亲水性非球面与球面人工晶状体植入术后高阶像差的研究

目的：比较亲水性球面和非球面人工晶状体（intraocular lenses,IOL）对术后高阶像差（higher order aberrations,HOA）的影响。方法：66例78眼行白内障超声乳化术并顺利植入球面Softec或者非球面Ocuva人工晶状体。术前和术后第3mo使用VISX Wavescan像差计进行像差测量与比较。结果：两组间统计学无显著性差异。术后的高阶像差均方根值（root-mean-square,RMS）：Softec组0.27±0.11,Ocuva组0.28±0.13,球面像差（spherical aberration,SA）：Softec组0.11±0.07,Ocuva组0.11±0.08。结论：与球面Softec人工晶状体比较,Ocuva非球面人工晶状体似乎没有减少术后高阶像差的优势。     

Optical quality and depth-of-field of eyes implanted with spherical and aspheric intraocular lenses

PURPOSE: To compare experimental optical performance in eyes implanted with spherical and aspheric intraocular lenses (IOLs). METHODS: Corneal, total, and internal aberrations were measured in 19 eyes implanted with spherical (n=9) and aspheric (n=10) IOLs. Corneal aberrations were estimated by virtual ray tracing on corneal elevation maps, and total aberrations were measured using a second-generation laser ray tracing system. Corneal and total wave aberrations were fit to a Zernike polynomial expansion. Internal aberrations were measured by subtracting corneal from total wave aberrations. Optical performance was evaluated in terms of root-mean-square (RMS) wavefront error and Strehl ratio (estimated from the modulation transfer function). Depth-of-field was obtained from through-focus Strehl estimates from each individual eye. RESULTS: Corneal aberrations increased after IOL implantation, particularly astigmatism and trefoil terms. Third and higher order RMS (and the corresponding Strehl ratio) were significantly better in eyes with aspheric IOLs than with spherical IOLs; however, this tendency was reversed when astigmatism was included. Spherical aberration was not significantly different in eyes with aspheric IOLs, whereas it was significantly positive in eyes with spherical IOLs. Third order aberrations were not significantly different across groups. Depth-of-field was significantly larger in eyes with spherical IOLs. Spherical IOLs showed better absolute optical quality in the presence of negative defocus >1.00 D. CONCLUSIONS: Our study shows a good degree of compensation of the corneal spherical aberration in eyes implanted with aspheric IOLs, as opposed to eyes implanted with spherical IOLs. Other sources of optical degradation, both with aspheric and spherical IOLs, are non-symmetric preoperative corneal aberrations, incision-induced aberrations, and third order internal aberrations. Although best corrected optical quality is significantly better with aspheric IOLs, tolerance to defocus tended to be lower.     

A comparison of higher order aberrations in eyes implanted with AcrySof IQ SN60WF and AcrySof SN60AT intraocular lenses

PURPOSE: To evaluate the efficacy of AcrySof SN60WF aspheric intraocular lens (IOL) in decreasing spherical aberration and total higher order aberrations (HOAs) after cataract surgery compared to the spherical SN60AT lens. METHODS: Wavefront analysis was conducted on 28 eyes of 28 patients that underwent un-complicated phacoemulsification with implantation of either SN60WF (15 eyes) or SN60AT lenses (13 eyes). Eyes with a history of uveitis, retinal diseases, and previous surgery were excluded. RESULTS: SN60WF eyes had less mean absolute spherical aberration than SN60AT eyes both at 4 mm (0.04+/-0.03 vs 0.11+/-0.03 RMS, p<0.0001) and 6 mm pupils (0.09+/-0.04 vs 0.43+/-0.12 RMS, p<0.0001). Mean total HOAs was lower in the SN60WF group at 6 mm pupils (0.44+/-0.14 vs 0.56+/-0.13 RMS, p=0.0274), while no difference was seen at 4 mm pupils (0.20+/-0.10 vs 0.25+/-0.08 RMS, p=0.160). There were no clinically significant differences between the SN60WF and SN60AT IOLs both at 4 and 6 mm pupils in terms of coma (0.16+/-0.07 vs 0.18+/-0.09 RMS, p=0.514 and 0.25+/-0.12 vs 0.23+/-0.12 RMS, p=0.664) and trefoil (0.14+/-0.09 vs 0.10+/-0.05 RMS, p=0.167 and 0.28+/-0.12 vs 0.23+/-0.07 RMS, p=0.199). There were no differences be-tween groups in mean age, axial length, postoperative spherical equivalent, IOL power, or corneal curvature. CONCLUSIONS: An aspheric posterior optic IOL design with thinner center effectively reduces the positive ocular spherical aberration observed in the pseudophakic and elderly eyes, especially at larger pupillary diameters (6 mm), with no notable increase in coma. However, reduction in total ocular HOAs was only significant at 6 mm pupils.     

