Clinical outcomes after implantation of a new hydrophobic acrylic toric IOL during routine cataract surgery

Real-world outcomes of cataract surgeries using a new type of enhanced monofocal toric intraocular lens

In this single-center study, 62 eyes of 41 patients with regular astigmatism, who received cataract surgery with TECNIS Eyhance Toric II intraocular lens (IOL) insertion between January 1, 2022, and June 30, 2023, were retrospectively investigated. At 3 months postoperatively, there were significant improvements in the mean logMAR uncorrected distance visual acuity (VA) (from 0.64 ± 0.42 to 0.11 ± 0.13, p < 0.001) and logMAR corrected distance VA (from 0.28 ± 0.30 to 0.03 ± 0.06, p < 0.001). An 81.9% reduction in astigmatism (from 1.66 ± 0.49 D corneal cylinder preoperatively to - 0.30 ± 0.39 D refractive cylinder at 3 months postoperatively, p < 0.001) was observed. In the vector analysis, the average of difference vector was 0.27 ± 0.35 D, and the average correction index was 1.09 ± 0.22, revealing a minimal overcorrection. Mean IOL misalignment at 3 months postoperatively was 0.68 ± 4.17°, and average absolute misalignment was 3.41 ± 2.44°. Defocus curves showed < 0.2 logMAR range between - 0.85 and 1.27 diopters, and distance-corrected near and intermediate VA were 0.38 ± 0.14 and 0.17 ± 0.13, respectively. These results indicate that the new enhanced monofocal toric IOL is a safe and effective treatment for astigmatic eyes with cataract.

The Influence of Corneal Thickness on Surgically Induced Corneal Astigmatism Derived from Total Keratometry Measured by Anterior Segment Swept-Source OCT

INTRODUCTION

The purpose of the study was to explore the possible correlations between the anterior segment parameters derived from anterior segment swept-source optical coherence tomography (AS-SS-OCT) with the surgically induced corneal astigmatism (CSIA) calculated from total keratometry (TK) measured by AS-SS-OCT.

METHODS

Seventy-one eyes of 67 patients with age-related cataract who underwent phacoemulsification combined with intraocular lens implantation with 2.2-mm incision were included. The CSIA values were calculated from anterior keratometry (CSIAKant) and TK (CSIATK) measured by AS-SS-OCT, respectively. Hotelling's T2 test was used to evaluate the difference. The correlation of CSIA with various parameters derived from AS-SS-OCT was tested with the Spearman correlation coefficient.

RESULTS

The centroid of CSIAKant and of CSIATK were 0.31 ± 0.55 D @ 54° and 0.41 ± 0.59 D @ 51°, with no significant difference (F = 1.283, p = 0.281, Hotelling's T2). The mean absolute CSIAKant and CSIATK were 0.58 ± 0.24 D and 0.65 ± 0.28 D. Spearman test showed that the magnitude of CSIAKant was negatively correlated with preoperative peripheral corneal thickness (PCT, p = 0.045) and the magnitude of anterior keratometry (p = 0.044). The magnitude of CSIATK was negatively correlated with preoperative central corneal thickness (CCT, p = 0.003) and preoperative PCT (p = 0.015).

CONCLUSIONS

The increased thickness of the peripheral cornea is correlated with the decrease in the magnitude of the CSIA. The correlation we identified between the corneal thickness and the CSIA indicated that certain preoperative parameters should be considered for the prediction of CSIA for a more precise refractive outcome.

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.

2022 Glenn A. Fry Award lecture: Enhancing clinical assessment for improved ophthalmic management

ABSTRACT

Detailed clinical assessment is critical to allow sensitive evaluation of the eye and its management. As technology advances, these assessment techniques can be adapted and refined to improve the detection of pathological changes of ocular tissue and their impact on visual function. Enhancements in optical medical devices including spectacle, contact, and intraocular lenses have allowed for a better understanding of the mechanism and amelioration of presbyopia and myopia control. Advancements in imaging technology have enabled improved quantification of the tear film and ocular surface, informing diagnosis and treatment strategies. Miniaturized electronics, large processing power, and in-built sensors in smartphones and tablets capacitate more portable assessment tools for clinicians, facilitate self-monitoring and treatment compliance, and aid communication with patients. This article gives an overview of how technology has been used in many areas of eye care to improve assessments and treatment and provides a snapshot of some of my studies validating and using technology to inform better evidence-based patient management.

Comparison of clinical outcomes of Eyecryl toric and Alcon toric intra-ocular lenses - A real world study

Purpose

To compare the visual outcomes and residual astigmatism following implantation of Eyecryl toric versus Alcon AcrySof IQ toric intra-ocular lenses (IOLs).

Methods

This retrospective, observational study included 143 eyes of 141 patients who underwent phaco-emulsification, followed by implantation of Eyecryl toric IOL (n = 83 eyes) or Alcon toric IOL (n = 60 eyes) in an eye hospital in South India from 2018 to 2021. At 1 month post-op, the uncorrected distance visual acuity (UCVA), best corrected distance visual acuity (BCVA), and residual astigmatism of the toric IOL were compared and analyzed.

Results

The mean pre-op corneal astigmatism was 2.02 ± 0.81 D and 1.70 ± 0.68 D in the Alcon and Eyecryl groups, respectively (P = 0.005). The mean post-op corneal astigmatism at 1 month was 0.50 ± 0.51 D and 0.36 ± 0.42 D in the Alcon and Eyecryl groups, respectively, with no statistically significant difference between them (P = 0.87). The mean post-op UCVA in logarithm of minimum angle of resolution (logMAR) at 1 month was similar between the groups at 0.17 ± 0.18 and 0.17 ± 0.16 in the Alcon and Eyecryl groups, respectively (P = 0.98). The mean post-op BCVA in logMAR at 1 month was 0.06 ± 0.09 and 0.03 ± 0.10 in the Alcon and Eyecryl groups, respectively (P = 0.02).

