Multifocal Intraocular Lenses and Extended Depth of Focus Intraocular Lenses

Design concepts for advanced-technology intraocular lenses [Invited]

An intraocular lens (IOL) replaces the natural crystalline lens during cataract surgery, and although the vast majority of implants have simple optics, "advanced technology" IOLs have multifocal and extended depth of focus (EDOF) properties. Optical concepts are evaluated here, with image contrast, focal range, and unwanted visual phenomena being the primary concerns. Visual phenomena with earlier bifocal diffractive lenses led to alternative diffractive designs (trifocals, etc.) and also to exploring increasing the depth of focus for monofocal IOLs using refractive methods, where although the defocus range might be more modest, visual phenomena are much less obvious. The designs cover a range of possibilities that might provide the best overall vision for patients with differing motivations, needs, and sensitivity to visual side effects.

Revisiting the Visual Acuity Curves. A Proposed Methodology for the Evaluation of Postoperative Visual Acuity in Presbyopia

Purpose

To identify the minimally required number of distances of visual acuity (VA) measurements for the reliable estimation of the visual acuity curve (VAC) and area of the curve (AoC) in presbyopia correction.

Patients and Methods

The study was divided into a validation and a clinical phase with a total recruitment of 120 participants (120 eyes) who underwent uncomplicated pseudophakic presbyopia surgery with bilateral premium intraocular lenses (IOL) implantation. This study was conducted in the Department of Ophthalmology, University Hospital of Alexandroupolis, Alexandroupolis, Greece. Postoperative VAC and AoC were calculated with VA measurements taken at nine pre-defined distances. A mathematical model based on cubic spline interpolation was developed and assessed comparing the VAC and AoC values obtained using nine distances, with the ones predicted when a subset of VA measurements was inserted into the model.

Results

Less than four measurements resulted in unreliable VAC and AoC assessment. Optimal distances for four to six VA measurements were determined. Mean error in the prediction of VAC and AoC of the clinical group ranged from 2.54 Letters/1.74% (6 measurements) to 2.90 letters/2.9% (4 measurements), respectively.

Conclusion

Mathematical models that use cubic spline interpolation provide reliable VAC and AoC estimation, even with four VA measurements, when obtained at specific distances.

Potential guidelines for cataract surgery and rehabilitation in visually impaired patients: Literature analysis

Cataracts can reduce the quality of vision in visually impaired patients who already have a visual impairment. The most common causes of low vision include age-related macular degeneration (AMD), high myopia (HM), diabetic retinopathy (DR), glaucoma (GL), and inherited degenerative ocular diseases. The surgery aims to improve their independence, quality of life, and ability to engage in daily, social, and work activities. Phacoemulsification and intraocular lens (IOL) implantation, combined with visual rehabilitation, can improve visual acuity of visually impaired patients. Therefore, comprehensive guidelines for cataract surgery in patients with low vision would be beneficial to ensure optimal surgical outcomes by improving surgical planning, execution, and postoperative care, along with a well-coordinated rehabilitation process. In cases of reduced metabolism, such as low vision, oxidative stress can be aggravated by light exposure and surgical interventions. Thus, maintaining redox balance is crucial for stabilizing retinal conditions. Patients with visual impairments rely on retinal regions with the greatest residual function, and cataract surgery aims to enhance focus on these areas, improving reading quality and reducing scotoma perception. Thorough informed consent is crucial, ensuring that patients are fully aware of the potential risks, benefits, and limitations of surgery. Close postoperative follow-up in the first 6 months is crucial to detect and manage any complications promptly, such as reactivation of maculopathy. The aim of this work is to establish potential guidelines for optimal rehabilitation outcomes through careful literature analysis.

Clinical Outcomes after Implantation of a Novel Binocular Complementary Extended Depth-of-Focus Intraocular Lens Compared to Bilateral Low Near-Add Multifocal Intraocular Lenses

INTRODUCTION

Nowadays, patients expect to be less spectacle dependent at all distances after cataract surgery. However, all intraocular lens (IOL) models that currently offer this function can also have negative visual effects. Aim of this study was therefore to compare the visual function performance of a novel and a conventional IOL solution for multifocality.

METHODS

Patients scheduled for bilateral cataract surgery were randomized to receive one of two different IOL combinations: either a binocular complementary extended depth-of-focus IOL set or a low near-add MIOL. Patients had visual acuity (VA) assessment at distance, intermediate, and near as well as evaluation of contrast sensitivity, halometry, and reading performance.

RESULTS

In total, 56 eyes of 28 patients were enrolled. At 6 months, there were no statistically significant differences in binocular VA between the ARTIS SYMBIOSE and the AT LARA. Contrast sensitivity, measured binocularly, at 1.5 cycles per degree under photopic conditions without glare was 1.54 logCS with the ARTIS SYMBIOSE and 1.43 logCS with the AT LARA (p = 0.046), under mesopic conditions with glare at 1.5 and 3 cycles per degree 1.31 logCS and 1.28 logCS with the ARTIS SYMBIOSE, respectively, compared to 0.58 logCS and 0.51 logCS with the AT LARA (p = 0.002; p = 0.006). Binocular halos and reading performance between both groups were similar.

CONCLUSION

There were no significant differences between both groups in VA at different distances, reading ability, or halometry. The contrast sensitivity at low spatial frequencies was better in the ARTIS SYMBIOSE group under photopic conditions without glare as well as mesopic conditions with glare, which could potentially improve quality of vision with these IOLs, especially under mesopic conditions.

Comparison of modal and zonal wavefront measurements of refractive extended depth of focus intraocular lenses

Extended depth-of-focus (EDoF) intraocular lenses (IOLs) are typically evaluated using commercially available aberrometers. Given the intricate optical design of these IOLs, employing an appropriate wavefront reconstruction method with a sufficient sampling resolution of the aberrometer is crucial. A high-resolution Shack-Hartmann wavefront sensor was developed by magnifying the pupil aperture by a factor of five onto a lenslet array (pitch: 133 µm) and utilizing a full-frame CMOS sensor (24 by 36 mm), resulting in a 26.6 µm sampling resolution. Zonal wavefront reconstruction was used and compared with Zernike-based modal wavefront reconstruction to retain detailed local slope irregularities. Four refractive EDoF IOLs with a power of 20D were examined, and the wavefront difference between the zonal and modal methods, expressed as the root mean squared error (RMSE), remained significant for two of the IOLs up to the 16th-order Zernike spherical aberrations (SAs). Conversely, a negligibly small RMSE was observed for the other two IOLs, as long as the Zernike SAs were higher than the 6th order. The raytracing simulation results from the zonal wavefronts exhibited a stronger correlation with the results of recent optical bench studies than those from the modal wavefronts. The study suggests that certain recent refractive EDoF IOLs possess a complex optical profile that cannot be adequately characterized by limited orders of SAs.

Visual performance and patient preference with bilateral implantation of an extended depth of focus or combined implantation of an extended depth of focus/trifocal intraocular lens

PURPOSE

Evaluate postoperative visual performance in patients with bilaterally implanted AT LARA or AT LARA/AT LISA tri (Carl Zeiss AG, Jena, Germany) intraocular lenses.

METHODS

Multicentered, comparative, open-label, retrospective/prospective study. Post-IOL implantation, patients were prospectively enrolled into this study; preoperative patient data were collected retrospectively. Follow-up was at 2-4 and 5-8 months post-surgery. The primary endpoint was binocular best corrected distance visual acuity (CDVA). The study was retrospectively registered on clinicaltrials.gov (#NCT05462067).

RESULTS

Seventy-one patients (142 eyes) were enrolled; 67 patients (134 eyes) have 5-8 months data. The mean binocular CDVA at 2-4 months was -0.10 ± 0.06 logMAR in the bilateral AT LARA group ("bilateral") and -0.11 ± 0.09 logMAR in the combined implantation AT LARA/ AT LISA tri group ("combined implantation"); (P = 0.4856). At 5-8 months, mean binocular CDVA was -0.13 ± 0.06 logMAR in the bilateral group and -0.11 ± 0.09 in the combined implantation group (P = 0.4003). At 5-8 months, more eyes in the bilateral group attained 0.2 logMAR or better binocular uncorrected intermediate VA (UIVA; 67 cm) than those in the combined implantation group (100% vs. 94%, respectively). The bilateral group achieved a mean of 0.24 ± 0.11 logMAR in uncorrected near VA (UCNVA), compared to a mean of 0.16 ± 0.12 logMAR in the combined implantation group at 5-8 months (P = 0.0041).

