Standard Monofocal Lenses Research Articles

Comparison of Visual Acuity and Defocus Curve after Cataract Surgery with Pure Extended Depth Focus Lens and Mini-Monovision - Interim Analysis -

Abstract
 Introduction & Objectives : Presbyopia after cataract surgery is still a problem despite recent surgical techniques and intraocular lens technology development. Mini-monovision techniques and pure extended depth of focus (EDoF) lenses are alternatives to achieve good distance and intermediate visual acuity at relatively inexpensive.This study aims to compare the clinical outcome after cataract surgery with binocular mini-monovision and cataract surgery using a pure monocular EDoF lens.
 Methods : Subjects were randomized into the mini-monovision group (standard monofocal lenses with -1.25 D of anisometropia) and the pure EDoF group. The blinding was achieved by masking the clinical outcome examiners.
 Results : Interim analysis of 16 patients revealed the outcome of uncorrected and corrected distance visual acuity (UCDVA and BCDVA) were not significantly different between groups. Median of uncorrected intermediate visual acuity (UIVA) and mean of uncorrected near visual acuity (UNVA) of binocular mini-monovision were 0.10 (0-0.10) LogMar and 0.26 + 0.12 LogMar. Median UIVA & mean UNVA monocular EDoF were 0.19 (0.14-0.50) LogMar and 0.54 + 0.11 LogMar, respectively. The Mann- Whitney U test of UIVA between groups revealed p=0.001, and the unpaired T-test of UNVA revealed p=0.000. Mean defocus curve of -2.50 D lens were 0.31 LogMar in binocular mini- monovision group and 0.51 LogMar monocular in EDoF group (p=0.019).
 Conclusion : UIVA, UNVA and defocus curve of -2.50 D lens in the mini-monovision group were better than the EDoF group.

Distance and intermediate visual acuity after a new generation monofocal intraocular lens compared with the standard monofocal intraocular lens implantation

Purpose The aim of this study was to determine the effectiveness of a novel innovative monofocal intraocular lens (Tecnis Eyhance ICB00) compared with the standard monofocal lens (Tecnis-1-piece ZCB00) in terms of contrast sensitivity, postoperative refraction, intermediate visual acuity (VA), and uncorrected and best-corrected distance VA. Patients and methods This prospective comparative interventional clinical study was conducted from January 2021 to November 2021. It included 40 eyes of 20 patients who were divided into two groups, with 10 patients each. Candidates for bilateral cataract extraction by phacoemulsification were included in this study and underwent thorough preoperative examination and postoperative evaluation at 3 months after the second eye operation. The outcome measures included intermediate and distance VA, near add, contrast sensitivity, and incidence of photic phenomena, which was evaluated using a printed questionnaire. The binocular defocus curves were analyzed. Results The study included 20 patients (seven males and 13 females). Binocular and monocular uncorrected and corrected distance VAs were statistically similar in both groups. The Eyhance group demonstrated significantly higher binocular uncorrected and corrected intermediate VA compared with the TECNIS 1-piece group (P<0.001). Defocus and contrast sensitivity values were not significantly different between the two groups. Conclusion Patients who were bilaterally implanted with the new monofocal intraocular lenses achieved significantly higher intermediate VA outcomes without affection of distance VA, with similar mean contrast sensitivity values and low incidence of photic phenomena like halo and glare compared with the standard monofocal lens.

Visual and optical quality of enhanced intermediate monofocal versus standard monofocal intraocular lens

