Latest Development in Extended Depth-of-Focus Intraocular Lenses: An Update

Clinical outcomes with a new diffractive multifocal intraocular lens optimized by the dynamic light utilization algorithm

BACKGROUND/OBJECTIVES

To evaluate the refractive outcomes, optical performance, and the quality of vision in patients implanted with a new diffractive intraocular lens (IOL), the Intensity Hanita.

SUBJECTS/METHODS

This observational, prospective, longitudinal study included 64 eyes underwent bilateral cataract surgery with the Intensity IOL (Hanita Israel) implantation. Main outcome measures after 6 months were the following visual acuities (VAs) of uncorrected and corrected distance (UDVA and CDVA), uncorrected and distance corrected intermediate VAs (UIVA and DCIVA), uncorrected and distance corrected near (UNVA and DCNVA), refraction, slitlamp biomicroscopy, defocus curve (DFC), high ocular aberrations (HOA), contrast sensitivity (CS), optical quality, subjective quality of vision (QoV) and near activity visual questionnaires (NAVQ).

RESULTS

Sixty-six percent of eyes having UDVA 0.10 logMAR or better. DFC showed maximum vision at distance (0.02 ± 0.07 LogMAR at 0.0 D), with flat decline through intermediate and near vision (0.11 ± 0.08 LogMAR at -1.5 D and 0.12 ± 0.12 at -2.5 D). No significant changes in CS were found (all spatial frequencies, p ≥ 0.06). The RMS of HOA, coma, trefoil, and SA were 0.21 ± 0.10, 0.10 ± 0.06, 0.11 ± 0.07, and 0.00 ± 0.04 μm and the Strehl ratio was 0.12 ± .04 at 6 months. Subjective symptoms (halos and glare) were reported mild but well tolerated, not causing significant disturbance in daily activities. The NAVQ showed high levels of satisfaction performing daily near-vision tasks.

CONCLUSIONS

The Hanita Intensity diffractive IOL successfully restores all distances of vision. The flat profile of the monocular defocus curve confirms the five-foci distribution principle that provides vision at all ranges while increasing the depth of focus.

Effects of long-term neural adaptation to habitual sspherical aberration on through-focus visual acuity in adults

We investigated how long-term visual experience with habitual spherical aberration (SA) influences subjective depth of focus (DoF). Nine healthy cycloplegic eyes with habitual SAs of different signs and magnitudes were enrolled. An adaptive optics (AO) visual simulator was used to measure through-focus high-contrast visual acuity after correcting all monochromatic aberrations and imposing + 0.5 μm and - 0.5 μm SAs for a 6-mm pupil. The positive (n = 6) and negative (n = 3) habitual SA groups ranged from 0.17 to 0.8 μm and from - 1.2 to - 0.12 μm for a 6-mm pupil, respectively. Although all optical conditions were identical, and the subjective DoFs were expected to be the same for all participants, the DoFs of individuals differed between the positive and negative habitual SA groups. For the positive habitual SA group, the mean DoF with positive AO-induced SA (2.14 D) was larger than that with negative AO-induced SA (1.88 D); for the negative habitual SA group, a smaller DoF was measured with positive AO-induced SA (1.94 D) than that with negative AO-induced SA (2.14 D). Subjective DoF tended to be larger when the induced SA in terms of sign and magnitude was closer to the participant's habitual SA. Our findings suggest that neural adaptation to habitual SA compensated for optical blur at multiple object distances, perceptually expanding DoF. As a result, the outcomes of optical treatments for presbyopia may differ due to the neural compensation mechanism influenced by an individual's visual experience with their habitual optics.

[Determination of refractive error and visual acuity after implantation of multifocal or extended depth of focus lenses]

There are many factors that can affect the postoperative satisfaction of patients after implantation of intraocular lenses with extended depth of focus (EDoF) and multifocal lenses (e.g., photic phenomena, postoperative complications and the presence of dry eye symptoms); however, achieving the target refraction should also be considered an important factor in the satisfaction. This article highlights the pitfalls in determining the refractive error in patients with a multifocal or EDoF lens and how uncorrected and corrected visual acuity can impact patient satisfaction.

