Comparison of different methods of correcting astigmatism in cataract surgery

CLINICAL RELEVANCE

Astigmatism causes a decrement in visual acuity, and deterioration in visual quality.

BACKGROUND

The aim of this study is to compare clear corneal incision (CCI) in the steepest meridian, opposed clear corneal incision (OCCI) and toric intraocular lens implantation methods for the correction of astigmatism in cataract surgery.

METHODS

Total of 93 preoperative patients with the rule corneal astigmatism (between 1.00-3.00 D)underwent uncomplicated cataract surgery are retrospectively included in this study. Whole patients are divided into three groups of equal number of patients of 31 by considering the astigmatism correcting methods that are as follows. Group 1 consists of patients underwent CCI on the steepest meridian, group 2 consists of the patients underwent paired OCCI, and group 3 consists of those with toric intraocular lens implantation. The preoperative and postoperative 3rd month uncorrected distance visual acuity, refraction and, keratometry values, and surgically induced astigmatism values calculated by Alpins method are recorded.

RESULTS

The age, preoperative and postoperative 3rd month spherical, spherical equivalent refraction and keratometry values of the groups are similar (p > 0.05). The preoperative uncorrected distance visual acuity values are similar in whole groups, postoperative uncorrected distance visual acuity values are the highest in group 1, and lowest in group 3 (p = 0.85, p = 0.02, respectively). The preoperative and postoperative 3rd month mean cylinder refraction values are -1.86 D, -1.00 D in group 1, -1.77 D, -0.70 D in group 2, and -1.95 D, -0.40 D in group 3. There is a statistically significant difference among the groups (p = 0.01). The surgically induced astigmatism values are statistically different among the groups [it was 0.46 ± 0.21 in group 1, 0.91 ± 0.44 in group 2, 0.33 ± 0.18 in group 3 (p < 0.001, respectively)].

CONCLUSION

This study indicated that; CCI, paired OCCI, and toric intraocular lens implantation should be preferred and performed for the steepest meridian in low D, middle D, and high D astigmatism patients, respectively. CCI can easily be applied for low to medium D without needing extra skills and tools. On the other hand, toric intraocular lens implantation is a better option for a high astigmatism with proper and accurate planning before the surgery.

Implantation of Hydrophobic Acrylic Toric Intraocular Lens with High-Water Contents Using Swept-Source Optical Coherence Tomography Biometer Integrated with a Surgical Guiding System

Purpose

To evaluate postoperative outcomes after implantation of toric intraocular lenses (IOLs) made of high-water-content hydrophobic acrylic material in Japanese patients using a swept-source optical coherence tomography (SS-OCT) biometer integrated with a surgical guiding system.

Patients and Methods

In this prospective observational study, toric IOL models CNW0T3 to CNW0T9 (Alcon) were implanted in 33 eyes of 33 patients and followed-up for one month. Powers and toric models were determined using an SS-OCT biometer ARGOS® Ver 1.5 (Alcon), and the IOLs were aligned using surgical guidance. Differences between planned and actual axis positions at the end of the surgery (misalignment) and rotations from the end of surgery to one month postoperatively were measured. Additionally, postoperative uncorrected visual acuity, refraction, and residual astigmatism were evaluated.

Results

Mean and median misalignments were 2.3° (standard deviation [SD]: 1.6, 95% confidence interval [CI]: 1.7-2.9) and 2°, and those of postoperative rotation were 2.4° (SD: 2.6, 95% CI: 1.5-3.4) and 2°, respectively. Mean postoperative refraction was 0.06 D (SD: 0.62). Prediction errors within ±0.5 and ±1.0 D were 69.7% and 93.9%, respectively. Mean residual astigmatisms were 0.19 D (SD: 0.41), and mean uncorrected visual acuity was 0.00 logMAR (SD: 0.11), and 64% of the eyes scored 20/20 or better.

Conclusion

Implantation of high-water-content hydrophobic acrylic toric IOLs using SS-OCT biometry integrated with a surgical guiding system effectively corrected corneal astigmatism with accurate IOL alignment in Japanese patients.

Evaluation of Clinical Results of Implantation of Toric Intraocular Lenses Including their Rotational Stability

PURPOSE

The aim of the study was to evaluate the clinical results of the implantation of the toric intraocular lens Acrysof IQ Toric SN6AT3_8 (Alcon Laboratories, Inc., Fort Worth, TX, USA), including an evaluation of its rotational stability.

MATERIAL AND METHODS

30 eyes of 16 patients (4 males, 12 females; mean age 68 years) with regular corneal astigmatism ranging from -1.5 to -4.0 Dcyl were included in this retrospective study. All the patients underwent uncomplicated cataract surgery with the implantation of a toric intraocular lens (TIOL) at the Department of Ophthalmology of the Faculty of Medicine and Dentistry of Palacký University in Olomouc and University Hospital Olomouc during the course of 2020. Follow-up examinations were performed 3-6 months after cataract surgery. We monitored the resulting uncorrected distance visual acuity (UDVA), postoperative refraction, rotational stability of the implanted lens and subjective patient satisfaction.

RESULTS

mean preoperative corneal astigmatism was -2.41 ±0.67 Dcyl. UDVA improved from a mean value of 0.45 ±0.25 (expressed in decimal Snellen optotype values) to 0.91 ±0.16. The spherical equivalent value of 0.41 ±2.92 improved to -0.11 ±0.27 postoperatively. The mean deviation from the planned axis was 4.87 ±4.75. Subjective satisfaction was rated by patients on a scale of 1-5, with a mean score of 1.5.

CONCLUSION

TIOL implantation is a safe and effective solution for patients with corneal astigmatism and cataract. Our results demonstrate improved UDVA, rotational stability of the TIOL and subjective patient satisfaction with the outcome of the surgery.

Accuracy of Astigmatism Calculation with the Barrett, Panacea, and enVista Toric Calculators

PURPOSE

To evaluate residual refractive astigmatism using the Panacea and enVista toric calculators, compared to the gold-standard Barrett toric calculator.

DESIGN

A retrospective and comparative study was conducted in one center.

METHODS

We reviewed the medical records of all patients with a diagnosis of senile cataracts and regular corneal astigmatism, without previous corneal or intraocular surgery, who underwent phacoemulsification with implantation of a toric intraocular lens, who had pre- and postoperative corneal topography, biometry, and refraction measurements.

RESULTS

The frequency of preoperative astigmatism according to the axis was 70 (84%) eyes showing with-the-rule (WTR) astigmatism, 9 (14%) eyes with against-the-rule (ATR) astigmatism, and 1 (2%) eye with oblique astigmatism. Regarding astigmatism prediction errors, there were statistically significant differences between the enVista and Panacea calculators (median of 0.39, 0.18, and 0.52 for Barrett, enVista, and Panacea, respectively). The residual astigmatism prediction error centroid was similar for the Barrett and enVista toric calculators, and both were lower compared to the Panacea calculator (x-component p < 0.001).

CONCLUSIONS

The enVista toric calculator incorporating the Emmetropia Verifying Optical (EVO) toric calculator provides similar results to the gold-standard Barrett calculator.

Premium Intraocular Lenses in Glaucoma-A Systematic Review

The incidence of both cataract and glaucoma is increasing globally. With increasing patient expectation and improved technology, premium intraocular lenses (IOLs), including presbyopia-correcting and toric IOLs, are being increasingly implanted today. However, concerns remain regarding the use of premium IOLs, particularly presbyopia-correcting IOLs, in eyes with glaucoma. This systematic review evaluates the use of premium IOLs in glaucoma. A comprehensive search of the MEDLINE database was performed from inception until 1 June 2023. Initial search yielded 1404 records, of which 12 were included in the final review of post-operative outcomes. Studies demonstrated high spectacle independence for distance and good patient satisfaction in glaucomatous eyes, with positive outcomes also in post-operative visual acuity, residual astigmatism, and contrast sensitivity. Considerations in patient selection include anatomical and functional factors, such as the type and severity of glaucomatous visual field defects, glaucoma subtype, presence of ocular surface disease, ocular changes after glaucoma surgery, and the reliability of disease monitoring, all of which may be affected by, or influence, the outcomes of premium IOL implantation in glaucoma patients. Regular reviews on this topic are needed in order to keep up with the rapid advancements in IOL technology and glaucoma surgical treatments.