Contrast sensitivity and higher order aberrations in eyes implanted with AcrySof IQ SN60WF and AcrySof SN60AT intraocular lenses

PURPOSE: To evaluate the efficacy of the aspheric optic of the AcrySof IQ SN60WF intraocular lens (IOL) in decreasing spherical and total higher order aberrations and improving contrast sensitivity after cataract surgery compared to the spheric AcrySof SN60AT. METHODS: Fifty-two eyes of 36 patients were evaluated at the University of Texas Southwestern Medical Center at Dallas 3 to 6 months after phacoemulsification with implantation of the AcrySof IQ SN60WF (27 eyes) or AcrySof SN60AT (25 eyes) IOL. Eyes with previous surgery or ocular pathology were excluded. RESULTS: Eyes implanted with the AcrySof IQ SN60WF had less total higher order and spherical aberrations than AcrySof SN60AT-implanted eyes at pupils of 4 mm (0.14+/-60.06 vs 0.18+/-0.04 microm and -0.01+/-0.03 vs 0.09+/-0.03 microm, respectively), 5 mm (0.24+/-0.07 vs 0.34+/-0.08 microm and 0.03+/-0.02 vs 0.23+/-0.08 microm, respectively), and 6 mm (0.42+/-0.13 vs 0.67+/-0.12 microm and 0.08+/-0.04 and 0.46+/-0.09 microm, respectively), (P<.05 for all), with similar mean coma, trefoil, and 5th order aberrations. AcrySof SN60WF eyes showed better contrast sensitivity than AcrySof SN60AT eyes at 12 and 18 cycles per degree (cpd) under mesopic conditions (1.65+/-0.23 vs 1.51+/-0.25 and 1.22+/-0.21 vs 1.01+/-0.19, respectively), and at 18 cpd under glare (1.12+/-0.30 vs 0.87+/-0.31, respectively) (P<.05). Photopic contrast sensitivity was similar in both groups. The two groups had comparable mean age, axial length, IOL power, and postoperative mesopic and photopic pupil sizes. CONCLUSIONS: Compared to a spheric optic, the aspheric design of the AcrySof IQ SN60WF reduces spherical aberration, especially under larger pupil sizes, and improves mesopic contrast sensitivity at higher frequencies with and without glare.     

Visual and optical performance of eyes with different corneal spherical aberration implanted with aspheric intraocular lens

AIM: To compare the visual and optical performance of eyes with different corneal spherical aberration (SA) implanted with spherical aberration-free intraocular lens (IOLs). METHODS: Thirty-six patients with different corneal SA had phacoemulsification with implantation of spherical aberration-free IOLs. Patients were divided into 3 groups according to the value of preoperative corneal SA. Eyes with corneal SA <0.10μm were assigned to group A, those with 0.10 ≤corneal SA <0.20μm to Group B, and those with 0.20≤ corneal SA <0.35μm to Group C. Best-corrected visual acuity (BCVA), contrast sensitivity, corneal SA, total ocular aberrations, and depth of focus were recorded 3 months postoperatively. Distance-corrected near and intermediate visual acuity was studied to measure depth of focus. RESULTS: BCVA and contrast sensitivity were similar between groups. There were no significant differences in distance-corrected near or intermediate visual acuity. Corneal SA was similar before and 3 months after surgery in the 3 groups. With a 5.0mm pupil diameter, root mean square values for total ocular higher-order aberrations (HOAs) were lower in groups A and B than in group C. Total ocular SA was lower in group A than in groups B and C. SA was also lower in group B than in group C. Coma and trefoil were similar between the groups. CONCLUSION: Implantation of spherical aberration-free IOLs in eyes with different corneal SA results in similar visual performance at BCVA, contrast sensitivity and depth of focus.     

