Visual function and higher order aberration after implantation of aspheric and spherical multifocal intraocular lenses:a meta-analysis

AIMTo assess the visual outcomes of aspheric multifocal intraocular lenses (IOLs) compared with spherical multifocal IOL after cataract surgery.

Visual performance of four types of diffractive multifocal intraocular lenses and a review of articles

AIM: To compare the clinical outcomes of a variety of multifocal intraocular lenses(MIOLs) in patients diagnosed with presbyopia or cataracts. METHODS: This clinical trial study included 141 patients(282 eyes) with different MIOLs implantation. The Symfony(60 eyes), the Re STOR(100 eyes), the AT LISAtri(60 eyes), and the Pan Optix(62 eyes) intraocular lenses were evaluated in this prospective interventional study. The near, intermediate, and distant visual acuities, contrast sensitivity, and defocus curve were measured as valid criteria. To statistically analyze the results, we used the Statistical Package for Social Science software, the non-parametric Wilcoxon signed-rank t, the one-way analysis of variance and the Tukey’s post-hoc test in our analysis. Moreover, we conducted a detailed literature search on the Pub Med database in English about MIOLs, in total 59 studies were included in this review article.RESULTS: The four approaches did not show any significant difference in the best-corrected distance visual acuity(P>0.05). The defocus curves at the contrast of 100% showed that trifocal IOLs had better intermediate performance than the bifocal IOL(P<0.05). There were no statistically significant differences between AT LISAtri and Pan Optix lenses for visual acuity at all distances. The eyes with Pan Optix, Symfony, and AT LISAtri IOL showed better contrast sensitivity than those Re STOR at spatial frequencies of 1, 3, and 6 cpd in photopic and mesopic conditions(P<0.001). CONCLUSION: All four groups of the multifocal lenses were satisfying in terms of distance and near vision. Also, the group of trifocal lenses led to satisfactory outcomes in intermediate vision, without degradation in quality of vision.

Potential of video games for the promotion of neuroadaptation to multifocal intraocular lenses: a narrative review

Multifocal intraocular lenses(IOLs) are currently usually implanted for the treatment of cataracts because they have been proved to be superior to monofocal IOLs with respect to spectacle independence. In turn, they are associated with a higher prevalence of dysphotopsia symptoms that is one of the most common causes of patient dissatisfaction. Neuroadaptation seems to play a major role in the optimal adaptation to multifocal IOLs. In this context, the development of strategies that facilitate the neuroadaptation process to multifocality might be an effective strategy to reduce patients' dissatisfaction. Video games have been proved to be effective for the improvement of visual acuity and for the promotion of neuroplasticity in elderly subjects and other populations with cortical-related visual impairment. This narrative review highlights the physiological potential of video games as a perceptual strategy to improve visual acuity and promote neuroplasticity in patients using multifocalIOLs, although research is still needed to confirm these benefits in this specific population, with only one comparative study to this date providing evidence of them.

Objective assessment of the effect of pupil size upon the power distribution of multifocal contact lenses

AIM： To analytically assess the effect of pupil size upon the refractive power distributions of different designs of multifocal contact lenses.METHODS： Two multifocal contact lenses of center-near design and one multifocal contact lens of center-distance design were used in this study. Their power profiles were measured using the NIMO TR1504 device （LAMBDA-X, Belgium）. Based on their power profiles, the power distribution was assessed as a function of pupil size. For the high addition lenses, the resulting refractive power as a function of viewing distance （far, intermediate, and near） and pupil size was also analyzed.RESULTS： The power distribution of the lenses was affected by pupil size differently. One of the lenses showed a significant spread in refractive power distribution, from about ？3 D to 0 D. Generally, the power distribution of the lenses expanded as the pupil diameter became greater. The surface of the lens dedicated for each distance varied substantially with the design of the lens.CONCLUSION： In an experimental basis, our results show how the lenses power distribution is affected by the pupil size and underlined the necessity of careful evaluation of the patient’s visual needs and the optical properties of a multifocal contact lens for achieving the optimal visual outcome.

