Comparison of near vision, intraocular lens movement, and depth of focus with accommodating and monofocal intraocular lenses

Multifocal and Accommodating Intraocular Lenses for the Treatment of Presbyopia: A Report by the American Academy of Ophthalmology

PURPOSE

To review the published literature assessing the efficacy and safety of presbyopia-correcting intraocular lenses (IOLs) for the treatment of presbyopia after cataract removal.

METHODS

Literature searches were undertaken in January 2018 and September 2020 in the PubMed, Medline, and Cochrane Library databases. This yielded 761 articles, of which 34 met the criteria for inclusion in this assessment and were assigned a level of evidence rating by the panel methodologist. Thirteen studies were rated level I and 21 studies were rated level II.

RESULTS

Presbyopia-correcting lenses were effective at improving distance and near visual acuity after cataract surgery. Near acuity at different focal lengths was related directly to the effective add power of multifocal and extended depth-of-focus (EDOF) IOLs. Most multifocal and EDOF lenses that were compared with a control monofocal lens demonstrated that patient-reported spectacle independence was superior to the monofocal lens. All patients who had multifocal and EDOF lenses implanted showed decreased contrast sensitivity and reported more visual phenomena as compared with control participants who received monofocal lenses.

CONCLUSIONS

Presbyopia-correcting lenses improve uncorrected near and distance visual acuity and decrease spectacle dependence after cataract surgery. Mesopic contrast sensitivity is decreased compared with monofocal lenses, and patient-reported visual phenomena are more likely in patients receiving multifocal or EDOF lenses.

Review of current status of refractive lens exchange and role of dysfunctional lens index as its new indication

Advances in phacodynamics and intraocular lenses (IOLs) has given second life to clear lens extraction (CLE) or refractive lens exchange (RLE) in recent years for the treatment of patients with high degrees of myopia, hyperopia, and astigmatism who are unsuitable for laser surgery. Furthermore, presbyopia treatment with RLE supplemented with multifocal or accommodating IOLs gives the dual benefit of correcting refractive errors with eliminating the need for cataract surgery. RLE should be consistent and effective for a good refractive outcome along with safety during the surgical procedure and in the postoperative period. Therefore, proper patient selection and accurate preoperative protocols for IOL power calculations and selection are important along with an appropriate choice of surgical procedure. Dysfunctional lens index is a new objective tool that helps surgeon to aid in diagnosing, counseling, and educating patients with dysfunctional clear lens. In this article, we give a brief overview about the application of RLE for individuals with presbyopia and refractive errors like myopia, hyperopia, and astigmatism who are not suitable for laser correction.

Lens-based surgical correction of presbyopia. Where are we in 2020?

INTRODUCTION

Presbyopia is the progressive and irreversible loss of accommodation due to aging. It is one of the main causes of loss of quality of life in people from 45 years of age, due to the, often novel, dependence on spectacles. The eagerness to correct it by ophthalmologists impulsed by the desire of millions of people who suffer from it, has become one of the main drivers for the development of intraocular lens (IOL) technology over the last twenty years.

MATERIAL AND METHODS

This review briefly presents the different alternatives that have allowed us to improve the crystalline lens surgical approach of presbyopia; from monofocal lenses and monovision technique, accommodative, refractive, and diffractive multifocal lenses, and finally the most recent extended depth of focus/field lenses known as EDOFs.

RESULTS

Each IOL has its advantages, limitations and disadvantages. Furthermore, there is no single lens that suits the needs of all patients.

CONCLUSIONS

It is necessary to know the variety of lenses available, and to have an in-depth understanding of their optical properties, as well as the impact that these will have later on their clinical performance and on the visual quality of the patients. This should help us to select the best alternative for each of them.

Small aperture IC-8 intraocular lens in cataract patients: achieving extended depth of focus through small aperture optics

BACKGROUND

To investigate visual outcomes following cataract surgery in patients who were implanted monocularly with an extended range of focus IC-8 IOL.

