Rotationally asymmetric multifocal intraocular lenses: preoperative considerations and postoperative outcomes

Clinical outcomes and optical performance of a new segmental refractive extended depth-of-focus intraocular lens

BACKGROUND

The visual performance and the optical quality of a segmental refractive extended depth-of-focus (EDoF) intraocular lens (IOL) were evaluated in a prospective, single-arm, single-center study.

METHODS

A total of 20 patients (40 eyes) after bilateral implantation of the refractive segmental EDoF Acunex Vario AN6V were included. Assessment procedure: refraction outcome, monocular and binocular uncorrected (UCVA) and distance-corrected visual acuity (DCVA), defocus curve, contrast sensitivity (CS), higher-order aberrations (HOAs) and patient satisfaction were evaluated 1 and 3 months after surgery.

RESULTS

At 3-month follow-up, mean spherical equivalent was - 0.23 ± 0.32 D. Binocular uncorrected distance visual acuity (VA) at distance, intermediate and near was - 0.08 ± 0.06 logMAR at 4 m, -0.03 ± 0.06 logMAR at 66 cm and 0.16 ± 0.06 logMAR at 40 cm, respectively. The binocular defocus curve showed a VA better than 0.20 logMAR over a range from + 1.50 to - 2.45 D. Contrast sensitivity aligned with monofocal lenses, highlighting the lens's clinical value. Aberrometry showed minimal changes in corneal aberrations. NEI-RQL-42-Questionnaire showed a high patient satisfaction for daily activities and revealed reduced dependence on glasses, particularly for near and intermediate vision. The Acunex Vario AN6V demonstrated minimal dysphotopsias, making it a promising option for those seeking spectacle independence.

CONCLUSION

This segmental refractive EDoF IOL provides a high degree of spectacle independence for far and intermediate distances with functional near VA. Although inducing residual coma aberrations, it showed subjectively good results with little dysphotopsias.

TRIAL REGISTRATION

This study protocol was reviewed and approved by ethics committee of Charité University, Berlin, Germany, with approval number EA4/126/20.

Comparative analysis of visual quality between unilateral implantation of a trifocal intraocular lens and a rotationally asymmetric refractive multifocal intraocular lens

AIM

To compare visual quality after unilateral cataract surgery with implantation of trifocal intraocular lens (IOL) and asymmetric refractive multifocal IOL.

METHODS

The prospective nonrandom, comparative study consisted of 60 eyes of 60 patients suffering unilateral cataract surgery with implantation of two different IOLs: AT LISA tri 839MP (30 eyes; Carl Zeiss Meditec, Germany) and LS-313 MF30 (30 eyes; Oculentis GmbH, Germany). Visual acuity, refractive outcome, contrast sensitivity, defocus curves, quality of vision, and optical phenomena were evaluated at 3mo postoperatively.

RESULTS

There were no statistical differences between groups in uncorrected distance visual acuity (P=0.13) and uncorrected near visual acuity (P=0.54). In contrast, uncorrected intermediate visual acuity was better in trifocal group compared to the refractive multifocal group (P=0.02). No significant statistical between-group difference was detected in cylinder (P=0.43). Compared to trifocal group, spherical refraction and spherical equivalent in refractive multi focal group were more myopic (P<0.01). Under photopic conditions, no significant statistical differences were found between groups in contrast sensitivity at 3 and 6 cycles per degree (cpd). The refractive multifocal group performed better at 12 and 18 cpd than the trifocal group (P=0.01, P=0.034, respectively). The questionnaires of quality of vision and optical phenomena showed no differences between groups.

CONCLUSION

Trifocal IOL is superior to refractive multifocal IOL in intermediate visual acuity. Rotationally asymmetric refractive multifocal IOL is more myopic in automated refraction and significantly better for the photopic contrast sensitivity at high frequency.

Outcomes of a Refractive Segmented Bifocal Intraocular Lens with a Lower Near Addition

Purpose

To evaluate clinical and subjective outcomes of a segmented bifocal IOL with a 2.0 D near addition.