PurposeIntraocular lens designs are constantly evolving, trying to obtain more spectacle independence after cataract surgery. This advantage can be linked to some disadvantages, such as optical quality decrease. For that reason, it is important to assess, not only the amount of vision provided but also the quality of vision once they are implanted. The purpose of the present work was to compare the visual performance between two monofocal intraocular models: a standard model and a monofocal with enhanced intermediate vision lens.MethodsProspective, randomized, comparative study. Sixty adult subjects scheduled to undergo bilateral cataract surgery and IOL implantation were randomized to receive one of the two IOLs in both eyes at Miranza IOA, Madrid, Spain (group A: monofocal with enhanced intermediate vision lens and group B: standard monofocal lens). Monocular outcomes (right eyes) determined 1 and 3 months postoperatively were photopic corrected distance visual acuity (CDVA), uncorrected distance visual acuity (UDVA), perceived halo, corrected intermediate-distance contrast sensitivity, and higher-order aberrations. The impact of the new IOL in the postoperative management with autorefraction devices was also evaluated.ResultsNo differences were found in CDVA between the two groups. Significant differences were detected between the two lenses evaluated in both total HOA (p = 0.028) and internal HOA (p = 0.037). Contrast sensitivity and halometry results obtained at 1 month were similar across the two IOL groups.ConclusionIn patients undergoing cataract surgery, monofocal with enhanced intermediate vision IOL offered similar distance performance and contrast sensitivity along with perceived HOA and halos compared with the standard monofocal IOLs tested.

Laboratory Investigation of Preclinical Visual-Quality Metrics and Halo-Size in Enhanced Monofocal Intraocular Lenses.

IntroductionThis study aims to compare preclinical visual-quality metrics and halo size of intraocular lenses (IOL) with enhanced intermediate vision to a standard monofocal lens.MethodsThree monofocal- IOL models with an extended-depth-of-focus (EDoF) intended for monocular implantation (Tecnis ICB00, AE2UV/ZOE, and IsoPure) and one for monovision (RayOne EMV) were compared against a standard monofocal lens (Tecnis ZCB00). An optical-metrology station was used in the assessment of IOLs' optical quality in polychromatic light. The imaging quality was compared with metrics derived from the optical transfer function. Halo size was estimated from the projection of the point spread function under scotopic pupil.ResultsThe monofocal IOL showed the highest image quality at the far focus. The ICB00’s, the AE2UV/ZOE’s, and the IsoPure’s performance at − 1D was superior to that of the monofocal lens. The monocular defocus tolerance of the RayOne EMV was comparable with that of the ZCB00. The RayOne EMV’s intermediate range was improved in a monovision configuration (− 1D offset). This approach, however, yielded the largest halo area, i.e., 53% of the ZCB00’s halo, compared to 34% for the IsoPure, 14% for the AE2UV/ZOE, and 8% for the ICB00.ConclusionThe mono-EDoF models have a clear advantage over the standard monofocal lens by expanded imaging capability beyond − 0.5D. Although the RayOne EMV provided the largest (binocular) visual-range extension, it was at the expense of monocular vision and higher susceptibility to halo. The ICB00’s and the AE2UV/ZOE’s halo-profile was similar to that of the ZCB00, indicating their low potential to induce photic phenomena.Supplementary InformationThe online version contains supplementary material available at 10.1007/s40123-021-00411-9.

Clinical evaluation of a new monofocal IOL with enhanced intermediate function in patients with cataract.

To evaluate the effectiveness and safety of 2 enhanced monofocal intraocular lenses (IOLs). The TECNIS Eyhance IOL (Model ICB00) was compared with a standard monofocal IOL (TECNIS Monofocal, Model ZCB00). European multicenter study. Prospective, bilateral, randomized, comparative/evaluator-masked, controlled study. Adult subjects scheduled to undergo bilateral, primary phacoemulsification cataract extraction and posterior IOL implantation were randomized to receive the enhanced monofocal ICB00 IOL or the monofocal ZCB00 IOL in both eyes. Monocular endpoints at 6 months included distance-corrected intermediate visual acuity (DCIVA), photopic corrected distance visual acuity, and uncorrected intermediate visual acuity (UIVA). Binocular visual acuities, monocular corrected distance contrast sensitivity (first eyes), patient-reported outcomes, and safety were assessed at 6 months. Overall, 139 patients were bilaterally implanted with the enhanced monofocal IOL (n = 67) or standard monofocal IOL (n = 72) and available for the 6-month visit. The enhanced monofocal IOL significantly improved mean monocular and binocular DCIVA and UIVA by at least 1-line logarithm of the minimum angle of resolution vs the standard monofocal IOL (all P ≤ .0001). Distance vision for the enhanced monofocal IOL was 20/20 or better and comparable with that of the standard monofocal lens at 6 months. Contrast sensitivity, photic phenomena outcomes, and rates of adverse events were similar between the 2 groups. In patients undergoing cataract surgery, TECNIS Eyhance IOL Model ICB00 provided enhanced intermediate vision and similar distance performance and photic phenomena compared with a standard monofocal IOL, along with improved functional performance in daily life.