Conclusion

Both Eyecryl toric and Alcon AcrySof IQ toric IOLs showed comparable post-operative outcomes in terms of UCVA and residual astigmatism. The post-op BCVA was clinically similar between groups but statistically better in the Eyecryl toric group.

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.

Toric intraocular lens versus limbal relaxing incisions for corneal astigmatism after phacoemulsification

BACKGROUND

Cataract is the leading cause of blindness in the world, and clinically significant astigmatism may affect up to approximately 20% of people undergoing cataract surgery. Pre-existing astigmatism in people undergoing cataract surgery may be treated, among other techniques, by placing corneal incisions near the limbus (limbal relaxing incisions or LRIs) or by toric intraocular lens (IOLs) specially designed to reduce or treat the effect of corneal astigmatism on unaided visual acuity.

OBJECTIVES

To assess the effects of toric IOLs compared with LRIs in the management of astigmatism during phacoemulsification cataract surgery.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register; 2019, Issue 9); Ovid MEDLINE; Ovid Embase and four other databases. The date of the search was 27 September 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing toric IOLs with LRIs during phacoemulsification cataract surgery.  DATA COLLECTION AND ANALYSIS: We used standard methods expected by Cochrane. We graded the certainty of the evidence using GRADE. Our primary outcome was the proportion of participants with postoperative residual refractive astigmatism of less than 0.50 dioptres (D) six months or more after surgery. We also collected data on mean residual refractive astigmatism. Secondary outcomes included: uncorrected distance visual acuity, vision-related quality of life, spectacle independence and adverse effects including postoperative lens rotation requiring re-alignment. To supplement the main systematic review assessing the effects of toric IOLs compared with LRIs in the management of astigmatism during phacoemulsification cataract surgery, we sought to identify economic evaluations on the subject.

MAIN RESULTS

We identified 10 relevant studies including 517 people (626 eyes). These studies took place in China (three studies), UK (three), Brazil (one), India (one), Italy (one) and Spain (one). The median age of participants was 71 years. The level of corneal astigmatism specified in the inclusion criteria of these studies ranged from 0.75 D to 3 D. A variety of toric IOLs were used in these studies, in all but one study, these were monofocal. Studies used three different nomograms to determine the size and placement of the LRI. Two studies did not specify this. None of the studies were at low risk of bias in all domains, but two studies were at low risk of bias in all domains except selective outcome reporting, which was unclear. The remaining studies were at a mixture of low, unclear or high risk of bias. People receiving toric IOLs were probably more likely to achieve a postoperative residual refractive astigmatism of less than 0.5 D six months or more after surgery (risk ratio (RR) 1.40, 95% confidence interval (CI) 1.10 to 1.78; 5 RCTs, 262 eyes). We judged this to be moderate-certainty evidence, downgrading for risk of bias. In the included studies, approximately 500 eyes per 1000 achieved postoperative astigmatism less than 0.5 D in the LRI group compared with 700 per 1000 in the toric IOLs group. There was a small difference in residual astigmatism between the two groups, favouring toric IOLs (mean difference (MD) -0.32 D, 95% CI -0.48 to -0.15 D; 10 RCTs, 620 eyes). Although all studies favoured toric IOLs, the results of individual studies were inconsistent (range of effects -0.02 D to -0.71 D; I² = 89%). We considered this to be low-certainty evidence, downgrading for risk of bias and inconsistency. People receiving a toric IOL probably have a small improvement in visual acuity at six months or more after surgery compared to people receiving LRI, but the difference is small and probably clinically insignificant (MD -0.04 logMAR, 95% CI -0.07 to -0.02; 8 RCTs, 474 eyes; moderate-certainty evidence). Low-certainty evidence from one study of 40 people suggested little difference in vision-related quality of life measured using the Visual Function Index (VF-14) (MD -3.01, 95% CI -8.56 to 2.54). Two studies reported spectacle independence and suggested that people receiving toric IOLs may be more likely to be spectacle independent (RR 1.56, 95% CI 1.14 to 2.15; 100 people; low-certainty evidence). There were no cases of lens rotation requiring surgery (very low-certainty evidence). Five studies (320 eyes) commented on a range of other adverse effects including corneal oedema, endophthalmitis and corneal ectasia. All these studies reported that there were no adverse events with the exception of one study (40 eyes) where one participant in the LRI group had a central de-epithelisation which recovered over 10 days. We found no economic studies that compared toric IOLs with LRIs.

AUTHORS' CONCLUSIONS

Toric IOLs probably provide a higher chance of achieving astigmatism within 0.5 D after cataract surgery compared with LRIs. There may be a small mean difference in postoperative astigmatism, favouring toric IOLs, but this difference is likely to be clinically unimportant. There was no evidence of an important difference in postoperative visual acuity or quality of life between the techniques. Evidence on adverse effects was uncertain. The apparent shortage of relevant economic evaluations indicates that economic evidence regarding the costs and consequence of these two procedures is currently lacking.

Efficacy of toric intraocular lens implantation with high corneal astigmatism within the United Kingdom's National Health Service

OBJECTIVES

To determine the efficacy of toric intraocular lens (TIOL) implantation in cataract surgery patients with high levels of pre-operative corneal astigmatism and ocular co-morbidities in a state funded, National Health Service (NHS) hospital.