Visual and optical performance of eyes with different corneal spherical aberration implanted with aspheric intraocular lens

AIM: To compare the visual and optical performance of eyes with different corneal spherical aberration (SA) implanted with spherical aberration-free intraocular lens (IOLs). METHODS: Thirty-six patients with different corneal SA had phacoemulsification with implantation of spherical aberration-free IOLs. Patients were divided into 3 groups according to the value of preoperative corneal SA. Eyes with corneal SA <0.10μm were assigned to group A, those with 0.10 ≤corneal SA <0.20μm to Group B, and those with 0.20≤ corneal SA <0.35μm to Group C. Best-corrected visual acuity (BCVA), contrast sensitivity, corneal SA, total ocular aberrations, and depth of focus were recorded 3 months postoperatively. Distance-corrected near and intermediate visual acuity was studied to measure depth of focus. RESULTS: BCVA and contrast sensitivity were similar between groups. There were no significant differences in distance-corrected near or intermediate visual acuity. Corneal SA was similar before and 3 months after surgery in the 3 groups. With a 5.0mm pupil diameter, root mean square values for total ocular higher-order aberrations (HOAs) were lower in groups A and B than in group C. Total ocular SA was lower in group A than in groups B and C. SA was also lower in group B than in group C. Coma and trefoil were similar between the groups. CONCLUSION: Implantation of spherical aberration-free IOLs in eyes with different corneal SA results in similar visual performance at BCVA, contrast sensitivity and depth of focus.     

不同设计的非球面人工晶状体植入术后的对比敏感度比较

目的 比较两种不同设计的非球面人工晶状体植入术后患者对比敏感度的改变.方法 选择连续入院并拟由同一临床经验丰富的医师完成白内障超声乳化联合人工晶状体植入手术的患者63例(90只眼),随机分为三组,每组30只眼.组A患者植入前表面非球面修饰的人工晶状体( AMO Tecnis ZA 9003型),组B植入后表面非球面修饰的人工晶状体(Alcon IQ SN60WF型),对照组植入单焦球面人工晶状体( AMO AR40e).术后6个月对三组患者进行不同照明条件下(3 cd/m2,85 cd/m2),四种不同空间频率下(3c/d,6 c/d,12 c/d,18 c/d)的对比敏感度(CS)测定并进行比较.结果 两组非球面晶状体植入的患者术后对比敏感度较球面晶状体植入术的患者更好,其中在低空间频率下( 3c/d 、6c/d)差异有统计学意义(P＜0.05).在眩光条件下,球面晶体植入患者在高空间频率( 18c/d)下的对比敏感度下降(P＜0.05),而非球面晶状体组患者则耐受良好.结论 两种非球面人工晶状体都能获得良好地视功能,相比传统的球面型人工晶状体,新的非球面设计理念可以带来更好地视觉质量.     

Spherical aberration and contrast sensitivity in eyes implanted with aspheric and spherical intraocular lenses: a comparative study

