Changes in visual performance after implantation of different intraocular lenses

AIM:To evaluate the trending visual performance of different intraocular lenses(IOLs)over time after implantation.METHODS:Ninety-one patients received cataract surgery with implantations of monofocal(Mon)IOLs,segmental refractive(SegRef)IOLs,diffractive(Dif)IOLs,and extendeddepth-of-focus(EDoF)IOLs were included.The aberrations and optical quality collected with iTrace and OQAS within postoperative 6mo were followed and compared.RESULTS:Most of the visual parameters improved over the postoperative 6mo.The postoperative visual acuity(POVA)of the Mon IOL,SegRef IOL,and EDoF IOL groups achieved relative stability in earlier states compared with the Dif IOL group.Nevertheless,the overall visual performance of the 3 IOLs continued to upturn in small extents within the postoperative 6mo.The optical quality initially improved in the EDoF IOL group,then in the Mon IOL,SegRef IOL,and Dif IOL groups.POVA and objective visual performance of the Mon IOL and EDoF IOL groups,as well as POVA and visual quality of the Dif IOL group,improved in the postoperative 1mo and stabilized.Within the postoperative 6mo,gradual improvements were observed in the visual acuity and objective visual performance of the SegRef IOL group,as well as in the postoperative optical quality of the Dif IOL group.CONCLUSION:The visual performance is different among eyes implanted with different IOLs.The findings of the current study provide a potential reference for ophthalmologists to choose suitable IOLs for cataract patients in a personalized solution.

Comparison of visual performance with iTrace analyzer following femtosecond laser-assisted cataract surgery with bilateral implantation of two different trifocal intraocular lenses

AIM:To compare the postoperative binocular visual performance with an iTrace analyzer following femtosecond laser-assisted cataract surgery(FLACS)combined with bilateral implantation of two different types of diffractive trifocal intraocular lenses(IOL).METHODS:During this retrospective observational study,patients who received bilateral FLACS combined with implantation of two different types of diffractive trifocal IOLs were evaluated.According to the IOLs’different types and design,the patients were divided into AT LISA tri839MP group(tri839 group)and AcrySof PanOptix TFNT00 group(TFNT group).Study parameters included preoperative and postoperative uncorrected distance visual acuity(UDVA)at 5 m,uncorrected near visual acuity(UNVA)at 30 cm and 40 cm,uncorrected intermediate visual acuity(UIVA)at 60 cm and 80 cm,postoperative refractive status,objective visual qualities and total high order aberrations(HOAs)postoperatively.The postoperative complications were also recorded.RESULTS:Totally 56 eyes of 28 patients(tri839 group,n=26;TFNT group,n=30)were included.Preoperative baseline characteristics between groups were not statistically significantly different.UDVA was not significantly different between groups except for 1wk follow-up due to the postoperative corneal edema.TFNT group showed statistically significant better UNIA at 60 cm than tri839 group at the 1wk(0.05±0.19 vs 0.15±0.10 logMAR,P=0.013),1mo(0.05±0.12 vs 0.15±0.09 logMAR,P=0.001)and 3mo(0.04±0.12 vs 0.15±0.11 logMAR,P=0.001)follow-up,while tri839 group showed statistically significant better UNIA at 80 cm than TFNT group at the 1d(0.14±0.15 vs 0.20±0.14 logMAR,P=0.041)and 1mo(0.09±0.07 vs 0.14±0.10 logMAR,P=0.042)follow-up.Postoperative refractive status showed stable at every visit.Modulated transfer function(MTF)values and strehl ratio(SR)values were improved and HOAs were lower significantly after surgery.CONCLUSION:FLACS with bilateral implantations of both tri839 and TFNT00 can achieve satisfactory natural whole-course vision,high postoperative refractive stability and good visual quality but without significantly difference.iTrace aberration instrument can accurately evaluate the visual quality under different status.

