Comparison of Visual Neuroadaptations After Multifocal and Monofocal Intraocular Lens Implantation

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.

The Mystification of Multifocal IOLs Needs Unfolding

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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.

Assessment of Visual Habituation Measured With the Halo & Glare Simulator and Its Impact on Patient Satisfaction Following Quadrifocal IOL Implantation

PURPOSE

To evaluate the levels of habituation and its influence on outcome satisfaction in patients who underwent bilateral multifocal intraocular lens (IOL) implantation.

METHODS

A total of 24 patients underwent bilateral multifocal IOL implantation surgery with the AcrySof IQ PanOptix trifocal diffractive IOL (Alcon Laboratories, Inc) following cataract extraction or for refractive purposes. Data were collected 3 and 6 months after surgery, which included subjective refraction, corrected and uncorrected visual acuity (distance, intermediate, near), a contrast sensitivity test, simulation with the Halo & Glare Simulator (Carl Zeiss Meditec AG), two visual quality surveys, and a slit-lamp examination by an ophthalmologist.

RESULTS

All patients were spectacle independent for distance vision and 92% (n = 22) needed no visual aid for near vision. Minor visual acuity improvement was detected between both examinations at monocular uncorrected distance visual acuity (P = .025). Improvements of presence, size, and intensity of visual disturbances were not statistically significant, but overall patient satisfaction (P = .009) and Weber-Contrast sensitivity under mesopic conditions (P = .029) increased significantly.

CONCLUSIONS

Diffractive multifocal IOLs are a stable treatment for presbyopia and/or cataract with a high spectacle independence rate. Visual disturbances caused by their optics do not decrease significantly between 3 and 6 months after surgery. Habituation and neuroadaptation play a significant role in patient satisfaction and contrast sensitivity during and possibly beyond that period. [J Refract Surg. 2023;39(8):510-517.].

Evaluation of color vision related quality of life changes due to cataract surgery

Questionnaires have been used as research tools to provide a standardized approach to assess quality of life at various time periods and populations. However, literature shows only a few articles about self-reported color vision changes. Our aim was to evaluate the subjective patient feelings before and after cataract surgery and compare the results with a color vision test result. Our method was as follows: 80 cataract patients filled out a modified color vision questionnaire and performed the Farnsworth-Munsell 100 Hue Color Vision Test (FM100) before, two weeks, and six months after cataract surgery. We analyzed the correlations between these two types of results, which reveal that FM100 hue performance and subjective perception improved after surgery. Additionally, subjective patient questionnaire scores correlate well with the FM100 test results before and two weeks after the cataract surgery, but this effect decreased with longer follow-up times. We conclude that subjective color vision changes can only be noticed at longer periods after the cataract surgery. Health care professionals can use this questionnaire to better understand the subjective feelings of patients and monitor their color vision sensitivity changes.

Clinical outcome of a quadrifocal (trifocal) intraocular lens in Chinese patients: prospective, observational case series

PURPOSE

To report the visual outcomes and quality of vision and life after bilateral implantation of a single-piece trifocal intraocular lens (IOL) in Chinese patients.

SETTING

Hong Kong Sanatorium & Hospital, Hong Kong, China.

DESIGN

Prospective, observational case series.

METHODS

Patients with bilateral implantation of AcrySof IQ PanOptix multifocal IOL were included. Distance, intermediate (60 cm), and near (40 cm) visual acuities (VAs) and contrast sensitivity (CS), defocus curve, preoperative higher-order aberration (HOA), dysphotopsia (0 to 5), satisfaction (1 to 5), spectacle independence, and quality of life were evaluated. The association between preoperative HOA and postoperative halos was also assessed.

RESULTS

54 eyes of 27 patients were included. The mean binocular distance, intermediate, and near uncorrected VA was -0.05 ± 0.06 (20/18), 0.06 ± 0.10 (20/23), and 0.04 ± 0.05 (20/22), respectively. No eyes lost more than 1 line of vision. Binocular CS was comparable with the monocular population norm of older adults. The defocus curve demonstrated that the binocular VA of 20/25 or better was achieved at a power of -3.00 to +0.50 diopters. The mean scores for halos, glare, and starbursts were 2.4 ± 1.4, 0.2 ± 0.8, and 1.4 ± 1.4 (of 5), respectively. The mean satisfaction score was 4.3 ± 0.7 (of 5). All the patients (100%) reported total spectacle independence. The mean vision-targeted composite score of the vision-related quality-of-life questionnaire was 97.2 ± 9.7 (of 100). Preoperative HOA was not associated with postoperative halos.

CONCLUSIONS

Implantation of the trifocal IOL provided satisfactory visual outcomes and quality of vision and life, which resulted in a high rate of spectacle independence.

