双光可调节型人工晶状体眼调节幅度的计算及影响因素

目的 推导计算双光可调节型人工晶状体(DO-AIOL)植入术后眼调节幅度(AA)的数学公式,分析影响人工晶状体眼AA的相关因素.方法 根据高斯近轴光学理论推导得出计算AA的数学计算公式,以眼轴长(AL)、角膜屈光力(K)、DO-AIOL两个光学部的屈光力(IOL1IMP,IOL2IMP)、人工晶状体(IOL)的有效位置(ELP)、IOL光学部的移动量(ΔELP)、DO-AIOL两个光学部的距离(d)、DO-AIOL两个光学部距离的变化量(Δd)计算AA,分析以上各参数对AA的影响.结果 双光可调节IOL眼AA与AL、IOL2IMP及两个光学部的距离不相关.在IOL1IMP=32 D,ELP=4 mm,ΔELP=1 mm,Δd=1 mm时,DO-AIOL可为任意眼轴长患者提供的AA为2.49 D.AA为IOL1IMP的二次函数,AA随IOL1IMP的增大而增大,表明通过增大IOL1IMP可获得较大的AA.AA为K的二次函数,AA随角膜屈光力的增大而增大.AA与ELP呈负相关,与ΔELP、Δd呈正相关,与两个光学部的距离无关,对于DO-AIOL设计的改进具有指导意义.结论 研究推导得出计算双光可调节IOL眼的AA的数学公式,AA受IOL1IMP、K、ELP、ΔELP、Δd等多因素影响,不受AL影响.     

有效晶状体位置预测的研究进展

有效晶状体位置(effective lens position,ELP)是指白内障术后人工晶状体(intraocular lens,IOL)的有效位置,对于白内障术后屈光状态的计算尤其重要,如今有许多研究发现了新的ELP预测方法,比如术前晶状体赤道平面预测ELP,沟到沟(angle to angle,ATA)预测ELP...     

非球面人工晶状体度数计算的最优化

目的：：通过评价非球面人工晶状体( intraocular lens, IOL)屈光度的可预测性,初步开发一种计算屈光度( PIOL )的优化算法。方法：本研究纳入植入非球面 IOL ( LENTIS L-313, Oculentis GmbH)65眼,并分为2组：A组8例12眼,PIOL≥23.0D;B组35例53眼,PIOL<23.0D。术后3mo进行屈光度可预测性评价。参考角膜屈光力估计所致的可变性屈光指数计算出校正的IOL度数( PIOLadj )及屈光结果,根据年龄和解剖学因素得出校正的有效晶状体位置( adjusted effective lens position, ELPadj )。结果：术后A、B两组等效球镜度数分别为-0.75~+0.75 D、-1.38~+0.75D。 A、B两组的PIOLadj和实际晶状体屈光度(PIOLReal)之间无统计学差异(P=0.64、0.82)。 Bland-Altman分析显示A、B两组PIOLadj和PIOLReal之间的一致性区间分别为+1.11~-0.96 D和+1.14~-1.18 D。 Hoffer Q公式和Holladay I公式计算PIOLadj和PIOL之间存在临床和统计学上的显著差异(P<0.01)。结论：植入非球面IOL白内障手术的屈光可预测性可通过平行轴光学联合线性法则使角膜屈光力及晶状体位置相关误差最小化。     

非球面人工晶状体植入术后患者的生存质量

目的 对植入非球面人工晶状体(aspherical intraocular lens,AIOL)的效果进行评价.方法 将2007年2月至2008年2月在本院行白内障超声乳化联合人工晶状体植入术患者96例随机分成AIOL组和球面人工晶状体(spherical intraocular lens,SIOL)组,并对2组患者术后满意度和生存质量进行比较.结果 AIOL组和SIOL组患者总满意率分别为42例(87.50%)和28例(58.33%),差异有显著统计学意义(P<0.01).AIOL组和SIOL组患者半年后视物舒适度及暗适应功能分值经比较,差异均有显著统计学意义(t=5.746 1,P<0.001;t=2.959 7,P<0.01).结论 AIOL值得在临床推广.     

