Multifocal Intraocular Lens Research Articles

Influence of angle Kappa on the optimal intraocular orientation of asymmetric multifocal intraocular lenses

Purposeto evaluate the effects of kappa angle and intraocular orientation on the theoretical performance of asymmetric multifocal intraocular lenses (MIOL). MethodsFor a total of 21 corneal aberrations, a computational analysis simulated the implantation of a computationally designed MIOL. An image quality parameter (IQ) (visually modulated transfer function metric) was calculated for a 5.0-mm pupil and for three conditions: distance, intermediate, and near vision. The procedure was repeated for each eye after a rotation of the MIOL with respect to the cornea from 0º to 360º in 5º steps. Kappa angles from 0 to 900 microns, in 150 microns steps, combined with two two variants of MIOL centration were tested: in the corneal apex or in the center of the entrance pupil. A p-value ≤ 0.05 was considered significant. ResultsThere were statistically significant differences of the IQ depending of the intraocular orientation of the MIOL. If kappa angle was increased, there was a statistically significant decrease of the IQ. The IQ maintained stable when the optimal intraocular orientation was re-calculated for each kappa angle. In general, the inter-variability of the results between subjects was very high. There were no strong evidences supporting that there exists a preferable centration point. ConclusionsOur results suggest that kappa angle theoretically affects significantly the performance of asymmetric MIOL implantation. However, its negative effect can be compensated if a customized intraocular orientation is calculated taking into account the presence of the kappa angle.

Multivariate Regression Analysis Identifying Predictors of Patient Satisfaction with Multifocal IOLs: +4.00/+4.00 vs +3.25/+3.25 vs +3.25/EDOF.

PurposeTo detect and compare the predictors of “overall patient satisfaction” with an EDOF/+3.25 versus +3.25/+3.25 versus +4.00/+4.00 diffractive multifocal IOLs.SettingBucci Laser Vision Institute, Wilkes-Barre, PA, USA.DesignNon-interventional, observational, retrospective-prospective.Patients and MethodsA total of 55 (EDOF/+3.25) “best case patients” with 1) 4 months neuroadaptation 2) corrected residual refractive error 3) necessary YAGs performed and 4) aggressive ocular surface management underwent regression analysis to identify predictors of “overall patient satisfaction”. Satisfaction was regressed against 40 independent variables – 31 clinical metrics such as reading speed and acuity, angle kappa, aberrations, mesopic pupil size, residual spherical equivalent and astigmatism, near, intermediate vision at fixed and preferred focal distances, etc., and 9 responses from a questionnaire evaluating the performance of everyday tasks. Results were compared to two prior cohorts (67 bilateral +3.25 and 55 bilateral +4.00) with identical methods.ResultsEighty percent (44/55) of the EDOF/+3.25 patients were “very satisfied” and 20% (11/55) were “satisfied” compared to 82% “very satisfied”/18% “satisfied” (+3.25/+3.25) and 64% “very satisfied”/36% “satisfied” (+4.00/+4.00). Subjective scores for near VA (p=0.02) were in favor of the +3.25/+3.25 (1.92/2.00) vs EDOF/3.25 (1.76/2.00). However, EDOF/+3.25 scores for intermediate VA (4.65/5.00 vs 4.32/5.00; p=0.02) and distance VA (4.76/5.00 vs 4.53/5.00; p=0.047) were significantly better than bilateral +3.25 and bilateral +4.00. In the bilateral +3.25 cohort, regression revealed that variables related to intermediate vision were responsible for outperforming the bilateral +4.00 cohort, and it also showed that smaller mesopic pupils (p=0.005) again predicted better intermediate vision as was observed in the bilateral +4.00 patients.ConclusionThe EDOF/+3.25 patients had equal patient satisfaction vs the bilateral +3.25, and greater satisfaction vs the bilateral +4.00 patients because of significantly better intermediate and distance vision, despite scoring less for near vision with fine print and no difference with moderate print. Regression predicted better intermediate vision with smaller mesopic pupils with the +3.25 and +4.00 IOLs.

Visual Acuity, Defocus Curve, Reading Speed and Patient Satisfaction with a Combined Extended Depth of Focus Intraocular Lens and Multifocal Intraocular Lens Modality.