A Multi Comparison of 8 Different Intraocular Lens Biometry Formulae, Including a Machine Learning Thin Lens Formula (MM) and an Inbuilt Anterior Segment Optical Coherence Tomography Ray Tracing Formula

A comparison of the accuracy of intraocular lens (IOL) power calculation formulae, including SRK/T, HofferQ, Holladay 1, Haigis, MM, Barrett Universal II (BUII), Emmetropia Verifying Optical (EVO), and AS-OCT ray tracing, was performed. One hundred eyes implanted with either the Rayone EMV RAO200E (Rayner Intraocular Lenses Limited, Worthing, UK) or the Artis Symbiose (Cristalens Industrie, Lannion, France) IOL were included. Biometry was obtained using IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany) and MS-39 AS-OCT (CSO, Firenze, Italy). Mean (MAE) and median (MedAE) absolute errors and percentage of eyes within ±0.25D, ±0.50D, ±0.75D, and ±1.00D of the target were compared, with ±0.75D considered a key metric. The highest percentage within ±0.75D was found with MM (96%) followed by the Haigis (94%) for the enhanced monofocal IOL. SRK/T (94%) had the highest percentage within ±0.75D, followed by Holladay 1, MM, BUII, and ray tracing (all 90%) for the multifocal IOL. No statistically significant difference in MAE was found with both IOLs. EVO showed the lowest MAE for the enhanced monofocal and ray tracing for the multifocal IOL. EVO and ray tracing showed the lowest MedAE for the two respective IOLs. A similar performance with high accuracy across formulae was found. MM and ray tracing appear to have similar accuracy to the well-established formulae and displayed a high percentage of eyes within ±0.75D.

Combination of a monofocal and one type of extended depth-of-focus (zonal refractive) intraocular lens (COMEDI) in bilateral cataract surgery protocol: a monocentric, randomised, parallel group trial in cataract surgery

INTRODUCTION

Modern intraocular lens (IOL) designs for cataract treatment can be broadly classified into three focal range categories; monofocal, extended depth-of-focus (EDOF) and multifocal IOLs.Monofocal IOLs allow spectacle independence for one focus, typically distance. In contrast, EDOF IOLs provide a greater range of vision, extending spectacle independence to intermediate distance, while multifocal IOLs enable spectacle independence at all distances with the drawback of positive dysphotopsias and reduced contrast perception.EDOF lenses are an attractive compromise with fewer dysphotopic side effects than multifocals. The purpose of this study is to assess whether implanting an EDOF IOL in the second eye of a patient who received a monofocal IOL in the first eye can improve spectacle independence while maintaining the same optical quality as bilateral monofocal IOL implantation.

METHODS AND ANALYSIS

This study compares combined monofocal and EDOF IOL implantation versus bilateral monofocal IOL implantation in terms of clinical and patient-reported outcomes in a monocentric, randomised, patient-masked and assessor-masked, parallel group trial in 88 bilateral cataract patients. The primary outcome measure is binocular photopic distance corrected intermediate visual acuity. The secondary outcome measures include (un)corrected distance and near visual acuity, reading speed at intermediate distance, quality of visual function assessments, patient-reported spectacle independence, contrast sensitivity, aberrometry, stereopsis and straylight measurement at the 3-month follow-up.

ETHICS AND DISSEMINATION

The protocol was approved by the ethical committee of the University Hospital of Brussels (BUN 23219_EDOF).

TRIAL REGISTRATION NUMBER

NCT06002399.

BCLA CLEAR presbyopia: Management with intraocular lenses

Cataract surgery including intraocular lens (IOL) insertion, has been refined extensively since the first such procedure by Sir Harold Ridley in 1949. The intentional creation of monovision with IOLs using monofocal IOL designs has been reported since 1984. The first reported implantation of multifocal IOLs was published in 1987. Since then, various refractive and or diffractive multifocal IOLs have been commercialised. Most are concentric, but segmented IOLs are also available. The most popular are trifocal designs (overlaying two diffractive patterns to achieve additional focal planes at intermediate and near distances) and extended depth of focus designs which leave the patient largely spectacle independent with the reduced risk of bothersome contrast reduction and glare. As well as mini-monovision, surgical strategies to minimise the impact of presbyopia with IOLs includes mixing and matching lenses between the eyes and using IOLs whose power can be adjusted post-implantation. Various IOL designs to mimic the accommodative process have been tried including hinge optics, dual optics, lateral shifts lenses with cubic-type surfaces, lens refilling and curvature changing approaches, but issues in maintaining the active mechanism with post-surgical fibrosis, without causing ocular inflammation, remain a challenge. With careful patient selection, satisfaction rates with IOLs to manage presbyopia are high and anatomical or physiological complications rates are no higher than with monofocal IOLs.

Trifocal versus extended depth of focus (EDOF) intraocular lenses after cataract extraction

BACKGROUND

Cataract, defined as an opacity of the lens in one or both eyes, is the leading cause of blindness worldwide. Cataract may initially be treated with new spectacles, but often surgery is required, which involves removing the cataract and placing a new artificial lens, usually made from hydrophobic acrylic. Recent advancements in intraocular lens (IOL) technology have led to the emergence of a diverse array of implantable lenses that aim to minimise spectacle dependence at all distances (near, intermediate, and distance). To assess the relative merits of these lenses, measurements of visual acuity are needed. Visual acuity is a measurement of the sharpness of vision at a distance of 6 metres (or 20 feet). Normal vision is 6/6 (or 20/20). The Jaegar eye card is used to measure near visual acuity. J1 is the smallest text and J2 is considered equivalent to 6/6 (or 20/20) for near vision.