Trifocal toric intra-ocular lens implantation in pediatric traumatic cataract

PurposeTo present the case of a 6-year-old child who presented with a traumatic cataract and was treated with trifocal toric intra-ocular lens implantation. ObservationsThe child's uncorrected distance visual acuity improved from +0.7 logMAR preoperatively to 0.00 logMAR after cataract surgery, with spectacle independence and no reported side effects Conclusions and importanceIn carefully selected pediatric patients with traumatic cataracts, trifocal toric intra-ocular lenses may offer some benefit over standard monofocal lenses

Astigmatic correction with implantation of a light adjustable vs monofocal lens: a single site analysis of a randomized controlled trial.

To evaluate the light adjustable lens (LAL) vs a standard monofocal lens in achieving target astigmatic refraction and improving postoperative uncorrected distance visual acuity (UDVA). This randomized controlled clinical trial included 40 patients with pre-existing astigmatism and visually significant cataract. Twenty-eight patients received the LAL and 12 control patients received a monofocal intraocular lens (IOL) after cataract extraction at a single institution. The patients with the LAL underwent adjustment by ultraviolet (UV) light postoperatively plus subsequent lock-in procedures and all patients returned to clinic for follow up of study parameters at 6, 9, and 12mo. Manifest refraction, distance visual acuity, and adverse events were recorded at each visit. The mean cylinder before adjustment in eyes with the LAL was -0.89±0.58 D (-2.00 to 0.00 D) and -0.34±0.34 D (-1.25 to 0.00 D) after lock-in (P=1.68x10-8). The mean cylinder in patients with the monofocal lens was -1.00±0.32 D (-1.50 to -0.50 D) at 17-21d postoperatively, which was statistically different from the LAL cylinder post lock-in (P=1.43x10-6). UDVA in the LAL group was 20/20 or better in 79% of patients post lock-in with good stability over 12mo compared with 33% of the control patients with UDVA of 20/20 or better. These results demonstrate that the LAL is more effective in achieving target refractions and improving postoperative UDVA in patients with pre-existing corneal astigmatism than a standard monofocal lens.

Revisiting monovision for presbyopia.

Presbyopia is an inevitable age-related loss of accommodation that results in spectacle dependence with common everyday near-vision tasks. Many surgical approaches to presbyopic correction have been investigated, with monovision correction being amongst the most common and attractive options. In this article, we will review the advantages and disadvantages of the new modalities of presbyopic monovision correction. New methods such as mini-monovision, corneal inlays, and multifocal corneal ablation aim to maximize stereopsis and decrease the anisometropic side effects of conventional monovision. These include inlays such as the KAMRA and Raindrop, and phakic intraocular lenses such as the hole ICL. Newer corneal laser refractive procedures such as small incision lenticule extraction have also shown good outcomes with monovision. Pseudophakic monovision using standard monofocal lenses still provides good results. Monovision for presbyopic correction continues to provide promising results. There are a number of new devices and techniques that have shown good visual acuity outcomes, patient satisfaction and spectacle independence.

Multifocal versus monofocal intraocular lenses after cataract extraction.