PurposeTo evaluate the vision, defocus curve, reading speed and patient satisfaction after implantation of an extended depth of focus (EDOF) IOL in one eye and a diffractive multifocal in the fellow eye.SettingOne clinical practice in the USA.DesignProspective unmasked non-randomized clinical trial.MethodsSubjects presenting for routine cataract surgery interested in reducing their dependence on spectacles were enrolled. Study endpoints included uncorrected and distance-corrected binocular distance (4 m), intermediate (66 cm) and near (40 cm) visual acuity at 3 months. Additional endpoints included the residual refraction, spectacle independence, overall satisfaction with vision, visual symptoms, reading speed and defocus curve.ResultsWith a best distance correction, 77% (30/39) of subjects had 20/25 or better VA at distance, intermediate and near and nearly all subjects had 20/32 or better VA at all three distances. Defocus curve results showed mean continuous vision of 20/25 or better from plano to −2.50 D. Nearly 80% (31/39) of subjects had 20/25 visual acuity from 0.00 D to −2.50 D. The critical print size was between 0.3 and 0.4 logMAR (20/40 to 20/50 Snellen Equivalent). Spectacle independence was 100% at distance, 95% at intermediate and approximately 70% at near. The percentage of subjects who were “not at all” or “slightly” bothered by visual disturbances ranged from 64% (16/25) for Halos to 88% (22/25) for Starbursts.ConclusionsEDOF/bifocal IOL blended implantation results in at least 20/25 mean visual acuity from distance to near with good spectacle independence and low reports of severe visual disturbances.

Matching the Patient to the Intraocular Lens: Preoperative Considerations to Optimize Surgical Outcomes

The intraocular lens (IOL) selection process for patients requires a complex and objective assessment of patient-specific ocular characteristics, including the quality and quantity of corneal astigmatism, health of the ocular surface, and other ocular comorbidities. Potential issues that could be considered complications after surgery, including dry eye disease, anterior or epithelial basement membrane dystrophy, Salzmann nodular degeneration, and pterygium, should be addressed proactively. Aspheric IOLs are designed to eliminate the positive spherical aberration added by traditional IOLs to the pseudophakic visual axis. Spherical aberration may be a consideration with patient selection. Patient desire for increased spectacle independence after surgery is one of the main drivers for the development of multifocal IOLs and extended depth-of-focus (EDOF) IOLs. However, no one single multifocal or EDOF IOL suits all patients' needs. The wide variety of multifocal and EDOF IOLs, their optics, and their respective impact on patient quality of vision have to be understood fully to choose the appropriate IOL for each individual, and surgery has to be customized. Patients who have undergone previous LASIK or who have radial keratotomy and ocular pathologic features, including glaucoma, age-related macular degeneration, and epiretinal membrane, require specific considerations for IOL selection. Subjectively, patient-centered considerations, including visual goals, lifestyle, personality, profession, and hobbies, are key elements for the surgeon to assess and factor into an IOL recommendation. This holistic approach will help surgeons to achieve optimal surgical outcomes and to meet (and exceed) the high expectations of patients.

Pseudophakic Dysphotopsia: Review of Incidence, Cause, and Treatment of Positive and Negative Dysphotopsia

We reviewed the literature concerning positive dysphotopsia (PD) and negative dysphotopsia (ND) regarding cause, incidence, and clinical and surgical management. In addition, we summarized our surgical experience in managing dysphotopsia. A PubMed review, limited to English language articles, yielded 149 citations; multifocal (diffractive optic) and phakic intraocular lens (IOL) dysphotopsia were excluded. Overall, 39 articles were determined to be relevant for the objectives of this investigation. Regarding PD, 7 articles corroborated that the cause of PD is related primarily to internal reflection of oblique light rays that strike the square (truncated) edge of the IOL and are reflected onto the retinal surface. No round-edged foldable IOLs are available in the United States at this time, although IOLs modified with a round anterior edge and square posterior edge show a trend toward decreased incidence of PD. High index of refraction (I/R), surface reflectivity, and IOL optic design are additional causative factors for PD. Regarding the authors' surgical experience, changing the optic material to have a lower I/R improved PD symptoms in the large majority of patients. The cause of ND seems to be multifactorial and less well understood, with some disparity between clinical and laboratory findings. Four articles that explore using ray-tracing optical modeling suggest an "illumination gap," in which some temporally incident light rays to the nasal retina pass anterior to the IOL and some are refracted posteriorly by the IOL, resulting in a gap and resultant temporal shadow. However clinically, ND is associated invariably with well-centered in-the-bag IOLs. Other implicating factors include nasal anterior capsule override, haptic orientation, large-angle κ value, and high hyperopia. Persistent ND has been treated successfully or reduced with reverse (anterior) optic capture, sulcus IOL placement, piggyback IOLs, and neodymium:yttrium-aluminum-garnet nasal capsulectomy. Two articles reference a new optic edge designed to capture the anterior capsulotomy, mimicking reverse optic capture. Persistent dysphotopsia after cataract surgery is a significant cause for patient dissatisfaction. The cause and management of both ND and PD are of significance, and new IOL designs and alternative surgical strategies may help to mitigate these unintended side effects of IOL implantation.

