Das „Frankfurt-Freiburg Contrast and Acuity Test System“ (FF-CATS)

BACKGROUND: The purpose of the present study was to evaluate a computerized test for measurement of contrast sensitivity thresholds under variable ambient and glare luminance levels.METHODS: A total of 40 eyes of 40 healthy subjects were examined with the FF-CATS and the Functional Acuity Contrast Test (FACT) at 0.167 cd/m(-2) (mesopic) and 167 cd/m(-2) (photopic). Measurements were performed twice with and without glare in a randomized fashion. Tests were evaluated according to three criteria: (1) repeatability, (2) discriminative ability, and (3) validity.RESULTS: The FF-CATS showed a higher discriminative ability between the two groups compared to the FACT charts. Under photopic conditions, the COR value was 0.39 for the FF-CATS and 0.26 for the FACT charts; under mesopic illumination, the COR value for the FF-CATS was 0.46 and 0.36 for the FACT charts.CONCLUSION: The FF-CATS is a reliable, sensitive, valid, and flexible test system for the determination of visual acuity and contrast sensitivity thresholds under variable ambient and glare luminance conditions.     

非球面人工晶状体植入术后对比敏感度观察

目的:评价白内障超声乳化吸除联合非球面人工晶状体(intraocularlens,IOL)植入术后对比敏感度(contrast sensitivity,CS)的变化。方法:对45例(48眼)老年性白内障患者实施超声乳化吸除联合IOL植入术,24例(25眼)植入Z9001非球面IOL(AIOL);21例(23眼)植入AR40e单焦球面IOL(SI-OL)。术后3mo应用美国Stereo Optical公司产的OPTEC 6500P视功能测试系统的对比敏感度测试包分别在空间频率为1.5,3,6,12,18cpd的昼及夜照明条件下对手术眼进行有眩光和无眩光的对比敏感度检查。所得数据进行t检验。结果:术后3mo,AIOL组在大部分空间频率下CS普遍优于SIOL组,差异有统计学意义(P<0.05),在1.5cpd有眩光昼及夜照明条件,AIOL组的CS与SIOL组无统计学差异。结论:植入Z9001非球面IOL后,提高了患者的对比敏感度,明显改善患者的视觉质量.     

Visual performance of aspherical and spherical intraocular lenses: intraindividual comparison of visual acuity, contrast sensitivity, and higher-order aberrations

PURPOSE: To intraindividually compare visual performance in terms of photopic high-contrast visual acuity (HCVA), mesopic HCVA, mesopic low-contrast visual acuity (LCVA), and contrast sensitivity (CS) in patients after implantation of either an aspherical or a spherical intraocular lens (IOL). SETTING: Department of Ophthalmology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. METHODS: Forty eyes of 20 patients were randomized to implantation of an aspherical IOL (Tecnis Z9000, AMO) in 1 eye and a spherical IOL (Sensar AR40e, AMO) in the other eye. Three to 4 months postoperatively, photopic HCVA (270 cd/m(2)) was measured with the observer-independent Frankfurt-Freiburg Contrast and Acuity Test System (FF-CATS) and high-mesopic HCVA and LCVA (8 cd/m(2)) were measured with Early Treatment Diabetic Retinopathy Study charts. CS was assessed with the FF-CATS under photopic (167 cd/m(2)), high-mesopic (1.67 cd/m(2)), and low-mesopic (0.167 cd/m(2)) luminance conditions with and without glare. For each individual eye, higher-order wavefront aberrations were reconstructed for a physiological mesopic pupil diameter. Intraindividual differences (Delta(i)) in visual acuity, contrast sensitivity, and higher-order aberrations (HOAs) were calculated, and the influence of age and Delta(i) HOA on Delta(i) contrast sensitivity (logCS) under high-mesopic conditions was investigated using multiple regression analysis. RESULTS: There were no statistically significant differences between the Tecnis IOL and the Sensar IOL in visual acuity measurements or contrast sensitivity measurements. For physiological mesopic pupil diameter, primary spherical aberration (Z(4)(0)) was significantly lower in the Tecnis group (P<.001). For all parameters studied except Z(4)(0), the Delta(i) values were distributed around zero. Multiple regression analysis showed only a partial influence of Delta(i) Z(4)(0) on Delta(i) logCS (adjusted R(2) = 0.49) but did not show any influence of age, coma-like aberration, or residual HOA. CONCLUSIONS: Although Z(4)(0) was significantly lower in the eyes with the aspherical IOL, no statistically significant differences were found between aspherical and spherical IOLs in LCVA, HCVA, and contrast sensitivity. Statistical analysis of intraindividual contrast sensitivity differences showed that in most patients, this Z(4)(0) difference was too low to have an effect on contrast sensitivity.     