METHODS

Retrospective cohort study involving consecutive cases of TIOL implantation in cataract surgery with over 3.00DC of pre-operative corneal astigmatism. Subjects were implanted with the Tecnis TIOL (Abbot Medical Optics) with capsular tension ring stabilisation using the Callisto system (Carl Zeiss Meditec). Visual acuity and refraction were assessed at 4-6 weeks post-operatively. Vector analysis was used to calculate the intended refractive correction, surgically induced refractive correction (SIRC), correction ratio (CR), error of magnitude (EM) and error vector (EV).

RESULTS

Sixty-six eyes of forty-seven subjects aged 73.8 ± 11.9 were included. Eyes with ocular co-morbidities included dry age-related macular degeneration (n = 13), amblyopia (n = 7), high myopia (n = 7), glaucoma (n = 6), previous corneal transplantation (n = 2), nanophthalmos (n = 2) and corneal scarring (n = 1). Pre-operative corneal astigmatism was 4.25 ± 1.69DC (range 3.00-12.00), post-operative refractive astigmatism was 1.31 ± 1.05DC (range 0.00-6.50DC) and post-operative unaided visual acuity was 0.25 ± 0.19 LogMAR. Vector analysis demonstrated an SIRC of 4.08 ± 1.39DC, CR = 1.1 ± 0.3, EM -0.4 ± 1.0 and EV of 1.23 ± 0.72.

CONCLUSIONS

The results demonstrate the efficacy of TIOL implantation in patients with high corneal astigmatism and provide strong evidence advocating their use in cataract surgery within a state funded hospital eye service. Refractive astigmatism was significantly lower than the pre-operative corneal astigmatism and a low error vector was achieved relative to the magnitude of correction.

Rotation of a toric intraocular lens with and without capsular tension ring: data from a multicenter non-inferiority randomized clinical trial (RCT)

BACKGROUND

Evaluation of clinical outcome in cohorts with versus without simultaneous implantation of a capsular tension ring (CTR) and a toric lens (Tecnis Toric). Main parameter was rotation referring - in contrast to misalignment - to the IOL axis change from immediately after implantation to the final postoperative position.

METHODS

Lens position was measured at baseline with the patient still in recumbent position, postoperative rotation was calculated by software. Postoperative evaluation included measurement three months after surgery or prior to an indicated revision surgery. Explorative re-evaluation of the underlying RCT's intent-to-treat population was performed for the entire sample and stratified for cohorts by 95% confidence intervals for binary endpoints' incidences (primary endpoint: absolute postoperative rotation ≤5 degrees; secondary endpoints: absolute deviation between achieved cylinder and target cylinder ≤0.5 dpt, postoperative corrected distance visual acuity (CDVA) ≥ 0.8). Data exploration was based on medians and quartiles.

SETTING

Outpatient study sites.

DESIGN

Re-evaluation based on data from a multicenter non-inferiority randomized clinical trial (RCT).

RESULTS

Sub cohorts (without CTR 89, with CTR 90 patients) did not present clinically relevant differences in preoperative characteristics: revision surgery was performed in 7 cases (3 without and 4 with CTR). Primary endpoint incidences for the total sample, without and with CTR were 90%/89%/90%; cylinder endpoint incidences were 46%/45%/46% and CDVA endpoint incidences 90%/92%/88%. Median absolute rotations were 1.74°/1.79°/1.72°, median absolute cylinder deviations 0.55/0.52/0.55 dpt and median visual acuity 1.0/1.0/1.0.

CONCLUSION

No clinically relevant differences between CTR subgroups were found; a satisfying three months rotational stability was achieved.

TRIAL REGISTRATION

The trial was registered retrospectively in the trial registry DRKS, trial registration number DRKS00015316 , date of registration 27. August 2018.

Efficacy of 4-Haptic Bitoric Intraocular Lens Implantation in Asian Patients with Cataract and Astigmatism

PURPOSE

To determine the efficacy of 4-haptic bitoric intraocular lens (IOL) implantation in Asian patients with cataract and astigmatism.

METHODS

A total of 19 eyes with ≤25.0 mm axial length and ≥0.75 diopters (D) corneal astigmatism were included in this prospective non-comparative study. All subjects underwent phacoemulsification with implantation of an AT Torbi 709M IOL. Visual and refractive outcomes as well as toric IOL axis were evaluated during a 3-month follow-up. Errors in predicted residual spherical equivalent were calculated by subtracting predicted residual spherical equivalent from postoperative refraction.

RESULTS

Uncorrected and corrected distance visual acuity improved significantly 3 months after surgery, from 0.43 to 0.05 and from 0.24 to -0.05, respectively. Mean refractive cylinders also decreased significantly, from -1.91 preoperatively to -0.54 D 3 months after surgery. Mean J0 and J45 decreased 3 months postoperatively, from 0.26 to 0.03 D and from 0.24 to -0.06 D, respectively. After 3 months, mean absolute IOL rotation was 1.81°. Errors in predicted residual spherical equivalent showed a hyperopic shift of 0.35 D.

CONCLUSIONS

Implantation of 4-haptic bitoric IOL proved to be effective for correcting astigmatism in Asian eyes during cataract surgery.

Comparison of clinical outcomes of toric intraocular lens, Precizon vs Tecnis: a single center randomized controlled trial

Background

To compare the clinical outcome of Precizon toric intraocular lens (IOL) (Ophtec Inc.) to that of Tecnis toric IOL (Abbott Medical Optics Inc.).

Methods

This randomized comparative study included 40 eyes (Precizon, 20 eyes; Tecnis, 20 eyes) of 40 patients with visually significant cataract and corneal astigmatism who underwent cataract surgery. Changes in uncorrected distant visual acuity (UCDVA), best corrected distant visual acuity (BCDVA), uncorrected intermediate visual acuity (UCIVA), refraction, residual astigmatism, rotation of the IOL axis, and higher order aberrations at 3 months postoperatively were evaluated. Vector analysis was performed using the Alpins method.