Aktuelle Übersicht: multifokale Linsen und Extended-Depth-of-Focus-Intraokularlinsen

Presbyopia and cataract patients' wish to be increasingly independent of spectacles after surgery and this is one of the main drivers for the development of multifocal intraocular lenses (MIOL) and extended depth of focus (EDOF) intraocular lenses (IOL). As education, biometry, diagnostics, surgical techniques, and MIOL/EDOF IOL designs have improved over the past decade, an increasing number of cataract surgeons have become cataract refractive surgeons to help address this need. There is not one single MIOL/EDOF IOL, however, that suits all patients' needs. The wide variety of MIOL and EDOF IOL, their optics, and their impact on our patients' quality of vision have to be fully understood if we have to choose the appropriate IOL for each individual; MIOL/EDOF IOL surgery has to be customized. This review article looks at the different optical aspects and clinical consequences of MIOL/EDOF IOL, in order to help surgeons find an appropriate solution for each of their individual patients.

Characteristics and factors associated with intraocular lens tilt and decentration after cataract surgery.

To analyze the characteristics and factors associated with intraocular lens (IOL) tilt and decentration after uneventful phacoemulsification with IOL implantation. Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. Cross-sectional study. All patients underwent a general ophthalmologic examination and anterior segment photography. IOL tilt and decentration were measured with a second-generation anterior segment optical coherence tomography (Casia2). Univariate and multivariate regression analyses were performed to assess the association between IOL tilt and decentration with ocular biometric and systemic parameters, and the visual acuity. A total of 196 eyes of 196 patients were enrolled in this study. IOLs showed a mean tilt of 4.8 degrees toward the inferotemporal direction, and the mean decentration was 0.21 mm. Both eyes presented a mirror symmetry relationship. Twenty-two eyes (11.22%) had a tilt greater than 7 degrees, and 21 eyes (10.72%) had a decentration more than 0.4 mm. Multivariate regression analysis showed previous pars plana vitrectomy (PPV) and short axial length (AL) were associated with greater IOL tilt (P = .014 and P < .001). In addition, long AL, thicker lens, and less capsulorhexis-IOL overlap were positively correlated with decentration (P < .001, P = .029, and P = .026). Corrected distance visual acuity did not directly correlate with IOL tilt and decentration (P = .417 and P = .550). PPV history and short AL were associated with greater IOL tilt, whereas longer AL, thicker lens, and overlarge capsulorhexis contribute to greater decentration. Implantation of toric and multifocal IOLs in these patients should be cautious.

Visual outcomes after bilateral implantation of a new generation diffractive trifocal intraocular lens

Cataract surgery today has become more of a refractive surgery with high patient expectations and demand of independence from glasses. Modern cataract surgery is characterized by obtaining precise postoperative target refraction with the premium intraocular lenses (IOLs) available today. The multifocal IOLs are designed to reduce the spectacle dependence after cataract surgery. Previously a variety of studies were performed that confirmed a significant improvement in uncorrected visual acuity after implantation of multifocal IOLs as compared to monofocal IOLs.1‒5 Initially multifocal IOLs that were designed were having a bifocal design which allowed the patient to have a good distance and near visual acuity post operatively, but near vision came at the expense of reduced contrast sensitivity.6‒8 Nowadays, due to increased use of computers the preference of spectacles has changed from near to intermediate distance. In this sense achieving an intermediate vision with an IOL is a good option. The IOL technologies in the latest times help in rehabilitating the distance and near visual acuities and also by incorporating a component of intermediate vision (ie, trifocal IOLs) to ensure spectacle independence.9‒11 The present study aims at assessing the performance of AT LISA tri 839MP trifocal diffractive IOL in terms of visual acuity and independence from spectacles. The other objectives are to assess changes in the distance, near and intermediate visual acuities, contrast sensitivity postoperatively and plotting the defocus curves.