OBJECTIVES

To compare visual outcomes after implantation of trifocal intraocular lenses (IOLs) to those of extended depth of focus (EDOF) IOLs. To produce a brief economic commentary summarising recent economic evaluations that compare trifocal IOLs with EDOF IOLs.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register), MEDLINE, Embase, and three trial registries on 15 June 2022. For our economic evaluation, we also searched MEDLINE and Embase using economic search filters to 15 June 2022, and the NHS Economic Evaluation Database (EED) from 1968 up to and including 31 December 2014. We did not use any date or language restrictions in the electronic searches.

SELECTION CRITERIA

We included studies comparing trifocal and EDOF IOLs in adults undergoing cataract surgery. We did not include studies involving people receiving IOLs for correction of refractive error alone (or refractive lens exchange in the absence of cataract).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Two review authors working independently selected studies for inclusion and extracted data from the reports. We assessed the risk of bias in the studies, and we assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included five studies that compared trifocal and EDOF lenses in people undergoing cataract surgery. Three trifocal lenses (AcrySof IQ PanOptix, ATLISA Tri 839MP, FineVision Micro F) and one EDOF lens (TECNIS Symfony ZXR00) were evaluated. The studies took place in Europe and North America. Follow-up ranged from three to six months. Of the 239 enroled participants, 233 (466 eyes) completed follow-up and were included in the analyses. The mean age of participants was 68.2 years, and 64% of participants were female. In general, the risk of bias in the studies was unclear as methods for random sequence generation and allocation concealment were poorly reported, and we judged one study to be at high risk of performance and detection bias. We assessed the certainty of the evidence for all outcomes as low, downgrading for the risk of bias and for imprecision. In two studies involving a total of 254 people, there was little or no difference between trifocal and EDOF lenses for uncorrected and corrected distance visual acuity worse than 6/6. Sixty per cent of participants in both groups had uncorrected distance visual acuity worse than 6/6 (risk ratio (RR) 1.06, 95% confidence intervals (CI) 0.88 to 1.27). Thirty-one per cent of the trifocal group and 38% of the EDOF group had corrected distance visual acuity worse than 6/6 (RR 1.04, 95% CI 0.78 to 1.39). In one study of 60 people, there were fewer cases of uncorrected near visual acuity worse than J2 in the trifocal group (3%) compared with the EDOF group (30%) (RR 0.08, 95% CI 0.01 to 0.65). In two studies, participants were asked about spectacle independence using subjective questionnaires. There was no evidence of either lens type being superior. One further study of 60 participants reported, "overall, 90% of patients achieved spectacle independence", but did not categorise this by lens type. All studies included postoperative patient-reported visual function, which was measured using different questionnaires. Irrespective of the questionnaire used, both types of lenses scored well, and there was little evidence of any important differences between them. Two studies included patient-reported ocular aberrations (glare and halos). The outcomes were reported in different ways and could not be pooled; individually, these studies were too small to detect meaningful differences in glare and halos between groups. One study reported no surgical complications. Three studies did not mention surgical complications. One study reported YAG capsulotomy for posterior capsular opacification (PCO) in one participant (one eye) in each group. One study reported no PCO. Two studies did not report PCO. One study reported that three participants (one trifocal and two EDOF) underwent laser-assisted subepithelial keratectomy (LASEK) to correct residual myopic refractive error or astigmatism. One study reported a subset of participants who were considering laser enhancement at the end of the study period (nine trifocal and two EDOF). Two studies did not report laser enhancement rates. No economic evaluation studies were identified for inclusion in this review.

AUTHORS' CONCLUSIONS

Distance visual acuity after cataract surgery may be similar whether the lenses implanted are trifocal IOLs or EDOF (TECNIS Symfony) IOLs. People receiving trifocal IOLs may achieve better near vision and may be less dependent on spectacles for near vision. Both lenses were reported to have adverse subjective visual phenomena, such as glare and halos, with no meaningful difference detected between lenses.

Risk Factors for Corneal Monochromatic Aberrations and Implications for Multifocal and Extended Depth-of-Focus Intraocular Lens Implantation

PURPOSE

To discuss factors influencing corneal aberrations that might influence the optical quality after intraocular lens (IOL) implantation.

METHODS

PubMed and Scopus were the main resources used to search the medical literature. An extensive search was performed to identify relevant articles concerning factors influencing the level of corneal aberrations as of August 27, 2023. The following keywords were used in various combinations: corneal, aberrations, defocus, astigmatism, spherical aberration, coma, trefoil, quadrafoil, intraocular lens, and IOL.