Rotational stability of plate haptic toric intraocular lenses after combined 25-gauge vitrectomy and cataract surgery

AIM

To evaluate the postoperative intraocular lens (IOL) rotational stability and residual refractive astigmatism following combined 25-gauge vitrectomy and cataract surgery with implantation of a plate haptic toric IOL.

METHODS

In this retrospective case series, 32 eyes of 32 patients underwent a combined 25-gauge vitrectomy and phacoemulsification for vitreoretinal diseases and cataract with regular corneal astigmatism of at least 1 diopter (D). A plate haptic toric IOL (AT Torbi 709M, Carl Zeiss Meditec AG) was implanted in all eyes. The outcome measures were rotational stability and refractive astigmatism up to 6mo postoperatively as well as the best corrected visual acuity (BCVA).

RESULTS

Preoperative refractive astigmatism was 2.14±1.17 D, which was significantly reduced to 0.77±0.37 D six to eight weeks postoperatively and remained stable throughout the observation period (0.67±0.44 D at three months and 0.75±0.25 D at six months; for all groups: P<0.0001 compared to baseline). BCVA improved significantly from 0.36±0.33 logMAR preoperatively to 0.10±0.15 logMAR following surgery (P=0.02). Mean IOL axis deviation from the target axis was 3.4°±2.9° after six to eight weeks and significantly decreased over time (2.4°±2.6° six months after surgery; P=0.04). In one patient IOL, re-alignment was performed.

CONCLUSION

Corneal astigmatism is significantly reduced following combined 25-gauge vitrectomy and cataract surgery. The plate haptic toric IOL position and axis remain stable during the observation period of six months.

Outcomes of preloaded toric intraocular lens implantation in eyes undergoing phacoemulsification

Purpose

To evaluate the clinical outcomes of preloaded toric intraocular lens (IOLs) implantation in eyes undergoing phacoemulsification.

Methods

This prospective study included 51 eyes of 51 patients with visually significant cataracts and corneal astigmatism ranging between 0.75 and 5.50 D. All patients underwent phacoemulsification with SupraPhob toric intraocular lens implantation under topical anesthesia. The main outcome measures were uncorrected distance visual acuity (UDVA), residual refractive cylinder, spherical equivalent, and IOL stability at 3 months follow-up.

Results

At 3 months, 49% (25/51) of patients had UDVA equal to or better than 20/25 with 100% of eyes achieving better than 20/40. Mean logMAR UDVA improved from 1.02 ± 0.39, preoperatively to 0.11 ± 0.10 at 3 months follow-up (P < 0.001, Wilcoxon signed-rank test). The mean refractive cylinder improved from - 1.56 ± 1.25 D preoperatively to - 0.12 ± 0.31 D at 3 months follow-up (P < 0.001) while the mean spherical equivalent value changed from - 1.93 ± 3.71D preoperatively to - 0.16 ± 0.27D (P = 0.0013). The mean root mean square value for higher order aberrations was 0.30 ± 0.18 μm while the average contrast sensitivity value (Pelli-Robson chart) was 1.56 ± 0.10 log unit, at the final follow-up. The mean IOL rotation at 3 weeks was 1.7 ± 1.61 degrees, which did not change significantly at 3 months (P = 0.988) follow-up. There were no intraoperative or postoperative complications.

Conclusion

SupraPhob toric IOL implantation is an effective method for addressing preexisting corneal astigmatism in eyes undergoing phacoemulsification with good rotational stability.

Correction of high astigmatism with toric intraocular lens in eyes with corneal transplant

OBJECTIVES

To evaluate the results of toric intraocular lens (IOL) implantation during cataract surgery in eyes with high regular astigmatism associated with prior penetrating keratoplasty (PK).

METHODS

A retrospective data analysis of patients with prior PK, who underwent uncomplicated cataract surgery with hydrophobic toric single piece IOL (EyeCryl Toric®, Biotech Vision Care, Luzern, Switzerland).

RESULTS

A total of 18 eyes of 18 patients were included in the study. The mean age was 53.4 ± 12.4 (25-70) years. The mean follow-up period was 15.5 (4-24) months. The mean best corrected visual acuity (BCVA) significantly increased from 1.36 ± 1.0 logMAR to 0.31 ± 0.17 logMAR (p < .001) pre- and post-operative 4 weeks, respectively. There was no significant change in mean BCVA during follow-up; mean BCVA was 0.32 ± 0.17 logMAR at the last visit. The mean pre-operative topographic astigmatism was 6.52 ± 1.80 diopters (D). The mean manifest refraction astigmatism was decreased from 6.55 ± 1.62 D to 2.80 ± 1.43 D (p˂0.001). The mean Surgically induced astigmatism (SIA) was 3.74 ± 0.77 D according to vector analysis. There was no patient with graft rejection or failure, the mean endothelial cell loss rate was 12.75 ± 3.76% (7-17%). There was no patient requiring IOL reposition.

CONCLUSIONS

Toric IOL implantation during cataract surgery provides an option to correct astigmatism in post-PK eyes with high regular astigmatism. When appropriate patients are selected it is a safe method to achieve significant improvements in visual acuity and astigmatism.

Saving of Time Using a Software-Based versus a Manual Workflow for Toric Intraocular Lens Calculation and Implantation

Background: To determine whether there is a significant saving of time when using a digital cataract workflow for digital data transfer compared to a manual approach of biometry assessment, data export, intraocular lens calculation, and surgery time. Methods: In total, 48 eyes of 24 patients were divided into two groups: 24 eyes were evaluated using a manual approach, whereas another 24 eyes underwent a full digital lens surgery workflow. The primary variables for comparison between both groups were the overall time as well as several time steps starting at optical biometry acquisition until the end of the surgical lens implantation. Other outcomes, such as toric intraocular lens misalignment, reduction of cylinder, surgically induced astigmatism, prediction error, and distance visual acuity were measured. Results: Overall, the total diagnostic and surgical time was reduced from 1364.1 ± 202.6 s in the manual group to 1125.8 ± 183.2 s in the digital group (p < 0.001). The complete time of surgery declined from 756.5 ± 82.3 s to 667.3 ± 56.3 (p < 0.0005). Compared to the manual approach of biometric data export and intraocular lens calculation (76.7 ± 12.3 s) as well as the manual export of the reference image to a portable external storage device (26.8 ± 5.5 s), a highly significant saving of time was achieved (p < 0.0001). Conclusions: Using a software-based digital approach to toric intraocular lens implantation is convenient, more efficient, and thus more economical than a manual workflow in surgery practice.

[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.

The Influence of Analysis Mode Selection on Prediction Accuracy of Corneal Astigmatism Using Pentacam

Purpose: To evaluate the influence of analysis mode selection on prediction accuracy of corneal astigmatism using Pentacam.

Methods: Fifty-nine eyes of 59 patients implanted with toric intraocular lenses (IOLs) were included in the retrospective study. Preoperative corneal astigmatism (total refractive power) measured with Pentacam was analyzed based on 2-, 3-, 4-, or 5-mm ring or zone mode either centered on corneal apex or pupil center. Actual corneal astigmatism was calculated based on residual astigmatism on the corneal plane, surgical-induced astigmatism, and effective toric power on the corneal plane. Prediction error, the difference between actual corneal astigmatism and measured astigmatism, was compared among different analysis modes. Influences of local topography on prediction error were also evaluated.

Results: Based on the zone mode, prediction error was lower when centered on corneal apex than on pupil center at different diameters, whereas based on the ring mode, this difference was only seen at 2-mm cornea (all P < 0.05). When centered on the corneal apex, the zone mode showed lower prediction error than the ring mode at 4- and 5-mm corneas (both P < 0.001), regardless of asymmetric or symmetric astigmatism. In symmetric bowtie, the zone mode showed lower prediction error than the ring mode at 2-mm cornea of the small bowtie, and 4- and 5-mm corneas of the large bowtie (all P < 0.05).

Conclusions: For toric IOL planning, the corneal apex may be a better reference center. At a cornea diameter ≥4 mm, the zone mode is more accurate than the ring mode. Local topography affects prediction accuracy in the symmetric bowtie.