PURPOSE: To determine whether implantation of an intraocular lens (IOL) with a modified anterior aspheric surface results in reduced spherical aberration and improved contrast sensitivity after cataract surgery. DESIGN: Prospective, comparative, interventional case series. METHODS: In an intraindividual randomized prospective study of 25 patients with bilateral cataract, an IOL with a modified anterior surface (Tecnis Z9001; Advanced Medical Optics, Santa Ana, California, USA; group 1) was compared with biconvex lens with spherical surfaces (ClariFlex; Advanced Medical Optics; group 2). Ocular aberrations for a 5.0-mm pupil and 6.0-mm pupil were measured with Hartmann-Shack aberrometer. Quality of vision was measured by visual acuity and contrast sensitivity under mesopic and photopic conditions. All patients were followed up for three months. RESULTS: No statistically significant difference in postoperative uncorrected and best-corrected distance vision acuity after a follow-up of three months existed between the groups. Postoperative contrast sensitivity testing revealed significant differences between the groups under photopic and mesopic conditions. These differences reached statistical significance under photopic conditions at three spatial frequencies and under mesopic conditions at all spatial frequencies. When analyzing higher-order aberrations, the difference between the groups was statistically significant at the 5.00-mm and 6.00-mm pupil diameters, with the group 1 inducing less higher-order aberration and also less spherical aberration compared with group 2. CONCLUSIONS: Results show the Tecnis Z9001 IOL with a modified anterior aspheric surface induced significantly less higher-order aberration and spherical aberration compared with the ClariFlex IOL. Contrast sensitivity revealed better values under photopic and mesopic conditions with the Tecnis Z9001 IOL.     

Ocular wavefront analysis and contrast sensitivity in eyes implanted with AcrySof IQ or AcrySof Natural intraocular lenses

Purpose: This study aimed to compare ocular wavefront aberrations for pupil diameters of 4 mm and 6 mm, and contrast sensitivity, in eyes with AcrySof IQ and AcrySof Natural intraocular lenses (IOLs). Methods: Sixty eyes of 60 patients were enrolled in this prospective randomized study. After phacoemulsification the eyes received either AcrySof IQ SN60WF or AcrySof Natural SN60AT IOLs. One month after surgery, all patients underwent complete ophthalmological examination including corneal topography, wavefront analysis for pupil diameters of 4 mm and 6 mm, and contrast sensitivity measurements with the CSV 1000E instrument under photopic and mesopic conditions with and without glare. Results: There was no statistically significant difference between groups in age, sex or other preoperative ocular characteristics (p > 0.05). Patients with AcrySof IQ IOLs had higher contrast sensitivity at 6 c.p.d. under photopic conditions, at 6 c.p.d. and 18 c.p.d. under mesopic conditions, and at 6 c.p.d., 12 c.p.d. and 18 c.p.d. under mesopic conditions with glare (p < 0.05). Corneal spherical aberration was 0.273 ± 0.074 μm in the AcrySof Natural group and 0.294 ± 0.086 μm in the AcrySof IQ group (p = 0489). Ocular spherical aberration was 0.362 ± 0.141 μm and 0.069 ± 0.043 μm (p < 0.001) for 6‐mm diameter pupils and 0.143 ± 0.091 μm and 0.017 ± 0.016 μm (p < 0.001) for 4‐mm diameter pupils, with AcrySof Natural and AcrySof IQ IOLs, respectively. There were no significant differences in other higher‐order aberrations between the groups (p > 0.05). Conclusions: Aspherical AcrySof IQ IOLs significantly reduced spherical aberration for pupil diameters of both 4 mm and 6 mm and also improved contrast sensitivity more than spherical AcrySof Natural IOLs, especially in mesopic conditions.     

Evaluation of neodymium:yttrium-aluminum-garnet capsulotomies in eyes implanted with AcrySof intraocular lenses