CONCLUSIONS

A combined implantation approach (AT LARA in the distance dominant eye/AT LISA tri in the non-dominant eye) produced similar CDVA outcomes but better UCNVA as bilateral implantation with the AT LARA. UIVA was comparable between groups. No new safety concerns were reported.

The tolerance of refractive errors of extended depth of focus intraocular lens in patients with previous corneal refractive surgery

PURPOSE

To evaluate the tolerance for refractive errors and visual outcomes of extended depth of focus intraocular lens (EDOF IOLs) in patients with previous corneal refractive surgery for myopia.

METHODS

Patients from Aier Eye Hospital of Wuhan University with previous myopia excimer laser correction underwent cataract surgery and implantation of an EDOF IOL. The follow-up period was three months. The uncorrected distance, intermediate, and near visual acuities (UDVA, UIVA, UNVA), corrected distance visual acuity (CDVA), spherical equivalent (SE), defocus curve, optical quality, including modulation transfer functions (MTF) and Strehl ratio (SR), National Eye Institute Visual Functioning Questionnaire-14 for Chinese people (VF-14-CN), spectacle independence, and dysphotopsia were assessed.

RESULTS

At the final visit, UDVA, CDVA, UIVA, and UNVA (LogMAR) were 0.06 ± 0.09, 0.01 ± 0.06, 0.11 ± 0.08, 0.20 ± 0.10, respectively. The mean spherical equivalent (SE) was - 0.57 ± 0.58D, sphere and cylinder were - 0.24 ± 0.60D, - 0.70 ± 0.58D respectively. No statistical difference in UDVA between eyes with SE in ± 0.50 D and in ± 1.0 D (p > 0.05). Corneal astigmatism > 1.00D has no significant effect on postoperative visual acuity (p > 0.05). The defocus curve showed that visual acuity could reach 0.2 in the refractive range of + 0.50D ~ - 1.50D. SR and MTF values were all higher than before the surgery. In bilateral implantation patients, the VF-14-CN questionnaire score and visual quality were quite excellent.

CONCLUSION

The EDOF IOL have a certain tolerance for refractive errors and corneal astigmatism, and it's recommended for patients with prior myopia excimer laser surgery to achieve satisfactory visual performance.

The Effect of Psychological Intervention on the Visual Quality of Patients with a Diffractive Multifocal Intraocular Lens Implant

OBJECTIVE

This study aimed to investigate the effect of psychological intervention on the visual quality of patients with a diffractive multifocal intraocular lens implant and its possible mechanism.

METHODS

Eighty-nine patients undergoing age-related cataract surgery were enrolled in the study at the Affiliated Hospital of Southwest Medical University between December 2015 and July 2017. They were randomly divided into two groups: multiple focus M1 group (n = 45) and multiple focus M2 group (n = 40). The M1 group was only given routine preoperative health education, treatment, and evaluation, while the M2 group also received psychological intervention.

RESULTS

After treatment, there was no statistical difference in the uncorrected distance and near visual acuity, corrected distance and near visual acuity, or the vision and near removal rate in either of the two groups (p > 0.05). However, postoperative glare was lower in the M2 group (p < 0.05), and patient satisfaction was higher in the M2 group (p < 0.05). The M2 group had a more obvious improvement in the Symptom Checklist-90 score (p < 0.05), the serum interleukin-6 (IL-6) was lower, and the serum brain-derived neurotrophic factor (BDNF) was higher in the M2 group (p < 0.05). In addition, serum IL-6 had a negative correlation with the depression score, and serum BDNF also showed a negative correlation with the anxiety score (p < 0.05).

CONCLUSIONS

Psychological intervention improved the stress state of patients with age-related cataracts and diffractive multifocal intraocular lens implants, reduced the level of inflammatory factors in the body, improved the level of BDNF, reduced postoperative visual interference, and improved postoperative satisfaction.

Light scattering from a diffractive-refractive intraocular lens: a goniometer-based approach for individual zone assessment

We proposed and tested a method to measure light scattering from the diffractive lens profile in an echelle element featuring 9 zones. Measurements were performed using a goniometer-based setup up to 7.5°. The proportion of scattered light was calculated to derive the loss of light. Material scattering was minimal (∼1 deg2/sr); however, each echelle zone acted as a scattering source. A nearly gradual straylight increase was found with the zone number showing peak intensity between 3° and 3.75°. An estimated 6.2% ± 0.1% was lost due to scattering, which ought to be considered when reporting an IOL's light loss.

Potential productivity loss from uncorrected and under-corrected presbyopia in low- and middle-income countries: A life table modeling study

Objective

To estimate the burden of potential productivity losses due to uncorrected and under-corrected presbyopia in LMICs among the working-age population in both the cross-sectional and longitudinal manner.

Methods

We extracted data for the prevalence of presbyopia from the Global Burden of Diseases (GBD), Injuries, and Risk Factors Study 2019. Data for the gross domestic product (GDP) per capita were extracted from the World Bank database and Central Intelligence Agency's World Factbook. We introduced life table models to construct age cohorts (in 5-year age groups) of the working-age population (aged from 40 to 64 years old) in LMICs, with simulated follow-up until 65 years old in people with and without uncorrected presbyopia. The differences in productivity-adjusted life years (PALYs) lived and productivity between these two cohorts were calculated. The potential productivity loss was estimated based on GDP per capita. The WHO standard 3% annual discount rate was applied to all years of life and PALYs lived.

Results

In 2019, there were 238.40 million (95% confidence interval [CI]: 150.92-346.78 million) uncorrected and under-corrected presbyopia cases in LMICs, resulting in 54.13 billion (current US dollars) (95% confidence interval [CI]: 34.34-79.02 billion) potential productivity losses. With simulated follow-up until retirement, those with uncorrected and under-corrected presbyopia were predicted to experience an additional loss of 155 million PALYs (an average loss of 0.7 PALYs per case), which was equivalent to a total loss of US$ 315 billion (an average loss of US$ 1453.72 per person).

Conclusions

Our findings highlight the considerable productivity losses due to uncorrected and under-corrected presbyopia in LMICs, especially in a longitudinal manner. There is a great need for the development of enabling eye care policies and programs to create access to eye care services, and more healthcare investment in the correction of presbyopia in the working-age population in LMICs. This study could provide evidences for some potential health-related strategies for socio-economic development.

Visual Outcomes after Implantation of Lucidis EDOF IOL

Purpose. To evaluate the visual performance and clinical outcomes after implantation of Lucidis EDOF IOL following cataract surgery. Design. In this retrospective study, medical records from all enrolled patients were analyzed, and the following information was extracted retrospectively over 3 months following surgery. Materials and Methods. We reviewed retrospectively 181 eyes of 98 patients, who underwent cataract surgery with Lucidis extended depth of focus IOL. Results. 44 patients were males (45%) and 54 were females (55%). The average age of the study population was 68 ± 11 years. The mean preoperative BCVA (logMAR) was 0.19 ± 0.18. The mean root mean square (RMS) high order aberration (HOA) was 0.18 ± 0.1. Monocular BCVA results were 0.02 ± 0.04 (logMAR) and 0.028 ± 0.04 (logMAR) 1 month and 3 months postoperatively, respectively. Between the baseline and 1-month measures, monocular distance BCVA improved by an average of 0.17 ± 0.14 logMAR ( $p$  = 0.0001). Between the baseline and 3-month postoperative measures, monocular distance BCVA improved by an average of 0.16 ± 0.13 logMAR ( $p$  = 0.0001). Monocular UDVA 1 and 3 months postoperatively was 0.08 ± 0.1 logMAR and 0.067 ± 0.08 logMAR, respectively. 1-Month postoperative binocular UDVA was 0.036 ± 0.05 logMAR, binocular UIVA was 0.1 ± 0.08 logMAR, and binocular UNVA was 0.12 ± 0.14 logMAR. 3-Month postoperative binocular UDVA was 0.038 ± 0.05 logMAR, binocular UIVA was 0.09 ± 0.1 logMAR, and binocular UNVA was 0.16 ± 0.14 logMAR. Conclusions. Lucidis EDOF IOL achieves good visual performances in all distances.