Visual performance after conventional LASIK and wavefront-guided LASIK with iris-registration:results at 1 year

AIM:To compare visual performance of wavefrontguided laser in situ keratomileusis(LASIK) with iris-registration(Wg-LASIK group) and conventional LASIK(LASIK group) one year after surgery and analyze the correlation between wavefront aberrations and visual performance.·METHODS:Eight hundred and fifty-two myopic eyes of 430 patients were enrolled in this prospective study and divided into two groups:Wg-LASIK group(436eyes) and LASIK group(416 eyes).A Wavescan Wavefront aberrometer was used to analyze Zernike coefficients and the root-mean-square(RMS) of higher order aberrations,and Optec 6500 visual function instrument was used to measure contrast sensitivity(CS)before and 3,6,12 months after surgery.·RESULTS:The mean spherical equivalent(SE) in WgLASIK group was significantly better than those in LASIK group one year after surgery(P =0.024).Wg-LASIK eyes showed better CS values than LASIK eyes at all spatial frequencies with and without glare after surgery(P all【0.01).Moreover,the increase of higher RMS(RMSh),coma,RMS3,RMS4,RMS5 in Wg-LASIK group were significantly lower than those in LASIK group 1 year after surgery(P all 【0.05).The increase of coma,spherical aberration(SA),RMS3 and RMS4 in Wg-LASIK and coma and RMS3 in LASIK group were negatively correlated with reduction of contrast sensitivity 1 year after surgery.·CONCLUSION:A significant better visual performance is got in Wg-LASIK group compared with LASIK group 1year after surgery,and the Wg-LASIK is particularly suitable for eyes with high-magnitude RMSh.

Visual performance with accommodating and multifocal intraocular lenses

AIM： To compare the visual functional outcomes with accommodating and multifocal intraocular lenses（IOLs）.METHODS： Our retrospective comparative study included 51 patients（60 eyes） received implantation of an accommodating IOL（Tetraflex;16 patients,20 eyes）,a refractive multifocal IOL（Re Zoom;18 patients,20 eyes）,or a diffractive multifocal IOL（ZMA00;17 patients,20 eyes）.Subjective refraction,visual acuity,contrast sensitivity（CS）,intraocular aberration,and subjective photic phenomena were detected at 3mo after surgery.RESULTS： The spherical equivalent in the three groups was-0.38±0.54 D,0.14±0.56 D,and 0.35±0.41 D,respectively.No statistically significant differences were found in uncorrected and corrected distance visual acuity and uncorrected intermediate visual acuity among the groups（P=0.39）.The Re Zoom group had significantly better distance-corrected intermediate visual acuity than the ZMA00 group（P=0.003）.The ZMA00 group had significantly better near visual acuity than the other groups（P〈0.05）.Better contrast sensitivity values were observed in the Tetraflex group under most of the spatial frequencies conditions（P=0.025）.The total aberration was lowest in the ZMA00 group（P=0.000）,and the spherical aberration was highest in the Tetraflex group（P=0.000）.The three groups had similar frequency of ghosting and glare,and the Tetraflex group had a low rate of halos（P=0.01）.CONCLUSION： Both accommodating and multifocal IOLs can successfully restore distance and uncorrected intermediate visual acuities.Tetraflex accommodating IOLs perform better in CS and with less halos of photic phenomena.Re Zoom refractive multifocal IOLs havebetter performance in distance-corrected intermediate visual acuity than ZMA00 diffractive multifocal IOLs,and the latter achieved better near visual acuity and efficiently decreased the optical aberration.