Rotational Stability of Intraocular Lenses: A Standardized Method for More Accurate Measurements in Future Studies

PURPOSE

To assess the reliability and reproducibility of a new semiautomated evaluation method, "Rotix," for intraocular lens (IOL) rotation and to define a standardized evaluation method for future toric IOL studies.

DESIGN

Reliability and reproducibility study.

METHODS

Setting: Department of Ophthalmology, Medical University of Vienna.

PATIENT POPULATION

A dataset of 25 patients with 2 consecutive follow-up visits was created to test the intra- and interrater reliability. A data test set of 10 patients including 30 pictures taken 5 minutes apart was created to test the short-term reproducibility.

INTERVENTION

Evaluation of IOL rotational stability using nontoric implants in 25 × 2 consecutive follow-up visits. Two experienced graders performed axis evaluation 3 times in a randomized order. One experienced grader performed axis evaluation for the short-term reproducibility study. Reference landmarks at the end of operation were used to assess the IOL axis.

MAIN OUTCOME MEASURES

Intra- and interrater reliability and short-term reproducibility of axis measurements.

RESULTS

Mean standard deviation for intrarater reliability was 0.16 degrees. The intraclass correlation coefficients were 0.97 for grader 1 and 0.96 for grader 2. A very high interrater correlation of 0.95 was found. The mean individual difference between grader 1 and grader 2 was 0.061 ± 0.28 degrees. Short-term reproducibility showed a mean standard deviation of 0.22 ± 0.14 degrees.

CONCLUSION

The novel semiautomated evaluation method showed an accurate inter- and intrarater reliability. Short-term reproducibility was below 0.25 degrees. The method of using nonmovable reference landmarks showed reliable results and should be used as a standard in future toric IOL studies.

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.

Astigmatism Management with Astigmatism-Correcting Intraocular Lens Using Two Toric Calculators - A Comparative Case Series

Background

To compare refractive outcomes after phacoemulsification and toric IOL implantation using two different toric calculators for initial astigmatism assessment in a real-world setting.

Methods

This was a retrospective, comparative, interventional case series. Patients over 30-year-old who underwent phacoemulsification and toric IOL implantation (AcrySof^® Toric IOL) by the same surgeon between 2017 and 2018 were included. Eyes with irregular astigmatism, previous corneal refractive surgery, intraocular surgery, corneal pathology, macular pathology and pupil abnormalities were excluded. IOL toricity was determined by using a calculator provided by the AcrySof Toric calculator before 2018 and Barrett Toric Calculator after 2018. Patient demographics, corneal topography, vector and preoperative and postoperative refraction were collected and analyzed at three months postoperative.

Results

Thirty-two eyes of 32 patients were included in the final analysis. 0.1D for surgically induced astigmatism was used. Group 1 included 14 eyes assessed with the original (AcrySof) toric IOL calculator, and group 2 included 18 eyes assessed with the Barrett toric IOL calculator. In group 1, postoperative astigmatism less than −1.00D, −0.75 D, and −0.5D was achieved in 88.2%, 76.1% and 53.7% of eyes, respectively, while, in group 2, 89% eyes achieved postoperative residual astigmatism less than 0.5D and all eyes achieved postoperative residual astigmatism less than 0.75D. The proportion of patients with lower postoperative astigmatism was significantly higher in Group 2 (p< 0.05 by chi-square test), a pattern that still held when we divided patients into multiple groups. Vector analysis with the Alpins methods also supported better outcomes in the Barrett group (0.71 D vs 0.35 D).

Conclusion

The Barrett Toric calculator resulted in better results in the prediction of residual astigmatism than original (AcrySof) toric calculators.

Toric Intraocular Lens Calculation Considering Anterior Surgically Induced Astigmatism and Posterior Corneal Astigmatism

Purpose: To evaluate the prediction error (PE) after applying the Abulafia-Koch formula in an online calculator with and without consideration of anterior corneal surgically induced astigmatism (SIA_Cornea).Methods: SIA_Cornea models were calculated with a historical database of 204 right eyes (REs) from a single surgeon, either for manual (2.2 mm) or femtosecond (2.5 mm) temporal clear corneal incisions. PE was assessed in 58 REs operated by the same surgeon with a monofocal toric IOL and calculated, considering the PCA estimation in an online calculator with the combination of each one of the following SIA_Cornea calculation approaches: (A) considering only significant centroids after stratification, (B) all centroids after stratification and (C) a single centroid without stratification.Results: The consideration of all centroids resulted in an underestimation of SIA_Cornea in cases of preoperative against-the-rule astigmatism (ATR-A) and an overestimation in with-the-rule astigmatism (WTR-A). After stratification, SIA_Cornea was only significant in preoperative ATR and oblique astigmatism cases for femtosecond incisions. PE considering PCA only was 0.03@160º. The combination with SIA_Cornea resulted in a WTR-A surprise in preoperative ATR-A and WTR-A, however only being significant for preoperative ATR-A in calculation approaches B (0.29@84º) and C (0.21@80º). SIA_Cornea addition to PCA estimation only reduced the centroid for oblique preoperative astigmatism.Conclusions: Surgeons should consider the calculation of the SIA_Cornea after stratification by astigmatism type when using the same incision location (i.e. temporal). However, SIA_Cornea derived from the anterior corneal surface should not be combined with PCA estimation for IOL power calculations.

Visual outcome and refractive status with monofocal toric intraocular lens implantation to correct astigmatism during cataract surgery

Purpose:

Measurement, calculations, visual assessment, and refractive status after monofocal toric intraocular lens (IOL) implantation were the purpose of this study.

Methods:

This was a hospital-based interventional prospective study, where 40 eyes were included with astigmatism of more than 2D. They underwent biometric assessment using Lenstar. Toric IOL power calculation was done based on Barrett's Toric calculation method. Preoperative axis marking was done using both bubble marker and direct slit beam to avoid cyclotorsion in sleeping position. On table, axis marking was reassessed. Post phacoemulsification, monofocal Supra Phob Toric IOL was rotated till its marking matches corneal axis marking. Postoperative best-corrected visual acuity was measured at 1 and 3 months.

Results:

Mean of refractive astigmatism reduced from 3.55 ± 0.97 preoperatively to 0.81 ± 0.28 at 1 month and 0.79 ± 0.27 at 3 months postoperatively. In total, 92.5% had residual astigmatism less than 1D at 3 months postoperatively, while 7.5% eyes had residual astigmatism more than 1D. In total, 72.5% patients had IOL rotation of less than or equal to 5°, 20% patients had it between 6° and 10° and 7.5% eyes had more than 10° at day 7 postoperatively, which required IOL repositioning.

Conclusion:

Accurate measurement of parameters and proper calculation reduce the postoperative residual astigmatism after toric IOL.

[Corneal astigmatism in patients with various ophthalmic pathologies]

PURPOSE

To analyze the prevalence, magnitude of corneal astigmatism, anatomical parameters of the eye and age of patients with the condition, as well as to assess the prospects of its correction with intraocular lenses (IOLs).

MATERIAL AND METHODS

The study involved a retrospective analysis of initial biometric data of 128 379 patients (256 630 eyes) referred to the S.N. Fedorov NMRC «MNTK «EYE MICROSURGERY» research center in the years 2013 to 2018. The patients previously operated for cataract were examined 6 months after surgery.

RESULTS

In 5 years, corneal astigmatism of over 1.0 D was diagnosed in 66 610 (25.96%) eyes. Among them, low astigmatism was observed in 86.30% of cases, with-the-rule - in 56.10%, compound - in 78.72%, and astigmatism combined with myopic refraction - in 61.48%. More severe astigmatism is characterized by thinner cornea and lens (p<0.05). Cataract surgery with implantation of toric IOLs was performed only on 2.56% of eyes. The average age of the operated patients was 68.42±13.3. Patients with implanted toric IOLs had 23% better uncorrected visual acuity (UCVA), and 15% better corrected visual acuity compared with outcomes of spherical IOL implantation.

CONCLUSION

Corneal astigmatism of more than 1.0 D was observed in 25.96% of examined subjects. Patients with corneal astigmatism apply for cataract surgery 10 years earlier, when they are still in the working age, due to inability to engage in professional activities; in most cases, those patients are female. Astigmatism of up to 0.75 D is more common on the right dominant eye, of 2.0 D and higher - on the left. The correlation coefficients determined for study data indicate a barely noticeable relationship between biometric parameters and the degree of astigmatism. The use of toric intraocular lenses provides a 2-fold increase in uncorrected visual acuity compared to spherical IOLs.