Tilt and decentration with various intraocular lenses: A narrative review

We find that tilt and decentration of intraocular lens (IOL) commonly cause visual quality deterioration after cataract surgery. Multiple factors affect IOL tilt and decentration in the pre-, mid-, and post-operation phases. Moreover, the tilt and decentration of 1-piece IOL are less correlated with internal ocular HOAs than those of 3-piece IOL. Aspherical IOLs are more sensitive to decentration or tilt than spherical IOLs. Furthermore, the optical performance of toric IOLs with an accurate axis remains stable irrespective of tilt and decentration. The optical quality of asymmetric multifocal IOLs varies significantly after decentration and tilt in different directions. The image quality enhances or deteriorates in the direction of the decentered IOL. An extended depth of focus IOL can achieve good visual acuity in the distant, intermediate, and near range. Additionally, its tilt and decentration have less impact on the vision than bifocal and trifocal IOL. This is the first review that compares the effect of IOL tilt and decentration on image quality for various IOL designs. The result indicates that a deeper understanding of tilt and decentration of various IOLs can help achieve a better visual effect to visually improve refractive cataract surgery.

Presbyopia-Correcting Intraocular Lenses Implantation in Eyes After Corneal Refractive Laser Surgery: A Meta-Analysis and Systematic Review

Purpose

To assess the efficacy, safety, and predictability of presbyopia-correcting intraocular lenses (IOLs) in cataract patients with previous corneal refractive surgery.

Methods

A systematic literature search was performed to identify studies evaluating the clinical outcomes of presbyopia-correcting IOLs implantation in cataract surgery after laser refractive surgery. Outcomes were efficacy, safety and predictability parameters.

Results

The authors identified 13 studies, involving a total of 128 patients and 445 eyes. Presbyopia-correcting IOLs were effective at improving distance, intermediate and near visual acuity aftercataract surgery. The proportion of post-laser surgery eyes with uncorrected distance visual acuity (UDVA) ≥ 20/25 was 0.82 [95% confidence interval (CI), 0.74-0.90] and the pooled rates of spectacle independence at near, intermediate, and far distances were 0.98 (95% CI, 0.94-1.00), 0.99 (95% CI, 0.95-1.00) and 0.78 (95% CI, 0.65-0.94) respectively. The percentage of participants who suffered from halos and glare was 0.40 (95% CI, 0.25-0.64) and 0.31 (95% CI, 0.16-0.60), respectively. The predictability had a percentage of 0.66 (95% CI, 0.57-0.75) and 0.90 (95% CI, 0.85-0.96) of eyes within ±0.5 diopters (D) and ±1.0 D from the targeted spherical equivalent.

Conclusions

Presbyopia-correcting IOLs provide satisfactory results in terms of efficacy, safety and predictability in patients with previous corneal refractive surgery, but have a higher risk of photopic side effects such as halos and glare.

Presbyopia correction after previous Intracor treatment: Combined implantation of a small-aperture and a non-diffractive extended-depth-of-focus lens

PURPOSE

We present the case of implantation of two different Extended depth of focus intraocular lenses (EDoF IOLs) in a patient with a history of unilateral intrastromal femtosecond laser treatment for presbyopia correction (Intracor).

OBSERVATIONS

The patient reported decreasing visual acuity at near distance and increasing spectacle dependence. Ten years earlier, he had Intracor treatment for presbyopia correction in his left eye. Corrected distance visual acuity (CDVA) was 0.08 logMAR for the right eye and 0.16 logMAR for the left eye. Apart from dysfunctional lens syndrome, the examination results were unremarkable. Phacoemulsification and subsequent IOL implantation was performed in both eyes. The left eye was implanted with an IC-8 (AcuFocus, Irvine, CA, USA), whereas the fellow eye was implanted with an AcrySof IQ Vivity IOL (Alcon, Fort Worth, TX, USA). Postoperatively, CDVA improved to 0.02 and 0.04 logMAR for the right and left eye. Uncorrected intermediate visual acuity (UIVA) was 0.24 logMAR for the right eye and -0.04 logMAR for the left eye, binocular UIVA was -0.04 logMAR. The patient reported a low level of photic phenomena and spectacle independence for far and intermediate distance.

CONCLUSIONS AND IMPORTANCE

Combined implantation of a non-diffractive and a small-aperture EDoF lens after previous unilateral Intracor treatment could successfully improve visual acuity at far and intermediate distance.

Comparison of Patient Outcomes following Implantation of Trifocal and Extended Depth of Focus Intraocular Lenses: A Systematic Review and Meta-Analysis

Purpose

The purpose is to compare the outcomes of implantation of trifocal intraocular lenses (TIOLs) and extended depth of focus (EDOF) intraocular lenses (IOLs).

Methods

A comprehensive search of PubMed, Cochrane Library, EMBASE, and ClinicalTrial.gov was conducted in March 2020 to identify relevant studies. A meta-analysis of the results was performed. Patients implanted with EDOF IOLs or TIOLs in previous studies were included. The primary outcomes of the study were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), uncorrected near visual acuity (UNVA), and defocus curve.

Results

TIOLs and EDOF IOLs provided comparable binocular UDVA (MD = -0.01, 95% CI: -0.04, 0.03, logMAR). However, EDOF IOLs provided better UIVA (MD: -0.08, 95% CI: -0.14, -0.01, logMAR) and worse UNVA (MD: 0.10, 95% CI: 0.06, 0.14, logMAR) than TIOLs. Fewer patients achieved spectacle independence after implantation of EDOF IOLs (RR: 0.74, 95% CI: 0.63, 0.87) than after implantation of TIOLs, especially for near vision (RR = 0.82, 95% CI: 0.68, 0.99). There was no statistically significant difference in contrast sensitivity (CS) under photopic or mesopic conditions with both IOLs. Patient satisfaction after implantation of both IOLs was high.

Conclusion

EDOF IOLs and TIOLs provide comparable distance vision. However, EDOF IOLs provide better intermediate vision and worse near vision than TIOLs. The advantages of EDOF IOLs over TIOLs in terms of CS, aberrations, and visual disturbance are not significant. Patients are satisfied with both types of IOLs.

[Outcomes of bilateral implantation of trifocal and extended depth of focus IOLs]

In recent years, a new class of extended depth of focus (EDOF) intraocular lenses (IOLs) has become available on the market. There is only a limited number of scientific papers comparing trifocal and EDOF IOL data, and the results are often contradictory.

PURPOSE

Comparative analysis of the results of trifocal and EDOF IOL implantation in patients with presbyopia and/or cataract.

MATERIAL AND METHODS

This prospective study included 72 patients (144 eyes) after bilateral implantation of either Tecnis Symfony EDOF IOL (18 patients, 36 eyes; group I) or AcrySof PanOptix trifocal IOL (54 patients, 108 eyes; group II). In 18 patients out of 72 (25%) the implantation involved mini-monovision, i.e. the calculation of the IOL power on the nondominant eye was performed at -0.5 D. The average follow-up period for the patients was 7.1±1.2 months.

RESULTS

There was a significant (p<0.05) increase in uncorrected near visual acuity (UCNVA), uncorrected intermediate visual acuity (UCIVA) and uncorrected distance visual acuity (UCDVA) at the maximum follow-up time compared to the preoperative indices in all groups. Group II was characterized by slightly better UCNVA dynamics (0.85±0.13 versus 0.2±0.04 before surgery, as comparted to 0.78±0.11 versus 0.19±0.06 before surgery in group I), but differences were not statistically significant (p>0.05). Statistically significant differences (p=0.046) were observed when comparing best corrected near vision acuity (BCNVA) in groups I and II (0.79±0.05 and 0.98±0.08, respectively) at 6 months compared to the preoperative period (0.62±0.09 and 0.6±0.11, respectively).