Comparison of visual performance between conventional LASIK and wavefront-guided LASIK with iris-registration

Background Laser in situ keratomileusis （LASIK） has become an efficient and commonly performed procedure to reduce refractive errors. In order to further increase the postoperative visual quality, the wavefront-guided refractive surgery has been a research hotspot in customized surgery. This study was conducted to compare the visual acuity, higher-order aberration, and contrast sensitivity of wavefront-guided LASIK with iris-registration and conventional LASIK. Methods Two hundred and eleven myopic eyes of 109 patients were enrolled in this prospective study and randomly divided into two groups： the wavefront-guided LASIK （wg LASIK） group （94 eyes） and conventional LASIK group （117 eyes）. A Wavescan Wavefront aberrometer was used to analyze Zernike coefficients and the root-mean-square （RMS） of higher order aberrations with 6.0 mm pupil size, and Optec 6500 visual function instrument was used to measure contrast sensitivity （CS） under 5 spatial frequencies before and after surgery in both groups.Results The uncorrected visual acuity （UCVA） and the mean spherical equivalent （SE） in wg LASIK group were significantly better than those in conventional LASIK （UCVA, z=2.339, P=0.019; SE, t=2.838, P=0.005） at 3 months after surgery. Moreover, the increase in Z3^-3, Z3^1, Z3^3, Z4^0, Z5^-1, Z5^1 Z5^-5 and Z6^-6 in wg LASIK group was statistically smaller than that in conventional LASIK group （P〈0.05）. In wg LASIK group, eyes with a higher amount of the preoperative RMS of the higher order aberrations （RMSh≥0.30μm） showed a statistically lower increase （13.5%） than those in conventional LASIK group at 3 months after surgery （33.3%） （P=0.004）. And the values of 4th order spherical aberration （4thSA） and the root mean square of 6th order aberration （RMS6） in wg LASIK group were significantly lower than those in conventional group in eyes which had higher preoperative astigmatism （≥1.0D） （4thSA, P=0.03; RMS6, P=0.02）. Wg LASIK group showed better CS values than the correspondingly preoperative values at all spatial frequencies with and without glare at 3 months after the surgery while conventional LASIK group displayed reduced CS values except for 1.5 and 3 cycles per degree with glare. The differences between the two groups were statistically significant （P〈0.001）. Conclusions Wavefront-guided LASIK with iris-registration is efficient to reduce higher order aberrations especially spherical and coma aberrations, and to improve postoperative visual acuity and contrast sensitivity compared with conventional LASIK. The application of wavefront-guided LASIK with iris-registration is particularly suitable for eyes with higher preoperative RMSh values and eyes with higher preoperative astigmatism.

Objective visual performance evaluation with visual evoked potential measurements based on an adaptive optics system

An objective visual performance evaluation with visual evoked potential （VEP） measurements was first inte- grated into an adaptive optics （AO） system. The optical and neural limits to vision can be bypassed through this system. Visual performance can be measured electrophysiologically with VEP, which reflects the objective func- tion from the retina to the primary visual cortex. The VEP ts without and with AO correction were preliminarily carried out using this system, demonstrating the great potential of this system in the objective visual performance evaluation. The new system will provide the necessary technique and equipment support for the further study of human visual function.

Effect of changing mesopic and photopic light conditions on visual functions

AIM:To determine the effects of change in light conditions on refractive error and visual functions including visual acuity,stereopsis and contrast sensitivity.METHODS:This cross-sectional study was conducted in the optometry clinic of the Shahid Beheshti School of Rehabilitation on 48 students in 2021-2022.All of them had eye health and normal visual function and could have refractive errors or not.Light intensity of 4 lx was considered equivalent to photopic light condition and light intensity of 1 lx was considered to be equivalent to mesopic light condition.The amount of refractive error was checked by auto refractometer and its changes in mesopic light condition were subjectively measured.Also,visual acuity,stereopsis and contrast sensitivity(in five spatial frequencies of 1.5,3,6,12,and 18 cycles per degree),were measured first in photopic light condition and then in mesopic light condition,by Snellen control vision chart,stereo butterfly test and the M&S technology monitor test respectively.RESULTS:In the 48 student subjects with an average age of 22.69±3.56y,mean of refractive error as sphere equivalent,visual acuity and stereopsis were-1.25±1.74 diopters,0 logMAR,44.37±13.03 seconds of arc,respectively in photopic light condition while in mesopic light was equal to-1.56±1.75 diopters,0.12±0.09 logMAR and 50.62±33.35 seconds of arc,respectively.The mean of contrast sensitivity measured at spatial frequencies of 1.5,3,6,12,and 18 cycles per degree in photopic condition was equal to 2.38±0.04,2.37±0.07,2.04±0.21,1.27±0.32,0.82±0.27 logarithm of contrast sensitivity,respectively and in mesopic lighting condition was equal to 2.34±0.12,2.30±0.16,1.84±0.28,1.02±0.28,0.63±0.24 logarithm of contrast sensitivity,respectively.Statistical analysis showed a significant difference between the two lighting conditions in all evaluated variables[refractive error(P<0.001),visual acuity(P<0.001),stereopsis(P=0.008)and contrast sensitivity(P<0.001)].CONCLUSION:The refractive error of the student subjects in mesopic light condition change towards myopia,and its amount is clinically significant.Also,the examination and comparison of the factors of visual acuity,stereopsis and contrast sensitivity in these two lighting conditions show that the decrease in brightness level to the mesopic level causes a decrease in the aforementioned visual functions.