Evaluation of refractive correction for standard automated perimetry in eyes wearing multifocal contact lenses

AIM：To evaluate the refractive correction for standard automated perimetry（SAP）in eyes with refractive multifocal contact lenses（CL）in healthy young participants.METHODS：Twenty-nine eyes of 29 participants were included.Accommodation was paralyzed in all participants with 1%cyclopentolate hydrochloride.SAP was performed using the Humphrey SITA-standard 24-2 and 10-2 protocol under three refractive conditions：monofocal CL corrected for near distance（baseline）;multifocal CL corrected for distance（m CL-D）;and m CL-D corrected for near vision using a spectacle lens（m CL-N）.Primary outcome measures were the foveal threshold,mean deviation（MD）,and pattern standard deviation（PSD）.RESULTS：The foveal threshold of m CL-N with both the24-2 and 10-2 protocols significantly decreased by 2.2-2.5 d B（P〈0.001）,while that of m CL-D with the 24-2 protocol significantly decreased by 1.5 d B（P=0.0427）,as compared with that of baseline.Although there was no significant difference between the MD of baseline and m CL-D with the24-2 and 10-2 protocols,the MD of m CL-N was significantly decreased by 1.0-1.3 d B（P〈0.001）as compared with that of both baseline and m CL-D,with both 24-2 and 10-2 protocols.There was no significant difference in the PSD among the three refractive conditions with both the 24-2 and 10-2 protocols.CONCLUSION：Despite the induced mydriasis and the optical design of the multifocal lens used in this study,our results indicated that,when the dome-shaped visual field test is performed with eyes with large pupils and wearing refractive multifocal CLs,distance correction without additional near correction is to be recommended.

Above-average defocus curves in photopic and mesopic vision with multifocal intraocular lenses after laser assisted in situ keratomileusis

I am Dr. David P Pifiero from the Department of Optics, Pharmacology and Anatomy of the University of Alicante and from the Department of Ophthalmology of Vithas Medimar （Oftalmar） and Vithas Virgen del Carmen （Qvision） hospitals in Spain.

Objective electrophysiological contrast sensitivity with monofocal and multifocal intraocular lenses:a prospective clinical study

Background:To compare objective electrophysiological contrast sensitivity function(CSF)in patients implanted with either multifocal intraocular lenses(MIOLs)or monofocal intraocular lenses(IOLs)by pattern reversal visual evoked potentials(prVEP)measurements.Methods:Fourty-five cataract patients were randomly allocated to receive bilaterally:apodized diffractive-refractive Alcon Acrysof MIOL(A),full diffractive AMO Tecnis MIOL(B)or monofocal Alcon Acrysof IOL(C).Primary outcomes:1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies.Secondary outcomes:psychophysical CSF measured with VCTS-6500,photopic uncorrected distance(UDVA),and mesopic and photopic uncorrected near and intermediate visual acuities(UNVA and UIVA respectively).Results:Electrophysiological CSF curve had an inverted U-shaped morphology in all groups,with a biphasic pattern in Group B.Group A showed a lower CSF than group B at 4 and 8 cpd,and a lower value than group C at 8 cpd.Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B.Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups.Mesopic UNVA and UIVA were better in group B.Conclusions:Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs.This may be related to the visual acuity under certain conditions or to IOL characteristics.This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.

Predictive factors for photic phenomena after refractive,rotationally asymmetric,multifocal intraocular lens implantation