Results

Both groups showed significant reduction in refractive astigmatism after the surgery (Precizon: − 1.06 ± 0.94 Diopter (D) to − 0.31 ± 0.29 D, p = 0.042; Tecnis: − 1.83 ± 1.29 D to − 0.41 ± 0.33 D, p = 0.015). There was no significant (p > 0.05) difference in postoperative UCDVA, BCDVA, or residual astigmatism between the two groups, although a tendency of better UCIVA was observed in the Precizon group. Vector analysis parameters showed no statistically significant difference beween groups(P > 0.05). Significant difference in rotation of toric IOL axis was found between the two groups (Precizon: 1.50° ± 0.84, Tecnis: 2.56° ± 0.68, p = 0.010). Spherical aberration in the Precizon group was significantly (p = 0.005) lower than that in the Tecnis group.

Conclusions

The Precizon toric IOL group had better rotational stability at 3-month postoperatively. Both Precizon toric IOL and Tecnis toric IOL could be effectively used by cataract surgeons to correct preexisting corneal astigmatism through cataract surgery.

Trial registration

http://clinicaltrials.gov, NCT03085901, retrospectively registered on 21 March 2017.

Electronic supplementary material

The online version of this article (10.1186/s12886-018-0955-3) contains supplementary material, which is available to authorized users.

Toric intraocular lenses in eyes with with-the-rule, against-the-rule, and oblique astigmatism: One-year results

PURPOSE

To assess 1-year clinical results of toric intraocular lenses (IOLs) in eyes having with-the-rule (WTR), against-the-rule (ATR), or oblique corneal astigmatism.

SETTING

Four ophthalmic surgical sites, Japan.

DESIGN

Prospective case series.

METHODS

One of 3 toric IOLs or 1 nontoric IOL was implanted in eyes having phacoemulsification and IOL implantation.

RESULTS

The study comprised 218 eyes (155 patients). Based on the suggestion of an online toric calculator with anterior corneal curvature data, 63 eyes received the SN6AT3 IOL with a cylinder power of 1.50 diopters [D] at IOL plane (1.50 D cylinder IOL) 55 eyes the SN6AT4 IOL with a cylinder power of 2.25 D at IOL plane (2.25 D cylinder IOL), and 58 eyes the SN6AT5 IOL with a cylinder power of 3.00 D at IOL plane (3.00 D cylinder IOL) (all Acrysof IQ toric), and 42 eyes received the SN60WF IOL (nontoric IOL). One hundred ninety-four eyes (89.0%) completed 1-year of follow-up. The centroid error in predicted residual astigmatism calculated using vector analysis was close to the origin in eyes with WTR astigmatism (0.17 diopter [D] @ 174.9 ± 0.54 D), while those with ATR and oblique astigmatism were significantly shifted toward the ATR direction (P < .001). The distance from the origin was significantly smaller in the WTR group than in ATR and oblique groups (P < .05). The centroid errors were shifted toward ATR in all toric IOL groups (P < .001); however, the distance from the origin was not different between groups (P = .52). Postoperatively, the mean absolute misalignment of the IOLs was 5.92 degrees ± 5.59 (SD) at 1 day and 6.24 ± 5.87 degrees at 1 year. The results of other clinical parameters were excellent, with no significant differences between astigmatism categories or IOL models.

CONCLUSION

Based on anterior corneal curvature alone, toric IOLs undercorrected ATR and oblique astigmatism; however, 1-year clinical results of toric IOLs were highly stable and satisfactory.

FINANCIAL DISCLOSURE

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

Improving the Toric Intraocular Lens Calculation by Considering Posterior Corneal Astigmatism and Surgically-induced Corneal Astigmatism

PURPOSE

To investigate the effect of surgically induced corneal astigmatism (SICA) and total corneal astigmatism (TCA) estimation on the anterior corneal astigmatism (ACA)-based toric intraocular lens (IOL) calculation.

METHODS

Data from preoperative and postoperative corneal astigmatism, postoperative visual acuities, and refractive outcomes were collected. The incision was superior in with the rule anterior corneal astigmatism (WTRA) eyes and temporal in against the rule anterior corneal astigmatism eyes. The following five methods of calculating the toric IOL were compared: (1) ACA only and estimated SICA; (2) ACA with a fixed posterior corneal astigmatism (PCA) and estimated SICA; (3) ACA with a fixed PCA value and actual SICA; (4) and (5) TCA derived from the regression equations of ACA and actual SICA. The residual astigmatism was simulated. The Alpins method was used to analyze the astigmatism.

RESULTS

Sixty eyes from 46 patients were enrolled. Thirty eyes had WTRA and the other thirty had against the rule anterior corneal astigmatism. The vector and arithmetic means of the difference vector decreased when the information regarding the actual SICA and PCA was added to the calculation (from 0.59 diopters [D] @ 87.5° to 0.15 D @ 48.5°, and from 0.95 ± 0.53 to 0.71 ± 0.63 D, respectively; p < 0.001). The mean difference vector across the whole sample was lowest using model 5. The correction index was significantly closest to 1.0 in the WTRA group.

CONCLUSIONS

Researchers may improve the accuracy of post-implantation predictions by calculating toric IOL using exact SICA and TCA, with consideration of the PCA derived from the regression equation of ACA.

Comparison of Two Toric IOLs with Different Haptic Design: Optical Quality after 1 Year

Background

The purpose of this prospective, randomised study was to interocularly compare the visual performance after implantation of two different toric IOLs with different haptic design.