Ransomware Classification Framework Using the Behavioral Performance Visualization of Execution Objects

A ransomware attack that interrupted the operation of Colonial Pipeline(a large U.S.oil pipeline company),showed that security threats by malware have become serious enough to affect industries and social infrastructure rather than individuals alone.The agents and characteristics of attacks should be identified,and appropriate strategies should be established accordingly in order to respond to such attacks.For this purpose,the first task that must be performed is malware classification.Malware creators are well aware of this and apply various concealment and avoidance techniques,making it difficult to classify malware.This study focuses on new features and classification techniques to overcome these difficulties.We propose a behavioral performance visualization method using utilization patterns of system resources,such as the central processing unit,memory,and input/output,that are commonly used in performance analysis or tuning of programs.We extracted the usage patterns of the system resources for ransomware to performbehavioral performance visualization.The results of the classification performance evaluation using the visualization results indicate an accuracy of at least 98.94%with a 3.69%loss rate.Furthermore,we designed and implemented a framework to perform the entire process—from data extraction to behavioral performance visualization and classification performance measurement—that is expected to contribute to related studies in the future.

Preliminary evaluation of the VIsion PERformance(VIPER) simulator

Background:This study evaluated the VIsion PERformance(VIPER)simulator’s ability to assess the functional visual performance in warfighters conducting civilian and military tasks.Methods:Thirty service members,aged 25–35 years old with a best corrected distance visual acuity(VA)better than or equal to 20/20 or logarithm of the minimum angle of resolution(logMAR)0.00,were randomized to locate and identify road signs and mock improvised explosive devices(IEDs)under either daytime conditions or with infrared imagery,with(cc)and without(sc)wearing their habitual correction.Participants also underwent binocular uncorrected(UDVA)and corrected(CDVA)visual assessment,refraction,contrast sensitivity testing and wavefront aberrometry.Results:The mean age was 28.47 years.The manifest spherical equivalent was–3.16±1.75 diopters(D),the UDVA in both eyes(OU)was logMAR 0.83±0.47,and the CDVA OU was–0.11±0.06.For VIPER,the mean difference in the detection distance(DD)for road signs ccDD vs.scDD was(76.7±52.8)m(P<0.001).The average difference in identification distance(ID)ccID vs.scID was(13.9±6.3)m(P<0.001).The mean accuracies were 83.5%and 27.9%for cc and sc,respectively(P<0.001).The regression analysis indicated that a 1.6 m change in the distance accounts for a 1%change in the accuracy(P=0.002).Without correction,a 4.1 m change accounts for a 1%change in the accuracy(P<0.001).The average IED ccDD was(29.9±8.2)m,and that for scDD was(13.2±13.6)m(P<0.001).The average IED ccID was(32.2±6.2)m and that for the scID was(7.4±10.3)m(P<0.001).The mean IED identification accuracy was 46.7 and 11.4%for cc and sc,respectively(P<0.001).Conclusions:The preliminary results reflect VIPER’s ability to assess functional visual performance when detecting and identifying signs and IEDs.Furthermore,VIPER is able to detect performance changes with and without correction.