PURPOSE: As of December 31, 2000, the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser posterior capsulotomy rate for the Alcon AcrySof intraocular lens (IOL) as measured in our database was 3.3%. This was the lowest of any IOL model used in the United States. Only 12 of 361 cases required treatment. We analyzed possible surgical reasons that may have been responsible for the posterior capsule opacification (PCO) in this small group. Special attention was given to the three surgical factors that we had previously identified as being important for PCO reduction: (1) quality of cortical clean up, (2) type of haptic fixation, and (3) continuous curvilinear capsulorhexis (CCC) size and shape. DESIGN: Comparative autopsy tissue analysis. PARTICIPANTS: Three hundred sixty-one human eyes obtained postmortem with Alcon AcrySof IOLs, accessioned between January 1995 and December 2000 from Lions Eye Banks. METHODS: The eyes were evaluated by the Miyake-Apple posterior photographic technique. MAIN OUTCOME MEASURES: The area and intensity of Soemmering's ring and type of fixation were studied in 361 eyes. The size and shape of the CCC and relation of the CCC edge to the IOL's optic rim were analyzed in 168 eyes. RESULTS: The amount of Soemmering's ring formation was significantly larger in the group of IOLs requiring Nd:YAG capsulotomy (Nd:YAG group). The not in-the-bag fixated IOLs required more Nd:YAG capsulotomies. Although the trend was clear, the number of specimens was not large enough to acquire statistical significance. The Nd:YAG group showed a highly significant difference compared with the No Nd:YAG group with regard to the amount of clock hours of the CCC edge on the optic rim's surface (P < 0.001). Mean CCC diameters were significantly larger in the Nd:YAG group (P < 0.05). CONCLUSIONS: The amount of Soemmering's ring correlates with the quality of cortical clean up. Cells within the Soemmering's ring are the direct precursors of PCO. This study confirms our previous laboratory studies and the clinical assumption that the incidence of PCO and thus the need for Nd:YAG capsulotomy is correlated with the cortical clean up. A second clinical assumption, that poor IOL fixation increases the risk of PCO, is also strongly suggested in this study. This study also verifies the relation of the CCC to PCO and the Nd:YAG laser, namely that a relatively small CCC without tears is best to prevent this complication. Use of a high-quality IOL combined with diligent attention to these three surgical factors should lower further the incidence of PCO.     

Comparison of wavefront aberrations and optical quality of eyes implanted with five different intraocular lenses

PURPOSE: We compared corneal and total higher order wavefront aberrations in 25 pseudophakic eyes implanted with five different types of intraocular lenses to obtain an objective evaluation of the optical quality of these pseudophakic eyes. Five IOLs per type were studied. METHODS: Implanted lenses were the Pharmacia Tecnis Z9000 with negative spherical aberration, Pharmacia 911 Edge, Alcon Acrysof SA60AT and MA60BM, and Allergan Sensar AR40e. Eyes were examined using the Topcon KR-9000PW topographer/aberrometer, which obtains simultaneous coaxial measurements of corneal and ocular aberrations, and displays the calculated Point Spread Function (PSF) and Modulation Transfer Function (MTF). RESULTS: Corneal spherical aberration was positive in all tested eyes. For a 4-mm optical zone, ocular spherical aberration was 0.0054+/-0.0172 microm root-mean-square (RMS) in eyes implanted with the Tecnis lens, and was 0.0562 to 0.0974 microm RMS in eyes implanted with the four other conventional IOLs. A myopic refractive shift with mydriasis of -0.08 D occurred with the Tecnis IOL; it was -0.57 to -0.90 D with the conventional IOLs. Coma did not show a substantial reduction with any of the IOLs. Total wavefront aberrations showed nonsignificant reduction with the Tecnis lens. The PSF and the MTF also showed nonsignificant improvements over conventional IOLs. CONCLUSIONS: The optical quality of pseudophakic eyes can be measured in vivo by aberrometers. Different IOLs resulted in measurably different outcomes. In this preliminary study, compensation of the spherical aberration observed with the Tecnis lens confirmed the theoretical predictions associated with this lens and resulted in no myopic shift in refraction with mydriasis.     