Good unaided distance visual acuity is now a realistic expectation following cataract surgery and intraocular lens (IOL) implantation. Near vision, however, still requires additional refractive power, usually in the form of reading glasses. Multiple optic (multifocal) IOLs are available which claim to allow good vision at a range of distances. It is unclear whether this benefit outweighs the optical compromises inherent in multifocal IOLs. The objective of this review was to assess the effects of multifocal IOLs, including effects on visual acuity, subjective visual satisfaction, spectacle dependence, glare and contrast sensitivity, compared to standard monofocal lenses in people undergoing cataract surgery. We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register), The Cochrane Library 2012, Issue 2, MEDLINE (January 1946 to March 2012), EMBASE (January 1980 to March 2012), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 6 March 2012. We searched the reference lists of relevant articles and contacted investigators of included studies and manufacturers of multifocal IOLs for information about additional published and unpublished studies. All randomised controlled trials comparing a multifocal IOL of any type with a monofocal IOL as control were included. Both unilateral and bilateral implantation trials were included. Two authors collected data and assessed trial quality. Where possible, we pooled data from the individual studies using a random-effects model, otherwise we tabulated data. Sixteen completed trials (1608 participants) and two ongoing trials were identified. All included trials compared multifocal and monofocal lenses but there was considerable variety in the make and model of lenses implanted. Overall we considered the trials at risk of performance and detection bias because it was difficult to mask patients and outcome assessors. It was also difficult to assess the role of reporting bias. There was moderate quality evidence that similar distance acuity is achieved with both types of lenses (pooled risk ratio, RR for unaided visual acuity worse than 6/6: 0.98, 95% confidence interval, CI 0.91 to 1.05). There was also evidence that people with multifocal lenses had better near vision but methodological and statistical heterogeneity meant that we did not calculate a pooled estimate for effect on near vision. Total freedom from use of glasses was achieved more frequently with multifocal than monofocal IOLs. Adverse subjective visual phenomena, particularly haloes, or rings around lights, were more prevalent and more troublesome in participants with the multifocal IOL and there was evidence of reduced contrast sensitivity with the multifocal lenses.

Accommodating intraocular lenses: a critical review of present and future concepts

Significant efforts have been made to develop lens implants or refilling procedures that restore accommodation. Even with monofocal implants, apparent or pseudoaccommodation may provide the patient with substantial though varying spectacle independence. True pseudophakic accommodation with a change of overall refractive power of the eye may be induced either by an anterior shift or a change in curvature of the lens optic. Passive-shift lenses were designed to move forward under ciliary muscle contraction. This is the only accommodative lens type currently marketed (43E/S by Morcher; 1CU by HumanOptics; AT-45 by Eyeonics). The working principle relies on various hypothetical assumptions regarding the mechanism of natural accommodation. Dual-optic lenses were designed to increase the dioptric impact of optic shift. They consist of a mobile front optic and a stationary rear optic which are interconnected with spring-type haptics. With active-shift lens systems the driving force is provided by repulsing mini-magnets. Lens refilling procedures replace the lens content by an elastic material and provide accommodation by an increase of surface curvature. Findings with passive-shift lenses have been contradictory. While uncorrected reading vision results were initially reported to be favorable with the 1CU, and excellent with the AT-45 lens, distant-corrected near vision did not exceed that with standard monofocal lenses in later studies. Mean axial shift from laser interferometric measurements under stimulation with pilocarpine showed a moderate anterior shift with the 1CU, while the AT-45 paradoxically exhibited a small posterior shift. With the 1CU, the shift-induced accommodative effect was calculated to be less than +0.5 D in most cases, while +1 D was achieved in a single case only. Ranges and standard deviations were very large in relation to the mean values. Under physiological near-point stimulation, however, no shift was seen at all. Prevention of capsule fibrosis by extensive capsule polishing did not enhance the functional performance. Dual optic lenses are under clinical investigation and are reported to provide a significant amount of accommodation. However, possible long-term formation of interlenticular opacifications remains to be excluded. Regarding magnet-driven active-shift lens systems, initial clinical experience has been promising. Prevention of fibrotic capsular contraction is crucial, and it has been effectively counteracted with a special capsular tension ring, or lens fixation technique, together with capsule polishing. Lens refilling has been extensively studied in the laboratory and in primates. Though it offers great potential for fully restoring accommodation, a variety of problems must be solved, such as achieving emmetropia in the relaxed state, adequate response to ciliary muscle contraction, satisfying image quality over the entire range of accommodation and sustained functioning. The key problem, however, is again after-cataract prevention. As opposed to psychophysical evaluation techniques, laser interferometry measures what shift lenses are designed to provide: axial shift on accommodative effort. While under pilocarpine some movement was recorded, no movement at all was found under near-point stimulation with any of the lenses currently marketed. In contrast, magnetic-driven active-shift lens systems carry the potential of sufficiently topping up apparent accommodation to provide for clinically useful accommodation while using conventional lens designs with proven after-cataract performance. Dual optic implants significantly increase the impact of axial optic shift. The main potential problem, however, is delayed formation of interlenticular regenerates. Lens refilling procedures offer the potential of fully restoring accommodation due to the great impact of increase in surface curvature on refractive lens power. However, various problems remain to be solved before clinical use can be envisaged, above all, again, after-cataract prevention. The concept of passive single-optic shift lenses has failed. Concomitant poor capsular bag performance makes these lenses an unacceptable trade-off. Magnet-assisted systems potentially combine clinically useful accommodation with satisfactory after-cataract performance. Dual optic lenses theoretically offer substantial accommodative potential but may allow for interlenticular after-cataract formation. Lens refilling procedures have the greatest potential for fully restoring natural accommodation, but will again require years of extensive laboratory and animal investigations before they may function in the human eye.