METHODS

A multicentre, non-randomised, retrospective case series of 126 consecutive patients implanted with the IC-8 IOL. Data were collected and pooled from six centres across Australia. Uncorrected distance visual acuity (UDVA), uncorrected intermediate visual acuity (UIVA) at 80 cm and uncorrected near visual acuity (UNVA) at 40 cm were measured in eyes implanted with the IC-8 IOL. Adverse events, spectacle independence, visual symptoms and patient satisfaction were assessed at final follow-up.

RESULTS

Over 90% of the patients without pre-existing ocular pathology (n = 109) achieved UDVA, UIVA and UNVA of 6/12 or better in the IC-8 eye. Binocularly, in this group, 98% achieved UDVA of 6/9, 94% UIVA of 6/12 and 91% UNVA of 6/12 or better. By final follow-up, over 50% of patients reported complete spectacle independence for distance, intermediate and near visual activity, with the remainder only using spectacles for specific tasks such as near-vision hobbies and reading in dim light.

CONCLUSIONS

The IC-8 IOL is capable of providing extended depth of focus following cataract surgery. It allows complete spectacle independence in more than half of the patients implanted with the IC-8 IOL.

Surgical correction of presbyopia

Presbyopia is the most common refractive disorder for people older than 40 years. It is characterized by a gradual and progressive decrease in accommodative amplitude. Many surgical procedures for the correction of presbyopia exist, with additional procedures on the horizon. This review describes the prevalent theories of presbyopia and discusses the available surgical options for correction.

FINANCIAL DISCLOSURE

Proprietary or commercial disclosures are listed after the references.

The efficacy of accommodative versus monofocal intraocular lenses for cataract patients: A systematic review and meta-analysis

INTRODUCTION

We performed a systematic review and meta-analysis to evaluate whether accommodative intraocular lenses (AC-IOLs) are superior for cataract patients compared with monofocal IOLs (MF-IOLs).

METHODS

Pubmed, Embase, Cochrane library, CNKI, and Wanfang databases were searched through in August 2018 for AC-IOLs versus MF-IOLs in cataract patients. Studies were pooled under either fixed-effects model or random-effects model to calculate the relative risk (RR), weighted mean difference (WMD), or standard mean difference (SMD) and their corresponding 95% confidence interval (CI). Distance-corrected near visual acuity (DCNVA) was chosen as the primary outcome. The secondary outcomes were corrected distant visual acuity (CDVA), pilocarpine-induced IOL shift, contrast sensitivity, and spectacle independence.

RESULTS

Seventeen studies, involving a total of 1764 eyes, were included. Our results revealed that AC-IOLs improved DCNVA (SMD = -1.84, 95% CI = -2.56 to -1.11) and were associated with significantly greater anterior lens shift than MF-IOLs (WMD = -0.30, 95% CI = -0.37 to -0.23). Furthermore, spectacle independence was significantly better with AC-IOLs than with MF-IOLs (RR = 3.07, 95% CI = 1.06-8.89). However, there was no significant difference in CDVA and contrast sensitivity between the 2 groups.

CONCLUSION

Our study confirmed that AC-IOLs can provide cataract patients with DCNVA and result in more high levels of spectacle independence than MF-IOLs. Further studies with larger data set and well-designed models are required to validate our findings.

Clinical application of accommodating intraocular lens

The present review describes recent advances in application of accommodating intraocular lenses (AIOLs). Standard monofocal intraocular lenses (MIOLs) only correct distance vision, while AIOLs are designed to allow both good distance vision and near vision, which is achieved through the contraction and relaxation of ciliary muscles by providing transformation of the axial movement or curvature of the lens. Thus, AIOLs may be a better choice for those patients who demand a higher level of visual performance. Since techniques to analyze the performance of AIOLs have not been standardized, and there is a variety of both subjective and objective methods, it is hard to measure the performance of these intraocular lenses. By evaluating advantages and disadvantages of various AIOLs, and introducing techniques for measurement the performance postoperative, this paper can provide some relative information on choosing the type of AIOLs in the clinic.

