal curvature as well as the effective lens position. Conventional manual marking has given way to image-guided systems and intraoperative aberrometry, which provide a mark-less IOL alignment and also aid in planning the incisions, capsulorhexis size, and optimal IOL centration. Postoperative toric IOL misalignment is the major factor responsible for suboptimal visual outcomes after toric IOL implantation. Realignment of the toric IOL is needed in 0.65%–3.3% cases, with more than 10° of rotation from the target axis. Newer toric IOLs have enhanced rotational stability and provide precise visual outcomes with minimal higher order aberrations.

Investigation of a real-time location system of corneal astigmatic axis

Background

To construct a real-time computerized location system (RCLS) to analyze and display the axis of corneal astigmatism and to compare its accuracy with the Scheimpflug method.

Methods

Fifty-seven eyes of 39 volunteers with corneal astigmatism more than 1.00 diopter (D) were recruited. The RCLS was composed of a circular light-emitting diode (LED) light source, surgical microscope, surgical video system, computer and self-programming image analysis software. Scheimpflug imaging measurements (Pentacam HR, Oculus, Wetzlar, Germany) were performed on all subjects to determine the axis and power of corneal astigmatism. Thereafter, the axis of corneal astigmatism was analyzed in real-time and displayed by the RCLS on supine position, and videos were recorded. The MB-Ruler 4.0 software was used to measure the astigmatic axis. The accuracy of the RCLS was compared with the Scheimpflug method.

Results

The RCLS was able to display the axis of corneal astigmatism in real-time. The axial deviation of corneal astigmatism between the two methods was 0.63 ± 3.78° when astigmatism was 1.00 to 2.00 D and decreased to 0.06 ± 1.38° when astigmatism was greater than 2.00 D. A linear correlation of astigmatic axis was noted between the two methods: Axis_RCLS = 1.01 × Axis_Scheimpflug − 1.02 (R² = 0.998, P < 0.001). The Bland-Altman analysis revealed that the RCLS agreed sufficiently well with the Scheimpflug method.

Conclusions

The RCLS can accurately analyze and display the axis for corneal astigmatism greater than 1.00 D in real-time. The RCLS simplifies marking procedures and may have potential clinical application to improve the postoperative visual outcomes in surgical correction of corneal astigmatism.

Bilateral implantation of +3.0 D multifocal toric intraocular lenses: results of a US Food and Drug Administration clinical trial

Purpose

The purpose of this study was to evaluate the clinical outcomes of apodized diffractive +3.0 D multifocal toric intraocular lens (IOL) implantations in subjects with preoperative corneal astigmatism.

Patients and methods

This was a prospective cohort study conducted at 21 US sites. The study population consisted of 574 subjects, aged ≥21 years, with preoperative astigmatism 0.75–2.82 D, and potential postoperative visual acuity (VA) ≥0.2 logMAR, undergoing bilateral cataract removal by phacoemulsification. The intervention was bilateral implantation of aspheric apodized diffractive +3.0 D multifocal toric or spherical multifocal nontoric IOLs. The main outcome measures were monocular uncorrected near and distance VA and safety at 12 months.

Results

A total of 373/386 and 182/188 subjects implanted with multifocal toric and nontoric IOLs, respectively, completed 12-month follow-up after the second implantation. Toric IOLs were nonin-ferior in monocular uncorrected distance (4 m) and near (40 cm) VA but had >1 line better binocular uncorrected intermediate VA (50, 60, and 70 cm) than nontoric IOLs. Toric IOLs reduced cylinder to within 0.50 D and 1.0 D of target in 278 (74.5%) and 351 (94.1%) subjects, respectively. Mean ± standard deviation (SD) differences between intended and achieved axis orientation in the first and second implanted eyes were 5.0°±6.1° and 4.7°±4.0°, respectively. Mean ± SD 12-month IOL rotations in the first and second implanted eyes were 2.7°±5.8° and 2.2°±2.7°, respectively. No subject receiving toric IOLs required secondary surgical intervention due to optical lens properties.

Conclusion

Multifocal toric IOLs were noninferior to multifocal nontoric IOLs in uncorrected distance and near VAs in subjects with preexisting corneal astigmatism and effectively corrected astigmatism of 0.75–2.82 D.

A comparison of three different corneal marking methods used to determine cyclotorsion in the horizontal meridian

During toric intraocular lens (IOL) implantation, surgeons must take particular care to ensure that inaccurate preoperative measurement and intraoperative misalignment do not cause unexpected postoperative residual astigmatism. This retrospective, comparative case series study aimed to analyze the rotational deviation, or cyclotorsion, of three corneal marking methods: VERION digital marker (VDM; reference), horizontal slit beam marking (HSBM), and subjective direct visual marking (SDVM) on the table (using a bevel knife tip). Subjects included 81 eyes of 61 patients (mean age: 65.70±13.14 years; range: 32–91 years) undergoing scheduled cataract surgery. A preoperative reference image was taken of each eye. Subsequently, a slit lamp with the light beam turned to the horizontal meridian was used to align the seated patient’s head, and two reference marks were placed at the 3- and 9-o’clock positions of the corneal limbus using a 27-gauge needle and marking pen (HSBM). Upon transfer to the surgical table, the VDM was used to display a real-time dial scale on the patient’s eye, with the entrance of the temporal clear corneal incision (CCI) at 0° (horizontal meridian). Simultaneously, a bevel knife tip was used to create a marker based on the surgeon’s visual determination of the temporal 0° point (SDVM). We used the VDM to quantitatively evaluate the accuracy of axis alignment via deviation from the horizontal reference meridian. Compared with the reference meridian, the SDVM (−3.46°±7.32°, range: −18° to 13°) exhibited greater average relative cyclotorsion versus the HSBM (0.41°±4.92°, range: −10° to 10°). Furthermore, the mean average misalignment was significantly less in the HSBM group versus the SDVM group (t=4.179, P<0.001). The VDM is likely a reliable marking method, similar to the HSBM. In contrast, the SDVM is not entirely reliable. The VDM usage may prevent inaccurate preoperative manual marking during toric IOL implantation.