Multifocal versus monofocal intraocular lenses after cataract extraction.

Good unaided distance visual acuity is now a realistic expectation following cataract surgery and intraocular lens implantation. Near vision however still requires additional refractive power, usually in the form of reading glasses. Multiple optic (multifocal) intraocular lenses are available that are claimed to allow good vision at a range of distances. It is unclear whether this benefit outweighs the optical compromises inherent in multifocal intraocular lenses. The objective of this review is to assess the effects of multifocal intraocular lenses, including effects on visual acuity, subjective visual satisfaction, spectacle dependence, glare and contrast sensitivity, compared to standard monofocal lenses. We searched the Cochrane Controlled Trials Register - CENTRAL (which includes the Cochrane Eyes and Vision Group specialised register), MEDLINE and EMBASE. The reference lists of relevant articles were searched. Investigators of included studies and manufacturers of multifocal intraocular lenses were contacted for information about additional published and unpublished studies. All randomised controlled trials comparing a multifocal intraocular lens of any type with a monofocal intraocular lens as control were included. Both unilateral and bilateral implantation trials were included. Data were collected and trial quality assessed. Where possible, statistical summary measures were calculated, otherwise data were tabulated. One ongoing and six completed trials were identified. There was significant variability between the trials in the outcomes reported. Unaided distance acuity was similar in multifocal and monofocal intraocular lenses (Peto odds ratio 1.27 (95% Confidence Interval (CI) 0.76 to 2.11)), with a small increase in the proportion of multifocal intraocular lens participants achieving less than 6/6 best corrected visual acuity (Peto odds ratio 1.64 (95% CI 1.10 to 2.42)). Unaided near vision tended to improve with the multifocal intraocular lenses. This resulted in decreased spectacle dependence with use of the multifocal intraocular lenses (Peto odds ratio 0.16 (95% CI 0.11 to 0.23)). Adverse effects included reduced contrast sensitivity and the subjective experience of haloes around lights. Multifocal intraocular lenses are effective at improving near vision relative to monofocal intraocular lenses. Whether that improvement outweighs the adverse effects of multifocal intraocular lenses will vary between patients, with motivation to achieve spectacle independence likely to be the deciding factor.

Optical quality of intraocular lenses

The ANSI Z80.7 standard for intraocular lens quality is being updated. This paper identities areas that require revision and suggests that a clear distinction between the lens design and the quality control test methods be made. The standard monofocal lens design consists of two spherical surfaces, and lens power can be specified by the thick lens equation, using body temperature refractive index values at a wavelength of 550 nm. Intcrferometry might he used as a primary manufacturing test method for poly(methyl methacrylate) lenses; tolerance values for lens surface errors are suggested. Other test methods can also be used. Measuring the modulation transfer function in fluid may be the most useful.