Toric IOL in Combined DMEK and Cataract Surgery

Introduction

Descemet membrane endothelial keratoplasty (DMEK) is the current gold standard surgical procedure to treat Fuchs endothelial keratoplasty. Cataract removal and intraocular lens (IOL) implantation can be safely combined with this corneal procedure. This paper presents a case series in which a toric intraocular lens (IOL) was used in combined DMEK and cataract surgery to correct corneal astigmatism.

Methods

Four eyes that had a toric IOL implanted in combined cataract and DMEK surgery were included.

Results

There was a reduction in manifest refractive cylinder and improvement in uncorrected and best-corrected vision in all cases.

Discussion

Surgeons may consider the use of toric IOLs in selected cases of combined DMEK and cataract surgery for Fuchs endothelial dystrophy.

Comparative evaluation of rotational stability of toric IOLs with four-eyelet vs two-eyelet capsular tension rings in eyes with high myopia

AIM

To compare the rotational stability of Toric intraocular lens (IOLs) implantation combined with four-eyelet or two-eyelet capsular tension rings (CTRs) in eyes with high myopia and cataract.

METHODS

This prospective randomized controlled interventional study included 33 eyes which had preoperative corneal astigmatism ≥1.5 D and ocular axial length ≥25.5 mm. These eyes were randomly divided into two groups to undergo phacoemulsification and toric IOL implantation with either four-eyelet CTR implantation (group A, n=16) or two-eyelet CTR implantation (group B, n=17). Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), phoropter examination results, and toric IOL rotation degrees were tested 6mo after the surgery.

RESULTS

In both groups, the toric IOL was in the capsular sac 6mo after surgery. The difference between the two groups in terms of visual outcome was not found to be statistically significant (P>0.05) at a follow-up of 6mo. The mean residual astigmatism values were 0.56±0.22 D and 0.92±0.24 D in A and B groups, respectively (P<0.001). The mean rotation degree of IOL was 1.00°±0.73° in group A and 3.53°±1.46° in group B (P<0.001).

CONCLUSION

In cataract patients with high myopia and astigmatism, four-eyelet CTR can effectively increase the rotation stability of toric IOLs, achieving the desired goal of correcting corneal astigmatism.

Comparison of the clinical efficacy of AcrySof® IQ and TECNIS® toric intraocular lenses: A real-world study

Corneal astigmatism significantly compromises uncorrected visual acuity (UCVA) after phacoemulsification with implantation of traditional spherical or non-spherical monofocal intraocular lens (IOL). Toric IOL provides an effective way to gain favorable postoperative UCVA for the patients with cataracts with corneal astigmatism. There are numerous types of toric IOLs; however AcrySof^® IQ toric IOL (Alcon Laboratories, Inc.) and TECNIS^® toric IOL (Johnson & Johnson Vision; Johnson & Johnson) are most frequently used in our clinical practice. The purpose of the current study was to compare the clinical efficacy of AcrySof IQ with TECNIS toric IOL implantation, and to provide a clinical basis on selecting an appropriate toric IOL before cataract surgery for patients with corneal astigmatism. A total of 30 patients with cataract (44 eyes) with corneal astigmatism [0.82-7.27 diopters (D)], who have undergone phacoemulsification with toric IOL implantation between October 2012 and December 2017, were included in the current retrospective cohort study. Patients were divided into two groups: One group (26 eyes) received the AcrySof IQ toric IOL (AcrySof group) and the other group (18 eyes) received the TECNIS toric IOL (Tecnis group). The indexes of curative effect, such as uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively), refractive outcomes, contrast sensitivity (CS), IOL rotation, and satisfaction, were evaluated. Both toric IOLs significantly improved UDVA and CDVA. Postoperative mean residual astigmatism was similar in the AcrySof group and in the Tecnis group (0.75±0.50 and 0.78±0.90 D; P=0.896). There was no statistically significant between postoperative CS in the AcrySof and Tecnis groups. Rotations of >10˚ were considered to be significant and were identified in three eyes. The mean IOL rotation showed no statistically significant difference (AcrySof group, 0.24±5.54˚; Tecnis group, -0.19±6.28˚; P=0.416). The mean patient satisfaction score was 8.46±1.21 in the AcrySof group and 8.78±1.44 in the Tecnis group (P=0.260). The results of the current study indicated that patients with cataracts with corneal astigmatism undergoing phacoemulsification with AcrySof IQ and TECNIS toric IOL implantation achieved similar clinical efficacy in term of visual outcomes, refraction correction, CS, rotational stability and satisfaction.

How Can We Improve Toric Intraocular Lens Calculation Methods? Current Insights

In this paper, we review current strategies for calculating toric intraocular lenses (IOLs). We discuss the prevalence and clinical relevance of astigmatism and the assessment of toric IOL candidates. We detail recommendations for evaluating astigmatism and current biometry and IOL power calculation techniques. Finally, error sources and results of current toric IOL calculators are discussed.

Accuracy of two devices and three different calculation methods for predicting residual astigmatism after intraocular lens implantation

This study examined how different methods of biometric measurement, types of intraocular lens calculation, and levels of surgeon experience affected predicted postoperative astigmatism with toric intraocular lens implantation. The error in predicted residual astigmatism was determined using the IOL Master 500 and Lenstar LS 900 devices and was calculated by the Alcon toric calculator, Alcon toric calculator with Baylor nomogram, and Barrett toric calculator. Results were reviewed from 147 eyes of 125 patients. Of the three calculations, the Barrett toric calculator had the lowest mean absolute error in predicted residual astigmatism (P < 0.0001). The mean absolute errors of the IOL Master 500 and the Lenstar LS 900 were not significantly different when compared using three different calculation methods (P = 0.54). The mean absolute error was significantly lower (P = 0.049) for ophthalmology staff than for ophthalmology residents when calculation methods were considered. In conclusion, the calculation method used for IOL selection in cataract surgery significantly affects the accuracy of both staff and residents.

Results of Callisto Eye System in Toric Intraocular Lens Alignment

OBJECTIVES

This study was an evaluation of the effectiveness of the Callisto eye image-guided, markerless system (Carl Zeiss Meditec AG, Jena, Germany) in toric intraocular lens (IOL) positioning.

METHODS

The results of a novel, markerless, alignment system used for IOL positioning were analyzed in this retrospective study. Preoperatively, reference image registration was performed with the IOLMaster 700 biometer (Carl Zeiss Meditec AG, Jena, Germany) and transferred to the Callisto eye system, which was used in conjunction with an Opmi Lumera 700 microscope (Carl Zeiss Meditec AG, Jena, Germany). Using the Callisto Z Align technology, a toric IOL was aligned precisely with the steep axis. One day after surgery, the pupil was fully dilated and a thin slit was placed on the marker of the toric IOL and the angle was measured using an axis calculator smartphone application. The degree of the measured angle and the preoperatively determined angle were compared.

RESULTS

Sixty eyes of 46 patients were included. The difference in the absolute angle between the intended and the postoperative (at day 1) axes was a mean of 2.71±1.64°.

CONCLUSION

The Callisto eye image-guided, markerless system successfully provided assistance in precisely positioning the toric IOL.

Comparative clinical outcomes of Tecnis toric IOL implantation in femtosecond laser-assisted cataract surgery and conventional phacoemulsification surgery

AIM

To compare the short-term visual outcomes, residual refractive cylinder, and rotation stability after Tecnis toric intraocular lens (IOL) implantation during femtosecond laser-assisted cataract surgery (Femto phaco) and conventional phacoemulsification surgery (Conventional phaco).

METHODS

In a prospective cohort study, Conventional phaco and Femto phaco (anterior capsulotomy and lens fragmentation by a femtosecond laser) with Tecnis toric IOL implantation were performed in 40 eyes from 36 patients and 37 eyes from 33 patients, respectively. The uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction were assessed during 1d, 1wk, and 1mo follow-ups. The orientation of the Tecnis Toric IOL was evaluated during 1wk and 1mo follow-ups.