RESULTS

Conclusive evidence is lacking regarding the correlation between age and changes in corneal aberrations. Patients with astigmatism have greater corneal higher-order aberrations than those with minimal astigmatism, particularly concerning trefoil and coma. Increased levels of corneal higher-order aberrations are noted following contact lens wear, in patients with dry eye disease, and with pterygium. Increased higher-order aberrations have been reported following corneal refractive surgery and for 3 months following trabeculectomy; regarding intraocular lens surgery, the results remain controversial.

CONCLUSIONS

Several factors influence the level of corneal higher-order aberrations. Multifocal and extended depth-of-focus IOLs can share similarities in their optical properties, and the main difference arises in their design and performance with respect to spherical aberration. Preoperative evaluation is critical for proper IOL choice, particularly in corneas with risk of high levels of aberrations. [J Refract Surg. 2024;40(6):e420-e434.].

Optical and clinical simulated performance of a new refractive extended depth of focus intraocular lens

OBJECTIVES

The purpose of this study is to evaluate the optical and expected clinical performance of a new refractive Extended Depth of Focus (EDF) intraocular lens (IOL) designed to maintain a monofocal-like dysphotopsia profile.

METHODS

Simulated visual acuity (sVA) with varying defocus was calculated using the area under the Modulation Transfer Function measured in an average eye model and from computer simulations in eye models with corneal higher-order aberrations. Tolerance to defocus was evaluated using computer simulations of the uncorrected distance sVA under defocus. To evaluate the dysphotopsia profile, halo pictures obtained using an IOL-telescope, as well as simulated images in a realistic eye model under defocus were assessed. The results of the refractive EDF were compared to those of a diffractive EDF of the same platform.

RESULTS

The refractive EDF IOL provides similar range of vision to the diffractive EDF IOL with the same distance, and similar intermediate and near sVA. The refractive EDF IOL provides the same tolerance to hyperopia as the diffractive EDF but more tolerance to myopia. Halo pictures and simulations showed that the refractive EDF provides comparable dysphotopsia profile to the monofocal IOL and better than the diffractive EDF.

CONCLUSIONS

The results of this preclinical study in clinically relevant conditions show that the new refractive EDF IOL is expected to provide similar range of vision to the diffractive IOL of the same platform and higher tolerance to refractive errors. The refractive EDF provides a dysphotopsia profile that is better than the diffractive EDF and comparable to that of the monofocal IOL, also in the presence of residual refractive errors.

Optical and aberrometric evaluation of a new enhanced monofocal intraocular lens with isofocal optic design

PURPOSE

To evaluate the optical and aberrometric outcomes of an enhanced monofocal intraocular lens (ISOPure) compared with those of a standard monofocal lens (MicroPure) having the same platform and material.

METHODS

A prospective, comparative and randomised clinical study. A total of 28 eyes of 28 patients were randomly assigned to either group. Monocular visual acuity (VA) was measured at distance and intermediate under photopic and mesopic conditions. Aberrometry was analysed for 3.0-, 4.0-, 4.5- and 5.0 mm pupils. The contrast sensitivity defocus curve was measured for 3.0- and 4.5-mm pupils, while the modulation transfer function (MTF) and Strehl ratio (SR) were assessed with a double-pass system. All measurements were performed monocularly 3 months after surgery.

RESULTS

No significant differences were found for distance VA. Under photopic conditions, intermediate VA was better with the ISOPure lens, while no significant differences were found between the lenses under mesopic conditions. Internal and total aberrations were higher for the ISOPure lens. No significant differences were found for corneal aberrations. Additionally, both the contrast sensitivity defocus curve and optical quality showed similar behaviour for each lens, with the MTF cut-off frequency exceeding 30 c/deg in both cases.

CONCLUSION

The isofocal ISOPure lens enhanced intermediate VA without affecting distance VA under photopic conditions. Moreover, there were no significant differences in visual quality between the ISOPure and MicroPure lenses, despite the former exhibiting higher internal and total aberrations than the monofocal model.

Patient-Reported Outcome Measures (PROMs) with Refractive and Diffractive Extended Depth of Focus (EDOF) Intraocular Lenses

BACKGROUND

Extended depth of focus intraocular lenses (EDOF-IOLs) provide unaided far- and mid-range vision. Refractive IOLs, in contrast to diffractive designs, are associated with a lower depth of focus and absence of dysphotopsia. The aim of this study was to assess spectacle independence for far-range, mid-range, and near-vision activities in patients after implantation of refractive or diffractive EDOF-IOLs using patient-reported outcome measures (PROMs) in a real-world setting.