Methods

59 subjects with corneal astigmatism greater than 1.25 diopter (D) were implanted with an AT TORBI 709M IOL (Carl Zeiss Meditec AG) in one eye and with a Tecnis toric aspheric IOL (Abbot Medical Optics) in the other eye. Observation procedure was performed 12 months postoperatively. Main outcome measures included uncorrected distance visual acuity (UDVA), manifest refraction, IOL rotation, and IOL position.

Results

Mean UCDVA was 0.04 ± 0.14 logMAR for AT TORBI eyes and 0.06 ± 0.15 logMAR for Tecnis eyes (p = 0.3). The postoperative spherical equivalent values were significantly lower in the AT TORBI group. Mean toric IOL axis rotation was 3.0 ± 2.26 degrees for AT TORBI eyes and 3.27 ± 2.37 for Tecnis eyes (p = 0.5). The mean vertical IOL tilt and vertical decentration values measured with the Visante OCT were significantly larger in the AT TORBI group (p < 0.05).

Conclusions

Both the Tecnis and the AT TORBI toric IOLs successfully reduced ocular astigmatism. Emmetropia could be better achieved with the AT TORBI IOL, whereas the Tecnis showed better positional stability. This trial is registered with ICMJE NCT03371576.

Visual outcomes after progressive apodized diffractive intraocular lens implantation

PURPOSE

To assess photopic and mesopic vision in patients implanted with the Bi-Flex® M 677 MY bifocal intraocular lens (IOL).

METHODS

In this prospective clinical study, 25 patients with cataract in both eyes were subjected to cataract surgery and bilateral implantation of the Bi-Flex® M 677MY (Medicontur, Hungary) IOL. Three months after surgery, high-contrast photopic uncorrected distance visual acuity (UDVA) and corrected distance visual acuity (CDVA) were determined. Intermediate at 65 cm (DCIVA) and near at 40 cm (DCNVA) visual acuity were also measured, both with best distance correction. The CSV-1000 test chart was used to assess contrast sensitivity (CS). Defocus curves were constructed under photopic and mesopic conditions, determining binocular best-corrected visual acuity over the range +1.50 D to -4.00 D in 0.50-D steps. A KR-1W Wavefront Analyzer was used to measure pupil size and aberrometric outcomes. Presence and type of dysphotopsia were evaluated with the Likert scale.

RESULTS

Mesopic mean pupil diameter was 4.58 ± 0.73 mm. The mean values at 3 months were UDVA 0.03 ± 0.09, CDVA -0.05 ± 0.06, DCIVA 0.20 ± 0.07, and DCNVA 0.11 ± 0.08. Mean CS for the 4 frequencies examined were 1.66 ± 0.16, 1.75 ± 0.14, 1.39 ± 0.22, and 0.96 ± 0.19. Significant differences were observed in defocus curves for photopic and mesopic conditions. A significant correlation between pupil diameter and the dysphotopic photopic was found (r = 0.62; p = 0.02).

CONCLUSIONS

The evaluated progressive apodized diffractive design IOL provides effective restoration of visual function in far and near vision distance with an adequate intermediate visual quality between -1.00 and -1.50 focus.

Introduction of a Toric Intraocular Lens to a Non-Refractive Cataract Practice: Challenges and Outcomes

AIM

To identify challenges inherent in introducing a toric intraocular lens (IOL) to a non-refractive cataract practice, and evaluate residual astigmatism achieved and its impact on patient satisfaction.

METHODS

Following introduction of a toric IOL to a cataract practice with all procedures undertaken by a single, non-refractive, surgeon (SB), pre-operative, intra-operative and post-operative data was analysed. Attenuation of anticipated post-operative astigmatism was examined, and subjectively perceived visual functioning was assessed using validated questionnaires.

RESULTS

Median difference vector (DV, the induced astigmatic change [by magnitude and axis] that would enable the initial surgery to achieve intended target) was 0.93D; median anticipated DV with a non-toric IOL was 2.38D. One eye exhibited 0.75D residual astigmatism, compared to 3.8D anticipated residual astigmatism with a non-toric IOL. 100% of respondents reported satisfaction of ≥ 6/10, with 37.84% of respondents entirely satisfied (10/10). 17 patients (38.63%) reported no symptoms of dysphotopsia (dysphoptosia score 0/10), only 3 respondents (6.8%) reported a clinically meaningful level of dysphotopsia (≥ 4/10). Mean post-operative NEI VF-11 score was 0.54 (+/-0.83; scale 0 - 4).

CONCLUSION

Use of a toric IOL to manage astigmatism during cataract surgery results in less post-operative astigmatism than a non-toric IOL, resulting in avoidance of unacceptable post-operative astigmatism.

Clinical Outcomes after Uncomplicated Cataract Surgery with Implantation of the Tecnis Toric Intraocular Lens

Purpose. To evaluate the clinical outcomes after uncomplicated cataract surgery with implantation of an aspheric toric intraocular lens (IOL) during a 6-month follow-up. Methods. Prospective study including 27 consecutive eyes of 18 patients (mean age: 66.1 ± 11.4 years) with a visually significant cataract and corneal astigmatism ≥ 0.75 D and undergoing uncomplicated cataract surgery with implantation of the Tecnis ZCT toric IOL (Abbott Medical Optics). Visual, refractive, and keratometric outcomes as well as IOL rotation were evaluated during a 6-month follow-up. At the end of the follow-up, patient satisfaction and perception of optical/visual disturbances were also evaluated using a subjective questionnaire. Results. At 6 months after surgery, mean LogMAR uncorrected (UDVA) and corrected distance visual acuity (CDVA) were 0.19 ± 0.12 and 0.14 ± 0.10, respectively. Postoperative UDVA of 20/40 or better was achieved in 92.6% of eyes. Mean refractive cylinder decreased significantly from -3.73 ± 1.96 to -1.42 ± 0.88 D (p < 0.001), while keratometric cylinder did not change significantly (p = 0.44). Mean absolute IOL rotation was 1.1 ± 2.4°, with values of more than 5° in only 2 eyes (6.9%). Mean patient satisfaction score was 9.70 ± 0.46, using a scale from 0 (not at all satisfied) to 10 (very satisfied). No postoperative optical/visual disturbances were reported. Conclusion. Cataract surgery with implantation of the Tecnis toric IOL is an effective method of refractive correction in eyes with corneal astigmatism due to the good IOL positional stability, providing high levels of patient's satisfaction.