AIM： To investigate the independent factors associated with photic phenomena in patients implanted with refractive,rotationally asymmetric,multifocal intraocular lenses（MIOLs）.METHODS： Thirty-four eyes of 34 patients who underwent unilateral cataract surgery,followed by implantation of rotationally asymmetric MIOLs were included.Distance and near visual acuity outcomes,intraocular aberrations,preferred reading distances,preoperative and postoperative refractive errors,mesopic and photopic pupil diameters,and the mesopic and photopic kappa angles were assessed.Patients were also administered a satisfaction survey.Photic phenomena were graded by questionnaire.Independent-related factors were identified by correlation and bivariate logistic regression analyses.RESULTS： The distance from the photopic to the mesopic pupil center（pupil center shift） was significantly associated with glare/halo symptoms [odds ratio（OR）=2.065,95% confidence interval（CI）=0.916-4.679,P=0.006] and night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007）.The preoperative photopic angle kappa was significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041）.The photopic angle kappa was also significantly associated with glare/halo symptoms（OR=2.155,95% CI=1.065-4.362,P=0.041） and with night vision problems（OR=1.832,95% CI=0.721-2.158,P=0.007） in patients implanted with rotationally asymmetric MIOLs.CONCLUSION： A large pupil center shift and misalignment between the visual and pupillary axis（angle kappa）may play a role in the occurrence of photic phenomena after implantation of rotationally asymmetric MIOLs.

Accuracy of eight intraocular lens power calculation formulas for segmented multifocal intraocular lens

AIM:To evaluate the accuracy of eight different intraocular lens(IOL)power calculation formulas for a segmented multifocal IOL.METHODS:A total of 53 eyes of 41 adult cataract patients who underwent phacoemulsification and implantation with the SBL-3 segmented multifocal IOL between January 1,2017 and January 31,2019 were included in this retrospective study.Preoperative biometry measurements were obtained using an IOL Master.Manifest refraction was performed at least 4 wk postoperatively.Accuracy of the eight formulas[Barrett Universal II,Emmetropia Verifying Optical(EVO),Haigis,Hill-RBF 2.0,Hoffer Q,Holladay 1,Kane,and SRK/T]was analyzed.RESULTS:Using current lens constants,all formulas exhibited errors of slight myopic shift in refractive prediction.The Barrett Universal II formula had a significantly lower median absolute error(MedAE)than did Holladay 1(P=0.02),Kane(P=0.001)and Hill-RBF 2.0(P<0.001)formulas.The Haigis formula had a lower MedAE value than did the Hill-RBF 2.0 formula(P=0.005).Differences in MedAE values among SRK/T,EVO and Hoffer Q formulas were not significant.After optimizing lens constants,the MedAE values of all formulas were reduced;significant changes were noted for EVO(P=0.022),Haigis(P=0.048);Hill-RBF 2.0(P=0.014),Holladay 1(P=0.045)and Kane(P=0.022)formulas.All formulas performed equally well after optimization of lens constants(P=0.203).CONCLUSION:All eight formulas tend to result in a myopic shift when using current lens constants.Optimized lens constants improve the accuracy of these formulas among adult Chinese patients.

Diffractive multifocal intraocular lens implantation in patients with monofocal intraocular lens in the contralateral eye

AIM:To evaluate clinical outcomes of unilateral implantation of a diffractive multifocal intraocular lens(IOL)in patients with contralateral monofocal IOL.METHODS:Twenty-two patients who already had implantation of a monofocal IOL in unilateral eye underwent implantation of a diffractive multifocal IOL in contralateral eye were enrolled.After 1,6,and 12 mo,uncorrected and distant corrected distant visual acuity(UCDVA and DCDVA),uncorrected and distant corrected intermediate-visual acuity(UCIVA and DCIVA),uncorrected and distant corrected near visual acuity(UCNVA and DCNVA),and contrast sensitivity were obtained.Halo/glare symptoms,spectacle dependence,and patient satisfaction were also evaluated.RESULTS:The mean age was 67.86±7.25 y and the average interval between two IOL implantations was 645.82±878.44 d.At 1 mo,binocular UCDVA was lower than 0.20 logMAR in 76%of patients(mean 0.12±0.13 logMAR),which increased to 90%by 6 and 12 mo.The binocular UCDVA was significantly better than the monocular results(P<0.05)at 1,6,and 12 mo.Additionally,UCNVA was lower than 0.40 logMAR in 82%of patients,increasing to 90%by 6 and 12 mo.Mean UCNVA in the multifocal IOL implanted eye was statistically significantly better than that in the monofocal IOL implanted eye(P<0.05)at 1,6,and 12 mo.About 5%of patients at 1 and 6 mo,reported"severe glare or halo".Patient satisfaction rates were 95%and 91%at 6 and 12 mo,respectively.CONCLUSION:Unilateral implantation of multifocal IOL in patients with a contralateral,monofocal IOL implantation results in high patient satisfaction rate,with low severe glare or halo rate during follow-up.It can represent a good option for patients who have previously had a monofocal IOL implantation regardless of two year interval duration between two IOL implantations.