RESULTS

There were no significant differences in UDCA or CDVA between two groups at 1mo postoperatively, though relatively more subjects had UDVA values of 20/25 or better in Femto phaco group than in the Conventional group (P>0.05). A lower but not significantly lower rate of having more than 5° of IOL rotation was observed in Femto phaco group at the 1-month follow-up, while a significant lower rate of residual astigmatism of ≤1 D was observed in Femto phaco group.

CONCLUSION

The Femto phaco group has significantly more subjects with the residual astigmatism of ≤1 D, but there are no significant differences in rotation stability and visual outcomes as compared with the Conventional phaco group after the application of the Tecnis toric IOL in this cohort.

Utility Of Three-Dimensional Heads-Up Surgery In Cataract And Minimally Invasive Glaucoma Surgeries

Purpose

This study aimed to assess the utility of the three-dimensional (3D) heads-up visualization system for minimal incision cataract surgery (MICS) and minimally invasive glaucoma surgeries (MIGSs).

Methods

Toric intraocular lens (IOL) implantation with phacoemulsification and trabecular microbypass stent implantation in patients with cataract and open-angle glaucoma were performed using the heads-up 3D visualization system combined with surgical navigation rather than the conventional microscope.

Results

This procedure was found to have the following advantages: the ability to clearly observe the anterior chamber angle image without requiring frequent focus adjustment owing to the extended depth of field and emphasized stereoscopic effect provided by this system and maintain the surgeon’s posture.

Conclusion

The feasibility and comfort of this system are greater than those of the conventional microscopic for performing MICS and MIGS.

Microincision cataract surgery with implantation of a bitoric intraocular lens using an enhanced program for intraocular lens power calculation

PURPOSE

To evaluate the potential benefit of a new version of an online toric intraocular lens calculator in eyes implanted with a bitoric intraocular lens.

PATIENTS AND METHODS

Retrospective observational comparative study in patients that underwent cataract surgery with implantation of the bitoric intraocular lens AT TORBI 709M (Carl Zeiss Meditec AG, Jena, Germany). Visual and refractive outcomes were evaluated at 1 month after surgery. The selection of the toric intraocular lens power was performed with the software Z CALC 2.0 (Carl Zeiss Meditec AG). The absolute refractive prediction errors for the spherical equivalent and cylinder were calculated and compared with the values that would have been obtained using version 1.5 of the same software.

RESULTS

A total of 393 eyes of 276 patients were evaluated. Mean postoperative sphere and cylinder were +0.03 ± 0.54 and -0.19 ± 0.30 D, respectively. A total of 95.67%, 98.22%, and 95.17% of eyes had a postoperative sphere, cylinder, and spherical equivalent within ±1.00 D, respectively. Mean absolute refractive prediction error for spherical equivalent was 0.34 ± 0.27 D with the two versions of the Z CALC software. In contrast, a significantly higher absolute refractive prediction error value for the cylinder was found with Z CALC 1.5 compared to version 2.0 (0.35 ± 0.32 vs 0.28 ± 0.30 D, p < 0.001). The absolute refractive prediction error for cylinder was ⩽0.25 D in 62.3% and 47.5% when using the versions 2.0 and 1.5, respectively.

CONCLUSION

The use of an optimized software for toric intraocular lens power calculation, considering the contribution of posterior corneal astigmatism, improved the astigmatic outcome with a bitoric intraocular lens.

Implantation of toric intraocular lenses in patients with cataract and keratoconus: a case series

Purpose

To describe the results of phacoemulsification and implantation of toric intraocular lenses (IOLs) in patients with cataract and keratoconus.

Patients and methods

Prospective study of 4 patients (4 eyes) with cataract and keratoconus who underwent phacoemulsification with implantation of a toric IOL. Two different toric IOLs were used: AcrySof IQ SN6AT9 and AT Torbi 709M(P). Corneal tomography was performed preoperatively using Scheimpflug technique with Pentacam. Astigmatism was regular or slightly irregular in all patients. Postoperatively, best-corrected visual acuity (BCVA), astigmatism, spherical equivalent, and complications were recorded for all patients. Follow-up time was between 4 weeks and 7 months.

Results

BCVA increased and astigmatism decreased in all patients. BCVA increased from 20/50 to 20/40 in patient 1, from 20/63 to 20/20 in patient 2, from 20/40 to 20/32 in patient 3, and from hand motion to 20/40 in patient 4. Astigmatism decreased from −6.12 to −3.75 D in patient 1, from −4.62 to −1.75 D in patient 2, from −9.0 to −3.0 D in patient 3, and from −8.0 to −2.75 D in patient 4. One patient developed pseudophakic cystoid macular edema, but at last follow-up after 6 months the edema had resolved. Another patient developed posterior capsular opacification after 2 months. No misalignment of the axis of the IOL was observed.

Conclusion

Correction of both astigmatism and cataract with phacoemulsification and implantation of a toric IOL can be an effective and safe choice for patients with cataract and keratoconus. However, predicting the refractive outcome in cataract surgery is difficult in patients with keratoconus, and the surgeon should be aware of different sources of biometric errors and the possible consequences.

Rotational stability and visual performance 3 months after bilateral implantation of a new toric extended range of vision intraocular lens

Purpose

To evaluate the clinical outcomes after implantation of Symfony^® toric extended range of vision (ERV) intraocular lenses (IOLs) in subjects with preoperative corneal astigmatism.

Setting

Ifocus Øyeklinikk, Haugesund, Norway.

Design

Prospective non-comparative study.

Patients and methods

The study population consisted of 30 patients, with preoperative corneal astigmatism between 0.88 and 3.29 D, undergoing bilateral cataract removal or refractive lens exchange with implantation of Tecnis Symfony toric ERV IOLs. Main outcome measures were visual acuity, refraction, IOL axis rotational stability, patient and surgeon satisfaction, photic phenomena, and quality of life at 3 months.

Results

Postoperatively, mean binocular uncorrected distance, intermediate, and near visual acuities (logMAR) were −0.05±0.11, −0.03±0.08, and 0.09±0.10, respectively. A significant reduction in manifest cylinder (P<0.001) and spherical equivalent (P=0.001) was found after 3 months. Monocular and binocular corrected distance visual acuity also improved significantly with surgery (P<0.001). In terms of binocular uncorrected intermediate and near visual acuity, a total of 96% and 82% of patients achieved 0.1 logMAR (Snellen: 20/25) or better, respectively. Toric IOL axis showed a median rotation of 2.0 degrees (range 0.0–16.0 degrees) from the end of surgery to 3 months. The median patient satisfaction scores for distance, intermediate, and near vision were 9.0, 9.0, and 8.0, respectively. Fifty percent of patients reported complete spectacle independence and most patients (89%) were not bothered by any photic phenomena.

Conclusion

Bilateral implantation of the Symfony toric ERV IOL appeared to be safe and achieved good visual performance and high satisfaction.

Surgical technique for management of isolated lenticular coloboma with high corneal astigmatism

We describe a surgical technique for the correction of isolated congenital lenticular coloboma associated with high corneal astigmatism. Transscleral fixation of the capsular bag with a single eyelet Cionni capsular tension ring was followed by in-the-bag implantation of a toric intraocular lens (IOL). This lead to complete correction of the lenticular defect and perfect alignment of the toric lens. In this case, the child attained an unaided distance visual acuity of 20/30 following amblyopia therapy and a well-aligned toric IOL at 12 months of follow-up. This technique can be used in cases with concomitant lenticular coloboma and significant corneal astigmatism.

Transitional conic toric intraocular lens for the management of corneal astigmatism in cataract surgery

Synopsis

Transitional toric intraocular lens (IOL) was developed to improve refractive outcomes in cataract surgery. We report refractive, vectorial outcomes, and stability of spherical equivalent over 12 months after implantation of this IOL.

Purpose

To evaluate visual and refractive outcomes of a transitional conic toric intraocular lens (IOL) (Precizon^®) for the correction of corneal astigmatism in patients undergoing cataract surgery.

Setting

The Ocular Microsurgery Institute (IMO), a private practice in Barcelona, Spain.

Design

This is a retrospective, non-randomized study.