PATIENTS AND METHODS

In 2021 and 2022, all patients in a single center referred for bilateral cataract surgery were assigned to 7 experienced cataract surgeons who either bilaterally implanted only a diffractive EDOF-IOL (Carl Zeiss Meditec AG, AT LARA Jena, Germany, three surgeons) or refractive EDOF-IOL (Johnson & Johnson Vision Inc., Tecnis Eyhance Irvine, California, USA, four surgeons) at the surgeon's discretion, with the aim of bilateral emmetropia. Six months after both cataract surgeries, all patients were contacted by telephone and asked to report their outcomes using a structured questionnaire investigating their spectacle usage for various daily activities and their experience with night glare or halos. Inclusion criteria were a normal postoperative visual potential based on the preoperative examination and completion of the questionnaire regarding postoperative visual experience.

RESULTS

Of the patients, 514 underwent bilateral cataract surgery aiming for bilateral emmetropia with the implantation of EDOF-IOLs (422 with Tecnis Eyhance and 92 with AT LARA). A complete questionnaire was obtained from 472 (92%) patients, who were included in the study (393 vs. 79). Comparing Tecnis Eyhance with AT LARA IOL, 54 vs. 57% patients were able to perform most of their daily activities without spectacles, 9 vs. 19% reported not being dependent on spectacles at all, 25 vs. 29% reported using their smartphones without spectacles, 15 vs. 49% patients reported experiencing glares or halos at night, and 1 vs.15% with driving disturbance. Overall, 95 vs. 93% patients described themselves as "satisfied" or "highly satisfied" with their IOL.

CONCLUSIONS

With both types of EDOF-IOLs, the majority of patients could perform most of their daily activities without spectacles, except reading, and were highly satisfied with their IOLs. Patients with diffractive Zeiss AT LARA EDOF-IOLs were more likely to accomplish unaided near-range visual tasks; however, they were also at a higher risk of experiencing glares or halos at night.

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.

Refractive extended depth-of-focus lens design based on periodic power profile for presbyopia correction

PURPOSE

Limitations of existing diffractive multifocal designs for presbyopia correction include discrete foci and photic phenomena such as halos and glare. This study aimed to explore a methodology for developing refractive extended depth-of-focus (EDoF) lenses based on a periodic power profile.

METHODS

The proposed design technique employed an optical power profile that periodically alternated between far, intermediate and near distances across the pupil radius. To evaluate the lens designs, optical bench testing was conducted. The impact on visual performance was assessed using a spatial light modulator-based adaptive optics vision simulator in human subjects. Additionally, the effects of pupil size change and lens decentration on retinal image quality were examined. A comparative performance analysis was carried out against a typical diffractive trifocal design and a monofocal lens.

RESULTS

The proposed design method was found to be effective in uniformly distributing light energy across all object distances within the desired depth of focus (DoF). While trade-offs between overall image quality and DoF still exist, the EDoF lens design, when tested in human subjects, provided a continuous DoF spanning over 2.25 D. The results also revealed that the EDoF design had a slightly higher dependence on changes in pupil size and lens decentration than the diffractive trifocal design.

CONCLUSION

The proposed design method showed significant potential as an approach for developing refractive EDoF ophthalmic lenses. These lenses offer a continuous DoF but are slightly more susceptible to variations in pupil size and decentration compared with the diffractive trifocal design.

Effects of Neural Adaptation to Habitual Spherical Aberration on Depth of Focus

We investigated how long-term visual experience with habitual spherical aberration (SA) influences subjective depth of focus (DoF). Nine healthy cycloplegic eyes with habitual SAs of different signs and magnitudes were enrolled. An adaptive optics (AO) visual simulator was used to measure through-focus high-contrast visual acuity after correcting all monochromatic aberrations and imposing +0.5 μm and -0.5 μm SAs for a 6-mm pupil. The positive (n=6) and negative (n=3) SA groups ranged from 0.17 to 0.8 μm and from -1.2 to -0.12 μm for a 6-mm pupil, respectively. For the positive habitual SA group, the median DoF with positive AO-induced SA (2.18D) was larger than that with negative AO-induced SA (1.91D); for the negative habitual SA group, a smaller DoF was measured with positive AO-induced SA (1.81D) than that with negative AO-induced SA (2.09D). The difference in the DoF of individual participants between the induced positive and negative SA groups showed a quadratic relationship with the habitual SA. Subjective DoF tended to be larger when the induced SA in terms of the sign and magnitude was closer to the participant's habitual SA, suggesting the importance of considering the habitual SA when applying the extended DoF method using optical or surgical procedures.

Functional Classification of Intraocular Lenses Based on Defocus Curves: A Scoping Review and Cluster Analysis

PURPOSE

To explore a potential functional classification of intraocular lenses (IOLs) based on monocular visual acuity defocus curves (VADCs) as a primary end-point.