屈光性白内障手术术后影响视觉质量的主要因素

人工晶状体(intraocular lens,IOL)屈光力计算误差,角膜散光,前房深度以及IOL的位置等因素能导致术眼屈光状态的改变,影响白内障术后的整体视觉质量。我们将对手术过程顺利的屈光性白内障手术术后影响视觉质量的主要因素进行综述。     

年龄相关性屈光异常的人工晶状体矫正

年龄相关性屈光异常包括年龄相关性白内障和老视,可通过白内障摘除联合植入老视矫正型人工晶状体(intraocular lens,IOL)治疗。老视矫正型IOL根据原理可分为单焦点增强型IOL、多焦点IOL、景深扩展型IOL和可调节IOL;IOL老视矫正方案包括双眼以正视为目标植入同款IOL、微单眼视和混搭。(国际眼科纵览,2020,44:379-385)     

儿童白内障手术人工晶状体度数计算准确性分析

目的 分析儿童眼人工晶状体度数计算的准确性.方法 回顾性研究37例(62只眼)行先天性白内障摘除加人工晶状体(IOL,intraocular lens)植入术患儿生物测量及屈光状态数据,应用SRKⅡ计算IOL度数.术后2个月行视网膜检影验光检测屈光状态.分析手术年龄,眼轴长度,IOL植入时机与IOL度数计算准确性关系.结果 全部平均绝对预测误差为(1.56±1.43)D.绝对预测误差低于1.0 D共32只眼,占总眼数52%.眼轴≤20 mm组绝对预测误差为(2.75±1.66)D,＞20 mm组为(1.06±0.93)D,2组间差异具有统计学意义(P＜0.01).年龄≤2岁组绝对预测误差为(2.38±1.65)D,＞2岁为(1.04±0.99)D,2组间差别具有统计学意义(P＜0.01).Ⅰ期IOL植入组绝对预测误差为(1.37±1.35)D,Ⅱ期IOL植入为(2.03±1.56)D,2组间差异无统计学意义(P=0.22).结论 全组植入的IOL度数安全有效.眼轴≤20 mm及年龄≤2岁患儿绝对预测误差明显增加.该研究证明,专门为儿童眼设计IOL计算公式是有必要的.

Abstract：

Objective To determine the accuracy of intraocular lens (IOL) power calculation in a group of pseudophakic children. Methods A relrospective analysis of biometric and refractive data was performed on 62 eyes of 37 infants and children, who successfully underwent cataract extraction and IOL implantation. SRKII were used to calculate the IOL power. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 2 months afier surgery by retinoscopy. The data were analyzed to assess the effects of age at the time of surgery, axial length, and primary or secondary intraocular lens implantation on the accuracy of calculation of IOL power. Results For the overall group the mean and median prediction errors were 1.56D (SD 1.43). There were 32 eyes'absolute predictions errors lower than 1D (52%). The mean absolute prediction errors in eyes with axial lengths≤20 mm were 2.75 D (SD 1.66), and in eyes ＞20 mm were 1.06 D (SD 0.93). The mean absolute prediction errors in eyes in children aged≤2 years were 2.38 D (SD 1.65), and in children aged ＞2 years were 1.04D (SD 0.99). The differences between the absolute prediction errors for both axial length and age were statistically significant (P ＜0.01). The mean-absolute prediction errors in eyes with primary IOL implantation were 1.37D (SD 1.35), and secondary intraocular lens implantation were 2.03D (SD 1.56). The differences between the absolute prediction errors primary or secondary intraocular lens implantation, were not statistically significant (P =.22). Conclusions For the overall group IOL power calculation is generally acceptable. In eyes with axial lengths less than 20 mm and in children younger than 2 years of age larger errors can arise, and the variations increase. This study demonstrates the need for an IOL formula specifically designed for pediatric use.     

非球面人工晶状体的临床应用思路及其视功能评价

白内障手术的终极目标是恢复人眼正常晶状体的生理功能.随着白内障手术技术和人工晶状体(intraocular lens,IOL)的不断发展和改进,现代白内障手术已经由传统意义上的复明性手术逐渐过渡为屈光性手术,IOL的功能也由单纯的屈光作用向同时恢复屈光、调节等晶状体生理功能的方向发展.     