A new treatment option for the resistant spasm of accommodation:clear lens extraction and multifocal intraocular lens implantation

Dear Editor,We write you to present a 20-year-old man with resistant spasm of accommodation without any organic cause treated with clear lens extraction（CLE）with phacoemulsification and multifocal intraocular lens（IOL）implantation.

Validity of automated refraction after segmented refractive multifocal intraocular lens implantation

AIM： To evaluate the clinical utility of automated refraction（AR） and keratometry（KR） compared with subjective or manifest refraction（MR） after cataract or refractive lens exchange surgery with implantation of Lentis Mplus X（Oculentis GmbH） refractive multifocal intraocular lens（IOL）.METHODS： Eighty-six eyes implanted with the Lentis Mplus X multifocal IOL were included. MR was performed in all patients followed by three consecutive AR measurements using the Topcon KR-8000 autorefractor. Assessment of repeatability of consecutive AR before and after dilation with phenylephrine 10%, and comparison of the AR and KR with MR using vector analysis were performed at 3 mo follow-up.RESULTS： Analysis showed excellent repeatability of the AR measurements. Linear regression of AR versus MR showed good correlation for sphere and spherical equivalent, whereas the correlation for astigmatism was low. The mean difference AR-MR was-1.28±0.29 diopters（D） for sphere. Astigmatism showed better correlation between KR and MR. CONCLUSION： We suggest AR sphere plus 1.25 D and the KR cylinder as the starting point for MR in eyes with a Lentis Mplus X multifocal IOL. If AR measurements are equal to MR, decentration of the IOL should be suspected.

Comparative analysis of visual quality between unilateral implantation of a trifocal intraocular lens and a rotationally asymmetric refractive multifocal intraocular lens

·AIM:To compare visual quality after unilateral cataract surgery with implantation of trifocal intraocular lens(IOL)and asymmetric refractive multifocal IOL.·METHODS:The prospective nonrandom,comparative study consisted of 60 eyes of 60 patients suffering unilateral cataract surgery with implantation of two different IOLs:AT LISA tri 839 MP(30 eyes;Carl Zeiss Meditec,Germany)and LS-313 MF30(30 eyes;Oculentis GmbH,Germany).Visual acuity,refractive outcome,contrast sensitivity,defocus curves,quality of vision,and optical phenomena were evaluated at3 mo postoperatively.·RESULTS:There were no statistical differences between groups in uncorrected distance visual acuity(P=0.13)and uncorrected near visual acuity(P=0.54).In contrast,uncorrected intermediate visual acuity was better in trifocal group compared to the refractive multifocal group(P=0.02).No significant statistical between-group difference was detected in cylinder(P=0.43).Compared to trifocal group,spherical refraction and spherical equivalent in refractive multi focal group were more myopic(P<0.01).Under photopic conditions,no significant statistical differences were found between groups in contrast sensitivity at 3 and 6 cycles per degree(cpd).The refractive multifocal group performed better at 12 and 18 cpd than the trifocal group(P=0.01,P=0.034,respectively).The questionnaires of quality of vision and optical phenomena showed no differences between groups.·CONCLUSION:Trifocal IOL is superior to refractive multifocal IOL in intermediate visual acuity.Rotationally asymmetric refractive multifocal IOL is more myopic in automated refraction and significantly better for the photopic contrast sensitivity at high frequency.