Functional results after intraocular lens implantation with or without blue light filter: an intraindividual comparison

BACKGROUND: The new generation of intraocular lenses (IOL) with an additional blue light filter has a slight yellowish colour (compared to the IOLs with only a UV filter) due to its different light transmitting properties. This could have an effect on contrast sensitivity and subjective visual perception. PATIENTS AND METHODS: In this intraindividual prospective comparative study including 14 cataract patients without further ocular pathology, a blue light filtering IOL (SN60AT, Alcon) was implanted in one eye and 1 month later a conventional single-piece IOL (SA60AT, Alcon) was fitted into the fellow eye. The visual acuity and the clinical findings were assessed at one day and four weeks post-operatively. Contrast sensitivity was tested under defined mesopic (6 cd/m(2)) and high mesopic (18.8 cd/m(2)) light conditions in the Ginsburg Box using the Functional Acuity Contrast Test (F.A.C.T.). Furthermore, subjective differences in the visual perception of both eyes were noted. RESULTS: The contrast sensitivity testing 1 day and 1 month postoperatively, revealed no statistically significant differences (P > 0.008) between both IOL types for all spatial frequencies (1.5/3/6/12/18 cpd) and light levels. 13 patients (85 %) reported no differences in the colour perception of both eyes, and none had visual disturbances. CONCLUSION: This intraindividual comparison revealed no relevant differences concerning mesopic contrast sensitivity and the subjective visual perception after implantation of one IOL with or without a blue light filter.     

Contrast sensitivity and glare disability after implantation of AcrySof IQ Natural aspherical intraocular lens: prospective randomized masked clinical trial

PURPOSE: To evaluate contrast sensitivity and glare disability after implantation of an AcrySof IQ Natural SN60WF aspherical intraocular lens (IOL) (Alcon Laboratories). SETTING: Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS: One hundred twenty consecutive patients who had phacoemulsification in a prospective triple-masked trial were randomized to receive an AcrySof SA60AT IOL (40 eyes), AcrySof Natural SN60AT IOL (40 eyes), or AcrySof IQ SN60WF IOL (40 eyes). At 3 months, contrast sensitivity was measured using the CSV-1000E contrast sensitivity chart test face (Vector Vision) at 3, 6, 12, and 18 cycles per degrees (cpd) under photopic conditions (85 cd/m(2)) and mesopic conditions (2.7 cd/m(2)) with 4.0 mm and 6.0 mm fixed central apertures, with and without glare. The Kruskal-Wallis test was used and a pair-wise comparison performed. The main outcome measure was the difference in contrast sensitivity between IOLs at each spatial frequency. RESULTS: The best corrected visual acuity was similar between the 3 IOL groups (P = .6). The AcrySof IQ group had significantly higher contrast sensitivity at 18 cpd under photopic conditions (P = .008); at 3, 6, 12, and 18 cpd during mesopic testing with a 4.0 mm aperture without glare (P = .018, P = .011, P = .007, and P = .0001, respectively) and with glare (P = .003, P = .006, P = .005, and P = .004, respectively); and at all spatial frequencies during mesopic testing with a 6.0 mm aperture without glare (P = .018, P = .006, P = .009, and P = .0001, respectively) and with glare (P = .019, P = .002, P = .01, and P = .017, respectively). CONCLUSION: Eyes with the AcrySof IQ SN60WF IOL had significantly higher contrast sensitivity than eyes with an AcrySof SA60AT or AcrySof Natural SN60AT IOL at all spatial frequencies during mesopic testing (with and without glare) with 4.0 and 6.0 mm artificial pupil.     