CONCLUSION

Trifocal IOL implantation was associated with acceptable near and far vision correction and a higher frequency of adverse optical phenomena, while implantation of the EDOF IOL was associated with slightly better correction of intermediate vision and a significantly lower incidence of halo and glare. Patients were satisfied with the outcomes of surgery in all cases.

The use of polyisobutylene-based polymers in ophthalmology

A novel polyolefin called poly(styrene-block-isobutylene-block-styrene) (“SIBS”) originated from Joseph P. Kennedy's laboratory at the University of Akron (Akron, Ohio, United States) and was developed as a biomaterial for long-term implant applications by the author. SIBS has no cleavable groups on its backbone or sidechains, is comprised predominantly of alternating secondary and quaternary carbons on its backbone, which prevents embrittlement and cracking under flexion, and undergoes multiple purification steps which renders it extremely biocompatible and well-suited for long-term applications in the eye. This article explores two ophthalmic devices; 1) the PRESERFLO® MicroShunt (Santen Pharmaceutical Co. Ltd., Osaka, Japan) made from SIBS that lowers intraocular pressure to thwart progression of vision loss from glaucoma, and 2) a novel intraocular lens (IOL) made from crosslinked polyisobutylene, which is under-development by Xi'an Eyedeal Medical Technology Co., Ltd. (Xi'an, China) that does not glisten nor cloud over time, as do most conventional IOLs.

•

A novel class of ultra-biostable polyisobutylene-based biomaterials for long-term implant applications.

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A novel class of polyisobutylene-based biomaterials that is not bioactive and elicits minimal foreign body reaction.

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A device called the PRESERFLO® MicroShunt to treat glaucoma made from poly(styrene-block-isobutylene-block-styrene) (SIBS).

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A novel crosslinked polyisobutylene material for intraocular lens applications that eliminates glistenings and halos.

Clinical Outcomes of Combined Implantation of an Extended Depth of Focus IOL and a Trifocal IOL in a Korean Population

Purpose

To evaluate monocular and binocular visual performance and patient-reported outcomes following combined implantation of a diffractive extended depth of focus (EDoF) IOL (Carl Zeiss AT LARA 829MP) and a diffractive trifocal IOL (Carl Zeiss AT LISA tri 839MP).

Methods

This prospective study enrolled consecutive patients undergoing lens phacoemulsification of cataract and combined implantation of an EDoF IOL in the dominant eye and a trifocal IOL in the nondominant eye. Assessment included uncorrected visual acuity at near distances (UNVA), intermediate distances (UIVA), and far distances (UDVA), uncorrected defocus curve, contrast sensitivity (CS), reading speed, and patient satisfaction, evaluated six months after the surgery with the Visual Function Questionnaire (VFQ-25).

Results

A total of 25 patients were enrolled. At six months postoperatively, outcomes of binocular UNVA, UIVA, and UDVA were superior to those of monocular outcomes. The binocular defocus curve showed significantly better results in comparison with the AT LISA tri IOL eyes at defocus levels of −1.0 D and −1.5 D (P=0.008 and P=0.002, respectively) and compared to the AT LARA IOL eyes at defocus levels of −3.0, −3.5 D, and −4.0 D (P=0.019, P=0.019, and P=0.035, respectively). All of the patients were spectacle-free at far and intermediate distances, while 4% of patients needed spectacles at the near distance. Reading speed showed a rather high and gentle slope curve between 0.1 logMAR and 0.4 logMAR, and optical phenomena were improved after combined implantation of IOLs except halos. There were no significant differences in CS between the binocular and monocular results of each IOL.

Conclusions

The combined implantation of an EDoF IOL and a trifocal IOL seems to be a good option for patients with demands for spectacle independence in their daily life, with minimal photic phenomena.

Binocular accommodative response with extended depth of focus under controlled convergences

Vergence and accommodation can be mismatched under virtual reality viewing conditions, and this mismatch has been thought to be one of the main causes of visual discomfort. The goal of this study was to investigate how optical conditions of the eyes affect accommodative responses to different convergence. Specifically, we hypothesized that extending the depth of focus (DoF) could weaken the control of the screen on accommodation, so that accommodation could be induced by convergence. To test this hypothesis, we extended the DoF using Zernike spherical aberrations (fourth and sixth orders) induced by a binocular adaptive optics (AO) vision simulator. Nine normal subjects between the ages of 21 and 34 (26 ± 5) years were recruited. Three optical conditions were generated: AO condition (aberration-free), monovision condition, and extended depth of focus (EDoF) condition. Binocular accommodative responses, along with binocular visual acuity and stereoacuity, were measured under all three optical conditions with varied binocular vergence levels. At 3 diopters of binocular convergence, the EDoF condition was the most efficient in inducing excessive accommodative response compared with the monovision condition and the AO condition. Visual acuity was impaired with EDoF as compared with the other two conditions. The average stereoscopic thresholds (at 0 vergence) under the EDoF condition were degraded compared with the AO condition but were superior to those of the monovision condition. Therefore, despite some compromise to visual performance, extending the DoF could allow for a more natural vergence–accommodation relationship, providing the potential for alleviating the vergence–accommodation conflict and associated visual fatigue symptoms in virtual reality.

Improvement of Presbyopia Using a Mixture of Traditional Chinese Herbal Medicines, Including Cassiae Semen, Wolfberry, and Dendrobium huoshanense

Background

Presbyopia is a primary cause of a decline in near vision. In this study, we developed a new mixed herbal medicine to retard presbyopic progression and increase the amplitude of accommodation (AA), which is beneficial for near vision.

Methods

A total of 400 participants between the ages of 45 and 70 years were recruited. We designed the mixed herbal drug to include Cassiae Semen (200 mg), wolfberry (200 mg), and Dendrobium huoshanense (DD) (40 mg) in one capsule. In experiment 1, the recruited subjects were directed to perform a push-up test to measure their AA; this was then converted to the additional diopters of reading glasses. In experiment 2, 240 subjects took three capsules daily for six months and then stopped medical therapy for a six-month follow-up. In experiment 3, 160 subjects were randomly categorized into four groups: a placebo group, low-dose group (LDG) (1 capsule daily), middle-dose group (MDG) (two capsules daily), and high-dose group (HDG) (three capsules daily). The 160 volunteers took different doses for six months and then stopped treatment, accompanied by another six-month follow-up. In experiments 2 and 3, the change in AA, uncorrected far visual acuity (UFVA), and uncorrected near visual acuity (UNVA) were recorded each month for one year.

Results

In experiment 1, AA was found to decrease with age and a great deal of additional power was needed in older individuals. In experiment 2, the mean AA reached a maximum value of 2.1D (P < 0.05) after six months, while the UNVA improved by about two to three lines of a Jaeger chart in most of the subjects. At nine months, all the means decreased slightly to 2.0 D (P < 0.05). This meant that the mixed herbal medicine could still maintain AA for another three months because the herbal therapy was stopped at the seventh month. In experiment 3, the maximal AA was 2.8D, 2.9D, and 3.2D (P < 0.05) in the LDG, MDG, and HDG after six-month treatments, respectively. Experiment 3 showed that AA gain occurred in a dose-dependent manner; the higher the dose, the greater the AA value.

Conclusion

Only two studies on the use of herbal drugs for presbyopia have been reported in PubMed. In our study, we found that taking a mixed herbal drug caused an excellent gain in AA. This is the first study to report that the characteristics of the new herbal regimen could retard and even ameliorate presbyopia.

Visual Performances of a New Extended Depth-of-Focus Intraocular Lens with a Refractive Design: A Prospective Study After Bilateral Implantation

Purpose

The aim of the present study was to evaluate the visual outcome of a new extended depth-of-focus (EDOF) intraocular lens (IOL) after bilateral implantation. A qualitative and quantitative analysis was performed and data were compared with those given by other studies regarding multifocal IOLs, which have the same purpose of giving spectacle independence to the patients.

