Refractive and Visual Outcomes After Implantation of a Secondary Sulcus Intraocular Lens with an Extended Depth of Focus

Purpose

To evaluate the range of vision, visual function, and quality of vision after implantation of a secondary extended depth of focus intraocular lens (EDOF IOL) implanted in the sulcus.

Setting

One clinical practice in Haugesund, Norway.

Design

Prospective single arm non-interventional study.

Methods

Eligible subjects presenting for surgery, or who had previous successful primary cataract or refractive lens exchange surgery in both eyes were subsequently implanted with the AddOn® secondary EDOF IOL in the sulcus. Manifest refraction and visual acuity at distance, intermediate and near were measured 3 months after surgery, along with the monocular defocus curve. Subjects also completed a visual function and a quality of vision questionnaire.

Results

The study included 32 eyes of 16 subjects. At 3 months postoperative, the mean refraction spherical equivalent (MRSE) was −0.16 ± 0.30 D, with a residual cylinder of 0.29 ± 0.27 D. The mean monocular uncorrected VA was 0.1 logMAR (20/25) or better at all test distances. The monocular defocus curves showed a depth of focus of 2.0 D. For every category except reading fine print, all but one subject (94%) had no difficulty or little difficulty with near tasks. Glare and halos were the most common visual disturbances, with no reports of starbursts. There was no evidence of any intralenticular opacification in any of the eyes, and no evidence of iris chafing/depigmentation.

Conclusion

This secondary EDOF IOL provided excellent distance and intermediate vision, and very good near vision to subjects. Subject reported near visual function was also very good and visual disturbances were limited. This lens appears to be a good option for patients who would like to improve their range of vision. Results appear as good or better than those reported for primary EDOF lenses.

Clinical outcomes in patients after duet procedure for reversible trifocality using a supplementary trifocal IOL

PURPOSE

We report the clinical outcomes of patients who had primary lens implantation in the capsular bag and subsequently a supplementary trifocal lens implanted in the ciliary sulcus (duet procedure) to create reversible trifocality.

DESIGN

Retrospective interventional case series.

METHODS

Twenty-five patients were included in this single center clinical study, who had undergone either refractive lens exchange for presbyopia correction or cataract surgery. All had lens removal by phacoemulsification and duet procedure to achieve reversible trifocality. Preoperatively and three months postoperatively, uncorrected (UDVA) and corrected distance visual acuity (CDVA) were assessed, as well as uncorrected (UNVA), distance corrected (DCNVA) and corrected near visual acuity (CNVA). At the postoperative examination, uncorrected (UIVA), distance corrected (DCIVA) and corrected intermediate visual acuity (CIVA), defocus curve testing and dysphotopsia evaluation were also performed.

RESULTS

Monocular UDVA and CDVA improved from 0.71 ± 0.43 logMAR and 0.12 ± 0.16 logMAR preoperatively to 0.04 ± 0.10 logMAR and -0.01 ± 0.09 logMAR postoperatively. Monocular UNVA and DCNVA were both 0.06 ± 0.08 logMAR and UIVA and DCIVA 0.00 ± 0.10 logMAR and -0.02 ± 0.10 logMAR postoperatively. Monocular defocus curve testing revealed a visual acuity of 0.2 logMAR or better from +0.75 to -3.5 diopters.

CONCLUSIONS

Duet procedure using a trifocal supplementary IOL provided excellent results for far, near and intermediate distance, comparable to those reported for capsular bag fixated trifocal IOLs. The duet procedure offers the advantage of an exit-strategy in cases with a future loss of function or side effects associated with the optics.

The effects of premium intraocular lenses on presbyopia treatments

Background

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

Main Text

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

Conclusions

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

Ratio of torus and equivalent power to refractive cylinder and spherical equivalent in phakic lenses - a Monte-Carlo simulation study

BACKGROUND

Spherical and astigmatic powers for phakic intraocular lenses are frequently calculated using fixed ratios of phakic lens refractive power to refractive spherical equivalent, and of phakic lens astigmatism to refractive cylinder. In this study, a Monte-Carlo simulation based on biometric data was used to investigate how variations in biometrics affect these ratios, in order to improve the calculation of implantable lens parameters.

METHODS

A data set of over sixteen thousand biometric measurements including axial length, phakic anterior chamber depth, and corneal equivalent and astigmatic power was used to construct a multidimensional probability density distribution. From this, we determined the axial position of the implanted lens and estimated the refractive spherical equivalent and refractive cylinder. A generic data model resampled the density distributions and interactions between variables, and the implantable lens power was determined using vergence propagation.