Patients and Methods

Retrospective analyses of patients who had undergone refractive lens exchange with bilateral implantation of the SBL-2 IOL (Lenstec, Inc., Christ Church, Barbados) were performed. The number of patients included in the study was 389 (778 eyes). Refractive, visual and patient-reported outcomes were presented for the last available visit (mean follow-up 2.05 ± 1.33 months).

Results

The percentage of eyes within ±0.50D and ±1.00D of emmetropia was 82.5% (642/778) and 97.8% (761/778), respectively. The mean uncorrected intermediate visual acuity (66 cm) of the last available visit was 0.08 ± 0.15 logMAR monocularly and 0.04 ± 0.14 logMAR binocularly. The mean monocular and binocular uncorrected near visual acuity (40 cm) were 0.30 ± 0.15 logMAR and 0.24 ± 0.14 logMAR, respectively. Of all patients, 97.2% (378/389) claimed never to use any correction for distance vision, while 93.1% (362/389) of patients did not require any correction for near vision. The mean scores for visual phenomena (on the scale from 1 – no difficulty to 7 – severe difficulty) were 1.8 ± 1.3, 1.7 ± 1.2, 1.7 ± 1.2 and 1.6 ± 1.2 for glare, halo, starburst, and ghosting/double vision, respectively.

Conclusion

Despite the lower near addition of SBL-2 segmented bifocal IOL, patients achieved reasonable rates of spectacle independence and a low incidence of visual phenomena.

Secondary positioning of rotationally asymmetric refractive multifocal intraocular lens in a patient with glaucoma: A case report

BACKGROUND

Asymmetric multifocal intraocular lenses (IOLs) are now widely used in the modern cataract surgery, providing a good level of visual performance over a range of distances and high postoperative patient satisfaction. We report a case of improved visual quality after shifting the near segment of an asymmetrical multifocal IOL to the superotemporal placement in the dominant eye of a glaucoma patient.

CASE SUMMARY

A 72-year-old woman with bilateral glaucoma underwent phacoemulsification in the dominant eye (left eye) with implantation of an asymmetrical multifocal IOL. Postoperative uncorrected distance visual acuity (UDVA) was 0.0 logMAR (20/20 Snellen) and uncorrected near visual acuity (UNVA) was 0.1 logMAR (20/25 Snellen). Two weeks later, the patient presented to our clinic with decreased vision due to migration of lens epithelial cells to IOL anterior surface and edema of corneal endothelial cells. Anterior capsule polishing and superotemporal placement of near segment [+3.00 diopter (D) addition (add)] of IOL were performed. As a result, UDVA at the first week and first year after reposition was 0.0 logMAR (20/20 Snellen), and compared with 0.3 logMAR (20/40 Snellen) in the first week, the UNVA was improved to 0.0 logMAR (20/20 Snellen) one year after surgery.

CONCLUSION

The postoperative inflammatory reaction and lens epithelial cells proliferation were obvious in this glaucoma patient. Capsule polishing and rotation of the lens were beneficial to the patient, which not only enhanced the patient's vision, but also improved the patient's satisfaction. Therefore, glaucoma patients need to be cautious of implanting multifocal IOLs. Placement of a near segment of an asymmetrical multifocal IOL in the dominant eye should be performed on an individual basis.

The effects of premium intraocular lenses on presbyopia treatments

Background

Presbyopia has become a global disease affecting the world's aging population. Among various treatments, cataract extraction and intraocular lens (IOL) implantation have become the most popular and common methods of presbyopia correction. During the twentieth century, IOLs have underwent significant innovation and advancements to meet the patients' high demands for functional vision at all distances.

Main Text

To meet the increasing needs for excellent near and intermediate vision for daily activities, some premium IOLs with more than one focus have been developed, for example, the refractive MfIOLs, diffractive MfIOLs, extended depth of field (EDOF) IOLs, and accommodating IOLs (AIOLs) were introduced to meet this need. In addition, the add-on MfIOLs have been explored as promising supplementary IOLs for pseudophakic presbyopia. When selecting the MfIOLs, the IOLs' features, patients' characteristics, preoperative eye conditions, and treatment expectations should be considered.