METHODS

A systematic literature search was conducted using PubMed. Two independent reviewers screened the literature for inclusion and data extraction. Inclusion criteria were full-text primary clinical studies of IOLs, published in English from 2010 onward, involving patients undergoing cataract or refractive lens exchange. A cluster analysis was conducted to explore similarities in the range of field (RoF) and increase of visual acuity from intermediate to near (ΔVA).

RESULTS

A total of 107 studies were ultimately included from the 436 identified in the systematic search, with an additional 5 studies added through the snowballing technique search. The cluster analysis was conducted using 69 reports that included monocular VADCs. Two main categories were identified based on the achieved RoF for 0.2 and 0.3 logMAR: full (FRoF) and partial (PRoF) RoF IOLs. Three subcategories were identified for FRoF depending on ΔVA: continuous (FRoF-C), smooth (FRoF-Sm), and steep (FRoF-St). On the other hand, PRoF IOLs shared the characteristic of monotonous decrease in visual acuity and were subclassified into two subcategories depending on the achieved RoF: narrowed (PRoF-N) and extended (PRoF-Ex). An additional subcategory was added to PRoF, enhanced (PRoF-En), for 7 reports alternating between PRoF-N and PRoF-Ex depending on the use of 0.2 or 0.3 logMAR as a cut-off for calculating the RoF.

CONCLUSIONS

IOLs can be functionally classified into six types depending on the RoF and shape of the monocular VADC. [J Refract Surg. 2024;40(2):e108-e116.].

Intra-Observer and Inter-Observer Variability of Intraocular Lens Measurements Using an Interferometry Metrology Device

The NIMO TEMPO (Lambda-X, Nivelles, Belgium) is a novel, user-friendly and compact device designed for in vitro optical analysis of refractive and diffractive intraocular lenses (IOLs). This device analyzes the IOL wavefront and generates a synthetic eye model for numerical computation. The objective of this study was to evaluate the precision of this innovative device. Intra- and inter-observer variability were calculated using a two-way analysis of variance (ANOVA) after conducting ten measurements of eight different IOL models, with each measurement being repeated by three distinct operators (resulting in a total of 30 measurements for each IOL). The device demonstrated satisfactory intra- and inter-observer variability in evaluating IOL power and modulation transfer function (MTF) profiles, with values of 0.066 and 0.078 diopters for IOL power and 0.018 and 0.019 for MTF measurements, respectively. Furthermore, this hybrid optical and numerical in vitro IOL wavefront analyzer appears to have several advantages over conventional optical bench devices. It reduces the need for operator manipulation, and allows for numerical modeling of various optical environments, including cornea models and apertures. In conclusion, this novel metrology device designed for refractive and diffractive IOLs appears to provide a satisfactory precision, making it a promising tool in the field of IOL metrology.

Clinical Results and Factors Affecting Visual Function in Eyes Implanted with an Enhanced Monofocal Intraocular Lens

Purpose

To compare the clinical results achieved with the enhanced monofocal intraocular lenses (IOLs) with those of the monofocal IOL and investigate factors affecting the distance, intermediate, and near vision.

Patients and Methods

Patients were included who underwent bilateral consecutive cataract surgeries using the same IOLs with follow-up to 1 month postoperatively. Refractions, monocular UDVA and CDVA, and binocular distance-corrected functional visual acuity at 5 meters (BDCFVA), at 66 centimeters (BDCIFVA) and at 40 centimeters (DCNVA) were assessed. Multiple regression analysis was used to assess the factors affecting binocular BDCFVA, BDCIFVA, and BDCNFVA. Subjective symptoms were assessed using the Near Activity Visual Questionnaire (NAVQ) and visual analogue scale (VAS).

Results

Sixty patients (120 eyes) implanted with the Tecnis Eyhance IOL (30 patients, 60 eyes) or the Tecnis monofocal IOL (30 patients, 60 eyes) were included. The Tecnis Eyhance IOL provided significantly better binocular BDCIFVA than the Tecnis monofocal IOL in patients under 70 years of age. Multiple regression analysis showed that age was the only factor affecting distance and intermediate visual function in eyes with the Tecnis Eyhance IOL; gender, pupillary diameter, axial length, and average keratometry were not significant. There were no significant differences in subjective symptoms.

Conclusion

The comprehensive cohort analysis did not confirm the advantage on the intermediate vision of the Tecnis Eyhance IOL. Younger age may be an important factor to benefit from the unique optical characteristics of this IOL.