Methods

Retrospective chart review of 156 patients with preoperative regular corneal astigmatism >0.75 diopters (D) who underwent consecutive phacoemulsification and Precizon toric IOL implantation between January 2014 and December 2015 was performed. Two groups were divided according to attempted residual refraction: group 1 with emmetropia and group 2 with mild myopia for monovision. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), and manifest refraction were analyzed preoperatively and 3, 6, and 12 months postoperatively.

Results

Precizon toric IOL was implanted in 97 eyes of 61 patients. Six months postoperatively, none of the eyes lost any line of CDVA. In all, 98% of the eyes were within ±1.00 D of attempted spherical correction. The mean preoperative keratometric cylinder was 1.92 ± 1.04 D (range 0.75–6.78), and the mean postoperative refractive cylinder was 0.77 ± 0.50 D (range 0–2.25), with 81% of the eyes with ≤1.00 D of residual cylinder. Two IOLs required realignment due to intra-operative positioning error. Eleven eyes required enhancement with corneal refractive surgery.

Conclusion

Preexisting regular corneal astigmatism was effectively and safely corrected by the implantation of the transitional conic toric IOL in patients undergoing cataract surgery.

Comparative evaluation of rotational stability and visual outcome of toric intraocular lenses with and without a capsular tension ring

Purpose:

To evaluate the rotational stability of toric intraocular lens (IOL) when co-implanted with a capsular tension ring (CTR) as compared to that of a toric IOL without a CTR.

Methods:

This was a prospective randomized clinical trial performed in a tertiary care centre in India. Fifty adult human eyes with visually significant cataract and regular corneal astigmatism ≥1.5D divided into two groups of 25 eyes each, A and B by simple randomization. Eyes with corneal pathology, lens subluxation, and a specular endothelial cell count <2000/mm² were excluded from the study. The eyes in both the groups underwent standard phacoemulsification and were implanted with a toric IOL. In Group A, a CTR was put in the bag before IOL implantation. The groups were called for follow-up on day 1, 1 week, 1 month, and 3 months, postoperatively. The axis of the toric IOL on each visit was measured by slit lamp imaging in retroillumination and analyzed digitally.

Results:

Mean rotation of toric IOL at 3 months postoperatively was 1.85 ± 1.72° in Group A and 4.02 ± 2.04° in Group B. The difference was statistically significant (P = 0.003).

Conclusion:

Coimplantation of a CTR is a safe and effective technique for ensuring better rotational stability of toric IOLs.

Suturing technique for scleral fixation of toric intraocular lens in the traumatic aphakic eye with corneal astigmatism

PURPOSE:

To describe the clinical outcomes of traumatic aphakic eyes with corneal astigmatism after using a novel technique for toric intraocular lens suture fixation.

METHODS:

In total, 12 eyes of 12 patients who underwent a new scleral suture fixation technique of one-piece toric intraocular lens (SN6AT series, Alcon Inc., TX, USA) were included in our retrospective study. Preoperative patient status, postoperative visual acuity and refractive outcomes, postoperative intraocular lens rotation, tilt, decentration, and complications were analyzed.

RESULTS:

The mean follow-up was 11.6 ± 1.0 months. The mean preoperative best-corrected visual acuity was 0.55 ± 0.32 in the logarithm of minimum angle of resolution equivalent; the postoperative best-corrected visual acuity was 0.45 ± 0.34. The mean preoperative total corneal astigmatism was 2.51 ± 1.67 D. The mean postoperative residual astigmatism was 0.77 ± 0.54 D. The mean intraocular lens rotation was 3.33° ± 1.37° (range, 1°-6°). The mean intraocular lens tilt in horizontal direction was 3.64° ± 1.02° (range, 2.6°-6.3°) and in vertical direction it was 3.19° ± 1.07 ° (range, 1.6°-5.2°). The mean intraocular lens decentration in horizontal direction was 0.14 ± 0.03 mm (range, 0.089-0.192 mm) and in vertical direction it was 0.15 ± 0.02 mm (range, 0.113-0.181 mm). One patient had mild vitreous hemorrhage and two other patients had high postoperative residual sphere and astigmatism, respectively. But no other serious complications were observed.

CONCLUSION:

Scleral suture fixation of foldable toric intraocular lens to correct corneal astigmatism can be a safe and effective alternative technique to manage traumatic aphakic eyes that lack adequate capsular support.

Toric Intraocular Lens for Astigmatism Correction in Cataract Patients

Background:

To assess the clinical consequences of AcrySof toric intraocular lens (IOL) and Hoya toric IOL implantation to correct preexisting corneal astigmatism in patients undergoing cataract surgery.

Materials and Methods:

In this study, we examined 55 eyes of 45 patients with at least 1.00 D corneal astigmatism who were scheduled for cataract surgery. After phacoemulsification, toric IOL was inserted and axis was aligned. We observed the patients, uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), keratometry, manifest refraction, and IOL axis alignment 6 months after surgery.

Results:

After 6 months, the UDVA was 0.17 ± 0.17 logMAR in the AcrySof group and 0.17 ± 0.18 logMar in the Hoya group. More than 78% of eyes in the AcrySof group and 80% of eyes in the Hoya toric IOL achieved a UDVA of 20/40 or better. In the AcrySof group, the mean preoperative corneal astigmatism was 2.73 ± 0.92 D. The mean postoperative refractive astigmatism was 0.84 ± 0.63 D. In the Hoya group, the preoperative corneal astigmatism was 2.58 ± 0.76 D and the postoperative refractive astigmatism was 0.87 ± 0.66 D (P < 0.05). The mean AcrySof IOL axis rotation was 1.88° ± 3.05°. In the Hoya group, the mean axis rotation was 1.53° ± 3.66°. All changes in visual and refractive data before and after surgery were statistically significant (P < 0.05). There was no significant difference between the two groups regarding refractive and visual outcome after surgery (P > 0.05 for all).

Conclusion:

Implantation of AcrySof toric IOL and Hoya toric IOL was an effective way to correct preexisting corneal astigmatism in cataract surgery.

Clinical outcomes after implantation of a toric intraocular lens with a transitional conic toric surface

PURPOSE

To evaluate the postoperative outcomes after implantation of a hydrophilic toric intraocular lens (tIOL) with a transitional conic toric surface in patients with astigmatism undergoing refractive lens exchange (RLE) or cataract surgery.

METHODS

In this monocentric study, clinical outcomes following implantation of the hydrophilic Precizon toric IOL model 565 (Ophtec) were analysed. For intraoperative axis alignment, the Verion Image Guided System was used. Intended versus achieved refraction, IOL position, visual acuity outcomes and power vector analyses were evaluated 3 months postoperatively.

RESULTS

Forty-three eyes of 28 patients (40 eyes cataract, 3 eyes RLE) received a Precizon toric IOL with a cylindrical power between 1.0 and 7.5 D. Target refraction was emmetropia except for four eyes that had a myopic target. The median postoperative IOL rotation at slit lamp was 3° with a range from 0° to 16°. Uncorrected distance visual acuity (UDVA) increased from median 0.5 logMAR preoperatively to median 0.06 logMAR at 3 months postoperatively. Corrected distance visual acuity increased from 0.20 to -0.02 logMAR. Median preoperative subjective cylinder was 1.5 D and 3 months postoperatively 0.25 D.

CONCLUSION

Preoperative diagnostics, IOL selection and correct intraoperative positioning of tIOLs are essential for good outcomes and postoperative spectacle independence following cataract or RLE surgery. Visual acuities and rotational stability of the Precizon toric IOL showed very good outcomes and the subjective postoperative astigmatism could be reduced significantly.

Toric intraocular lens implantation in children with developmental cataract and preexisting corneal astigmatism

PURPOSE

To evaluate the effect of toric intraocular lens (IOL) implantation on the refractive outcomes in children with cataract and preexisting corneal astigmatism.

METHODS

We included children between the age group of 8-14 years who were randomized into group I (toric) and group II (non-toric), in which toric and spherical IOLs were implanted, respectively, after phacoaspiration. Primary outcome measure was comparison of preoperative keratometric and postoperative refractive cylinder. Secondary outcome measure was comparison of pre- and postoperative visual outcome.