Conclusions

In this review, we focus on the multifocal IOLs (MfIOLs) commonly used for presbyopia correction and systematically summarized their optical designs and clinical outcomes. More evidence-based studies are required to provide guidelines for MfIOL selection, provide maximum visual benefits, and develop personalized visual solutions in the future.

Comparing prediction accuracy between total keratometry and conventional keratometry in cataract surgery with refractive multifocal intraocular lens implantation

We aimed to compare refractive outcomes between total keratometry using a swept-source optical biometer and conventional keratometry in cataract surgery with refractive multifocal intraocular lens (IOL) implantation. We included patients who underwent cataract surgery with refractive multifocal IOL implantation. The IOL power was calculated using conventional formulas (Haigis, SRK/T, Holladay 2, and Barrett Universal II) as well as a new formula (Barrett TK Universal II). The refractive mean error, mean absolute error, and median absolute error were compared, as were the proportions of eyes within ± 0.25 diopters (D), ± 0.50 D, and ± 1.00 D of prediction error. In total 543 eyes of 543 patients, the absolute prediction error of total keratometry was significantly higher than that of conventional keratometry using the SRK/T (P = 0.034) and Barrett Universal II (P = 0.003). The proportion of eyes within ± 0.50 D of the prediction error using the SRK/T and Barrett Universal II was also significantly higher when using conventional keratometry than total keratometry (P = 0.010 for SRK/T and P = 0.005 for Barrett Universal II). Prediction accuracy of conventional keratometry was higher than that of total keratometry in cataract surgery with refractive multifocal IOL implantation.

Visual Outcomes, Patient Satisfaction, and Light Distortion Analysis After Blended Implantation of Rotationally Asymmetric Multifocal Intraocular Lenses

PURPOSE

To evaluate the visual outcomes and patient satisfaction after blended implantation of rotationally asymmetric multifocal intraocular lenses (IOLs) (LENTIS Mplus LS-313 +3.00 and +1.50 diopters [D], Oculentis GmbH).

METHODS

This was an interventional prospective study that included 40 eyes of 20 patients who underwent uneventful refractive lens exchange. Patients were implanted with the LENTIS Mplus LS-313 +3.00 D IOL in the non-dominant eye and the +1.50 D IOL in the dominant eye. Twelve months after surgery, binocular and monocular uncorrected and corrected near, intermediate, and distance visual acuity, defocus curve, contrast sensitivity, and light distortion analysis (LDA) were evaluated. Monocular total ocular aberrometry with a pyramidal wavefront sensor (Osiris; CSO) and patient satisfaction was evaluated with the 10-item Near Activity Vision Questionnaire (NAVQ-10).

RESULTS

There was a statistically significant improvement in the uncorrected distance visual acuity in both eyes after surgery (P < .001), with good uncorrected near and intermediate distance visual acuity (0.18 and 0.38 logMAR, respectively). The binocular defocus curve showed good levels of visual acuity for the most important ranges of vision. Contrast sensitivity and LDA had significantly better results when measured binocularly than monocularly. Higher order aberrations were significantly higher in the +3.00 D eye (P < .001). The mean Rasch score for the NAVQ-10 questionnaire was 26.9 ± 27.66.

CONCLUSIONS

Visual outcomes, defocus curve, LDA, and contrast sensitivity were significantly better binocularly than monocularly. The implantation of a blended IOL combination with different near addition complements the advantages of each IOL, improving binocular visual outcomes and providing good patient satisfaction. [J Refract Surg. 2020;36(12):796-803.].

Comparison of the visual performance between Oculentis MF30 and Tecnis ZMB00 multifocal intraocular lenses

Background

To compare the visual performance of MF30 asymmetric refractive multifocal intraocular lenses (MIOLs) with ZMB00 all optic zone diffractive MIOLs.

Methods

This is a prospective study. Patients that underwent phacoemulsification were divided into two groups according to the type of MIOLs used: 35 patients were implanted with asymmetric refractive MIOLs and 35 patients with all optic zone diffractive MIOLs. Visual acuity (VA), refraction, defocus curves, objective optical quality, and a questionnaire evaluating quality of life were measured at 3 months postoperatively.