Contrast sensitivity after LASIK flap creation with a femtosecond laser and a mechanical microkeratome

PURPOSE: To compare the effects on contrast sensitivity of the IntraLase femtosecond laser for flap creation (IntraLASIK) and standard LASIK for myopia. METHODS: Two hundred eyes of 100 consecutive patients underwent LASIK treatment using the VISX S2 laser system. The femtosecond laser (15 kHz IntraLase) was used for flap creation in 100 eyes (50 patients) and a mechanical microkeratome (Carriazo-Barraquer) was used in 100 eyes (50 patients). Best spectacle-corrected contrast sensitivity was measured before and 6 months postoperatively in the IntraLASIK and mechanical LASIK groups. The IntraLASIK and mechanical LASIK-induced changes in contrast sensitivity were compared under photopic (85 cd/m2) and mesopic (5, 2.5, and 0.1 cd/m2) conditions. RESULTS: Contrast sensitivity for eyes after IntraLASIK did not differ from preoperative values at the photopic level (85 cd/m2). However, under mesopic conditions, a statistically significant reduction (P < .01) in contrast sensitivity was found at high spatial frequencies (12 and 18 cpd), although no significant contrast sensitivity differences were observed at low and middle spatial frequencies (P > .01 for 1.5, 3, and 6 cpd). No statistically significant differences were found between IntraLASIK and mechanical LASIK for 1.5, 3, and 6 cpd at any luminance level (P > .01). IntraLASIK showed better contrast sensitivity than mechanical LASIK under mesopic conditions at 12 cpd and photopic and mesopic conditions at 18 cpd (P < .01). CONCLUSIONS: IntraLASIK surgery demonstrated better contrast sensitivity at high spatial frequencies under photopic and mesopic conditions than mechanical LASIK.     

Visual acuity and contrast sensitivity comparison between Tecnis and AcrySof SA60AT intraocular lenses: A multicenter randomized study

PURPOSE: To evaluate best corrected visual acuity (BCVA) and photopic and mesopic contrast sensitivity in pseudophakic patients implanted either with the aspheric intraocular lens (IOL) designed to correct for corneal spherical aberration or with a conventional IOL. SETTING: Three surgical centers participated this prospective randomized masked comparative study. METHODS: Thirty eyes of 30 patients after aspheric lens implantation (Pfizer/Pharmacia Tecnis Z9000) were compared with 30 eyes of 30 age-matched patients after conventional lens implantation (Alcon AcrySof SA60AT). Two to three months after surgery, best spectacle corrected distance visual acuity was measured using the Early Treatment Diabetic Retinopathy Study chart. Contrast sensitivity was measured by sinusoidal grating charts for distance at photopic (85 cd/m(2)) and mesopic (6 cd/m(2)) luminance level with optical correction in place. Tested spatial frequencies were 1.5, 3, 6, 12, and 18 cycles per degree (cpd). RESULTS: The mean BCVA was -0.053 +/- 0.044 logMAR in eyes with the aspheric Tecnis IOL and 0.006 +/- 0.059 logMAR in eyes with the conventional AcrySof IOL (P=.0001). Eyes with the aspheric IOL showed better contrast sensitivity at spatial frequencies of 3 cpd (P<.05) and 6, 12, and 18 cpd (P<.01) in photopic and in mesopic conditions. Peak improvement occurred at 18 cpd and was 36% (0.29 log units) in photopic and 54% (0.27 log units) in mesopic conditions. CONCLUSIONS: The aspheric Tecnis IOL yielded better BCVA and better distance contrast sensitivity than the conventional IOL. The differences were clinically significant for higher spatial frequencies. The results give some suggestions for further studies.     

人工晶状体前表面非球面化改良能够改善视觉质量

目的:根据对比敏感度结果比较前表面改良的非球面Tecnis Z9000 IOL和标准的911A IOL的光学性能.方法:Tecnis Z9000硅凝胶IOL和911A IOL具有共同的基本特征包括12mm总长度、三片直边双凸6mm的光学直径和成角的聚丙乙烯C襻.对连续10例双侧白内障患者(20眼)进行了随机前瞻研究,所有患者都接受了白内障超声乳化手术并随机于1眼植入Tecnis Z9000IOL,另1眼在术后6wk内植入911A IOL作为对照,术后6wk进行对比敏感度检查,所得数据采用秩和检验进行比较.结果:随机植入Tecnis IOL组的术前平均最佳Snellen矫正视力为6/8.5(0.70),植入911A I0L组为6/9.4(0.64),所有20眼术后最佳矫正视力都达到了6/6(1.0).术后对比敏感度分析发现两组在12和18 cpd(明视)、1.5和3 cpd(暮视)以及1.5和3 cpd(暮视伴眩光)均有统计学差异(P＜0.05)结论:Tecnis Z9000 I0L被证明其对比敏感度在明视高空间频率和暮视低空间频率方面均显著优于911A IOL.     