Optical and Clinical Outcomes of an Isofocal Intraocular Lens vs. a Monofocal Standard Lens

The aim of this study is to evaluate the results obtained on the optical bench and clinically with an isofocal lens (ISOPure, BVI medical, Belgium) to compare them to a standard monofocal one (MicroPure, BVI medical, Belgium). To do so, we have combined laboratory investigation and a prospective, comparative, and randomized clinical study. First, we have measured the wavefront of the two models studied using a NIMO TR1504 (Lambda-X, Belgium) deflectometer for three nominal powers: +10.00, +20.00 and +30.00 D. In the randomized study with 48 patients, half of them implanted with ISOPure and the other with MicroPure, we have measured visual acuities and contrast sensitivity under photopic and mesopic conditions. The optical bench results show that the isofocal lens presented higher power than the monofocal one, at the lens center, due to the spherical aberration (coefficients Z(4,0), Z(6,0) and Z(8,0)) induced by the greater asphericity of its design. The addition obtained depended on the nominal power, from +1.00 to +1.50 D. The results of the clinical study showed that the ISOPure lens presented better visual outcomes, which were statistically significant, at intermediate distance compared to the MicroPure lens (p-values of 0.014 and 0.022 for 80 and 60 cm, respectively) without decreasing the contrast sensitivity. Clinical outcomes were not affected by pupillary size. In conclusion, due to the increase in power at the lens center due to its highly aspherical design, the isofocal lens evaluated showed better intermediate vision than the monofocal one.

Comparative analysis of visual outcomes with 2 enhanced monofocal intraocular lenses

PURPOSE

To compare the visual performance, spectacle independence, and subjective visual quality of 2 enhanced monofocal intraocular lenses (IOLs): Eyhance ICB00 and ZOE Primus-HD.

SETTING

Ophthalmology Department, San Raffaele Scientific Institute, Milan, Italy.

DESIGN

Prospective case series.

METHODS

Patients without ocular comorbidities and corneal astigmatism <0.75 diopters (D) undergoing cataract surgery with bilateral implantation of enhanced monofocal Eyhance and ZOE were included. 6 months postoperatively, the following parameters were analyzed: subjective and objective refraction; monocular and binocular corrected (4 m) and uncorrected (UDVA) distance visual acuities; corrected distance, intermediate (66 cm), and near (40 cm) visual acuities, as well as uncorrected intermediate (UIVA) and uncorrected near (UNVA) visual acuities; photopic contrast sensitivity; binocular defocus curve; halo and glare perception; and spectacle independence.

RESULTS

100 eyes of 50 patients were evaluated (25 patients per IOL group). The 2 IOLs showed superimposable visual performances, without significant differences in terms of refractive and visual outcomes, defocus curves, contrast sensitivity, scores of vision quality, and spectacle independence. Of note, monocular and binocular UDVA was excellent in both groups. The 2 IOL models achieved satisfactory binocular UIVA, with more than 70% of patients reaching a binocular UIVA of ≤0.1 logMAR. Up to 84% of patients eventually declared to feel comfortable frequently while staying at intermediate distance.

CONCLUSIONS

The general visual outcome of the Eyhance ICB00 and the ZOE Primus-HD enhanced monofocal IOLs is similar, with special reference to the satisfactory spectacle independence for intermediate distance.

Visual Performance After Unilateral Implantation of an Extended Depth-of-Focus Intraocular Lens in Patients With Unilateral Cataract

PURPOSE

To investigate the visual performance after unilateral implantation of an extended depth-of-focus intraocular lens (IOL) in patients with unilateral cataracts.

METHODS

In this prospective study, uneventful phacoemulsification with LuxSmart IOL (Bausch & Lomb) implantation was performed in 25 eyes of 25 patients with unilateral cataracts. At postoperative 1, 4, 12, and 24 weeks, uncorrected and corrected visual acuity at far, intermediate, and near distances and the spherical equivalent in manifest refraction were measured. A Visual Function Index and modified Visual Function Index questionnaire were used to investigate glare, spectacle dependence, and satisfaction at 24 weeks in the eye that had surgery.

RESULTS

At 6 months postoperatively, uncorrected distance visual acuity was 20/20 (0.0 logMAR) in 96% of cases, distance corrected intermediate visual acuity was 20/32 (0.2 logMAR) in all cases (60 cm), and distance corrected near visual acuity was 20/32 (0.2 logMAR) in 60% of cases (40 cm). The patient satisfaction score was 100% based on the Visual Function Index questionnaire for far and intermediate distance, respectively. No patients complained of the permanent photic phenomenon. No patients reported bilateral imbalance. All of the patients became spectacle independent for most of their intermediate activities at 60 cm. A total of 96% of the patients reported 100% contrast sensitivity in the Pelli-Robson test.