Methods

The study enrolled 40 eyes of 20 patients who underwent cataract surgery with bilateral implantation of an EDOF IOL (Evolve Soleko, Rome, Italy). The mean age was 74.5±9 years (range 59-83ys). Refractive outcomes and contrast sensitivity were evaluated preoperatively and at 6-month follow-up. We also examined reading speed, glare, halos, difficulties in the night driving, the requirement for spectacles, and overall satisfaction with vision. Two questionnaires were administered for this purpose.

Results

At 6 months, the percentage of eyes within ±0.50 diopters (D) from emmetropia was 82.5%. Of all patients, 90% were satisfied with their vision. The percentage of spectacle-free for near and distance vision patients was 70% and 95%, respectively. A postoperative binocular uncorrected 60cm intermediate visual acuity (UI60VA) of 0.2 logMAR or better was achieved in 92% of patients. Contrast sensitivity significantly improved postoperatively (p<0.001) and mean reading speed was good.

Conclusion

This new EDOF IOL seems to provide an effective alternative to patients who desire a spectacle-free lifestyle postoperatively. These lenses can supply a satisfactory distance, intermediate and near vision, and retain good contrast sensitivity, with most patients reporting excellent satisfaction.

Optical design and performance of a trifocal sinusoidal diffractive intraocular lens

Two theoretical sinusoidal diffractive profile models to build up a trifocal intraocular lens (IOL) are analysed. Topographic features of the diffractive zones such as their shape, step height and radii, as well as the energy efficiency (EE) of the foci, depends on the particular model, and are compared to the ones experimentally measured in a trifocal lens that claims to be designed with a generic sinusoidal diffractive profile: the Acriva Trinova IOL (VSY Biotechnology, The Netherlands). The topography of the IOL is measured by confocal microscopy. The EE is experimentally obtained through-focus with the IOL placed in a model eye. The experimental results match very accurately with one of the theoretical models, the optimum triplicator, once that a spatial shift in the sinusoidal profile is introduced in the model.

Visual outcomes of binocular implantation of a new extended depth of focus intraocular lens

Purpose:

To evaluate the visual outcomes of bilateral implantation of a new hydrophobic foldable extended depth of focus (EDOF) IOL.

Methods:

All cases undergoing phacoemulsification with bilateral implantation of Supraphob Infocus IOL between December 2017 and July 2018 at a tertiary eye care center were recruited in this prospective interventional study. The primary outcome measures were uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA), and uncorrected near visual acuity (UNVA). Postoperative follow-up was done on day 1, 1 week, 1 month, and 3 months.

Results:

One hundred and four eyes of 52 patients with a mean age of 58.4 ± 9.3 years were included. The mean UDVA improved from 0.84 ± 0.32 logMAR preoperatively to 0.11 ± 0.08 logMAR at 3 months following surgery. At the final follow-up, the binocular UDVA, UIVA, and UNVA was 0.03 ± 0.07, 0.14 ± 0.06, and 0.36 ± 0.05 logMAR, respectively. The mean CS was 1.47 ± 0.06 logCS. The distance and near stereopsis was 90.2 ± 24.8 s of arc (arcsec) and 62.5 ± 19.4 arcsec, respectively. The mean total higher-order aberration (HOA), point spread function, and modulation transfer function were 0.30 ± 0.13, 0.07 ± 0.08, and 0.26 ± 0.07, respectively.

Conclusion:

The Supraphob Infocus EDOF IOL provides good unaided visual acuity for distance, intermediate, and near along with a high quality of vision as assessed by contrast sensitivity, HOAs, and stereoacuity. It may be a potential alternative to the currently available EDOF IOLs in providing good visual acuity at variable distances.

Visual and Refractive Outcomes and Patient Satisfaction Following Implantation of Monofocal IOL in One Eye and ERV IOL in the Contralateral Eye with Mini-Monovision

Title

Visual and refractive outcomes and patient satisfaction following implantation of monofocal intraocular lens in one eye and ERV intraocular lens in the contralateral eye with mini-monovision.

Purpose

To evaluate the outcomes following implantation of monofocal intraocular lens in one eye and ERV intraocular lens in the contralateral eye with mini-monovision.

Methods

Twenty-five subjects underwent bilateral cataract surgery, wherein the dominant eye received monofocal Tecnis-1 IOL, while in the contralateral eye received the Tecnis Symphony ERV IOL. The dominant eye was targeted for emmetropia and the non-dominant eye for myopia of −0.50 to −0.75D. Binocular uncorrected and corrected distance (UDVA, CDVA), intermediate (UIVA, CIVA), and near (UNVA, DCNVA) visual acuity; reading speeds, defocus curve and contrast sensitivity were studied at 6 months post-operatively.

Results

At 6 months post-operatively the mean binocular UDVA, CDVA, UNVA and DCNVA were 0.007±0.07, −0.13±0.06, 0.26±0.09 and 0.44±0.10 LogMAR, respectively. Binocular UIVA and DCIVA at 60 cm were 0.22±0.10 and 0.18±0.08 LogMAR and at 80 cm was 0.16±0.11 and 0.15±0.10 LogMAR, respectively. Mean uncorrected reading speeds evaluated with SRD at 40, 60 and 80 cm were 114.4±6.9, 126.4±7.9 and 123.16±5.8 words per minute. Contrast sensitivity values did not show significant difference for any spatial frequency tested. At 6 months, only 12% (3 patients) reported mild halos. Spectacle independence satisfaction scores were 96%, 100% and 88% for distance, intermediate and near.

Conclusion

Implantation of monofocal intraocular lens in one eye and ERV intraocular lens in the contralateral with mini-monovision resulted in good outcomes for far and intermediate, and satisfactory outcomes for near vision, with good tolerance to mini-monovision at the end of 6 months.

Laboratory analysis and ray visualization of diffractive optics with enhanced intermediate vision

BACKGROUND

To assess the optical behavior of a new diffractive intraocular lens (IOL) and compare its performance to that of an established extended-depth-of-focus (EDOF) IOL.

METHODS

This study assessed the Proming EDOF Multifocal AM2UX [Eyebright Medical Technology (Beijing) Co., Ltd., China] and the AT LARA 829MP [Carl Zeiss Meditec, Germany]. An experimental set-up with 0.01% fluorescein solution and monochromatic light (532 nm) was used to visualize the IOLs' ray propagation. In addition, the optical quality of the IOLs was assessed by measuring the modulation transfer function (MTF) values at 50lp/mm and 3.0 and 4.5 mm apertures on the optical bench OptiSpheric® IOL PRO II [Trioptics GmbH, Germany].

RESULTS

The ray propagation of the two IOLs showed two distinct foci. Light intensity assessment revealed that both IOLs allocate more energy to primary than secondary focus. At 3.0 mm pupil, the MTF values at 50lp/mm for the primary focus were 0.39 and 0.37, and for the secondary focus, 0.29 and 0.26 for the AT LARA and Proming IOLs, respectively. At 4.5 mm pupil, the single-frequency MTF for the primary focus was 0.51 and 0.24 and for the secondary focus 0.21 and 0.15 for the AT LARA and Proming IOLs, respectively.

CONCLUSIONS

When tested with an aberration-free model cornea under monochromatic conditions, the Proming behaved as a low-add bifocal lens; however, its properties did not differ much from the well-established AT LARA EDOF IOL. The AT LARA outperformed the Proming at low defocus (up to 2D), while the latter demonstrated better image quality in the 2-3D range.

Comparison of trifocal or hybrid multifocal-extended depth of focus intraocular lenses: a systematic review and meta-analysis

This meta-analysis aimed to evaluate the clinical outcomes following implantation of trifocal intraocular lenses (IOLs) or a hybrid multifocal-extended depth of focus (EDOF) IOL in cataract or refractive lens exchange surgeries. We examined 13 comparative studies with bilateral implantation of trifocal (898 eyes) or hybrid multifocal-EDOF (624 eyes) IOLs published through 1 March 2020. Better uncorrected and corrected near visual acuity (VA) were observed in the trifocal group (MD: − 0.143, 95% CI: − 0.192 to − 0.010, P < 0.001 and MD: − 0.149, 95% CI: − 0.217 to − 0.082, P < 0.001, respectively), while the hybrid multifocal-EDOF group presented better uncorrected intermediate VA (MD: 0.055, 95% CI: 0.016 to 0.093, P = 0.005). Trifocal IOLs were more likely to achieve spectacle independence at near distance (RR: 1.103, 95% CI: 1.036 to 1.152, P = 0.002). The halo photic effect was generated more frequently by the trifocal IOLs (RR: 1.318, 95% CI: 1.025 to 1.696, P = 0.031). Contrast sensitivity and subjective visual quality yielded comparable results between groups. Trifocal IOLs demonstrated better performance at near distance but apparently led to more photic disturbances. Our findings provided the most up-to-date and comprehensive evidence by comparing the benefits of advanced IOLs in clinical practice.