Vector Analysis, Rotational Stability, and Visual Outcome After Implantation of a New Aspheric Toric IOL

PURPOSE

To evaluate vector analysis, rotational stability, and refractive and visual outcome of a new toric intraocular lens (IOL) for correction of preexisting corneal astigmatism during routine cataract surgery.

METHODS

In this prospective, interventional case series, 30 toric, aspheric Bi-Flex T toric IOLs (Medicontur Medical Engineering Ltd., Inc., Zsámbék, Hungary) were implanted in 20 consecutive patients with topographic corneal astigmatism between 1.50 and 4.00 diopters (D) and evaluated within the first year after implantation. Appropriate IOL-toric alignment was facilitated by combined imaging/eye tracking technology. Postoperative evaluation included refraction and uncorrected and corrected distance visual acuities (UDVA, CDVA). For each visit, photodocumentation in retroillumination was performed to evaluate toric alignment and potential toric IOL rotation. Vector analysis of refractive astigmatism was performed using the Alpins method.

RESULTS

At 12 months postoperatively, a reduction of the refractive astigmatism from 1.93±0.90 D (range: 0.50 to 4.00 D) to 0.28±0.61 D (range: 0.00 to 1.50 D) could be found, with patients achieving a mean UDVA of 0.06±0.16 logMAR (range: -0.18 to 0.40 logMAR; Snellen 20/20). Intraoperative to 12-month postoperative comparison of IOL axis alignment showed low levels of rotation (0.2°±2.41°; range: +4° to -5°). Vector analysis showed target induced astigmatism of 0.60 D @180°, surgically induced astigmatism of 0.80 D @177°, correction index of 1.02±0.25, and a difference vector of 0.30 D @82°.

CONCLUSIONS

Implantation of the new Bi-Flex T IOL was a safe, stable, and effective method to correct preexisting regular corneal astigmatism during cataract surgery.

Vector analysis of astigmatism correction after toric intraocular lens implantation

PURPOSE

To determine astigmatic changes by vector analysis and postoperative refractive and visual outcomes after implantation of the monofocal aspheric bitoric AT Torbi 709M toric intraocular lens (IOL).

SETTING

Three centers in Salzburg, Austria, and Alicante and San Sebastián, Spain.

DESIGN

Prospective interventional case series.

METHODS

Preoperative and postoperative visual acuity, subjective and objective refractions, and corneal radii using a topographer were examined in all patients. All patients had postoperative examinations within the first week and at 6 to 12 weeks. Astigmatic changes were evaluated using the Alpins vector method based on 3 fundamental vectors as follows: target induced astigmatism (TIA), surgically induced astigmatism (SIA), and difference vector. The various relationships between these 3 vectors were calculated, providing an extensive description of the astigmatic correction achieved.

RESULTS

Eighty-eight eyes (71 patients) were included. Postoperatively, refractive cylinder was reduced significantly (P < .001), concurrent with visual improvement. The mean magnitude of the SIA vector (2.54 diopters [D] ± 1.21 [SD]) was slightly higher than the mean magnitude of the TIA vector (2.37 ± 1.15 D) at the last follow-up. The mean difference vector was 0.46 ± 0.46 D, the mean magnitude of error was 0.16 ± 0.46 D, and the mean correction index was 1.09 ± 0.21, all indicating minimal overcorrection at 3 months that remained stable during the follow-up.

CONCLUSION

Implantation of the toric IOL was safe and effective for the treatment of eyes with cataract in combination with preexisting regular corneal astigmatism over a short-term follow-up.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Toric intraocular lens versus monofocal intraocular lens implantation and photorefractive keratectomy: a randomized controlled trial

PURPOSE

To compare the outcomes of phacoemulsification with toric intraocular lens implantation vs phacoemulsification with monofocal intraocular lens implantation followed by photorefractive keratectomy (PRK) for correction of pre-existing astigmatism.

DESIGN

Randomized controlled trial, 6-month study.

METHODS

setting: Institutional.

STUDY POPULATION

Sixty eyes of 52 patients with age-related senile cataract and regular corneal astigmatism ranging from 1.50 to 3.00 diopters, enrolled and randomly allocated in 2 groups based on computer-generated random number table.

INTERVENTION

Group 1 patients underwent phacoemulsification with toric intraocular lens (IOL) implantation and Group 2 patients underwent phacoemulsification with monofocal IOL implantation followed by PRK 3 months later.

MAIN OUTCOME MEASURES

The main outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), residual cylinder, contrast sensitivity, glare acuity, pain score, and higher-order aberrations.

RESULTS

At 6 months 53.3% of eyes in the toric IOL and 60% eyes in the monofocal IOL with PRK group attained UDVA of 20/20. Median residual refractive cylinder value was higher in the toric IOL group (toric IOL = -0.5, monofocal IOL with PRK = 0; P = .02). Mean root mean square value of total aberrations (5 mm pupil) was higher in monofocal IOL with PRK eyes (toric IOL= 1.02 ± 0.44, monofocal IOL with PRK = 1.28 ± 0.5; P = .04). Mean contrast sensitivity values were comparable. Mean toric IOL rotation was 1.3 ± 2.1 degrees. Mean glare acuity was better in toric IOL eyes (toric IOL = 0.46 ± 0.16, monofocal IOL with PRK = 0.73 ± 0.12; P < .001). Median postoperative pain scores were higher in monofocal IOL with PRK eyes.