RESULTS

50 000 artificial data sets were used to calculate the phakic lens spherical equivalent and astigmatism required for emmetropization, and to determine the corresponding ratios for these two values. The spherical ratio ranged from 1.0640 to 1.3723 and the astigmatic ratio from 1.0501 to 1.4340. Both ratios are unaffected by the corneal spherical / astigmatic powers, or the refractive cylinder, but show strong correlation with the refractive spherical equivalent, mild correlation with the lens axial position, and moderate negative correlation with axial length. As a simplification, these ratios could be modelled using a bi-variable linear regression based on the first two of these factors.

CONCLUSION

Fixed spherical and astigmatic ratios should not be used when selecting high refractive power phakic IOLs as their variation can result in refractive errors of up to ±0.3 D for a 8 D lens. Both ratios can be estimated with clinically acceptable precision using a linear regression based on the refractive spherical equivalent and the axial position.

Calculation of equivalent and toric power in AddOn lenses based on a Monte Carlo simulation

BACKGROUND

Additional lenses implanted in the ciliary sulcus (AddOn) are one option for permanent correction of refractive error or generate pseudoaccommodation in the pseudophakic eye. The purpose of this paper was to model the power and magnification behaviour of toric AddOn and to show the effect sizes with a Monte-Carlo simulation.

METHODS

Anonymized data of a cataractous population uploaded for formula constant optimization were extracted from the IOLCon platform. After filtering out data with refractive spherical equivalent (RSEQ) between -0.75 to 0.25 dpt and refractive cylinder (RCYL) lower than 0.75, for each of the N=6588 redcords a toric AddOn was calculated which transfers the refraction error from spectacle plane to AddOn plane using a matrix-based calculation strategy based on linear Gaussian optics. The equivalent (AddOnEQ) and toric (AddOnCYL) power of the AddOn and the overall lateral magnification change and meridional magnification was derived for the situations before and after AddOn implantation, and a linear modelling was fitted for all 4 parameters.

RESULTS

RSEQ is the dominant effect size in the prediction of AddOnEQ and overall change in magnification (ΔM) , whereas the lens position (LP), corneal thickness (CCT) and mean corneal radius (CPa) play a minor role. In a simplified model AddOnEQ can be estimated by 0.0179 + 1.4104 · RSEQ. RCYL and corneal radius difference (CPad) are the dominant effect sizes in the prediction of AddOnCYL and the change in meridional magnification (ΔMmer) , whereas LP, CCT, CPa and RSEQ play a minor role. In a simplified model AddOnCYL can be predicted by -0.0005+ 0.0328 · CPad + 1.4087 · RCYL. Myopic eyes gain in overall magnification whereas in hyperopic eyes we observe a loss. Meridional distortion could be in general reduced to 35% on average with a toric AddOn.

CONCLUSION

Our simulation shows that with a linear model the equivalent and toric AddOn power as well as overall change in magnification, meridional distortion before and after AddOn implantation as well as the reduction in meridional distortion can be easily predicted from the biometric data in pseudophakic eyes with moderate refractive error.

Systematic Review of the Use of Supplemental Multifocal Intraocular Lenses in the Ciliary Sulcus for Presbyopia Correction

PURPOSE

To conduct a critical review of the peer-reviewed literature on the use of supplemental multifocal intraocular lenses in the ciliary sulcus.

METHODS

This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. According to the inclusion and exclusion criteria defined, 15 articles were selected for the current systematic review. Each of them was analyzed carefully and their risk of bias was assessed with the Quality Assessment Tool for Case Series Studies from the National Heart, Lung, and Blood Institute.

RESULTS

Data of 384 eyes from 227 patients were analyzed. Most of the studies reviewed had a short follow-up and poor or limited design, including case reports, case series, and clinical trials with several gaps in their methodology. Post-operative uncorrected distance and near visual acuity ranged from 20/40 to 20/20 and from 0.4 to 0.02 logMAR, respectively. Pigment dispersion (12 eyes) and deposits (13 eyes) were the most described complication. Dysphotopsia, glare, and halos were the more frequently reported visual disturbances. However, most of the patients reported a high level of satisfaction with their surgery. Most articles reviewed (13 of 15) achieved a risk of bias score between 6 and 8, representing a high level of evidence despite the study design limitations.

CONCLUSIONS

Supplemental multifocal intraocular lenses seem to offer good distance and near visual results, leading to high levels of spectacle independence and patients' satisfaction, with limited complications associated. However, more studies with a more robust design are needed to confirm these trends. [J Refract Surg. 2021;37(12):830-835.].