Study of road tunnel threshold zone lighting reduction coefficient

The luminance in the road tunnel threshold zone attracts broad attention due to its enormous energy consumption and direct influence on tunnel transportation security.Current lighting design methods in threshold zones mostly adopt the reduction coefficient method.However,the determination of reduction coefficient k simply considers tunnel design speed and flow rate,while excluding outside tunnel luminance and threshold zone color temperature and luminance,which have a major impact on driver visual adaptation.Existing problems in the determination of k value are analyzed;a visual performance experiment is utilized;and the reaction time of drivers in changeable outside tunnel luminance and threshold zone color temperature and luminance conditions is obtained;thus,the equations concerning reduction coefficient variation law are derived.In the end,a comparative analysis is made of the k values of the reduction coefficient stipulated by various norms under different color temperature conditions.

Effects of smartphone icon background shapes and figure/background area ratios on visual search performance and user preferences

Smartphones are becoming increasingly popular, users are provided with various interface styles with different designed icons. Icon, as an important competent of user interface, is regarded to be more efficient and pleasurable. However, compared with desktop computers, fewer design principles on smartphone icon were proposed. This paper investigated the effects of icon background shape and the figure/background area ratio on visual search performance and user preference. Icon figures combined with six different geometric background shapes and five different figure/ background area ratios were studied on three different screens in experiments with 40 subjects. The results of an analysis of variance （ANOVA） showed that these two inde- pendent variables （background shape and figure/background area ratio） significantly affected the visual search performance and user preference. On 3.5-in （1 in=0.025 4 m） and 4.0-in displays, unified backgroundwould be optimal, shapes such as square, circle and transitions between them （e.g., rounded square, squircle, etc.） are recommended because backgrounds in these shapes yield a better search time performance and subjective satisfaction for ease of use, search and visual preference. A 60% figure/background area ratio is the most appropriate for smartphone icon design on the 3.5-in screen, while a 50% area ratio could be a suggestion for both relatively optimized search performance and user preference on 4.0-in. In terms of the 4.7-in, icon figure is used di- rectly for its better performance and preference compared with icons with background.

Macular carotenoid supplementation improves disability glare performance and dynamics of photostress recovery

Background:The so-called macular carotenoids(MC)lutein(L),zeaxanthin(Z),and meso-zeaxanthin(MZ)comprise the diet-derived macular pigment(MP).The purpose of this study was to determine effects of MC supplementation on the optical density of MP(MPOD),repeated-exposure photostress recovery(PSR),and disability glare(DG)thresholds.Methods:This was a double-blind,placebo-controlled trial.Fifty-nine young(mean age=21.7),healthy volunteers participated in this study.Subjects supplemented their daily diet with either 10 mg L+2 mg total Z(1 mg Z+1 mg MZ;n=24),20 mg L+4 mg total Z(2 mg Z+2 mg MZ;n=25),or placebo(n=10)for 12 months.The primary outcome was a composite measure of visual performance in glare,defined by change in DG and PSR.Secondary outcomes included MPOD and visual fatigue.The primary endpoint for outcomes was 12 months.MPOD was assessed with customized heterochromatic flicker photometry.PSR times for an 8 cycle/degree,15%contrast Gabor patch target were determined after each of five successive exposures to intense LED lights.DG threshold was defined as the intensity of a ring of lights through which subjects were able to maintain visibility of the aforementioned target.Measures of all parameters were conducted at baseline,6 months,and 12 months.Repeated-measures ANOVA,and Pearson product-moment correlations were used to determine statistically significant correlations,and changes within and between groups.Results:MPOD for subjects in both supplementation groups increased significantly versus placebo at both 6-and 12-month visits(p<0.001 for all).Additionally,PSR times and DG thresholds improved significantly from baseline compared to placebo at 6-and 12-month visits(p<0.001 for all).At baseline,MPOD was significantly related to both DG thresholds(r=0.444;p=0.0021)and PSR times(r=-0.56;p<0.001).As a function of MPOD,the repeated-exposure PSR curves became more asymptotic,as opposed to linear.The change in subjects’DG thresholds were significantly related to changes in PSR times across the study period(r=-0.534;p<0.001).Conclusions:Increases in MPOD lead to significant improvements in PSR times and DG thresholds.The asymptotic shape of the repeated-exposure PSR curves suggests that increases in MPOD produce more consistent steady-state visual performance in bright light conditions.The mechanism for this effect may involve both the optical filtering and biochemical(antioxidant)properties of MP.Trial registration:ISRCTN trial registration number:ISRCTN54990825.Data reported in this manuscript represent secondary outcome measures from the registered trial.