Results

There were no significant differences between the two groups in uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), best-corrected distance visual acuity (BCDVA), or distance-corrected near visual acuity (DCNVA). However, the uncorrected intermediate VA was 0.24±0.10 in the refractive group and 0.31±0.13 in the diffractive group (P<0.05), and the distance-corrected intermediate VA was 0.22±0.09 in the refractive group and 0.31±0.14 in the diffractive group (P<0.05). Defocus curves showed two peaks of maximum vision in both groups. However, the curve between the two peaks in the refractive group was smoother than that of the diffractive group. The modulated transfer function cut-off frequency was 22.74±12.29 c/d in the refractive group and 30.50±10.04 c/d in the diffractive group (P<0.05). The Optical Quality Analysis System (OQAS) values 100% (OV100%) was 0.75±0.41 in the refractive group and 1.02±0.34 in the diffractive group (P<0.05), while the OV20% was 0.52±0.34 in the refractive group and 0.71±0.25 in the diffractive group (P<0.05). There was no significant difference between the two groups in overall satisfaction, spectacle independence ratio, or visual interference phenomenon.

Conclusions

Both MIOLs achieve good VA at distance and near vision. Oculentis MF30 showed better intermediate VA, and Tecnis ZMB00 appears to have better objective visual quality.

Trial registration

NCT02234635 (http://www.clinicaltrials.gov).

Influence of angle kappa-customized implantation of rotationally asymmetric multifocal intraocular lens on visual quality and patient satisfaction

PURPOSE

To evaluate the visual outcomes and patient satisfaction with angle kappa-customized implantation of SBL-3 (Lenstec, Inc.; +3 D), a rotationally asymmetric multifocal intraocular lens (MIOL).

METHODS

This was a prospective randomized control study. Data from consecutive patients, who underwent bilateral implantation of SBL-3 MIOL from June 2017 to August 2018, were enrolled in the study. One eye of each patient was randomly chosen to receive a horizontal IOL placement (control group), while the other eye received angle kappa-customized placement (design group). The outcomes include uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), defocus curve, contrast sensitivity, quality of vision and patient satisfaction. The follow-up was 3 months.

RESULTS

The study enrolled 80 eyes of 40 patients. There was no significant difference in mean UDVA, UIVA and UNVA between the two groups. The design group showed significantly better visual acuity at -1.50 D of defocus, based on the defocus curve (p = 0.022), and less vertical coma (p = 0.002) than the control group. No significant differences in contrast sensitivity, modulation transfer function, Strehl ratio and patient satisfaction were found between the two groups.

CONCLUSION

Angle kappa-customized implantation of SBL-3 had little impact on visual outcomes and patient satisfaction, except for a moderate impact on intermediate visual acuity.

Comparative Analysis of Visual Performance and Optical Quality with a Rotationally Asymmetric Multifocal Intraocular Lens and an Apodized Diffractive Multifocal Intraocular Lens

Purpose

To compare the short-term visual outcomes and intraocular optical performance of a rotationally asymmetric multifocal intraocular lens (MIOL) (SBL-3, Lenstec, Inc., Christ Church, Barbados) and an apodized diffractive MIOL (the Acrysof IQ ResTOR SN6AD1, Alcon Laboratories, Inc., Fort Worth, Texas, United States).

Methods

A prospective, comparative, nonrandomized, and single-center study. Sixty-eight age-related cataract patients (81 eyes) after phacoemulsification cataract surgery and in-the-bag MIOL implantation were enrolled. Thirty-eight eyes received SBL-3, and 43 eyes received SN6AD1. Ophthalmological evaluation included uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), modulation transfer function (MTF), Strehl ratio (SR), intraocular aberrations (4 mm optical zone), and defocus curve at 3 months postoperatively. The Chinese version of the visual function index-14 (VF-12-CN) and spectacle independence were assessed in all patients.