Through-Focus Energy Efficiency and Longitudinal Chromatic Aberration of Three Presbyopia-Correcting Intraocular Lenses

Purpose

To compare the chromatic performance of the Bausch & Lomb Versario 3F trifocal intraocular lens (IOL) with the PhysIOL FineVision MicroF trifocal IOL and the Johnson & Johnson Vision TECNIS Symfony ZXR00 extended range of vision (ERV) IOL.

Methods

The through-focus energy efficiency (TF-EE) was measured in vitro with red (R), green (G), and blue (B) wavelengths and was used to obtain the focus powers and longitudinal chromatic aberrations (LCAs) for each IOL. Other metrics, derived from the RGB TF-EE curves, were assessed for a more complete description of the chromatic performance of the IOLs.

Results

Both of the trifocal IOLs, although not specifically designed to tackle chromatic aberrations, showed acceptable LCA (≤0.50 D) in all foci with more balanced R and B efficiencies of their foci. Despite having the lowest TF-EE value at all foci, the Versario 3F demonstrated the most balanced chromatic performance with the smoothest energy transition among all foci and the smallest chromatic span. The Symfony lens effectively reduced LCA at distance and intermediate foci (≤0.36 D), despite the unbalanced and asymmetric R and B efficiencies at its foci.

Conclusions

To fully describe the chromatic performance of an IOL it is necessary to take into account not only the LCA but also the RGB TF-EE and chromatic span. This comprehensive analysis suggests that, in comparison with the other IOLs under study, the Versario 3F lens might contribute to further mitigating the impact of chromatic aberration.

Translational Relevance

The in vitro bench testing of the optical properties of modern presbyopia-correcting intraocular lenses (more specifically in this work, the polychromatic through-focus energy efficiency and longitudinal chromatic aberration) provides objective and complementary information that helps to interpret the visual quality outcomes of pseudophakic patients obtained in clinics.

Influence of implantations of extended depth-of-focus on standard automated perimetry

This prospective study aimed to investigate the influence of an extended depth-of-focus intraocular lens (EDOF IOL) on standard automated perimetry. Ninety eyes of 90 patients who had undergone cataract surgery from February 2018 to December 2018 were included. No patients had any diseases that might affect the visual field. ZMB00 (+ 4.00 D add), ZXR00V (+ 1.75 D add), and ZCB00V (Johnson & Johnson Surgical Vision, Santa Ana, CA, USA) were used as multifocal, EDOF, and monofocal IOLs, respectively. Humphrey Visual Field 10–2 testing was performed 2–3 months after cataract surgery, acceptable reliability indices were measured, and mean deviation (MD), pattern standard deviation (PSD), foveal sensitivity and mean sensitivity (MS) were compared. Seventy-one eyes (ZXR00V: 24 eyes, ZMB00: 25 eyes, ZCB00V: 22 eyes) were used for the analyses. The MD and MS of the EDOF and monofocal groups were significantly higher than those of the multifocal group (P < 0.0051). However, the MD and MS of the EDOF and monofocal groups were not different (P > 0.23). The PSD and foveal sensitivity were not different among the groups. In non-glaucomatous patients, the MD and MS of the EDOF IOL were comparable to those of the monofocal IOL and better than those of the multifocal IOL.

Straylight in Different Types of Intraocular Lenses

Purpose

To show the importance of measuring the angular distribution of straylight as an in vitro test for intraocular lenses (IOLs).

Methods

The optical integration method was implemented to measure the point spread function, up to 5.1°, of IOLs immersed in a wet cell. The straylight parameter was calculated as the product of the point spread function by the squared angle. The effect of the scattered light is shown in extended images of a target surrounded by headlamps as glare sources. Three different IOLs were tested: (1) AcrySof IQ SN60WF, monofocal, (2) AcrySof IQ PanOptix, trifocal, and (3) Tecnis Symfony ZRX00, bifocal with extended depth of focus. Measurements were compared to previously reported clinical studies where the same IOL models were implanted.

Results

The mean amount of scattered light, between 1.0° and 5.1°, generated by each IOLs were, in deg²sr^{- 1} units: (1) 1.2, (2) 12.1, and (3) 33.4. Lens (3) present a high amount of straylight related to a halo of an approximate diameter of 2°.

Conclusions

In vitro measurements of the angular distribution of the point spread function of different types of IOLs showed important aspects related to their manufacturing quality. These results are in line with previous clinical findings where glare sensitivity was tested in the same angular range.

Translational Relevance

In vitro measurement of angular dependence of straylight in IOLs, regardless their design, provides a valuable feedback to improve their optical quality. The minimization of the amounts of straylight positively impacts the recurrence of photic phenomena.

A Comparative Evaluation of Visual, Refractive, and Patient-Reported Outcomes of Three Extended Depth of Focus (EDOF) Intraocular Lenses

Objective

To compare visual, refractive, and patient-reported outcomes of patients implanted with one of three types of extended depth of focus (EDOF) intraocular lenses.

Setting

Asian Eye Institute, Philippines.

Design

Retrospective cohort study.

Methods

Subjects implanted with Symfony (Johnson and Johnson, USA), IC-8 (AcuFocus, USA), and WIOL (Medicem, Czech Republic) EDOF intraocular lenses were recruited. Spherical equivalent, uncorrected and corrected visual acuity, defocus curve, and modulation-transfer function, Strehl ratio, and visual Strehl optical transfer function values, photic phenomena, and questionnaire answers were measured and assessed.

Results

A total of 32 eyes with the Symfony lens, 30 with the IC-8 lens, and 32 with the WIOL lens were included in the study. Mean postoperative spherical equivalent was -0.24 D for the Symfony, -0.17 D for the IC-8, and 0.27 D for WIOL. There were no significant differences in postoperative monocular and binocular uncorrected and corrected visual acuity. On a monocular defocus curve, the IC-8 and Symfony showed significantly better vision than WIOL. The Symfony had significantly better modulation-transfer function, Strehl ratio, and visual Strehl optical transfer function. No difference was seen among the three lenses with regard to glare or starburst, while patient satisfaction remained high in all groups for far, intermediate, and near vision.

Conclusion

All eyes implanted with the three EDOF designs achieved excellent far and intermediate vision, with acceptable near vision. The IC-8 and Symfony exhibited a better range of vision on defocus-curve testing. The Symfony showed superior results in quality of vision. Patient satisfaction was high in all three EDOF groups.

Binocular visual function after staged implantation of extended-depth-of-focus intraocular lens targeting emmetropia and -0.5 diopter: A prospective comparison

The prospective comparative case series aimed to evaluate the binocular uncorrected visual acuities (BUCVAs) after staged implantations of extended-depth-of-focus intraocular lenses (EDOF IOLs) targeting emmetropia and -0.5 diopter (D). Diffractive EDOF IOLs with an add power of +1.75 D were implanted in the first eyes targeting emmetropia or -0.5 D according to the patients’ preferences, then the targets for the second eyes were determined 1 week or longer after the implantation. IOL powers were determined with the SRK/T formula. Consequently, the subjects were divided into 3 groups: those with emmetropia targeted bilaterally (group EE, 22 patients), those with -0.5 D targeted bilaterally (group MM, 21 patients), and those with monovision of emmetropia and -0.5 D (group EM, 21 patients). Manifest refraction spherical equivalent (MRSE), BUCVA from 0.3 to 5 meters, spectacle use, and questionnaire regarding photic symptoms and patient satisfaction were assessed 3 months postoperatively. No significant differences were seen in the mean BUCVAs at any distance (P > 0.23), spectacle use (P = 0.13), or photic symptoms and patient satisfaction (P>0.65). When the EE and MM groups were assigned based on the MRSE, the EE group was better at 5 m (P = 0.005) while the MM group at 0.5 m (P = 0.031). The effect of different targeted refractions was not identified due to insufficient accuracy in the use of the SRK/T power calculation.