Comparing the Effect of Monofocal and Multifocal Intraocular Lenses on Macular Surgery.

Aim To compare the effects of previously implanted monofocal and multifocal intraocular lenses (IOL) on macular surgery. Methods Seventy eyes of 70 patients with epiretinal membrane (ERM) and symptomatic vitromacular traction syndrome that previously had IOL implantation for cataract surgery were included in this prospective randomized clinical trial. Cases were divided into two groups. Group 1 and Group 2 were composed of eyes with monofocal and multifocal IOLs, respectively. The effects of refraction error and IOL decentration at the time of macular surgery performed for ERM and ILM peeling, according to the lens type, were investigated. Pars plana vitrectomy (PPV) was performed to peel ERM and ILM in all cases. Complete ophthalmological examination, fundus fluorescein angiography, and optical coherence tomography imaging were made to all cases, preoperatively and postoperatively. Results The mean BCVA in Group 1 and Group 2 improved from 0.69 ± 0.15 and 0.38 ± 0.14 logMAR to 0.40 ± 0.14 and 0.10 ± 0.04 logMAR, respectively, at the 6th month. There was no statistically significant difference between the groups in terms of the mean spherical refraction error (P > 0.05) and IOL decentration level (P > 0.05). The mean time required for macular surgery in Group 2 was statistically significantly longer than that for Group 1 (P < 0.05). There was no statistically significant relationship between IOL decentration and macular surgery time in Group 1 (P > 0.05), but there it was found in Group 2 (P < 0.05). In Group 2, there was a positive correlation between IOL decentration and macular surgery time. Conclusion In cases with multifocal IOL implants, especially with lens decentration, the time of macular surgery for ERM and ILM peeling during PPV is longer than that of eyes with monofocal IOL due to fluctuations in the clarity of the surgeon's view.

Clinical outcomes with a new design in multifocal intraocular lens: a pilot study

PurposeTo evaluate the clinical and visual outcomes, quality of near vision and the influence of photic phenomena in patients bilaterally implanted with a new Precizon Presbyopic multifocal intraocular lens (IOL).MethodsIn this prospective consecutive case series, 20 eyes of 10 patients were included (mean age 63.80 ± 12.55 years). Uncorrected and corrected visual acuity (far, intermediate and near), subjective refraction, binocular defocus curve, contrast sensitivity (CSV-1000) and quality of vision and satisfaction questionnaires were measured. The follow-up was 12 months after surgery.ResultsAt 12 months after surgery, uncorrected distance visual acuity (UDVA) improved with surgery (p = 0.001) with a value of 0.08 ± 0.08 logMAR. Uncorrected near visual acuity (UNVA) was 0.22 ± 0.12 logMAR and distance corrected near visual acuity (DCNVA) was 0.16 ± 0.13 logMAR. Intermediate distance visual acuity (UIVA) was 0.22 ± 0.10 logMAR. Contrast sensitivity outcomes were similar to normal population in photopic conditions and slightly reduced in mesopic conditions of lighting. Defocus curve showed that this multifocal IOL was able to provide a visual acuity (VA) equal or better to 0.16 logMAR between defocus levels of + 1.00 to − 2.50 D. Good patient satisfaction was obtained in quality of vision and satisfaction questionnaires outcomes.ConclusionsThe Precizon Presbyopic NVA IOL (OPHTEC BV) provides good visual outcomes. This multifocal IOL provides a high percentage of spectacle independence due to good VA at far, intermediate and near distances and satisfactory contrast sensitivity. High patient satisfaction was observed in quality of vision and satisfaction questionnaires with a low percentage of patients manifesting photic phenomena.

Trifocal diffractive intraocular lens implantation in patients after previous corneal refractive laser surgery for myopia