Clinical performance of presbyopia correction with a multifocal corneoscleral lens

AIM:To assess the clinical performance of a multifocal corneoscleral lens for the presbyopia correction.METHODS:A prospective clinical trial of the OnefitTM A multifocal corneoscleral lens was conducted with 40 participants with presbyopia.At 4 wk of continuous wear of the corneoscleral lens,changes in the distance,intermediate,and near visual acuity(VA)were evaluated.The safety of the corneoscleral lens,central corneal thickness(CCT),corneal endothelial cell count,binocular stereopsis,tear film break-up time(BUT),corneal staining,corneal edema,corneal neovascularization(NV),and conjunctival hyperemia were examined.In addition,a subjective questionnaire addressing satisfaction(rated from 1 to 5 points)and discomfort(rated from 1 to 5 points)was administered.RESULTS:Forty participants were enrolled in this study.Six participants were excluded because of poor compliance with lens fitting(n=2)and loss to follow-up(n=4).The mean age of the participants was 53.0±4.9 y.At 4 wk of continuous wear of the corneoscleral lens,the best corrected far,intermediate,and near VA was 0.08±0.11,0.10±0.12,and 0.10±0.12 log MAR,respectively.These results were significant improvements over the baseline uncorrected VA(far:P=0.004;intermediate:P=0.004;near:P=0.002).CCT,corneal endothelial cell count,binocular stereopsis,BUT,corneal staining,corneal edema,corneal NV,and conjunctival hyperemia were not significantly different between baseline and after corneoscleral lens use.The average satisfaction scores for fit sensation;corrected far,intermediate,and near VA;and ease of handling were 4.1,3.4,3.6,3.5,and 3.4,respectively.The average discomfort scores for dryness,irritation,foreign body sensation,redness,fogging,and halo were 1.7,1.8,1.5,1.7,1.7,and 1.3,respectively.CONCLUSION:Far,intermediate,and near VA are improved in presbyopic patients with the multifocal corneoscleral lens compared to uncorrected baseline VA,without adverse ocular effects.This evidence supports the safety and effectiveness of presbyopia correction with multifocal corneoscleral lenses.

Secondary positioning of rotationally asymmetric refractive multifocal intraocular lens in a patient with glaucoma:A case report

BACKGROUND Asymmetric multifocal intraocular lenses(IOLs)are now widely used in the modern cataract surgery,providing a good level of visual performance over a range of distances and high postoperative patient satisfaction.We report a case of improved visual quality after shifting the near segment of an asymmetrical multifocal IOL to the superotemporal placement in the dominant eye of a glaucoma patient.CASE SUMMARY A 72-year-old woman with bilateral glaucoma underwent phacoemulsification in the dominant eye(left eye)with implantation of an asymmetrical multifocal IOL.Postoperative uncorrected distance visual acuity(UDVA)was 0.0 logMAR(20/20 Snellen)and uncorrected near visual acuity(UNVA)was 0.1 logMAR(20/25 Snellen).Two weeks later,the patient presented to our clinic with decreased vision due to migration of lens epithelial cells to IOL anterior surface and edema of corneal endothelial cells.Anterior capsule polishing and superotemporal placement of near segment[+3.00 diopter(D)addition(add)]of IOL were performed.As a result,UDVA at the first week and first year after reposition was 0.0 logMAR(20/20 Snellen),and compared with 0.3 logMAR(20/40 Snellen)in the first week,the UNVA was improved to 0.0 logMAR(20/20 Snellen)one year after surgery.CONCLUSION The postoperative inflammatory reaction and lens epithelial cells proliferation were obvious in this glaucoma patient.Capsule polishing and rotation of the lens were beneficial to the patient,which not only enhanced the patient's vision,but also improved the patient's satisfaction.Therefore,glaucoma patients need to be cautious of implanting multifocal IOLs.Placement of a near segment of an asymmetrical multifocal IOL in the dominant eye should be performed on an individual basis.