Limitations of correcting spherical aberration with aspheric intraocular lenses

PURPOSE: Aspheric intraocular lenses (IOLs) are deigned to correct spherical aberration in pseudophakic eyes. We predict the benefit from correcting spherical aberration based on simulations and aberrometry of pseudophakic eyes implanted with spherical IOLs. METHODS: Ray tracing was performed through a model eye with an equi-biconvex spherical IOL and with a spherical aberration-correcting aspheric IOL. The IOLs were increasingly tilted and/or displaced, and the resulting transverse aberrations of 169 rays were transformed into Zernike coefficients for different pupil sizes. The benefit from correcting spherical aberration at individual esopic pupils was investigated by canceling C4(0) in the sets of Zernike coefficients for 41 eyes implanted with spherical IOL. RESULTS: Both the model eye and the real eye data predict that age-related miosis reduces spherical aberration in the eye implanted with a spherical IOL to approximately 1/3 of the spherical aberration at a 6-mm pupil. A reduction of similar magnitude occurs when spherical aberration-induced non-paraxial defocus is corrected by a spectacle lens. For natural mesopic pupils, canceling the Zernike C4(0) coefficient improved the objective image quality at a rate similar to changing defocus by 0.05 diopters. Average decentration and tilt levels diminish the lead of aspheric IOLs over spherical IOLs, depending on the direction of decentration. CONCLUSIONS: The benefit from correcting spherical aberration in a pseudophakic eye is limited for some or all of the following reasons: wearing glasses, age-related miosis, tilt and decentration of IOL, small contribution of spherical aberration to all aberrations, and intersubject variability.     

非球面多焦点人工晶状体植入眼不同背景亮度及不同对比度视功能观察

目的 分析非球面多焦点人工晶状体（MIOL）[ReSTOR MIOL（SN6AD3）]植入眼在不同背景亮度不同对比度下的视功能.方法 采用前瞻性研究.2009年2月至2009年7月行白内障超声乳化吸除并植入SN6AD3且随访资料完整的病例26例（42眼）,术后6个月在最佳远矫正状态下,采用多功能电子视力测量仪（MFVA-100）测试不同背景亮度（250、85、25 cd/m^2）下不同对比度（100%、25%、10%、5%）视标的LogMAR视力.采用Dunnett＇s T3多重比较法对所得视力进行统计分析.结果 在250 cd/m^2背景亮度下,不同对比度（100%、25%、10%、5%）视力平均值分别为0.01、0.23、0.40、0.62;85 cd/m^2背景亮度下为0.02、0.26、0.46、0.74;25 cd/m^2背景亮度下为0.08、0.32、0.49、0.63;在这3种背景亮度下,视力随着对比度下降而下降,差异有统计学意义（P均＜0.05）.同一对比度视标,不同背景亮度（250、85、25 cd/m^2）下的视力采用Dunnett＇s T3多重比较法分析,结果示差异无统计学意义（P均＞0.05）.结论 植入非球面ReSTOR MIOL（SN6AD3）患者无论在高亮（250 cd/m^2）、标准（85 cd/m^2）、中间（25 cd/m^2）背景亮度下均可获得满意的视力.视标的对比度对视力的影响较背景亮度更大.     

Wavefront aberrations in eyes with Acrysof monofocal intraocular lenses

PURPOSE: To characterize and measure the ocular aberrations in eyes implanted with monofocal intraocular lenses (IOLs) and to study any correlation between postoperative aberrations and surgical factors. METHODS: A Tscherning aberroscope was used to measure the wavefront aberrations of 62 eyes that had undergone phacoemulsification with the implantation of foldable monofocal Acrysof MA60BM IOLs (Alcon Laboratories Inc, Ft Worth, Tex). The Zernike coefficients, measured with a pupil diameter of 6 mm, were compared with those of a normal dataset of 82 eyes of healthy young myopes. RESULTS: Spherical aberration (Z(0)4) was the most predominant higher order aberration, with a mean value of 0.37 +/- 0.16 microm. A statistically significant linear relationship was noted between the magnitude of postoperative spherical aberration and the dioptric power of the IOL. The mean spherical aberration was 33 times more in the pseudophakic group than in normal young myopic eyes. The other major higher order aberrations were trefoil (Z(-3)3) with a mean of -0.13 +/- 0.22 microm and vertical coma (Z(-1)3) with a mean value of -0.11 +/- 0.23 microm. On average, the root-mean-square of higher order aberrations in pseudophakic eyes was 2.1 times that in a normal population of young myopic eyes. CONCLUSIONS: Eyes that undergo cataract surgery with monofocal IOL implantation suffer from significant higher order aberrations. The optical design of the IOL is most likely responsible for the increase in spherical aberration, the magnitude of which is a function of the dioptric power of the IOL.