CONCLUSION

PRK yields lesser residual cylinder compared to toric IOL. However, it causes greater postoperative pain and corneal aberrations, and poor glare acuity.

Clinical Outcomes and Capsular Bag Stability of a Four-Point Haptic Bitoric Intraocular Lens

PURPOSE

To evaluate the visual, refractive, and aberrometric outcomes of a bitoric intraocular lens (IOL) and its stability and alignment within the capsular bag.

METHODS

A retrospective study including 41 eyes of 24 patients with preexisting corneal astigmatism of 0.75 diopters or greater undergoing cataract surgery with implantation of the bitoric IOL AT TORBI 709M (Carl Zeiss Meditec, Jena, Germany). Visual and refractive outcomes were evaluated during a 3-month follow-up period. The misalignment between intended and real axis and the levels of corneal, internal, and ocular aberrations (KR-1W; Topcon, Tokyo, Japan) were also evaluated.

RESULTS

A total of 76% and 97% of eyes had a postoperative spherical equivalent within ± 0.50 and ± 1.00 diopters of emmetropia, respectively. Likewise, a total of 86% and 95% of eyes had a postoperative absolute value of refractive cylinder of 0.50 or less and 1.00 or less diopters, respectively. Mean postoperative corrected distance visual acuity was 0.00 logMAR (20/20 Snellen). Mean values of postoperative monocular and binocular uncorrected distance visual acuity were 0.10 and 0.00 logMAR (20/25 and 20/20 Snellen), respectively. The aberrometric analysis confirmed that the magnitude of ocular higher-order aberrations was mainly due to corneal optics and that the corneal astigmatism correction was sufficient with the toric IOL. Mean absolute IOL misalignment was 3.5° with values ranging from 0° to 10°.

CONCLUSIONS

The bitoric IOL AT TORBI 709M is able to provide a predictable correction of corneal astigmatism with low postoperative levels of ocular higher-order aberrations.

Software-based evaluation of toric IOL orientation in a multicenter clinical study

PURPOSE

To evaluate the rotational stability of a new one-piece hydrophobic acrylic toric intraocular lens (IOL) using a custom-developed software for analysis of slit-lamp photographs.

METHODS

In a prospective, multicenter study, 174 eyes were implanted with the TECNIS Toric IOL (Abbott Medical Optics, Inc., Santa Ana, CA). A custom-developed software was used to analyze high-resolution slit-lamp photographs of 156 eyes taken at day 1 (baseline) and 1, 3, and 6 months postoperatively. The software uses iris and sclera landmarks to align the baseline image and later images for comparison. Validation of software was performed through repeated analyses of protractor images rotated from 0.1° to 10.0° and randomly selected photographs of 20 eyes.

RESULTS

Software validation showed precision (repeatability plus reproducibility variation) of 0.02° using protractor images and 2.22° using slit-lamp photographs. Good quality slit-lamp images and clear landmarks were necessary for precise measurements. At 6 months, 94.2% of eyes had 5° or less change in IOL orientation versus baseline; only 2 eyes (1.4%) had axis shift greater than 30°. Most eyes were within 5° or less of rotation between 1 and 3 months (92.9%) and 3 and 6 months (94.1%). Mean absolute axis change (± standard deviation) from 1 day to 6 months was 2.70° ± 5.51°.

CONCLUSIONS

The new custom software was precise and quick in analyzing slit-lamp photographs to determine postoperative toric IOL rotation.

Clinical outcomes of TECNIS toric intraocular lens implantation after cataract removal in patients with corneal astigmatism

PURPOSE

To evaluate safety and effectiveness of the TECNIS toric intraocular lenses (IOLs).

DESIGN

Prospective, multicenter, 2-armed, bilateral, 6-month clinical trial following the American National Standards Institute (ANSI) standard for Toric IOLs.

PARTICIPANTS

Subjects implanted with a TECNIS toric IOL (n = 172) or a TECNIS 1-piece control IOL (ZCB00; n = 93).

METHODS

Subjects underwent standard cataract surgery with IOL implantation. The randomized control arm consisted of subjects requiring cylinder correction of 0.75 to 1.50 diopters (D) who were implanted with either toric (ZCT150) or nontoric (ZCB00) IOLs. The open-label arm (OLA) consisted of subjects requiring cylinder correction of 1.50 to 3.62 D and implanted with ZCT225, ZCT300, or ZCT400 IOLs.

MAIN OUTCOME MEASURES

Assessments were at 1 day, 1 week, and 1, 3, and 6 months and included uncorrected distance visual acuity (UCDVA) and best-corrected distance visual acuity (BCDVA), manifest refraction, keratometry, adverse events, spectacle use, and photographic documentation of IOL rotational stability.

RESULTS

Mean percent reduction in cylinder (± standard deviation) was statistically significantly greater (P < 0.0001) for ZCT150 eyes (74.53 ± 72.25%) versus ZCB00 eyes (31.61 ± 78.73%). In the OLA, mean percent reduction in cylinder was 76.27 ± 33.09%. A UCDVA of 20/20 or better was achieved by 43.6% (44/101) of ZCT150 eyes and by 23.7% (22/93) of ZCB00 eyes (P = 0.0026). In the OLA, 38.0% (27/71) achieved 20/20 or better UCDVA. Mean UCDVA was 0.10 ± 0.14 for ZCT150 eyes and 0.16 ± 0.16 for ZCB00 eyes (P = 0.0009); in the OLA, mean UCDVA was 0.11 ± 0.12. The BCDVA was 20/40 or better for all eyes. Mean absolute lens rotation between visits for toric eyes pooled was less than 3°. Lens rotation of 5° or less occurred in 92.9% of toric eyes between 1 and 3 months and in 94.1% between 3 and 6 months, exceeding the ANSI standard for stability (≥ 90% of eyes with ≤ 5° of rotation between visits). Four lenses (2.3%) were repositioned during the study.