Ocular aberrations and contrast sensitivity after cataract surgery with AcrySof IQ intraocular lens implantation Clinical comparative study

PURPOSE: To determine whether implantation of an intraocular lens (IOL) with a modified posterior aspherical surface (AcrySof IQ, Alcon Surgical Laboratories) results in reduced ocular aberrations (spherical aberration) and improved contrast sensitivity after cataract surgery. SETTING: Brasilia Ophthalmologic Hospital, Brasilia, and Sao Geraldo Eye Hospital, Federal University of Minas Gerais, Belo Horizonte, Brazil. METHODS: In an intraindividual randomized prospective study of 25 patients with bilateral cataract, an IOL with a modified posterior surface (AcrySof IQ) was compared with a biconvex IOL with spherical surfaces (AcrySof Natural, Alcon). Ocular aberrations with a 5.0 mm and 6.0 mm pupil were measured with a Hartmann-Shack aberrometer. Quality of vision was measured by visual acuity and contrast sensitivity under mesopic and photopic conditions. All patients were followed for 3 months. RESULTS: There were no statistically significant differences between eyes in postoperative uncorrected and best corrected distance visual acuities after a follow-up of 1 month and 3 months. Postoperatively, there was a statistically significant between-group difference in contrast sensitivity under photopic conditions without glare at 18 cycles per degree (cpd) (P = .04) and under mesopic conditions without glare at all spatial frequencies (3 cpd, 6 cpd, 12 cpd, and 18 cpd; P = .03, P = .009, P = .003, and P = .003, respectively) and with glare at 3 cpd and 6 cpd (P = .001 and P = .02, respectively). The difference in higher-order aberration (HOA) values between groups was statistically significant with a 5.0 mm and 6.0 mm pupil, with the AcrySof IQ IOL inducing less HOA than the AcrySof Natural IOL. Eyes with an AcrySof IQ IOL also had statistically significant less spherical aberration than eyes with an AcrySof Natural IOL with both pupil diameters (P<.001). CONCLUSIONS: The AcrySof IQ IOL with a modified posterior surface induced significantly less HOA and spherical aberration than the AcrySof Natural IOL. Contrast sensitivity was better under mesopic conditions with the AcrySof IQ IOL.     

Contralateral comparison of visual outcome of AcrySof IQ and SA60AT intraocular lenses

Objective: To compare the visual performance of aspherical AcrySof IQ (SN60WF) and SA60AT spherical intraocular lenses after cataract surgery. Design: Prospective comparative study.Participants: Seventy eyes of 35 patients who underwent phacoemulsification for cataract surgery.Methods: The IQ lens was implanted in one eye and the SA60AT lens in the other eye of every patient. Refraction, uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA) were measured 1 and 3 months after surgery. At 3 months’ follow-up, the quality of vision, in terms of contrast sensitivity (CS) with and without glare and higher-order aberrations (HOA), was also determined.Results: At 3 months postoperative, the mean UCVA in the IQ and SA60AT groups was 0.25 (SD 0.26) and 0.30 (SD 0.27), respectively, and BSCVA was 0.10 (SD 0.16) in both groups. Spherical refractive error was -0.56 (SD 1.03) D and -0.47 (SD 0.64) D in the IQ and SA groups, respectively. In photopic conditions without glare, IQ eyes had statistically significant better CS at 12 cycles per degree (cpd) and better function at 3 and 18 cpd, and in mesopic conditions without glare, IQ eyes also had better results at 3, 12, and 18 cpd. In mesopic conditions with glare, IQ eyes also had better CS in 6 and 18 cpd. In terms of aberrations, the IQ group had significantly (p < 0.05) lower spherical aberrations, root mean-square, and coma X and Y values with 6 mm pupil size than the SA group.Conclusions: In terms of refraction, no significant difference was found between these 2 types, but there was a difference in the quality of vision in photopic and mesopic conditions and also HOA. Those with reactive and dilated pupils, such as younger patients and night drivers, may be more satisfied with IQ aspherical lenses.     