人工晶状体睫状沟植入术后屈光结果分析

目的:通过对人工晶状体睫状沟植入术后眼的屈光结果分析,为临床提供一种此类患者人工晶状体度数修正可以借鉴的方法。方法:回顾分析我院2007-08/2010-12白内障手术患者术中发生后囊破裂并Ⅰ期人工晶状体睫状沟植入25例25眼,根据眼轴长度(A-Scanlength,AL)分为<22mm,22～25mm和>25mm三组,分别比较术后3mo的实际屈光值与术前预测囊袋内植入人工晶状体后屈光度数的差别。结果:所有患者术后视力较术前均有不同程度改善,术后3mo视力平均0.49±0.21,术前预测囊袋内植入人工晶状体后屈光值分别为-0.43±0.34D(AL<22mm),-0.36±0.22D(AL:22～25mm)和-1.16±0.80D(AL>25mm);术后3mo三组患者眼实际屈光度数分别为-1.25±0.98D(AL<22mm),-1.22±0.82D(AL:22～25mm)和-2.4±1.39D(AL>25mm),各组间预测与实际屈光值比较,AL=22～25mm组差异有统计学意义(P=0.001),术后实际屈光值较预测偏近视0.8D,其余两组差异无统计学意义(P=0.148,0.061)。结论:为纠正人工晶状体睫状沟植入术后近视漂移,人工晶状体度数应根据AL做相应的调整。建议AL=22～25mm睫状沟植入人工晶状体度数应比预测囊袋内植入晶状体度数减0.8D。     

小儿人工晶状体置换术后视力的长期变化及早期屈光不正的观察

目的检查弱视期间行白内障摘除术及人工晶状体(intraocular lens,IOL)植入术患儿的最佳矫正视力(best corrected visual acuity,BCVA),探讨白内障摘出术后早期屈光不正与长期BCVA的关系。方法 采用回顾性病例研究,共收集26例(36眼)患者。所有患者至少随访2a。纳入标准:IOL植入时所有患者年龄均小于8.5岁;能够参加主观视觉检查。排除标准:先天性青光眼、严重     

虹膜固定型有晶状体眼人工晶状体植入对高度近视患者睫状肌调节性微波动及调节力的影响

目的通过测量睫状肌调节性微波动高频成分(high frequency component,HFC)来分析有晶状体眼人工晶状体(phakic intraocular lens,P-IOL)植入对高度近视患者睫状肌收缩能力及调节力的影响。方法收集2004年12月～2006年3月在我院进行虹膜固定型有晶状体眼人工晶状体Verisyse植入的患者54例(54眼)。采用NIDEK ARK-730A红外验光仪中调节性微波动分析软件,分别在术后1周、3个月对该54例患者(54眼)进行睫状肌调节性微波动高频成分检查。并与患者术后调节力进行相关性分析。结果HFC与Verisys植入术后1周及3个月的调节力均正相关(术后1周r=0.628,P<0.01;术后3个月r=0.835,P<0.01);Verisyse植入术后3个月的HFC及调节力均较术后1周的HFC及调节力有明显提高。结论高度近视患者有晶状体眼人工晶状体植入有利于术后睫状肌收缩能力及调节力的提高。     

Potential of the 1 CU accommodative intraocular lens

AIM: To assess the accommodative power of a new foldable monofocal intraocular lens. METHOD: A prospective randomised non-masked clinical interventional study. The study included 40 patients attending the hospital for cataract surgery and who were randomly distributed into a study group receiving a new foldable monofocal intraocular lens with flexible haptics, and a control group receiving a standard foldable intraocular lens. Mean follow up period was 8.51 (SD 1.34) months (range 4-11 months) Standard cataract surgery consisted of clear cornea incision, capsulorrhexis, phacoemulsification, and intraocular lens implantation, with topical anaesthesia. The main outcome measures were preoperative and postoperative visual acuity for near and distance; range of accommodation; change in anterior chamber depth. RESULTS: In the study group compared with the control group, range of accommodation was significantly (p = 0.01) higher (1.01 (SD 0.4) dioptres versus 0.50 (0.11) dioptres) and change in anterior chamber depth was significantly more pronounced (0.82 (0.30) versus 0.40 (0.32), p = 0.01). Both groups did not vary significantly in best corrected vision (0.94 (0.12) versus 0.93 (0.18); p = 0.74). CONCLUSION: During a mean follow up period of 8 months after implantation, the new foldable monofocal intraocular lens with flexible haptics showed an accommodative power of about 1 dioptre, which was significantly higher than the accommodative power of a conventional monofocal flexible intraocular lens. The difference in the accommodative power between the two intraocular lenses was paralleled by a difference in the change of the anterior chamber depth.     