Results

There was no statistically significant difference between groups in postoperative UDVA (p = 0.186). Postoperative UIVA and UNVA were significantly better for the SBL-3 group than for the SN6AD1 group (p < 0.01). Statistically significant differences were revealed in defocus levels from –3.50 D to −4.00 D with better visual acuities for the SBL-3 group (p < 0.01). For intraocular optical quality outcomes, statistically significant differences between groups were observed in RMS of intraocular total aberrations, coma, and trefoil high-order aberrations, presenting significantly higher values of these parameters in the eyes of the SBL-3 group (p < 0.01). Statistically significant differences were revealed in the MTF values at spatial frequencies of 5 and 10 cycles/degree between groups. There were no significant differences in scores of VF-12-CN, and spectacle independence between the groups (p > 0.05).

Conclusions

Both MIOLs were able to successfully restore visual function after cataract surgery. SBL-3 provided better UIVA and UNVA with a wider range of intermediate vision.

Model of the light sword intraocular lens: in-vitro comparative studies

This work presents the first models of light sword intraocular lenses (LS IOLs) with angularly modulated optical power. We performed an experimental, comparative study with multifocal and extended depth of focus intraocular lenses, which are available on the market. The measurements conducted in an original optical bench were utilised for an analysis of point spread functions, elongated foci, modulation transfer functions and the areas defined by them. The LS IOL models perform homogeneous imaging in the whole range of designed defocus. The proposed concept of extended depth of focus seems to be promising for the development of presbyopia-correcting intraocular lenses capable of regaining fully functional vision.

Comparison of the Clinical Performance of Refractive Rotationally Asymmetric Multifocal IOLs with Other Types of IOLs: A Meta-Analysis

Objective

To compare the clinical performance of refractive rotationally asymmetric multifocal intraocular lens (IOLs) with spherical monofocal, accommodating, and bifocal IOLs.

Methods

A comprehensive literature search of PubMed, EMBASE, Cochrane Controlled Trials Register, and Web of Science up to February 2017 was performed to identify randomized controlled trials (RCT) and comparative cohort studies. Main outcomes were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), higher-order aberrations (HOAs), MTF, Strehl ratio, and residual sphere and cylinder.

Results

Mplus provided significantly worse UDVA than spherical monofocal IOLs (WMD: 0.13, P=0.008), but significantly better UIVA than high-add bifocal IOLs (WMD: −0.19, P < 0.00001), spherical monofocal IOLs (WMD: −0.12, P < 0.0001), and accommodating IOLs (WMD: −0.21, P < 0.00001). Mplus provided significantly worse UNVA than high-add bifocal IOLs (WMD: 0.07, P < 0.00001), but significantly better UNVA than spherical monofocal IOLs (WMD: −0.19, P < 0.00001). Mplus resulted in significantly higher HOAs than high-add bifocal IOLs (WMD: 0.38, P < 0.00001) and spherical monofocal IOLs (WMD: 0.51, P=0.0004). Mplus provided a significantly lower MTF cut-off and Strehl ratio than other type of IOLs.

Conclusion

The Mplus IOLs perform best regarding intermediate visual acuity whereas they lack in distance visual acuity compared to monofocal IOLs and near visual acuity compared to bifocal IOLs. These results may be due to structure of Mplus IOLs resulting in higher-order aberrations.

Presbyopia: Effectiveness of correction strategies

Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations, due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries. Definitions of presbyopia are inconsistent and varied, so we propose a redefinition that states "presbyopia occurs when the physiologically normal age-related reduction in the eye's focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual's requirements". Strategies for correcting presbyopia include separate optical devices located in front of the visual system (reading glasses) or a change in the direction of gaze to view through optical zones of different optical powers (bifocal, trifocal or progressive addition spectacle lenses), monovision (with contact lenses, intraocular lenses, laser refractive surgery and corneal collagen shrinkage), simultaneous images (with contact lenses, intraocular lenses and corneal inlays), pinhole depth of focus expansion (with intraocular lenses, corneal inlays and pharmaceuticals), crystalline lens softening (with lasers or pharmaceuticals) or restored dynamics (with 'accommodating' intraocular lenses, scleral expansion techniques and ciliary muscle electrostimulation); these strategies may be applied differently to the two eyes to optimise the range of clear focus for an individual's task requirements and minimise adverse visual effects. However, none fully overcome presbyopia in all patients. While the restoration of natural accommodation or an equivalent remains elusive, guidance is given on presbyopic correction evaluation techniques.