Accommodative intraocular lenses: where are we and where we are going

Presbyopia still remains the last frontier of refractive surgery. Its surgical management is under constant evolution due to the limitations that exist today with respect to its management, which is probably in relation with the multifactorial basis in which presbyopia is clinically developed in the human. Until currently, virtually all surgical techniques that have been proposed for its correction are based on the induction of pseudoaccommodation in the presbyopic eye, including multifocality. However, the real restoration of accommodation is more complex, and it has been tried by the use of different, so called, “accommodative” pseudophakic intraocular lenses (AIOL). Overall, the reported results with these lenses by independent authors have been modest in relation with the restoration of the accommodative power of the eye and these modest benefits are usually lost with time due to the long term changes in the capsular bag. This fact made these lenses to be almost abandoned in the last few years, but there are currently other AIOL models being used with innovative mechanisms of action and different anatomical support outside the capsular bag that offer encouraging preliminary results that could bring a new potential of application to these types of lenses.

In this article, we will update the modern refractive surgeon about the fundamentals and provide updated information about the outcomes of AIOLs by reviewing the concept of accommodation, the different attempts that have been accomplished in the past, their demonstrated published results in human clinical trials, and the future alternatives that may arrive in the near future.

Visual outcomes 24 months after LaserACE

Background

To evaluate the effects on near and intermediate visual performance after bilateral Laser Anterior Ciliary Excision (LaserACE) procedure.

Methods

LaserACE surgery was performed using the VisioLite 2.94 μm erbium: yttrium–aluminum–garnet (Er:YAG) ophthalmic laser system in 4 oblique quadrants on the sclera over the ciliary muscle in 3 critical zones of physiological importance (over the ciliary muscles and posterior zonules) with the aim to improve natural dynamic accommodative forces. LaserACE was performed on 26 patients (52 eyes). Outcomes were analyzed using visual acuity testing, Randot stereopsis, and the CatQuest 9SF patient survey.

Results

Binocular uncorrected near visual acuity (UNVA) improved from +0.20 ± 0.16 logMAR preoperatively, to +0.12 ± 0.14 logMAR at 24 months postoperatively (p = 0.0014). There was no statistically significant loss in distance corrected near visual acuity (DCNVA). Binocular DCNVA improved from +0.21 ± 0.17 logMAR preoperatively, to +0.11 ± 0.12 logMAR at 24 months postoperatively (p = 0.00026). Stereoacuity improved from 74.8 ± 30.3 s of arc preoperatively, to 58.8 ± 22.9 s of arc at 24 months postoperatively (p = 0.012). There were no complications such as persistent hypotony, cystoid macular edema, or loss of best-corrected visual acuity (BCVA). Patients surveyed indicated reduced difficulty in areas of near vision, and were overall satisfied with the procedure.

Conclusions

Preliminary results of the LaserACE procedure show promising results for restoring visual performance for near and intermediate visual tasks without compromising distance vision and without touching the visual axis. The visual function and visual acuity improvements had clinical significance. Patient satisfaction was high postoperatively and sustained over 24 months.

Trial registration

NCT01491360 (https://clinicaltrials.gov/ct2/show/NCT01491360). Registered 22 November 2011.

Pseudo-accommodation in non-amblyopic children after bilateral cataract surgery and implantation with a monofocal intraocular lens: prevalence and possible mechanisms

BACKGROUND

Some pseudophakic patients implanted with a monofocal intraocular lens (IOL) have good near visual acuity (VA) with their distance correction. The objective was to evaluate the prevalence of pseudo-accommodation in children after bilateral cataract surgery, without amblyopia, and to define its mechanisms.