Clinical outcomes with a new design in multifocal intraocular lens: a pilot study

Purpose

To evaluate the clinical and visual outcomes, quality of near vision and the influence of photic phenomena in patients bilaterally implanted with a new Precizon Presbyopic multifocal intraocular lens (IOL).

Methods

In this prospective consecutive case series, 20 eyes of 10 patients were included (mean age 63.80 ± 12.55 years). Uncorrected and corrected visual acuity (far, intermediate and near), subjective refraction, binocular defocus curve, contrast sensitivity (CSV-1000) and quality of vision and satisfaction questionnaires were measured. The follow-up was 12 months after surgery.

Results

At 12 months after surgery, uncorrected distance visual acuity (UDVA) improved with surgery (p = 0.001) with a value of 0.08 ± 0.08 logMAR. Uncorrected near visual acuity (UNVA) was 0.22 ± 0.12 logMAR and distance corrected near visual acuity (DCNVA) was 0.16 ± 0.13 logMAR. Intermediate distance visual acuity (UIVA) was 0.22 ± 0.10 logMAR. Contrast sensitivity outcomes were similar to normal population in photopic conditions and slightly reduced in mesopic conditions of lighting. Defocus curve showed that this multifocal IOL was able to provide a visual acuity (VA) equal or better to 0.16 logMAR between defocus levels of + 1.00 to − 2.50 D. Good patient satisfaction was obtained in quality of vision and satisfaction questionnaires outcomes.

Conclusions

The Precizon Presbyopic NVA IOL (OPHTEC BV) provides good visual outcomes. This multifocal IOL provides a high percentage of spectacle independence due to good VA at far, intermediate and near distances and satisfactory contrast sensitivity. High patient satisfaction was observed in quality of vision and satisfaction questionnaires with a low percentage of patients manifesting photic phenomena.

Laboratory evaluation of the optical properties of two extended-depth-of-focus intraocular lenses

Background

To experimentally compare the optical performance of two different Extended-Depth-of-Focus (EDOF) intraocular lenses (IOLs) using a standardized optical bench set-up.

Methods

In this experimental study, following IOLs were assessed: the TECNIS® Symfony ZXR00 (Johnson&Johnson, Santa Ana, USA) and the AT LARA 829MP (Carl Zeiss Meditec, Jena, Germany) IOLs. The through-focus modulation transfer function (MTF) values were measured at a spatial frequency of 50 lp/mm and at aperture sizes of 2, 3, and 4.5 mm. Each IOL was measured while centered using ISO 11979-2 Model 1 (aberration-free) and Model 2 (+ 0.28 μm spherical aberration) corneas. United States Air Force (USAF) target images were also recorded for a qualitative evaluation.

Results

At 2 mm pupil with ISO1 cornea, the primary and secondary foci of both IOLs appeared to merge, providing an elongated depth of focus. At 3 and 4.5 mm pupil sizes, the through-focus MTF curves of both IOLs showed a bifocal-like V-pattern. While the Symfony IOL showed an overall superior MTF values when measured with the ISO2 cornea, the opposite propensity could be observed with the AT LARA IOL. This optical behavior could be qualitatively confirmed by the USAF target images.

Conclusions

Although the two EDOF IOLs share similarities in their optical properties, the main difference lies in their optical design and performance with respect to spherical aberration. Such characteristics should be taken into account during IOL and patient selection.

Optimization of the Light Sword Lens for Presbyopia Correction

Purpose

We propose and evaluate the modifications of a light sword lens (LSL) to obtain better performance for distance vision while maintaining good operation for near and intermediate vision.

Methods

The modifications consisted of assigning angular or circular windows for distance vision while rescaling the LSL profile in the remaining area of the element. The objective performance of the redesigned LSLs was verified numerically by the Strehl ratio and experimentally using correlation coefficients and Michelson contrast. Subjective assessments were provided by monocular visual acuity (VA) and contrast sensitivity (CS) through-focus curves for six patients with paralyzed accommodation. The tested object vergence range was [-4.0, 0.0] diopters (D). All experiments were conducted in a custom-made monocular visual simulator.

Results

Computational simulations and objective experiments confirmed the better performance of the modified LSL for the imaging of distant objects. The proposed angular and radial modulations resulted in flat VA and CS through-focus curves, indicating more uniform quality of vision with clearly improved distance vision. The VA provided by the modified LSL profiles showed a maximal improvement of 1.5 lines of acuity with respect to the VA provided by the conventional LSL at distance vision.

Conclusions

Optimized LSLs provide better imaging of distant objects while maintaining a large depth of focus. This results in comparable and acceptable quality for distance, intermediate, and near vision. Therefore, the modified LSLs appear to be promising presbyopia correctors.

Translational Relevance

The new design of LSL reveals an improved performance for all ranges of vision and becomes a promissory element for a real presbyopia correction in clinical applications.

Disruptive Innovation and Refractive IOLs: How the Game Will Change With Adjustable IOLs

The light-adjustable lens is the first Food and Drug Administration (FDA)-approved product from an entirely new category of intraocular lenses (IOLs). The 3-piece foldable silicone light-adjustable lens is implanted through a small incision after phacoemulsification. A slit-lamp-based digital light delivery device is used to adjust and then lock-in the IOL power during the first postoperative month. Up to 4.5 diopters (D) of cylindrical or spherical adjustment can be achieved. This should offer significant advantages in difficult IOL power calculation cases, such as postrefractive eyes. In addition to achieving better refractive accuracy, an adjustable IOL will now allow patients to test and elect a different refractive target postoperatively. This paradigm shift will change how cataract patients choose their refractive objectives, and how ophthalmologists will be able to achieve them. For example, adjustable IOLs may increase the popularity of pseudophakic monovision and bilateral same-day sequential surgery. For those electing adjustable IOL, preoperative patient counseling will change and certain pre- and intraoperative technologies, such as intraoperative aberrometry and digital astigmatic axis marking, would become superfluous.

Visual acuity and defocus curves with six multifocal intraocular lenses

PURPOSE

The purpose of this prospective, randomized, double-masked, study was to compare the visual performance of patients after bilateral implantation of six different IOLs.

METHODS

The following IOLs were used in the study: SV25T0 (n = 19), ATLISA 809M (n = 18), ATLISA Tri 839MP (n = 19), ZKB00 (n = 20), ZLB00 (n = 20) and Symfony ZXR00 (n = 20). Visual performance was assessed by the monocular distance-corrected visual acuity at 4 m (CDVA), distance-corrected intermediate visual acuity (DCIVA) at 60 cm and distance-corrected near visual acuity (DCNVA) at 40 cm. Binocular defocus curves were obtained for a range of defocus from + 1.50 D to - 4.50 D, in 0.50 D steps. Quality of life was assessed with the VF-14 questionnaire.

RESULTS

CDVA was better with the Symfony ZXR00 than with the SV25T0 (p = 0.032), ATLISA Tri 839MP (p = 0.032) and ATLISA 809M (p = 0.018). The Symfony ZXR00 offered the best DCIVA, followed by the ZKB00. The best and worst DCNVA results corresponded to the ZLB00, and the SV25T0 and Symfony ZXR00, respectively. Defocus curves at distance were good in all groups, although the Symfony had a wider range of clear vision (- 1.50 D to + 0.50 D), with no decay. For intermediate vision, only the Symfony obtained sharp visual acuity. The ATLISA 809M, ATLISA Tri 839MP and ZLB00 were superior at near distance.

CONCLUSIONS

The extended depth of focus of the Symfony ZXR00 offers a superior range of clear vision at far and intermediate distances than other multifocal designs, with worse results at near distance. Visual outcomes reflect the particular optical, geometrical and power distribution characteristics of each IOL.