Reversibility of the duet procedure: Bilateral exchange of a supplementary trifocal sulcus-fixated intraocular lens for correction of a postoperative refractive error

Purpose

We present the case of a 49-year old female who underwent bilateral exchange of a supplementary trifocal sulcus-fixated intraocular lens (IOL) to correct a residual refractive error. Six months beforehand, she had been treated for hyperopia, astigmatism and presbyopia with a duet procedure to create reversible trifocality.

Observations

Refractive lens exchange with combined implantation of a monofocal toric IOL into the capsular bag and a trifocal supplementary IOL into the ciliary sulcus (duet procedure) had been performed in both eyes. Decreased uncorrected distance visual acuity due to the refractive outcome of −0.75 diopter sphere (DS)/-0.25 diopter cylinder (DC)x10° for the right eye and −1.0DS for the left eye as well as the perception of photic phenomena were inacceptable for the patient. In the second operations, we exchanged the supplementary IOLs to correct the residual refractive error and achieve the target refraction of emmetropia. UDVA increased from 0.50 logMAR in both eyes prior to the IOL exchange to −0.22 logMAR in the right eye and −0.20 logMAR in the left eye. Binocular uncorrected near and intermediate visual acuity were −0.10 logMAR and 0.00 logMAR respectively after exchanging the sulcus-fixated supplementary IOLs, allowing for complete spectacle independence.

Conclusions

This case demonstrates one of the most important benefits of the duet procedure: the possibility, if necessary, to easily remove or exchange the supplementary IOL from the ciliary sulcus. The duet procedure offers a safe treatment option in the event of postoperative complications like residual refractive error or intolerance to a multifocal optic.

Outcomes in randomised controlled trials of multifocal lenses in cataract surgery: the case for development of a core outcome set

BACKGROUND/AIMS

To describe and summarise the outcomes reported in randomised controlled trials of multifocal versus monofocal intraocular lenses in cataract surgery.

METHODS

We identified all randomised controlled trials of multifocal versus monofocal lenses in a Cochrane review (last search date June 2016). We extracted and summarised data on all outcomes reported using the framework of domain, measurement, metric and method of aggregation.

RESULTS

All studies collected data on distance and near visual acuity but there was considerable variation in the measures used and whether these outcomes were unaided or best corrected. Most studies reported final value measurements, rather than change from baseline. Approximately half of the studies reported data as a continuous measure only, one-third reported both continuous and categorical measures and a minority reported categorical measures only. There was little consensus as to cut-points. Although a majority of studies included one or more patient-reported outcome measures, none of the studies reported patient involvement in the choice of outcomes.

CONCLUSION

The collection and analysis of data on outcome measures in studies of multifocal intraocular lenses in cataract surgery are complicated. As a result, there is considerable heterogeneity in collection and reporting in the medical literature. This makes it difficult to synthesise such data to provide robust estimates of effect and is a potential source of research waste. Investigators in this field must produce a core outcome set that is informed by patients' views and we propose an initial set of outcomes on which these could be based.

Enhancement-procedure outcomes in patients implanted with the Precisight multicomponent intraocular lens

Purpose

Eyes that have undergone phacoemulsification with implantation of a multicomponent intraocular lens (MCIOL) may further undergo an enhancement procedure for correction of residual refractive errors. The enhancement procedure is accomplished by exchanging the front lens used in the primary surgery with another lens containing the correct dioptric power. We evaluated the efficacy and safety of enhancement procedures among eyes that received an MCIOL.

Methods

A total of 25 eyes that had undergone phacoemulsification with implantation of an MCIOL were found to have a residual error of refraction (spherical equivalent ≥0.75 D) 3 months after primary cataract surgery, and underwent further enhancement surgery. The main study outcomes were uncorrected and corrected distance visual acuity, subjective refraction, anterior-chamber depth, pachymetry, and endothelial cell count.

Results

There was a statistically significant improvement in uncorrected distance visual acuity of approximately two lines after enhancement surgery (0.20±0.20-0.02±0.08 logMAR, P<0.001) and a significant decrease in residual spherical equivalent from 1.3±1.1 D to 0±0.38 D (P<0.001). There were no statistically significant changes in pre- and postenhancement corrected distance visual acuity, anterior-chamber depth, pachymetry, or keratometry. There was a statistically significant decrease (2.6%) in endothelial cell count (P<0.01), which could have been endothelial equilibration from the primary procedure. All enhancement surgeries were uneventful, and no major complications were observed.

Conclusion

The MCIOL-enhancement procedure demonstrates statistical and clinical improvement in uncorrected distance visual acuity and correction of postoperative refractive errors. The Precisight IOL may be a useful choice for patients with high risk of having significant residual refractive errors after primary cataract surgery.