BackgroundWith the difficulties in IOL power calculation and the potential side effects occurring postoperatively, multifocal IOL implantation after previous corneal refractive surgery are rarely reported especially for the trifocal IOL. Herein we report the clinical observation of trifocal IOL implantation in patients with previous myopia excimer laser correction. In this study, a multi-formula average method was performed for the IOLs power calculation to improve the accuracy. Visual and refractive outcomes were analyzed, and the subjective quality of patients’ life was evaluated by questionnaires survey.MethodsThis retrospective case series included patients with previous myopia excimer laser correction who underwent femtosecond laser assisted phacoemulsification and trifocal IOL (AT LISA tri 839 MP) implantation. Follow-up was done at 1-day, 1-month and 3-month to assess the visual outcomes. Outcome measures were uncorrected distance, intermediate and near visual acuity (UDVA, UIVA, UNVA), manifest refraction, defocus curve, and subjective quality of vision.ResultsTwenty-one Eyes from sixteen patients (14 eyes with previous laser in situ keratomileusis and 7 eyes with previous photorefractive keratectomy) were included. Mean postoperative spherical equivalent (SE) at 3-month was − 0.56 D ± 0.49 SD, wherein, 10 eyes (47.6%) were within ±0.50 D of the desired emmetropia and 19 eyes (90.5%) were within ±1.0 D. Mean monocular UDVA, UIVA and UNVA (logMAR) at last visit were 0.02 ± 0.07, 0.10 ± 0.10, and 0.15 ± 0.11 respectively. Three patients (19%) reported halos and glare in postoperative 3 months, two of them needed to use spectacles to improve the intermediate visual acuity. Fifteen patients (94%) reported a satisfaction score of ≥3.5 out of 4.0, without any difficulty in daily activity. Thirteen patients (81%) did not need spectacles at all distances, while the other 3 patients (19%) used spectacles for near-distance related visual activity. Mean composite score of the VF-14 questionnaire was 95.00 ± 7.29 out of 100.ConclusionsTrifocal IOL implantation after myopia excimer laser correction could restore good distance, intermediate visual acuity and acceptable near visual acuity, and provide accurate refractive outcomes as well as high spectacles independence rate.

Pupil dependence assessment with multifocal intraocular lenses through visual acuity and contrast sensitivity defocus curves.

To identify the most sensitive visual performance metric for evaluating the pupil-dependency of a multifocal intraocular lens (MIOL) and to determine the pupil measurement method most correlated with such metric. Twenty-seven right eyes implanted with a MIOL were included in the analysis. Three pupil size measurements were obtained preoperatively and at 1 month after surgery with the Keratograph 5M system: photopic (PP), mesopic (MP), and the average from both (AP). Pupil was also measured with a rule (RP) under the same light conditions of postoperative visual performance measurements that included, corrected visual acuities (VA) at three distances (far, 67 cm and 40 cm), visual acuity (VADC) and contrast sensitivity defocus curves for optotype sizes of 0.3 logMAR (CSDC3) and 0.7 logMAR (CSDC7). Differences in visual performance were also analyzed for eyes with RP > 3 mm (Group A) and RP ⩽ 3 mm (Group B). PP diameter decreased after surgery by 16% (p = 0.001), whereas MP (p = 0.013) and AP (p = 0.008) decreased by 10%. The best agreement with RP was obtained for AP. Group B showed a trend to better performance than Group A for all the included metrics (p > 0.05). From the three types of defocus curves, CSDC3 obtained generally highest statistical power for testing differences between groups. The strongest statistically significant correlations between pupil size and CSDC3 were obtained for RP and AP. The CSDC3 was the most sensitive metric to detect MIOL pupil-dependency. PR and AP were more correlated with CSDC3 than PP and MP.

Premium intraocular lens implantation in eyes with vitrectomy done.

Phacoemulsification with premium intraocular lens (IOL) implantation has been increasingly popular in the recent years. However, it is not commonly implanted in eyes who had underwent previous vitrectomy surgery as the contrast sensitivity is thought to be reduced and surgeons are worried about poor visualization of the posterior segment after implantation. Since cataract and vitreoretinal diseases often coexist, premium IOLs should be a considerable option for implantation in carefully selected cases. This study aims at reporting the postoperative near and distance visual acuity and subjective quality of vision in eyes with premium IOLs implantation and vitrectomy done. Twenty eyes with posterior vitrectomy and premium IOL implantation from 2006 to 2018 were included. Fourteen eyes were included in Group 1 with patients who underwent a combined phacovitrectomy surgery in the same setting, and six eyes were included in Group 2 with patients who received premium IOL implantation after previous posterior vitrectomy. Both the postoperative corrected distance and near visual acuity at 1month, 3month and 1year are improved in both groups. The subjective quality of vision as graded by the National Eye Institute Refractive Error Quality of Life Instrument-42 questionnaire also showed high patient satisfaction in both groups. We conclude that the presence of a multifocal IOL does not impede visualization of the posterior segment during vitrectomy surgery and surgical complications were not raised. With careful patient selection and preoperative assessment, premium IOLs can be a considerable option in patients requiring posterior vitrectomy. Retrospectively registered with the HKSH Medical Group Research Committee (Ref No. RC-2019-31, Date of registration: December 13, 2019).