[Enhancement Options after Lens and Corneal Refractive Surgery]

BACKGROUND

 Modern preoperative diagnostics as well as current surgical techniques allow cataract and refractive surgery to deliver precise refractive results.Occasionally, unsatisfactory refractive and visual results occur despite all the care taken. In these cases, subsequent improvement is required to achieve the best final visual outcome. This article shows the therapeutic options for the treatment of residual refractive errors after lens and corneal refractive surgery.

KEY MESSAGES

 The causes of postoperative refractive errors after refractive laser- or lens-based procedures are very diverse and require extensive workup of the cause as well as an individual solution to achieve the desired result. Before any further surgical intervention, specific complications of the primary procedure as well as concomitant ocular diseases must be excluded or treated. The appropriate enhancement after keratorefractive surgery depends primarily on the type of primary surgery, residual stromal thickness, possible complications from the initial surgery, and the patient's personal preference. For enhancements using surface treatments, such as PRK, the use of mitomycin C is recommended for prophylaxis of haze formation. After lens surgery, for low-grade postoperative refractive errors (spherical and astigmatic), keratorefractive enhancements provide the most accurate results. For higher refractive errors, lens-based procedures can be used, with add-on IOLs being safer and more precise compared with one IOL exchange. Low astigmatisms can be successfully treated with LRI or keratorefractive surgery, but higher astigmatisms should be corrected with an IOL exchange in the early postoperative period and with an add-on IOL in the later postoperative period. IOL explantations should be performed very cautiously, especially in cases of pronounced capsular fibrosis, previous posterior capsulotomy, and existing weakness of the zonular apparatus.

Enhancement-Optionen nach Linsen- und refraktiver Hornhautchirurgie

Gelegentlich kommt es trotz aller Sorgfalt und präziser Operationstechnik in der Katarakt- und Refraktivchirurgie zu unbefriedigenden refraktiven und visuellen Ergebnissen. In diesen Fällen ist eine nachträgliche Korrektur erforderlich, um das beste endgültige visuelle Ergebnis zu erzielen. Dieser Beitrag zeigt die Möglichkeiten zur Behandlung residualer Refraktionsfehler nach Linsen- und refraktiver Hornhautchirurgie auf.

Comparative Visual Outcome Analysis of a Diffractive Multifocal Intraocular Lens and a New Diffractive Multifocal Lens with Extended Depth of Focus

This study compares the visual and refractive performance of the TECNIS Synergy (DFR00V-DFW150-225-300-375) multifocal intraocular lens (IOL) and the AcrySof IQ PanOptix (TFAT00-30-40-50-60) multifocal IOL. Patients who underwent phacoemulsification and cataract extraction and received either a multifocal Synergy or PanOptix IOL were included. Monocular uncorrected distance (UDVA), intermediate (UIVA), near (UNVA), and corrected distance (CDVA) visual acuities were assessed at three and six months postoperatively. Secondary outcome measures of photic phenomena were also assessed. A total of 140 patients (224 eyes) were included in this study, with 69 patients (105 eyes) in the Synergy group and 71 patients (119 eyes) in the PanOptix group. There were no statistically significant differences in UIVA or CDVA measurements across all time points. When assessing UDVA, at three months postoperatively, there were more eyes in the PanOptix group with vision better than 20/40 (p = 0.04). At three and six months postoperatively, the average UNVA was superior in the Synergy group (p = 0.01, 0.002). While the Synergy group reported more night vision disturbances at one and three months (p = 0.01, 0.03), the PanOptix group had more night vision disturbances at six months (p = 0.02). Although not statistically significant, the AcrySof IQ PanOptix multifocal IOL demonstrated better UDVA and UIVA sooner postoperatively than the TECNIS Synergy multifocal IOL. The Synergy IOL provided statistically better UNVA compared to the PanOptix IOL at three and six months postoperatively. Synergy patients reported more early photic phenomena than PanOptix patients, which later diminished.

A prospective study of a new presbyopia pseudophakic intraocular lens: Safety, efficacy and satisfaction

Purpose

To evaluate the safety, visual performance, and patient satisfaction of a new presbyopic pseudophakic intraocular lens (IOL).

Methods

A prospective non-randomized case-series study was performed in Buenos Aires, Argentina. Patients included in the study underwent a programmed Femtosecond laser assisted cataract surgery (FLACS), performed between October and December 2020, with a 6-month follow-up period. The Intensity (Hanita Lenses) IOL was bilaterally implanted. Spherical equivalent (SE) refraction, uncorrected distance and near visual acuity (UDVA/UNVA), defocus curve, endothelial cell density (ECD), central corneal thickness (CCT), and a satisfaction questionnaire were evaluated.

Results

A total of 56 patients (112 eyes), aged 65 ± 6.12 years were included. The mean ± SD of preoperative SE was 1.85 ± 2.24 D (range; -4.50 to 4.75), which had decreased 6 months after surgery to -0.08 ±0.32 D (range; -0.75 to 0.63). No eyes experienced a loss of lines of vision, and 94% obtained SE values between ± 0.50 D. Defocus curve for different additions was 0.03 LogMAR (logarithm of the minimum angle of resolution) for -3.0 D, -0.005 LogMAR for -1.5 D, and -0.07 LogMAR for 0 D. The ECD, CCT remained stable (P: 0.09 and 0.58, respectively) and all patients achieved their preoperative expectations, with a 6-month follow-up period.