CONCLUSIONS

The TECNIS toric IOLs successfully reduce ocular astigmatism and are a safe and effective treatment for cataract patients with corneal astigmatism.

Changes in corneal astigmatism among patients with visually significant cataract

OBJECTIVE

To determine the prevalence of corneal astigmatism, changes in astigmatism, and biometry measurements with age and to correlate fellow eye measurements of patients undergoing cataract surgery.

DESIGN

Prospective, observational study.

PARTICIPANTS

3498 eyes of 1814 patients undergoing cataract surgery.

METHODS

Setting was a single center teaching hospital. Preoperative biometry data measured by partial coherence interferometry (IOLMaster; Carl Zeiss Meditec, Jena, Germany) were collected and analyzed.

RESULTS

Mean age of the cohort was 74.52 ± 10.23 years. Mean corneal astigmatism was 1.04 ± 0.78 D OD and 1.04 ± 0.79 D OS. About 19.7% and 4.9% of eyes had corneal astigmatism greater than 1.5 and 2.5 D, respectively. The prevalence of against-the-rule astigmatism significantly increased with age bilaterally. Paired fellow eye analysis found a positive correlation for corneal astigmatism, axial length, anterior chamber depth, and white-to-white distance (p < 0.001). About 33.33% of right eyes with corneal astigmatism greater than 2.5 D had more than 2.5 D of astigmatism in the fellow eye. This is in comparison with only 1.5% of right eyes with corneal astigmatism of less than 1.5 D having corneal astigmatism greater than 2.5 D in the fellow eye.

CONCLUSIONS

Patients with high corneal astigmatism in 1 eye are more likely to have significant astigmatism in the fellow eye. This may necessitate the need for bilateral toric intraocular lens (IOL) implantation during cataract surgery. Against-the-rule astigmatism should be treated more aggressively during cataract surgery, because this is likely to worsen with age. Such information is useful when calculating toric IOL power at the time of surgery.

Technology and Intraocular Lenses to Enhance Cataract Surgery Outcomes-Annual Review (January 2013 to January 2014)

PURPOSE

This article is aimed to provide a clinical update on recent developments in cataract surgical techniques, with specific focus on femtosecond laser technology. The article also focuses on recent improvements in the technology used in implanting intraocular lenses (IOLs).

DESIGN

Literature review.

METHODS

The authors conducted a review of literature available in the last 12 months in the English language using PubMed. The period used to conduct the literature search was from January 1, 2013, to December 31, 2013. The following search terms were used during the PubMed search: phacoemulsification, femtosecond laser, toric IOLs, multifocal IOLs, multifocal toric IOLs, manual small-incision cataract surgery, outcomes, surgically induced astigmatism, rotational stability, trifocal IOLs, laser cataract surgery, safety, and efficacy.

RESULTS

This review incorporates selected original articles that provide fresh insights and updates on the fields of toric and multifocal IOLs, femtosecond laser cataract surgery, and manual small-incision cataract surgery. Particular attention has been paid to observational, randomized controlled clinical trials, experimental trials, and analyses of larger cohorts with prospective and retrospective study designs. Letters to the editor, unpublished works, and abstracts do not fall under the purview of this review.

CONCLUSIONS

This review is not designed to be all-inclusive. It highlights and provides insights on literature that is most useful and applicable to practicing ophthalmologists.

Rotational performance and corneal astigmatism correction during cataract surgery: aspheric toric intraocular lens versus aspheric nontoric intraocular lens with opposite clear corneal incision

PURPOSE

To compare the astigmatism-reducing effect of an aspheric toric intraocular lens (IOL) and an aspheric nontoric IOL with an opposite clear corneal incision (OCCI) in cataract surgery.

SETTING

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

DESIGN

Prospective randomized clinical study.

METHODS

Patients with low to moderate corneal astigmatism scheduled for cataract surgery received an aspheric toric IOL (Lentis L-312T) or an aspheric nontoric IOL (Lentis L-312) combined with an OCCI. Keratometry and corneal tomography were performed 1 hour, 1 week, 3 months and 9 months postoperatively. Postoperative residual astigmatism was measured using an autorefractor. Rotational toric IOL stability was analyzed using retroillumination photography.

RESULTS

Fifty-five patients were included. Three months postoperatively, the mean reduction in corneal astigmatism was 0.67 diopter (D) ± 0.58 (SD) in the toric group and 0.18 ± 0.52 D in the nontoric-OCCI group. The mean uncorrected distance visual acuity was 0.29 ± 0.30 logMAR and 0.09 ± 0.18 logMAR, respectively (P=.02). The mean refractive astigmatism was 1.02 ± 0.54 D and 0.68 ± 0.52 D, respectively (P=.05). One hour, 3 months, and 9 months postoperatively, the mean absolute IOL misalignment of toric IOLs was 4.99 ± 4.66 degrees, 13.59 ± 11.29 degrees, and 19.90 ± 14.48 degrees, respectively.

CONCLUSIONS

The toric IOL tended to rotate significantly postoperatively. Visual acuity was good in both groups. Residual refractive cylinder was significantly lower in the toric IOL group.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.