Clinical outcomes of topography-guided femtosecond laser-assisted in situ keratomileusis after multifocal intraocular lens implantation

This retrospective study is to evaluate refractive and visual outcomes of topography-guided femtosecond laser-assisted in situ keratomileusis (TGL) for correcting corneal high-order aberrations (HoA) after multifocal intraocular lens (mIOL) implantation. Twenty-eight eyes of 28 patients with both corrected distance visual acuity (CDVA) under 20/25 and subjective visual discomfort at 3 months after mIOL implantation were included in the study. TGL was performed to correct corneal HoA. Visual acuity, manifest refraction, and corneal HoA were measured 3 months after TGL. CDVA was improved in 22 (78.57%) of 28 eyes after TGL. Uncorrected distance visual acuity (0.12 ± 0.16 logMAR) and uncorrected near visual acuity (0.081 ± 0.16 logMAR) were better than those before TGL (P < 0.001). Residual refractive astigmatism showed no difference compared to that before TGL. Root mean square (RMS) of HoA (P = 0.012), spherical aberration (P = 0.013), and RMS of coma (P = 0.001) were reduced relative to those before TGL. Amount of improvement in CDVA was correlated with amount of reduced coma RMS (R = 0.524; P = 0.005) and spherical aberration (R = 0.443; P = 0.021). TGL showed to improve both refractive and visual outcomes in patients with mIOL implantation by correcting corneal HoA.

Intraocular Lens Power Calculations in Eyes with Previous Corneal Refractive Surgery: Review and Expert Opinion

Intraocular lens (IOL) power calculations are less accurate in eyes that have undergone corneal refractive surgery. A wide range of methods have been proposed. We reviewed the methods and outcomes of IOL power calculations in eyes with previous LASIK, excimer laser photorefractive keratectomy (PRK), or radial keratotomy (RK). The PubMed database was searched for articles that (1) discuss methods and outcomes of IOL power calculation in eyes with previous corneal refractive surgery and (2) evaluate the outcomes of toric, multifocal, or extended depth-of-focus (EDOF) IOLs in these eyes. We excluded review articles, case reports or case studies, and non-English reports. Seventy full-text articles were included in this review. Three categories of methods exist based on whether and how they use historical data acquired before the corneal refractive surgery. The American Society of Cataract and Refractive Surgery (ASCRS) postrefractive IOL calculator incorporates many commonly used methods. In eyes with previous myopic LASIK or PRK, hyperopic LASIK or PRK, and RK, 0% to 85%, 38.1% to 71.9%, and 29% to 87.5% of eyes, respectively, showed refractive prediction errors within ±0.5 diopter (D); in eyes with toric IOL implantation that met certain inclusion criteria, 80%, 84%, and 69% of eyes, respectively, achieved postoperative astigmatism of 0.50 D or less. Intraocular lenses with negative spherical aberration (SA) will reduce the positive corneal spherical aberration induced in eyes by myopic LASIK or PRK or by RK. Intraocular lenses with 0 SA on average best match corneal SA in eyes with prior hyperopic LASIK or PRK. Studies have reported excellent outcomes of postrefractive eyes implanted with multifocal or EDOF IOLs; however, corneal topographic enrollment criteria were not specified. Despite availability of new measurement technologies and development of new IOL calculation formulas, further advances are needed to improve outcomes of cataract surgery in eyes that have undergone corneal refractive surgery. Tools like the ASCRS postrefractive IOL calculator are useful for the clinician by incorporating a variety of formulas. Toric, EDOF, and multifocal IOLs may provideexcellent outcomes in selected cases that meet certain corneal topographic criteria.