Conclusion

Patients who underwent a safe bilateral implantation with Intensity IOL achieved a high degree of spectacle independence and satisfaction, 6 months after surgery.

Characteristics of the Fractional Amplitude of Low-Frequency Fluctuation in Ocular Hypertension Patients: A Resting-State fMRI Study

Background

The fractional amplitude of low-frequency fluctuation (fALFF) method has been underutilized in research on the pathogenesis and clinical manifestations of ocular hypertension (OH).

Purpose

This study uses resting state functional magnetic resonance imaging (rs-fMRI) and fALFF to investigate the nature of spontaneous brain activity in OH patients and the relationship, if any, between changes in activity and clinical features.

Materials and Methods

A total of 18 subjects (9 females and 9 males) with ocular hypertension (OH) and 18 healthy controls (HCs) matched for gender, age, and educational level were recruited to this study. All participants underwent an rs-fMRI scan, and spontaneous brain activity was assessed using the fALFF method. Receiver operating characteristic curves were plotted to investigate differences between OH and HC groups.

Results

The fALFF values of OH patients were significantly higher in the left precuneus lobe (LP), compared with the same region in controls (P < 0.05). Conversely, values in the left anterior cingulate lobe (LAC), were significantly lower (P < 0.05) in OH than in controls. However, no significant association was found between the mean fALFF values and clinical characteristics in either brain area.

Conclusion

High spontaneous activity in two brain areas may reflect neuropathological mechanisms underpinning visual impairment in OH patients.

The Influence of Angle Alpha, Angle Kappa, and Optical Aberrations on Visual Outcomes after the Implantation of a High-Addition Trifocal IOL

The aim of our investigation was to examine the possible correlations between optical aberrations, angle kappa, angle alpha, and visual outcomes following cataract surgery. In total, 56 eyes of 28 patients were implanted with the Liberty 677MY trifocal intraocular lens (IOL). Pre- and postoperative higher-order aberrations, coma, astigmatism, angle alpha, and angle kappa were registered, along with uncorrected and corrected visual acuities at multiple distances. Visual acuity and contrast sensitivity defocus curves were plotted, and the areas under the curve were calculated 1 and 3 months postoperatively. Excellent visual outcomes were found at all distances. Patients reported low levels of dysphotopsia, and 96.4% of patients achieved complete spectacle independence. While angle kappa significantly decreased during cataract surgery (p = 0.0007), angle alpha remained unchanged (p = 0.5158). Angle alpha correlated with postoperative HOAs and had a negative impact on near vision (p = 0.0543). Preoperative corneal HOA and coma had a strong adverse effect on future intermediate and near vision. Residual astigmatism significantly affected postoperative intermediate vision (p = 0.0091). Our results suggest that angle kappa is not an optimal predictive factor for future visual outcomes, while angle alpha and the preoperative screening of optical aberrations might help patient selection prior to multifocal IOL implantation.

Clinical Outcomes and Quality of Vision Associated with Bilateral Implantation of a Wavefront Shaping Presbyopia Correcting Intraocular Lens

Purpose

To provide normative visual acuity and quality of vision data related to bilateral implantation of a wavefront shaping presbyopia correcting intraocular lens (IOL).

Patients and Methods

This was a non-interventional research study of the refraction, visual acuity (VA) and quality of vision achieved after bilateral implantation of a wavefront shaping presbyopia correcting intraocular lens between 3 months and 12 months post-surgery. The manifest refraction, and uncorrected and distance corrected VA at near, intermediate and distance (40 cm, 50 cm, 66cm, 4 m) were tested. Binocular mesopic VA at 4m and uncorrected photopic low contrast (25%) VA at 4 m were also tested, the latter with and without a glare source. A patient reported outcome questionnaire was administered. Defocus curve testing with and without simulated myopia in the non-dominant eye was also tested (reported elsewhere).

Results

Forty subjects completed the study. There was no statistically significant difference between the uncorrected and distance corrected VA at any distance. Mean logMAR binocular VAs were (−0.07 ± 0.07) at 4 m, (0.00 ± 0.07) at 66 cm and (0.07 ± 0.11) at 40 cm. Uncorrected photopic low contrast VA was statistically significantly better without glare (0.09 ± 0.10) compared to with glare (0.44 ± 0.21, p < 0.01). Reported glare, halos and starbursts were “not at all” Or “a little” bothersome for more than 95% of subjects. Hazy vision and blurred vision were reported most often.

Conclusion

The Vivity IOL provided patients with good distance and intermediate vision, and functional near vision with low reported bother from glare, halos, or starbursts.

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