RESULTS

This study included 21 eyes of 17 children with developmental cataract. The mean spherical power of the toric IOLs implanted in the group I was 22.42 ± 4.84 D (range 12.50-29.00 D) and the mean cylindrical power of toric IOL was 3.37 ± 1.43 D (range 1.50-6.00D). The mean spherical power implanted in non-toric (group II) was 20.70 ± 7.09 D (range 10-31D). Mean preoperative keratometric cylinder in group I was 2.99 ± 0.96 D (range 1.85-5.12 D) and in group II it was 3.35 ± 0.63 D (range 2.03D-4.33 D) (p = 0.31) while the mean refractive cylinder at one year postoperatively in group I was 0.50 ± 0.39 D (range 0.00-1.00 D) and in group II it was 2.05 ± 0.39 D (range 1.25D-2.50 D; p = 0.006). Twelve months postoperatively, group I had a mean spherical equivalent (SE) 0.41 ± 0.26 D (range 0.00-0.88 D) and group II had 1.8 ± 1.03 D (range 0.63-4.00 D) (p = 0.002). Uncorrected distance visual acuity (UDVA) improved from 0.94 log MAR ± 0.51 (range 0.60-2.00) to 0.43 log MAR ± 0.33 (range 0.00-1.00) in the group I at the end of 1 year and in group II, it improved from 1.52 log MAR ± 1.12 to 0.75 log MAR ± 0.70 (range 0.00-2.00) at the end of 1 year. Corrected distant visual acuity (CDVA) improved in group I from 0.72 log MAR ± 0.17 (range 0.48-1.00) to 0.19 log MAR ± 0.26 (range 0.00- 0.78) at the end of one year while in group II, it improved from 1.33 ± 1.08 (range 0.18-3.00) to 0.49 log MAR ± 0.80 (range 0.00-2.00) at the end of 1 year.

CONCLUSIONS

Toric IOL implantation in children significantly reduces postoperative astigmatism and thereby improves visual outcome.

Clinical application of TICL implantation for ametropia following deep anterior lamellar keratoplasty for keratoconus: A CONSORT-compliant article

BACKGROUND

This study aimed to investigate the clinical application of phakic toric intraocular collamer lens (TICL) implantation in treating ametropia following deep anterior lamellar keratoplasty (DALK) for patients with keratoconus, especially the effectiveness and safety of high astigmatism and indications of TICL implantation after corneal transplantation.

METHODS

Using the self-controlled case series observation approach, 9 patients with ametropia (9 eyes) who underwent DALK surgery for keratoconus 1.5 years ago with stitches removed 3 months ago were kept under observation from May 2013 to April 2014 in Ophthalmic Center of Nanjing Drum Tower Hospital affiliated to Nanjing Medical University. TICL implantation was performed in all patients. The uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) were examined before surgery and 1 week, 6 months, 1 year, and 2 years after surgery. Corneal astigmatism, corneal thickness, anterior chamber depth, corneal endothelial cell density (ECD), and preoperative and postoperative intraocular pressures at different time points were measured. Intraoperative or postoperative complications of TICL implantation were observed, and the safety of the operation was evaluated.

RESULTS

The UCVA and BCVA in all operated eyes were better 6 months after surgery than before surgery. The spherical diopter and cylindrical diopter decreased to different degrees after surgery. Six months after surgery, the deviation of TICL axis in all operated eyes was less than 10 degrees, tending to be stable. No severe intraoperative or postoperative complication occurred.

CONCLUSION

TICL implantation was an optional choice for ametropia correction after DALK surgery, especially in patients with high astigmatism.

Vector analysis investigation of toric intraocular lens with no deviation from the intended axis

AIM

The aim of this research was to evaluate vector analysis after implantation of toric intraocular lenses (IOLs) without deviation from the intended axis.

METHODS

The study included 18 eyes of 16 patients who underwent cataract surgery with the insertion of a toric implant (AcrySof IQ Toric). The postoperative IOL meridian placement completely corresponded to that planned. Using vector analysis, surgically induced astigmatism (SIA) was derived from the refractive outcome versus the predicted postoperative keratometric astigmatism and was compared with targeted induced astigmatism (TIA). The difference vector (DV) was derived by calculating the vector expression of the remaining astigmatic change.

RESULTS

The mean postoperative remaining refractive astigmatism of 0.73±0.55 diopters (D) was achieved versus the mean target of 0.44±0.28 D. There was a difference of 0.29 D between the target and achieved values. The mean SIA value was 1.90±0.99 D compared with the mean TIA value of 2.00±0.85 D. The mean DV value was 0.87±0.56 D. The astigmatism correction index (SIA/TIA) was 0.95, which was near the ideal value of 1. The index of success (DV/TIA) was 0.44, which was far from the ideal value of 0.

CONCLUSION

The implantation of toric IOLs is an effective, predictable method for astigmatic correction. However, some remaining astigmatism is present even if toric IOLs are placed accurately.

Toric intraocular lenses for correction of astigmatism in keratoconus and after corneal surgery

PURPOSE

To describe the results of cataract extraction with toric intraocular lens (IOL) implantation in patients with preexisting astigmatism from three corneal conditions (keratoconus, postkeratoplasty, and postpterygium surgery).

METHODS

Cataract patients with topographically stable, fairly regular (although sometimes very high) corneal astigmatism underwent phacoemulsification with implantation of a toric IOL (Zeiss AT TORBI 709, Alcon Acrysof IQ toric SN6AT, AMO Tecnis ZCT). Postoperative astigmatism and refractive outcomes, as well as visual acuities, vector reduction, and complications were recorded for all eyes.

RESULTS

This study evaluated 17 eyes of 16 patients with a mean age of 60 years at the time of surgery. Mean follow-up in this study was 12 months. The corrected distance Snellen visual acuity (with spectacles or contact lenses) 12 months postoperatively was 20/32 or better in 82% of eyes. The mean corneal astigmatism was 6.7 diopters (D) preoperatively, and 1.5 D of refractive cylinder at 1-year follow-up. No vision-compromising intra- or postoperative complications occurred and decentration or off-axis alignment of toric IOLs were not observed.

CONCLUSION

Phacoemulsification with toric IOL implantation was a safe and effective procedure in the three mentioned corneal conditions. Patient selection, counseling, and IOL placement with optimal astigmatism correction are crucial.

Comparison of two different methods of preoperative marking for toric intraocular lens implantation: bubble marker versus pendulum marker

AIM

To compare the accuracy of two different methods of preoperative marking for toric intraocular lens (IOL) implantation, bubble marker versus pendulum marker, as a means of establishing the reference point for the final alignment of the toric IOL to achieve an outcome as close as possible to emmetropia.

METHODS

Toric IOLs were implanted in 180 eyes of 110 patients. One group (55 patients) had preoperative marking of both eyes done with bubble marker (ASICO AE-2791TBL) and the other group (55 patients) with pendulum marker (Rumex(®)3-193). Reference marks were placed at 3-, 6-, and 9-o'clock positions on the limbus. Slit-lamp photographs were analyzed using Adobe Photoshop (version 7.0). Amount of alignment error (in degrees) induced in each group was measured.

RESULTS

Mean absolute rotation error in the preoperative marking in the horizontal axis was 2.42±1.71 in the bubble marker group and 2.83±2.31in the pendulum marker group (P=0.501). Sixty percent of the pendulum group and 70% of the bubble group had rotation error ≤3 (P=0.589), and 90% eyes of the pendulum group and 96.7% of the bubble group had rotation error ≤5 (P=0.612).

CONCLUSION

Both preoperative marking techniques result in approximately 3 of alignment error. Both marking techniques are simple, predictable, reproducible and easy to perform.

Astigmatism management in cataract surgery with Precizon(®) toric intraocular lens: a prospective study

Purpose

The purpose of this study was to evaluate the visual and refractive outcomes and rotational stability of the new aspheric Precizon^® toric intraocular lens (IOL) for the correction of corneal astigmatism in cataract surgery.

Setting

Department of Ophthalmology, Hospital Geral de Santo António – Centro Hospitalar do Porto, EPE and Hospital de Pedro Hispano, Matosinhos, Portugal.

Design

This was a prospective clinical study.