Presbyopia Correction at the Time of Cataract Surgery

In this article, we review the latest research related to presbyopia management at the time of cataract surgery with attention focused on available options in the USA. With refractive cataract surgery, patient satisfaction is largely dependent on preoperative expectations with regard to spectacle independence and photic phenomena. Monovision with monofocal intraocular lenses have the highest rates of spectacle dependence but the lowest rate of photic phenomena. Extended depth of focus lenses provides excellent distance and intermediate vision, but patients often require glasses for near vision in addition to having mild glare and halos. Refractive multifocal lenses tend to have the highest rates of photic phenomena. Both diffractive and refractive multifocal lenses had excellent near and distance visual acuity but difficulty with intermediate vision. Trifocal lenses provided the most consistent vision at near, intermediate, and distance and only had moderate amounts of glare and halos with excellent patient satisfaction. The current market of intraocular lenses provides patients with the opportunity to experience spectacle independence following refractive cataract surgery. Current options include monovision with monofocal lenses, multifocal intraocular lenses, extended depth of focus intraocular lenses, and pseudo-accomodative intraocular lenses. Future technology is focusing on accommodation, pinhole apertures, and improved multifocality.

Rainbow halos occur less following implantation of extended range of vision one-piece intraocular lenses vs diffractive bifocal intraocular lenses.

To evaluate clinical outcomes following implantation of an extended range of vision intraocular lens (IOL), the ZXR00, and a diffractive multifocal IOL with +2.75 diopters (D) add power, the ZKB00. Totally 30 patients who underwent either bilateral implantation of the ZXR00 IOL with intended emmetropia (ZXR00 emmetropia group: 20 eyes) and intended micromonovision (ZXR00 monovision group: 20 eyes), or bilateral implantation of the ZKB00 IOL with intended emmetropia (ZKB00 group: 20 eyes) were included in this study. Visual acuity at 4 m, 80, and 40 cm; and the types of halos (misty, fine, and rainbow) were analyzed at one and three months after surgery. There were no significant differences in distance visual acuity among the three groups. The mean uncorrected intermediate visual acuity was better in the ZXR00 emmetropia and monovision groups (0.02 logMAR and 0.02 logMAR, respectively) than in the ZKB00 group (0.14 logMAR). The mean uncorrected near visual acuity was worse in the ZXR00 emmetropia group (0.26 logMAR) than in the ZXR00 monovision and ZKB00 groups (0.12 logMAR and 0.10 logMAR, respectively). There was an increased incidence of rainbow halos in the ZKB00 group vs in either ZXR00 group (P=0.033). Implantation of the ZXR00 IOL with intended micromonovision provide superior visual acuity than implantation of the ZXR00 IOL with intended emmetropia. The ZXR00 IOLs tend to show a lower incidence of rainbow halos than did the ZKB00 IOL.

Accuracy of five intraocular lens formulas in eyes with trifocal lens implant.

Accuracy of intraocular lens (IOL) calculation formulas SRK/T, Hoffer Q, Holladay 1, Haigis and Barrett Universal II were compared in prediction of postoperative refraction for multifocal and implants using a single optical biometry device. The authors included 88 refractive lens exchange and cataract surgeries, with AcrySof IQ PanOptix implant (Alcon Laboratories, Inc.). All eyes were divided into three groups based on axial length (AL), group 1: <22 mm (14 eyes), group 2: 22-24.5 mm (68 eyes) and group 3: >24.5 mm (6 eyes). The refractive prediction error (RPE) and mean absolute error (MAE) were calculated for 5 different formulas: SRK/T, Hoffer Q, Holladay 1, Haigis and Barrett Universal II. For eyes with the AL between 22 mm and 24.5 mm the greatest percentage of eyes with RPEs within ±0.25 D was 32.4% for Haigis formula, followed by Barrett Universal II, Hoffer Q and Holladay 1 with 29.4%. The percentage of eyes with RPEs within ±0.50 D was 100% only for Barrett Universal II and Holladay 1, 94.1% for SRK/T and 91.2% for Haigis and Hoffer Q. The first and third group with AL <22 and >24.5 mm were too small to have statistical significance due to the reluctancy to use multifocal IOLs on extreme ALs. ANOVA test showed no statistical difference (P=0.166) between the RPEs measured for each formula in this cohort. This study showed no statistical difference between formulas for this trifocal lens implant. There was a tendency for the RPE to be within ±0.25 D for most of the eyes with the Haigis formula, and within ±0.50 D for all the eyes with the Barrett Universal II formula in the group with the AL between 22 and 24.5 mm.

Результаты докоррекции остаточного астигматизма после имплантации мультифокальных интраокулярных линз

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Исследование возможности имплантации мультифокальной ИОЛ с малой степенью аддидации при наличии на парном глазу имплантированной монофокальной модели

Исследование возможности имплантации мультифокальной ИОЛ с малой степенью аддидации при наличии на парном глазу имплантированной монофокальной модели