Decentration and tilt of plate-haptic multifocal intraocular lenses in myopic eyes

Background:To investigate the decentration and tilt of plate-haptic multifocal intraocular lenses(MfIOLs)in myopic eyes.Methods:Myopic(axial length[AXL]>24.5 mm)and non-myopic(21.0 mm<AXL≤24.5 mm)cataract eyes were enrolled in this prospective study and randomly assigned to receive implantation of Zeiss AT LISA tri 839MP lenses(Group A)or Tecnis ZMB00 lenses(Group B).In total,122 eyes of 122 patients were available for analysis.Decentration and tilt of MfIOLs,high-order aberrations(HOAs),and modulation transfer functions(MTFs)were evaluated using the OPD-Scan III aberrometer 3 months postoperatively.Subjective symptoms were assessed with a Quality of Vision questionnaire.Results:Near and distance visual acuities,tilt and horizontal decentration did not differ between the two groups,postoperatively.However,myopic eyes of Group B showed greater vertical decentration than those of Group A(−0.17±0.14 mm vs.-0.03±0.09 mm,respectively),particularly when the MfIOLs were placed horizontally or obliquely.Overall decentration of myopic eyes was greater in Group B than in Group A(0.41±0.15 mm vs.0.16±0.10 mm,respectively).In Group B,AXL was negatively correlated with vertical decentration and positively correlated with overall decentration.No such correlations were found in Group A.Intraocular total HOAs,coma,trefoil and spherical aberrations were lower in Group A than in Group B for a 6.0 mm pupil among myopic eyes.Generally,Group A had better MTFs and fewer subjective symptoms than Group B among myopic eyes.Conclusions:Plate-haptic design of MfIOLs may be a suggested option for myopic cataract eyes due to the less inferior decentration and better visual quality postoperatively.

Visual quality of juvenile myopes wearing multifocal soft contact lenses

Background:It is unclear whether multifocal soft contact lenses(MFSCLs)affect visual quality when they are used for myopia control in juvenile myopes.The aim of this study was,therefore,to investigate the effect of MFSCLs on visual quality among juvenile myopia subjects.Methods:In a prospective,intervention study,thirty-three juvenile myopes were enrolled.Visual perception was assessed by a quality of vision(QoV)questionnaire with spectacles at baseline and after 1 month of MFSCL wear.At the one-month visit,the high(96%)contrast distance visual acuity(distance HCVA)and low(10%)contrast distance visual acuity(distance LCVA)were measured with single vision spectacle lenses,single vision soft contact lenses(SVSCLs)and MFSCLs in a random order.Wavefront aberrations were measured with SVSCLs,with MFSCLs,and without any correction.Results:Neither distance HCVA(p>0.05)nor distance LCVA(p>0.05)revealed any significant difference between MFSCLs,SVSCLs and single vision spectacle lenses.The overall score(the sum of ten symptoms)of the QoV questionnaire did not show a statistically significant difference between spectacles at baseline and after 1 month of MFSCL wear(p=0.357).The results showed that the frequency(p<0.001),severity(p=0.001)and bothersome degree(p=0.016)of halos were significantly worse when wearing MFSCLs than when wearing single vision spectacle lenses.In contrast,the bothersome degree caused by focusing difficulty(p=0.046)and the frequency of difficulty in judging distance or depth perception(p=0.046)were better when wearing MFSCLs than when wearing single vision spectacle lenses.Compared with the naked eye,MFSCLs increased the total aberrations(p<0.001),higher-order aberrations(p<0.001),trefoil(p=0.023),coma aberrations(p<0.001)and spherical aberrations(SA)(p<0.001).Compared with the SVSCLs,MFSCLs increased the total aberrations(p<0.001),higher-order aberrations(p<0.001),coma aberrations(p<0.001)and SA(p<0.001).The direction of SA was more positive(p<0.001)with the MFSCLs and more negative(p=0.001)with the SVSCLs compared with the naked eye.Conclusions:Wearing MFSCLs can provide satisfactory corrected visual acuity(both distance HCVA and distance LCVA).Although the lenses increased the aberrations,such as total aberrations and higher-order aberrations,there were few adverse effects on the distance HCVA,distance LCVA and visual perception after 1 month of MFSCL use.