CONCLUSIONS

The unilateral implantation of this EDOF IOL seems to be tolerated and effective in improving the visual function of patients with unilateral cataract with limited optical side effects such as halos or glare, providing spectacle-independent vision from far to intermediate object distances. [J Refract Surg. 2023;39(8):518-523.].

Results of an Extended Depth-of-Focus Intraocular Lens Implantation in the Second Eye of Monofocal Pseudophakic Patients: A Pilot Study

PURPOSE

The purpose of this study was to investigate the visual results and patient satisfaction after implantation of an extended depth-of-focus (EDOF) intraocular lens (IOL) in the second eye of patients implanted previously with a monofocal IOL in the first eye.

METHODS

The medical records and self-reported questionnaires from patients who were implanted with monofocal IOLs in the first eye and EDOF IOLs in the second eye (group A) and from patients implanted bilaterally with EDOF IOLs (group B) were compared for visual acuity (VA), spectacle independence, patient satisfaction, and photic phenomena.

RESULTS

Group A (23 eyes of 23 patients) had similar distance uncorrected VA and intermediate uncorrected VA compared with group B (72 eyes of 36 patients) (0.03±0.05 vs. 0.04±0.16; P =0.136 and 0.660, respectively). There was a tendency toward a better near uncorrected VA in group A compared with group B (0.15±0.14 vs. 0.23±0.17; P =0.074). Patients' perception of their VA was similar between groups. Spectacle independence for distance vision was reported by 16/17 (94.1%) and 35/36 (97.2%) patients ( P =0.543), 13/17 (76.5%) and 32/36 (88.9%) patients ( P =0.252) for intermediate vision, and 4/17 (23.6%) and 22/36 (61.1%) patients for near vision ( P =0.011), in groups A and B, respectively. There was no difference in complaints of photic phenomena between groups.

CONCLUSIONS

Patients previously implanted with a monofocal IOL in 1 eye who are interested in improving their spectacle independence can be considered for an EDOF IOL implantation in the second eye and may have similar results to those implanted bilaterally with EDOF IOLs.

Current State of the Art and Next Generation of Materials for a Customized IntraOcular Lens according to a Patient-Specific Eye Power

Intraocular lenses (IOLs) are commonly implanted after surgical removal of a cataractous lens. A variety of IOL materials are currently available, including collamer, hydrophobic acrylic, hydrophilic acrylic, PHEMA copolymer, polymethylmethacrylate (PMMA), and silicone. High-quality polymers with distinct physical and optical properties for IOL manufacturing and in line with the highest quality standards on the market have evolved to encompass medical needs. Each of them and their packaging show unique advantages and disadvantages. Here, we highlight the evolution of polymeric materials and mainly the current state of the art of the unique properties of some polymeric systems used for IOL design, identifying current limitations for future improvements. We investigate the characteristics of the next generation of IOL materials, which must satisfy biocompatibility requirements and have tuneable refractive index to create patient-specific eye power, preventing formation of posterior capsular opacification.

Evaluation of extended depth-of-focus hydrophobic intraocular lens with an optic concept based on combination of high-order aberrations

Background

Extended depth-of-focus (EDOF) intraocular lenses (IOLs) provide a continuous range of uncorrected vision at different distances.

Objective

To assess visual acuity, refractive outcomes, and patient satisfaction after cataract surgery using the LuxSmart EDOF IOL (Bausch+Lomb).

Design

A two-center, prospective observational clinical study.

Methods

This study includes patients who have undergone bilateral phacoemulsification with bilateral implantation of the LuxSmart EDOF IOL, with the aim of achieving emmetropia. Visual acuity (VA) and subjective refraction were obtained in all patients preoperatively and at 1 week, 1 month, 3 months, and 6 months postoperatively. Subjective measures were obtained using the Catquest-9SF questionnaire and the Patient-Reported Spectacle Independence Questionnaire (PRSIQ). Contrast sensitivity and a glare assessment were undertaken postoperatively. Safety outcomes were additionally assessed.

Results

Sixty eyes from thirty patients were recruited for this study. The mean spherical equivalent was 1.04 ± 1.67 D preoperatively and -0.30 ± 0.46 D at 6 months. Monocular uncorrected distance VA was 0.57 ± 0.32 (logMAR) preoperatively and 0.09 ± 0.12 (logMAR) at 6 months. Mean 6-month monocular uncorrected VA was 0.11 ± 0.13, 0.12 ± 0.15, and 0.31 ± 0.15 (logMAR) at 80, 66, and 40 cm, respectively. More than 90% of patients were either fairly or very satisfied with their vision. There was one case of suspected vitreomacular traction postoperatively.

Conclusion

The LuxSmart EDOF IOL offers good refractive, VA, and safety outcomes. The single elongated focal point designed to enhance the DOF shows good results for VA and patient satisfaction.