AcrySof IQ PanOptix Intraocular Lens Versus Extended Depth of Focus Intraocular Lens and Trifocal Intraocular Lens: A Clinical Overview

AcrySof IQ PanOptix Model TFNT00 (Alcon Laboratories, Fort Worth, TX) is a 1-piece aspheric hydrophobic presbyopia-correcting intraocular lens (IOL) launched in 2015. Unlike traditional trifocal IOLs that usually have an intermediate focal point of 80 cm, the PanOptix IOL is designed to have an intermediate focal point of 60 cm (arms-length), a more natural and comfortable working distance to perform functional tasks on computers, laptops, mobiles, among others. The non-apodized PanOptix IOL uses the ENhanced LIGHT ENergy (ENLIGHTEN; Alcon Laboratories, Fort Worth, TX) optical technology that provides high (88%) utilization of light energy, low dependence on pupil size in all lighting conditions, and a more comfortable near-to-intermediate range of vision than traditional trifocal IOLs. This review provides an overview of the clinical performance of the PanOptix IOL and discusses it in the context of other commercially available trifocal IOLs, FineVision Micro F (PhysIOL, Liege, Belgium), the AT LISA tri 839MP (Carl Zeiss Meditec AG, Jena, Germany) and the extended depth of focus IOL, TECNIS Symfony (Abbott Medical Optics, Santa Ana, CA). A literature search was performed in the PubMed database to identify studies that have assessed the visual and other clinical outcomes with the PanOptix IOL. In total, 12 studies were included in this review article. Overall, the clinical evidence suggests that in general good visual outcomes, along with a high degree of spectacle independence, are achieved in patients implanted with the PanOptix, FineVision, AT LISA and Symfony IOLs. However, every MIOL has its benefits and limitations, which along with patient's needs and clinical conditions are important factors to consider while selecting an IOL to achieve best possible post-operative outcomes.

Performance of a New-Generation Extended Depth of Focus Intraocular Lens-A Prospective Comparative Study

PURPOSE

The aim was to study the visual performance of a new refractive extended depth of focus (EDOF) intraocular lens (IOL).

DESIGN

Prospective, comparative study.

METHODS

Consenting patients with age-related cataract willing for bilateral cataract surgery within 2 weeks were implanted with the Supraphob EDOF IOL and those willing for 1 eye surgery were implanted with a monofocal IOL. The uncorrected and best-corrected distance, intermediate and near visual acuity, and contrast sensitivity were evaluated at 1 and 3 months postoperatively. We also inquired about glare, halos, difficulties in night driving, requirement for spectacles, and overall satisfaction with vision.

RESULTS

The Supraphob EDOF group (n = 72 eyes) and the monofocal IOL group (n = 54 eyes) were comparable with respect to all preoperative parameters including biometry, visual acuity, and cataract status. The mean age of participants was 58.4 ± 10.6 years. Both groups had similar distance vision but the EDOF group had significantly better intermediate (0.2 ± 0.2 logMAR vs 0.75 ± 0.19 logMAR, P < 0.001) and near vision (median = N6 vs N12, P < 0.001) compared to the monofocal group at 3 months. The contrast sensitivity was similar in both groups. Patients in the EDOF IOL group had much greater satisfaction for intermediate and near vision. Less than 10% patients reported glare, halos, and difficulty in driving at night in the EDOF group.

CONCLUSIONS

The Supraphob EDOF IOL was effective in improving the distance, intermediate and near vision in majority of patients, and retained good contrast sensitivity with most patients reporting excellent satisfaction.

Visual quality and performance following bilateral implantation of TECNIS Symfony intraocular lenses with or without micro-monovision

Purpose: To evaluate the visual quality and performance of TECNIS Symfony intraocular lenses (IOLs) implanted with or without micro-monovision approach. Setting: Chongqing Aier Mega Eye Hospital, Chongqing, China; Daping Hospital of Army Medical University, Chongqing, China. Design: Prospective study. Methods: The study comprised 70 cataract patients who had bilateral implantation of TECNIS Symfony extended range of vision IOLs, either with intended micro-monovision (monovision group: 35 patients) or with intended emmetropia (control group: 35 patients). Visual acuity, modulation transfer function (MTF), defocus curve, spectacle independence, and photic phenomena were analyzed 3 months postoperatively. Results: There was no significant difference between the two groups in binocular uncorrected visual acuity at distance. Mean binocular uncorrected visual acuity at intermediate (monovision: 0.81 dec; control: 0.58 dec) and near (monovision: 0.59 dec; control: 0.30 dec) were significantly better in the monovision group. In the monovision group, the difference of MTF values between the dominant and the non-dominant eyes was not statistically significant and MTF values were within the normal range for both eyes. Spectacle independence at intermediate and near was statistically significantly higher in the monovision group compared to the control group. The incidence of photic phenomena was similar in both groups. Conclusion: Micro-monovision implantation of TECNIS Symfony IOLs provided a superior range of visual acuity from far to near and higher spectacle independence compared to a control group targeted for emmetropia.

Visualization of Light Propagation with Multifocal Intraocular Lenses Using the Ouzo Effect

The number of presbyopia correcting intraocular lenses (IOLs) is increasing and new technologies are constantly emerging with the aim of correcting the loss of accommodation after cataract surgery. Various optical designs have been proposed to implement multifocality or an extended depth of focus (EDOF). Depending on the optical principle of an implanted lens, the visual performance often is deteriorated by superposition of individual image planes and halos of varying intensity. This experimental study presents a concept to visualize the light fields and especially the halos of mono- and multifocal IOLs using the well known alcoholic beverage “ouzo” in order to obtain qualitative data on the imaging characteristics. We conclude that ouzo is a useful, cost effective, and nonpolluting medium for beam visualization and an alternative to fluorescein or milk, which could find an application for educational purposes.

Intraocular lens correction of presbyopia

The continued development of intraocular lens (IOL) technology has led to a dramatic improvement in refractive outcomes. New and innovative ways of achieving the desired postoperative refractive goals continue to be developed. This article aims to review the currently available IOL modalities for correction of presbyopia at the time of cataract surgery, including reference to high-quality comparative studies, where available, and discussion of strengths as well as limitations of the currently available IOL technologies. It has been shown that multifocal compared to monofocal IOL was associated with higher rates of spectacle independence, but higher rates and severity of symptomatic glare as well as reduced contrast sensitivity. Within multifocal IOLs, diffractive compared to refractive IOLs tended to have better near vision and a lower rate of symptomatic glare. Extended depth-of-focus IOLs compared to diffractive multifocal IOL demonstrated equal or superior intermediate visual acuity, with less than or equal rates of glare. Accommodative IOLs represent a broad range of technologies that continue to develop, and new technologies offering opportunities for postoperative adjustment of refractive outcome are emerging.

Premium intraocular lenses: The past, present and future

Purpose

To present potential benefits as well as limitations of premium intraocular lens (IOL) use, and provide insight in future of premium cataract surgery.

Methods

Bibliographic research was performed in PubMed/Medline database, and the most recently updated papers were evaluated. Keywords used were: premium intraocular lens, multifocal intraocular lens, toric intraocular lens, toric multifocal intraocular lens, accommodative intraocular lens, and the respective brand names.

Results

Multifocal IOLs provide uncorrected distance visual acuity (UDVA) of 0.03 logMAR in 82.3%–95.7% of patients and overall spectacle independence in 81%–85% of patients. Toric IOLs provide UDVA of 0.3 logMAR in 70%–95% of patients, residual astigmatism of 1 D or less is noted in 67%–88% of patients, and spectacle independence is reported in 60%–85% of patients. Toric multifocal IOLs provide UDVA of 0.3 logMAR in 92%–97% of patients, and spectacle independence is reported in 79%–90% of patients. Accommodative IOLs represent intensively developing field in ophthalmology, and the results are still variable depending on the IOL model.

Conclusions

Premium IOL technology and advanced surgical techniques have significantly improved postoperative visual outcomes. Future developments will potentiate development of new premium IOL designs that will provide spectacle independence and excellent visual outcomes after cataract surgery.