Visual quality of juvenile myopes wearing multifocal soft contact lenses

Background:It is unclear whether multifocal soft contact lenses(MFSCLs)affect visual quality when they are used for myopia control in juvenile myopes.The aim of this study was,therefore,to investigate the effect of MFSCLs on visual quality among juvenile myopia subjects.Methods:In a prospective,intervention study,33 juvenile myopes were enrolled.Visual perception was assessed by a quality of vision(QoV)questionnaire with spectacles at baseline and after one month of MFSCL wear.At the one month visit,the high(96%)contrast distance visual acuity(distance HCVA)and low(10%)contrast distance visual acuity(distance LCVA)were measured with single-vision spectacle lenses,single-vision soft contact lenses(SVSCLs)and MFSCLs in a random order.Wavefront aberrations Were measured with SVSCLs,MFSCLs and,without anycorrection.Results:Neither distance HCVA(P>0.05)nor distance LCVA(P>0.05)revealed any significant difference between MFSCLs,SVSCLs and single-vision spectacle lenses.The overall score(the sum of ten symptoms)of the QoV questionnaire did not show a statistically significant difference between spectacles at baseline and after one month of MFSCL wear(P=0.357).The results showed that the frequency(P<0.001),severity(P=0.001)and bothersome degree(P=0.016)of halos were significantly worse when wearing MFSCLs than when wearing single-vision spectacle lenses.In contrast,the bothersome degree caused by focusing difficulty(P=0.046)and the frequency of difficulty in judging distance or depth perception(P=0.046)were better when wearing MFSCLs than when wearing single-vision spectacle lenses.Compared with the naked eye,MFSCLs increased the total aberrations(P<0.001),higher-order aberrations(P<0.001),trefoil(P=0.023),coma aberrations(P<0.001)and spherical aberrations(SA)(P<0.001).Compared with the SVSCLs,MFSCLs increased the total aberrations(P<0.001),higher-order aberrations(P<0.001),coma aberrations(P<0.001)and SA(P<0.001).The direction of SA was more positive(P<0.001)with the MFSCLs and more negative(P=0.001)with the SVSCLs compared with the naked eye.Conclusions:Wearing MFSCLs can provide satisfactory corrected visual acuity(both distance HCVA and distance LCVA).Although the lenses increased the aberrations,such as total aberrations and higher-order aberrations,there were few adverse effects on the distance HCVA,distance LCVA and visual perception after one month of MFSCL Wear.

The impact of posterior corneal astigmatism on the surgical planning of toric multifocal intraocular lens implantation

Purpose:To investigate the influence of posterior corneal astigmatism on the prediction accuracy of toric multi­focal intraocular lens(IOL)calculation.Methods:The keratometric astigmatism measured by Lenstar LS 900(KCA_(L)),keratometric astigmatism(KCAp)and total corneal astigmatism(TCA)measured by Scheimpflug camera(Pentacam HR)were documented and analyzed accordingly.Three deduction models using different parameters were compared.Model 1:KCA_(L)+keratometric comeal surgically induced astigmatism(KCSIA,0.30 D@50°);Model 2:KCA_(P)+KCSIA);Model 3:TCA 4-total CSIA(TCSIA,0.23 D@50°).The prediction errors of each model as the difference vector between the actual and the intended residual astigmatism were compared.Results:Seventy-six eyes implanted with toric multifocal IOLs were included in this study.The vector differences of the actual KCSIA and TCSIA were statistically significant in the total sample and against-the-rule(ATR)sub­group(both P<0.05).Model 1 deduced the smallest mean values of prediction error,while that of Model 3 were smaller than that of Model 2,both in the total sample and the ATR subgroups(all P<0.05).Meanwhile,in the total sample and ATR subgroups,the centroid vector magnitudes of Model 3 were smaller than that of Model 1(0.31±0.76 D and 0.39±0.76 D).Conclusions:The calculation of toric multifocal IOL should be individualized especially in the ATR eyes for the impact of PCA on the estimation of the preoperative comeal astigmatism and the CSIA.

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.