Ocular higher-order aberrations features analysis after corneal refractive surgery

Background The recent studies have shown that visual performance might be affected by the ocular aberration after the corneal refractive surgery, and try to minimize it. This study was to investigate the effects of photorefractive keratectomy （PRK） and laser in situ keratomileusis （LASIK） on the higher order of wavefront aberration and analysis of their characteristics. Method This prospective study involved 32 eyes with similar refractive powers （-5.0 D to -6.0 D preoperatively）. LASIK and PRK were performed with the same parameters of 6 mm diameter optical zone and 7 mm diameter transition zone ablation. Wavefront aberrations were tested using a ray tracing technique preoperatively and 3 months postoperatively. Three measurements were obtained for each condition; the root mean squared wavefront error （RMS）, values for overall wavefront aberrations and each order of the Zernike aberrations were analyzed using the Matlab software. The 2-tailed t test was used for statistical analysis. Results Overall higher order aberrations were increased from （0.55±0.26） pm preoperatively to （0.93±0.37） pm for PRK and （0.79±0.38） pm for LASlK postoperatively. This was a 1.69 fold increase in the PRK group （t=3.95, P〈0.001） and a 1.43 fold increase in the LASIK group （t=2.60, P〈0.05）. At 3 months, the mean RMS value for higher-order （3rd to 6th） were significantly increased compared with the corresponding preoperative values （P〈0.05）. The fourth order aberrations, spherical like aberration, were dominant by a 2.64 fold in PRK and a 2.31 fold in LASIK. Different influences of the PRK group and LASIK group were shown in the various zernike components. The statistically significant differences were seen in C4^0. C4^4. C5^3,C5^3. C5^5 and C6^2 of the PRK group and C3^-3, C4^0, C5^-5, C5^5, C6^-2 of the LASIK group, which represents a 7.42, 3.58, 9.21,2.72 and 5.3 ford increases in PRK group, and 6.40, 10.80, 11.06, 3.47 and 6.09 fold increases in LASIK group, respectively. C3^3 in LASIK was higher and C5^＋1 and C5^＋3 were lower than those in the PRK group. C4^0 （spherical aberration） values were similar between PRK and LASIK, however, C3^-1 and C3^1 （coma） in LASIK were higher than those in PRK, but these differences are of no statistical significance. Conclusions PRK and LASIK may increase ocular higher-order aberrations, but they both have their own features. The difference between the two types of surgery may be correlated with the change of the corneal shape, the conversion of biodynamics, the healing of the corneal cut, and re-structured corneal epithelium and/or the stroma.

Neurofeedback Treatment Study for ADHD by Using the Brain-Computer Interface Neurofeedback System

Neurofeedback or electroencephalogram(EEG) biofeedback technology is widely used in clinical rehabilitation field. In this paper, we used a brain-computer interface(BCI) neurofeedback system for attention deficit hyperactivity disorder(ADHD) children treatment.After 20 training sessions, integrated visual and auditory-conhnuous performance test(IVA-CPT), DSM-IV and conner scale results suggested that the attention ofsubjectshad been strengthened, which showed that the BCI neurofeedback system could provide an effective therapyfor treating ADHDchildren.