The usefulness of Vistech and FACT contrast sensitivity charts for cataract and refractive surgery outcomes research

AIM: To investigate the repeatability and sensitivity of two commonly used sine wave patch charts for contrast sensitivity (CS) measurement in cataract and refractive surgery outcomes. METHODS: The Vistech CS chart and its descendant, the Functional Acuity Contrast Test (FACT), were administered in three experiments: (1) Post-LASIK and age matched normal subjects; (2) Preoperative cataract surgery and age matched normal subjects; (3) Test-retest repeatability data in normal subjects. RESULTS: Contrast sensitivity was similar between post-LASIK and control groups and between the Vistech and FACT charts. The percentage of subjects one month post-LASIK achieving the maximum score across spatial frequencies (1.5, 3, 6, 12, 18 cycles per degree) were (50, 33, 13, 13, 0 respectively) for FACT, but only (0, 0, 13, 4, 0 respectively) for Vistech. A small number of cataract patients also registered the maximum score on the FACT, but up to 60% did not achieve the minimum score. Test-retest intraclass correlation coefficients varied from 0.28 to 0.64 for Vistech and 0.18 to 0.45 for FACT. Bland-Altman limits of agreement across spatial frequencies were between +/-0.30 and +/-0.85 logCS for Vistech, and +/-0.30 to +/-0.75 logCS for FACT. DISCUSSION: The Vistech was confirmed as providing poorly repeatable data. The FACT chart, likely because of a smaller step size, showed slightly better retest agreement. However, the reduced range of scores on the chart due to the smaller step size led to ceiling (post-LASIK) and floor (cataract) effects. These problems could mask subtle differences between groups of patients with near normal visual function as found post-refractive or cataract surgery. The Vistech and FACT CS charts are ill suited for refractive or cataract surgery outcomes research.     

Tritan colour contrast sensitivity function in refractive multifocal intraocular lenses

AIMS: To compare tritan colour contrast sensitivity (CCS), without and with glare, in patients with refractive multifocal intraocular lenses (IOLs) and with monofocal intraocular lenses. METHODS: Tritan CCS was determined (Moorfields Vision System, CH Electronics) in 15 eyes (14 patients, 75.7 (+/-6.6) years) with a refractive multifocal IOL (Allergan SA 40N) and in 11 eyes (10 patients, 73.7 (+/-6.4) years) with a monofocal IOL (Allergan SI 40 NB). Measurements were made monocularly under mesopic conditions at a distance of 2 metres from the monitor with best distance refraction plus 0.5 D at 0.5, 1, 3, 6, 11.4, and 22.8 cycles per degree (cpd). The test was then repeated for the multifocal IOLs, adding minus 2.5 D to the best distance refraction to force the patient to use the near focus. Both lenses were also investigated under glare conditions with the same set-up and using the brightness acuity tester (BAT). RESULTS: The tritan CCS function without glare in multifocal lenses through the distance focus was nearly identical to that through the near focus. The following statistically significant differences were measured: the CCS function without glare for the multifocal lens was worse at 0.5 cpd and 1.0 cpd than that of the monofocal lens. In CCS testing of the multifocal group with glare at 6 cpd, the results through the distance focus were better than the results through the near focus. For the CCS function with glare, the values for the distance focus in the multifocal lens were worse than the values for the monofocal lens at 0.5 cpd and 1 cpd. In CCS testing with glare through the near focus and CCS testing through the monofocal lens, the monofocal lens performed better at 0.5 cpd, 1 cpd, 3 cpd, and 6 cpd. CONCLUSION: Refractive multifocal intraocular lenses influence tritan CCS function compared to monofocal lenses.     