METHODS

Observational study that took place in a pediatric ophthalmology department, Paris, France. A total of 68 eyes were included, 40 from 23 children and 28 from 14 adults, with a corrected distance VA above 20/25 and a normal near VA (20/25) with +3 addition. Pseudo-accommodation was defined as a near VA better than 20/50 with the distance correction and without addition. Prevalence of pseudo-accommodation was calculated in each group. In order to determine the possible mechanisms of pseudo-accommodation in children, we compared children with pseudo-accommodation and adults without pseudo-accommodation regarding several parameters: refraction, axial length, corneal topography, aberrometry, pupillary diameter and IOL shift after cyclopentolate instillation.

RESULTS

Among the children group, 36 (90 %) had pseudo-accommodation versus 2 (7 %) in the adult group. We found that spherical equivalent, implant power, corneal multifocality and corneal higher-order aberrations (mainly coma and trefoil) were significantly higher in the pseudo-accommodation group, while pupil diameter and implant shift were not significantly different.

CONCLUSIONS

Pseudo-accommodation has a high prevalence among non-amblyopic pseudophakic children. Several possible mechanisms have been found to explain pseudo-accommodation in children: a high power of the IOL and a small axial length, maximizing the effect of the IOL shift, corneal multifocality and corneal higher-order aberrations.

Visual Outcomes and Accommodative Response of the Lumina Accommodative Intraocular Lens

PURPOSE

To compare visual acuity, accommodation, and contrast sensitivity of the AkkoLens Lumina accommodative intraocular lens (AkkoLens Clinical b.v., Breda, The Netherlands) with a standard monofocal intraocular lens (IOL).

DESIGN

Randomized clinical trial.

METHODS

The study enrolled 86 eyes with cataract that all required cataract surgery and IOL implantation. The study group included 61 eyes that were implanted with the Lumina. The control group included 25 eyes that were implanted with an Acrysof SA60AT (Alcon, Fort Worth, TX, USA) monofocal IOL. The distance and near visual acuities, contrast sensitivity, and accommodation were measured over a 1-year follow-up period. Accommodation was measured subjectively, using defocus curves, and objectively, with an open-field autorefractor.

RESULTS

Uncorrected (UDVA) and corrected (CDVA) distance visual acuities did not differ significantly between the groups (P ≥ .21) over the 12 months. However, the uncorrected near visual acuity (UNVA) was 0.07 ± 0.08 logRAD for the Lumina group and 0.37 ± 0.19 logRAD for the control group (P < .01) and the corrected distance near visual acuity (CDNVA) was 0.11 ± 0.12 LogRAD for the Lumina group and 0.41 ± 0.15 LogRAD for the control group (P < .01). Defocus curves showed a statistically significant difference between groups for defocus ranging from -4.50 to -0.50 diopters (D) (P < .01) with significantly higher visual acuities for the Lumina group. Subjective accommodation, as determined from defocus curves, was 3.05 ± 1.06, 3.87 ± 1.27, and 5.59 ± 1.02 D for the Lumina group and 1.46 ± 0.54, 2.00 ± 0.52, and 3.67 ± 0.75 D for the control group at visual acuities of 0.10, 0.20, and 0.4 logMAR for both groups, respectively. The objective accommodation, measured by an open-field autorefractor, was 0.63 ± 0.41, 0.69 ± 0.45, 0.91 ± 0.51, and 1.27 ± 0.76 D for the Lumina group and 0.10 ± 0.15, 0.12 ± 0.15, -0.06 ± 0.09 and 0.07 ± 0.10 D for the control group at accommodation stimuli of 2.0, 2.5, 3.0, and 4.0 D, respectively. Contrast sensitivity was the same for both groups (P ≥ .26).

CONCLUSIONS

The Lumina accommodative IOL effectively restores the visual function, accommodation, and contrast sensitivity after cataract surgery with no influence on the postoperative contrast sensitivity.