Patients and methods

A total of 40 eyes of 27 patients with corneal astigmatism greater than 1.0 diopter (D) underwent cataract surgery with implantation of Precizon^® toric IOL. IOL power calculation was performed using optical coherence biometry (IOLMaster^®). Outcomes of uncorrected (UDVA) and best-spectacle corrected distance visual acuities (BCDVA), refraction, and IOL rotation were analyzed at the 1st week, 1st, 3rd, and 6th month’s evaluations.

Results

The median postoperative UDVA was better than preoperative best-spectacle corrected distance visual acuity (0.02 [0.06] logMAR vs 0.19 [0.20] logMAR, P<0.001). At 6 months, postoperative UDVA was 0.1 logMAR or better in 95% of the eyes. At last follow-up, the mean spherical equivalent was reduced from −3.35±3.10 D to −0.02±0.30 D (P<0.001) with 97.5% of the eyes within ±0.50 D of emmetropia. The mean preoperative keratometric cylinder was 2.34±0.95 D and the mean postoperative refractive cylinder was 0.24±0.27 D (P<0.001). The mean IOL rotation was 2.43°±1.55°. None of the IOLs required realignment.

Conclusion

Precizon^® toric IOL revealed very good rotational stability and performance regarding predictability, efficacy, and safety in the correction of preexisting regular corneal astigmatism associated with cataract surgery.

The use of toric intraocular lens to correct astigmatism at the time of cataract surgery

Background:

To evaluate the visual and refractive outcomes of cataract surgery with toric intraocular lens (IOL) implantation at a teaching hospital of the United Kingdom.

Design:

Prospective interventional case series.

Materials and Methods:

This study compared the outcome of 3 groups of patients: Group 1 included 25 eyes with cataract and more than 2.5 diopters (D) of corneal astigmatism receiving a toric monofocal IOL; Group 2 had 18 patients with cataract and more than 2.5 D of astigmatism but receiving a non-toric monofocal IOL; while Group 3 had 25 patients with cataract and less than 1.5 D of astigmatism and receiving a non-toric monofocal IOL. Data collected included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction and corneal keratometry. Postoperative examinations were scheduled at 1 and 6 weeks.

Results:

Postoperatively the mean UDVA was LogMAR 0.27 ± 0.20 (equivalent snellen acuity of 20/37) in Group 1, 0.54 ± 0.22 (20/69) in Group 2 and 0.16 ± 0.20 (20/29) in Group 3. The mean CDVA was LogMAR 0.08 ± 0.13 (20/24) in Group 1, 0.23 ± 0.16 (20/34) in Group 2 and 0.04 ± 0.13 in Group 3 (20/22). The mean preoperative keratometric cylinder was 3.78 ± 1.0 D in Group 1, 3.41 ± 1.47 D in Group 2 and 0.97 ± 0.43D in Group 3; the mean postoperative subjective cylinder was 1.2 ± 0.68 D in Group 1, 3.23 ± 1.41 D in Group 2 and 0.95 ± 0.58 D in Group 3. The difference was statistically significant for the postoperative refractive cylinder values when comparing Group 1 to Group 2 (P = <0.0001) but the difference was insignificant between Group 1 and Group 3 (P = 0.23).

Conclusion:

Toric IOL implantation is an effective option to manage corneal astigmatism at the time of cataract surgery and to optimise visual outcomes for astigmatic patients when comparing to outcomes for their non-astigmatic counterparts.

Optical quality of toric intraocular lens implantation in cataract surgery

AIM

To analyze the optical quality after implantation of toric intraocular lens with optical quality analysis system.

METHODS

Fifty-two eyes of forty-four patients with regular corneal astigmatism of at least 1.00 D underwent implantation of AcrySof toric intraocular lens, including T3 group 19 eyes, T4 group 18 eyes, T5 group 10 eyes, T6 group 5 eyes. Main outcomes evaluated at 3mo of follow-up, included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), residual refractive cylinder and intraocular lens (IOL) axis rotation. Objective optical quality were measured using optical quality analysis system (OQAS II(®), Visiometrics, Spain), included the cutoff frequency of modulation transfer function (MTFcutoff), objective scattering index (OSI), Strehl ratio, optical quality analysis system value (OV) 100%, OV 20% and OV 9% [the optical quality analysis system (OQAS) values at contrasts of 100%, 20%, and 9%].

RESULTS

At 3mo postoperative, the mean UDVA and CDVA was 0.18±0.11 and 0.07±0.08 logMAR; the mean residual refractive cylinder was 0.50±0.29 D; the mean toric IOL axis rotation was 3.62±1.76 degrees, the mean MTFcutoff, OSI, Strehl ratio, OV 100%, OV 20% and OV 9% were 22.862±5.584, 1.80±0.84, 0.155±0.038, 0.76±0.18, 0.77±0.19 and 0.78±0.21. The values of UDVA, CDVA, IOL axis rotation, MTFcutoff, OSI, Strehl ratio, OV100%, OV20% and OV9% depending on the power of the cylinder of the implantation were not significantly different (P>0.05), except the residual refractive cylinder (P<0.05).

CONCLUSION

The optical quality analysis system was useful for characterizing the optical quality of AcrySof toric IOL implantation. Implantation of an AcrySof toric IOL is an effective and safe method to correct corneal astigmatism during cataract surgery.

Prediction of residual astigmatism after cataract surgery using swept source fourier domain optical coherence tomography

PURPOSE

To compare corneal measurements obtained by a swept source fourier domain OCT (CASIA SS-1000), an autokeratometer (Haag-Streit Lenstar), a hybrid topographer (Tomey TMS-5), a Placido topographer (Tomey TMS-5 in Placido mode) and a Scheimpflug tomographer (Oculus Pentacam) to manifest subjective refraction.

METHODS

One hundred and four pseudophacic patients with non-toric IOLs were measured at least 6 months after surgery. Corneal astigmatism as measured on the anterior corneal surface as well as total corneal astigmatism including posterior surface data was compared to manifest refractive cylinder (cross-cylinder strategy) by computing difference vectors and correlation analysis of power vectors.

RESULTS

The OCT (0.43 ± 0.25 D) and the hybrid topographer (0.44 ± 0.25 D) yielded the smallest difference vector to subjective cylinder and by far the lowest percentage of outliers >0.75 D (≈10%). The rotating Scheimpflug camera showed the largest (0.70 ± 0.41 D) difference vector. The best predictive precision (0.37 ± 0.22) could be achieved by vector averaging Lenstar keratometry and OCT.

CONCLUSIONS

Autokeratometry yielded the least measuring noise but OCT as well as hybrid topography had better predictive precision due to posterior curvature data. Scheimpflug tomography suffered from high measuring noise. Combination of keratometry and OCT data yielded the best precision for planning of toric IOL implantation. To get a reliable target cylinder for TIOL calculation, accuracy of the measuring device is crucial. Keratometry and Placido topography lack the information of the posterior corneal curvature while Scheimpflug devices suffer from higher measuring noise. In this paper, a combination of ssOCT with autokeratometry yielded the best predictive quality.

High-cylinder toric intraocular lens implantation versus combined surgery of low-cylinder intraocular lens implantation and limbal relaxing incision for high-astigmatism eyes

Clinical outcomes were compared between high-cylinder toric intraocular lens (IOL) implantation and the combined surgery of low-cylinder toric IOL implantation and limbal relaxing incision (LRI) for correcting preexisting high-amplitude corneal astigmatism. Fifty-seven eyes with preexisting corneal astigmatism of 2.5 diopter (D) or greater were divided into the following two groups: (1) eyes that underwent Alcon AcrySof® IQ Toric T6, T7, T8, or T9 IOL implantation (toric group); and (2) eyes that underwent the combined surgery of AcrySof® IQ Toric T5 IOL implantation and LRI (LRI group). Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest, refractive and corneal cylinder (MC, RC, CC), were compared postoperatively. Corneal and ocular higher-order aberrations (HOA) were also compared. At 1 day postoperative, UCVA was significantly better and MC and RC were significantly less in the toric group, however, at 1 and 6 months postoperative, there was no significant difference in those parameters. Postoperative corneal and ocular HOA were significantly greater in the LRI Group. For correcting astigmatism in eyes with a high amount of preexisting astigmatism, high-cylinder toric IOL implantation achieves better clinical outcomes, especially in the early postoperative period, than the combined procedure of moderate-cylinder toric IOL implantation and LRI.