Contrast sensitivity after LASIK, LASEK, and wavefront-guided LASEK with the VISX S4 laser

PURPOSE: To evaluate the changes in contrast sensitivity and glare after corneal refractive surgery for moderate myopia. METHODS: The study comprised 267 eyes of 149 patients who underwent LASIK, laser epithelial keratomileusis (LASEK), or wavefront-guided LASEK with the VISX STAR S4. Contrast sensitivity was measured with VCTS 6500 before surgery and at 2 and 6 months postoperatively. Glare was evaluated using questionnaires and the ALC glare test at last follow-up. Contrast sensitivity at 2 and 6 months was compared with preoperative contrast sensitivity in each group. Glare sensitivity in each group was compared to normal controls. RESULTS: Contrast sensitivity did not change after LASIK (P > .05). Contrast sensitivity of 3 and 6 cycles per degree (cpd) at 2 months increased after LASEK (P < .05) and contrast sensitivity of 6, 12, and 18 cpd at 2 months and 3, 6, 12, and 18 cpd at 6 months improved in wavefront-guided LASEK (P < .05). Glare test and questionnaires did not show any significant difference between the groups. CONCLUSIONS: Wavefront-guided LASEK induced significant increases in contrast sensitivity of moderate myopes at high spatial frequencies under mesopic conditions by 6 months. Glare was not affected by the different refractive procedures.     

Improved contrast sensitivity and visual acuity after wavefront-guided laser in situ keratomileusis: in-depth statistical analysis

PURPOSE: To evaluate changes in contrast sensitivity and visual acuity following wavefront-guided laser in situ keratomileusis (LASIK) procedures with the Visx CustomVue system. SETTING: Six clinical sites that participated in an Investigational Device Exemption clinical study. METHODS: Two hundred seventy-four myopic astigmatic eyes (spherical equivalent range -0.63 to -6.00 diopters) completed 6 months of follow-up examinations. Wavefront-guided procedures using the WaveScan aberrometer and Star S4 excimer laser system with variable spot scanning were performed at 6 clinical locations. Visual acuity and contrast sensitivity under photopic, mesopic, and mesopic-with-glare lighting conditions were tested preoperatively and over a 6-month follow-up period. This study was a retrospective analysis of contrast sensitivity data with controls for the effects of retinal magnification, mesopic pupil size, and the influence of prior soft contact lens wear on visual outcome. RESULTS: Patients experienced statistically significant improvements in contrast sensitivity at all spatial frequencies and under all lighting conditions (P<.05, Student t test). Contrast sensitivity under mesopic conditions with glare improved in 40% of patients. There was more improvement at higher (12 cycles per degree [cpd], 18 cpd) than lower (3 cpd) spatial frequencies. No correlation was found between mesopic pupil size and contrast sensitivity. Results stratified by spectacle or soft contact lens wear were similar. Soft contact lens wearers had slightly higher disability glare scores than spectacle wearers. CONCLUSIONS: A significant number of patients experienced improved corneal optical quality after wavefront-guided LASIK. The contrast sensitivity in most patients was unchanged. Contrast sensitivity improved in a significant number of patients. There was no correlation between mesopic pupil size and mesopic or mesopic-with-glare contrast performance. Spectacle wearers improved more than soft contact lens wearers.     

Using the Freiburg Acuity and Contrast Test to measure visual performance in USAF personnel after PRK.

PURPOSE: Photorefractive keratectomy (PRK) may be an alternative to spectacle and contact lens wear for United States Air Force (USAF) aircrew and may offer some distinct advantages in operational situations. However, any residual corneal haze or scar formation from PRK could exacerbate the disabling effects of a bright glare source on a complex visual task. The USAF recently completed a longitudinal clinical evaluation of the long-term effects of PRK on visual performance, including the experiment described herein. METHODS: After baseline data were collected, 20 nonflying active duty USAF personnel underwent PRK. Visual performance was then measured at 6, 12, and 24 months after PRK. Visual acuity (VA) and contrast sensitivity (CS) data were collected by using the Freiburg Acuity and Contrast Test (FrACT), with the subject viewing half of the runs through a polycarbonate windscreen. Experimental runs were completed under 3 glare conditions: no glare source and with either a broadband or a green laser (532-nm) glare annulus (luminance approximately 6090 cd/m) surrounding the Landolt C stimulus. RESULTS: Systematic effects of PRK on VA relative to baseline were not identified. However, VA was almost 2 full Snellen lines worse with the laser glare source in place versus the broadband glare source. A significant drop-off was observed in CS performance after PRK under conditions of no glare and broadband glare; this was the case both with and without the windscreen. As with VA, laser glare disrupted CS performance significantly and more than broadband glare did. CONCLUSIONS: PRK does not appear to have affected VA, but the changes in CS might represent a true decline in visual performance. The greater disruptive effects from laser versus broadband glare may be a result of increased masking from coherent spatial noise (speckle) surrounding the laser stimulus.     

非球面人工晶状体植入术后视觉质量对比分析

目的:评价3种非球面人工晶状体(AcrySof SN60WF、TecnisZ9001和KS-3Ai)植入术后的视觉质量。方法:采用前瞻性随机对照研究方法,收集我院老年性白内障手术患者88例126眼,平均年龄67.3±8.7岁,将入选患者按植入不同的人工晶状体(Intraocular lens,IOL)随机分为4组:AcrySofSN60WF(IQ)组(23例33眼)、TecnisZ9001组(23例33眼)、KS-3Ai组(20例29眼),SN60AT球面人工晶状体组为对照组(22例31眼)。术后随访3mo,观察指标:裸眼视力(uncorrected visual acuity,UCVA)及最佳矫正视力(best corrected visual acuity,BCVA),眼压,等效球镜度数,角膜Q值,瞳孔直径,6mm全眼球总高阶像差及四阶球差均方根值(root mean square,RMS),夜光、昼光及夜眩光3种视觉条件下的对比敏感度(contrast sensitivity,CS)。结果:术后各组的UCVA、BCVA、等效球镜度数和瞳孔直径均无统计学差异。总高阶像差和四阶球差RMS:非球面组低于球面组,差异具有统计学意义(P<0.05);非球面组间比较无统计学差异。术后角膜Q值与球差成正相关(r=0.183,P<0.05)。术后对比敏感度:与球面IOL相比,IQ,Tecnis可提高术后3种视觉条件下的CS,KS-3Ai可提高术后夜光、夜眩光两种视觉条件下的CS;非球面IOL组间比较,IQ组在昼光、夜眩光视觉条件下的CS好于Tecnis组和KS-3Ai组,TECNIS组和KS-3Ai组之间在3种视觉条件下均无统计学差异。结论:3种非球面IOL均可有效地减少术眼的总高阶像差和四阶球差。3种非球面IOL均可以提高术眼术后的CS,IQ组在昼光、夜眩光视觉条件下的CS与Tecnis组和KS-3Ai组相比较差异具有统计学意义,Tecnis组和KS-3Ai组之间在3种视觉条件下的CS均无统计学差异。     

Improving quality of vision with an anterior surface modified prolate intraocular lens: A prospective clinical trial

AIM: To compare the optical performance of the anterior surface modified prolate Tecnis Z9000 IOL with the standard 911A IOL in terms of contrast sensitivity outcomes. · METHODS: The Tecnis Z9000 silicone IOL shares the same basic characteristics with the 911A IOL including a 12.0mm overall diameter, 3-piece equiconvex 6.0mm optic and angulated cap C polyvinylidene fluoride haptics. This is a randomized prospective study that involved ten consecutive patients (20 eyes) with bilateral cataracts. Each patient underwent phacoemulsification and received randomly the Tecnis Z9000 IOL in one eye and the control (911A IOL) in the fellow eye within 6 weeks period of one another. Contrast sensitivity was measured after six postoperative weeks. The collected data were analyzed through using Mann Whitney U test. · RESULTS: The mean pre-operative best spectacle corrected Snellen visual acuity in the eyes that were randomly selected to receive the Tecnis IOL was 6/8.5 (0.70) and in the eye selected to receive the 911A IOL was 6/9.4(0.64). Postoperatively all 20 eyes achieved best corrected Snellen visual acuity of 6/6 (1.0). Postoperative contrast sensitivity testing showed statistically significant differences (P <0.05) between the two IOLs at 12 and 18 cpd under photopic, at 1.5 and 3 cpd under mesopic, and at 1.5 and 3 cpd under mesopic with glare conditions. · CONCLUSION: The Tecnis Z9000 IOL proved to have statistically significant superior contrast sensitivity to the 911A IOL at high spatial frequencies under photopic conditions and at low spatial frequencies under mesopic and mesopic with glare conditions.     

Association between intensity of posterior capsule opacification and contrast sensitivity

PURPOSE: To investigate the correlation between change in contrast sensitivity (CS) and difference in objective posterior capsule opacification (PCO) score before and after Nd:YAG laser capsulotomy. DESIGN: Prospective interventional case series. METHODS: CS (Functional Acuity Contrast Test, or FACT, chart), distance visual acuity (Early Treatment Diabetic Retinopathy Study [ETDRS] chart), and pupil size of 30 pseudophakic eyes with PCO of varying intensity were measured before and after capsulotomy. Digital retroillumination images were taken, and the area corresponding to the pupil size was evaluated with an automated PCO analysis program known as AQUA. RESULTS: The correlation between change in PCO score and change in CS was highest (r = 0.85) for row B on the FACT chart and lowest (r = 0.09) for row E. The correlation with change in ETDRS visual acuity was 0.57. CONCLUSIONS: Objective PCO assessment by an automated image analysis system correlates well with PCO-induced loss of CS and is therefore an appropriate method for clinical studies on the development and prevention of PCO.     

Visual performance with multifocal intraocular lenses: mesopic contrast sensitivity under distance and near conditions

OBJECTIVE: To evaluate distance and near visual performance under bright (photopic) and dim (mesopic) conditions in patients who had undergone uncomplicated cataract extraction with multifocal or monofocal intraocular lens (IOL) implantation. DESIGN: Prospective, nonrandomized, masked, comparative, observational case series. PARTICIPANTS: Thirty-two eyes of 32 patients after zonal-progressive multifocal IOL implantation (Allergan Medical Optics Array SA-40N) and 32 eyes of 32 age-matched patients after monofocal IOL implantation (Allergan Medical Optics SI-40NB). INTERVENTION: All eyes underwent phacoemulsification and IOL implantation. MAIN OUTCOME MEASURES: At 18 months after surgery, the monocular contrast sensitivity (CS) function was measured with sinusoidal grating charts at distance and near, at one photopic luminance level and 2 mesopic luminance levels (85, 5, and 2.5 candelas per square meter). RESULTS: Under bright conditions, CS at distance in the multifocal group was not statistically different (P>0.01) from that in the monofocal group at any tested grating spatial frequency (1.5, 3, 6, 12, and 18 cycles per degree [cpd]). At low luminances, distance CS for the multifocal group was worse than that for the monofocal group at the highest test spatial frequencies (12 and 18 cpd; P<0.01). At near, photopic CS in the multifocal group was lower than at distance; patients with only a monofocal distance correction, however, could not detect the test gratings, even at the highest available contrast. With optimal near spectacle additions (i.e., using the distance correction of the multifocal IOL), there were no significant differences between the photopic near CS values for the multifocal and monofocal groups. When the luminance was decreased, near CS at all spatial frequencies was reduced in both groups. Contrast sensitivity in the near-corrected, multifocal group was significantly worse than in the near-corrected, monofocal group at high spatial frequencies (12 and 18 cpd). CONCLUSIONS: This work supports the findings of earlier authors that the Array multifocal IOL, with its center-distance design, is distance biased. Distance CS is within normal limits under bright photopic conditions but shows deficits at higher spatial frequencies (more than approximately 12 cpd) under dim mesopic conditions. Near CS obtained with the multifocal IOL is below that which can be achieved by an appropriate monofocal near correction, for all spatial frequencies and illumination conditions.     

Tecnis Z9000人工晶状体植入术后的视功能改变

目的:评价非球面人工晶状体(intraocular lens,IOL)TecnisZ9000对提高年龄相关性白内障患者术后视功能的作用。方法:选取年龄相关性白内障患者34例36眼,其中18眼为Tecnis Z9000组,18眼为传统球面人工晶状体组。检查术后3mo最佳矫正远视力,不同亮度环境及有、无散瞳条件下的对比敏感度(contrast sensitivity,CS)。结果:手术后3mo最佳矫正远视力Tecnis Z9000组为0.89±0.17,球面人工晶状体组为0.76±0.16,两组差异有显著性(P<0.05)。正常瞳孔下,两组晶状体在不同空间频率(1.5,3,6,12,18c/d)、不同照明条件下CS无显著差别。散瞳后Tecnis组亮环境(亮度为85cd/m2)下的12,18c/dCS及暗环境(亮度为3cd/m2)下1.5,3c/dCS均分别与同条件下的球面人工晶状体组比较差异有显著性。结论:白内障术后早期,Tecnis Z9000可提高最佳矫正远视力和对比敏感度,改善术眼视功能。