A mathematical model of factors that influence the performance of accommodative intraocular lenses

In this work a mathematical model of capsule movement during pseudophakic accommodation is described to allow identification and evaluation of factors that may explain the variation in effect of accommodative intraocular lenses (IOLs) between patients. The model assumes that increasing vitreous pressure pushes the lens capsule forward as a circular diaphragm and that this movement is from a fixed fulcrum. With an IOL in situ, the capsule is taken to have a non-uniform thickness due to the presence of the anterior capsulorhexis. The model assumes a uniform capsular elasticity and ignores contributions from cellular elements such as posterior capsule opacification. Using our model and a regression formula to calculate capsular bag size, taking into account axial length and keratometry values, we are able to predict accommodative effect in individual patients. By simple geometry we have developed a mathematical model to identify variables that are important in pseudophakic accommodation. It provides the basis for the development of a more complex model that would address the movement of a lens taking into account the influence of the zonular system during accommodation.     

可调节人工晶状体植入术后的视觉质量及拟调节力

目的:研究Tetraflex可调节人工晶状体(IOL)植入术后视力、调节幅度、对比敏感度及主观视觉功能的临床应用效果。方法:病例对照研究。选择2010-03/2012-12在我院接受白内障超声乳化摘除联合囊袋内IOL植入术的白内障患者48例72眼,其中23例35眼植入Tetraflex可调节IOL(Tetraflex组),25例37眼植入AcrySof SA60AT单焦点IOL(SA60AT组),对比研究两组患者术后1,3,6mo裸眼远视力、最佳矫正远视力、裸眼近视力、最佳矫正近视力、最佳矫正远视力下近视力、拟调节力、脱镜率以及患者满意度情况,采用主观移近法测量调节力。采用SPSS13.0统计软件包进行统计学处理。结果:术后随访期间,两组患者的裸眼远视力、最佳矫正近视力和最佳矫正远视力差异无统计学意义(P>0.05);Tetraflex组患者的裸眼近视力和最佳矫正远视力下近视力与单焦组比较差异有统计学意义(P<0.05)。术后Tetraflex组拟调节力均高于SA60AT组(P<0.05),于术后6mo Tetraflex组拟调节力有所下降,与1,3mo比较差异均有统计学意义(P<0.05),两组间对比敏感度差异无统计学意义。脱镜率及和主观视功能满意度,Tetraflex可调节IOL组均明显优于单焦组,差异有统计学意义(P<0.05)。结论:可调节IOL可提供较好的远近视力,增加拟调节力,有效降低患者术后对老视镜的依赖,改善主观视功能。但其拟调节力仍需要进一步的研究。     

Pseudophakic accommodation with translation lenses – dual optic vs mono optic

PURPOSE: To investigate the pseudophakic accommodation effect in dual and mono optic translation accommodative intraocular lenses (AIOL) using linear matrix methods in the paraxial space. METHODS: Dual (anterior optic of power +32 D linked to a compensatory posterior optic of negative power) and mono lens power was determined in the non-accommodated state using linear geometric optics based on the Gullstrand model eye. The position of the AIOL was calculated from a regression formula. Pseudophakic accommodation was assessed with three systems: (1) forward shift of the mono optic lens, (2) anterior translation of the anterior optic in the dual optic lens system with an unchanged position of the posterior minus lens and (3) symmetrical anterior and posterior translation of the anterior and posterior lens. The Gullstrand model eye was modified by changing the axial length (and proportionally changing the phakic anterior chamber depth) to investigate the accommodative effect in myopic and hyperopic eyes. RESULTS: The dual optic lens system (2) yields a nearly constant accommodation amplitude of 2.4-2.5 D mm(-1) movement over the total range of axial lengths. The mono optic lens (1) provides a higher accommodative effect only in extremely short eyes (high refractive power of the lens), whereas for normal eyes (1.4-1.5 D mm(-1) movement) and for long (myopic) eyes the accommodative effect is much less than the dual optic lens. The dual optic lens system under condition (3) yields less accommodation amplitude compared with the dual optic system under condition (2) over the total range of axial length but provides higher accommodation amplitude compared with the mono optic lens system (1) with axial lengths greater than 22.3 mm (lens power 25.5 D). In the accommodated state, with lens translation of 1 mm, the absolute value of the lateral magnification increases with the refractive power of the mono optic lens (1) and decreases in both dual optic lens systems (under conditions 2 and 3). CONCLUSIONS: A mathematical strategy is presented for calculation of the accommodative effect of mono-optic and dual optic AIOL. The dual optic lens yielded a nearly constant accommodation amplitude of about 2.4-2.5 D mm(-1) translation, whereas the mono optic lens yielded an accommodative response of <2 D mm(-1) translation in long myopic or normal eyes. Only in extremely short eyes is the accommodative amplitude of the mono-optic lens higher than the dual optic lens.     

可调节人工晶状体矫治老视的效果

目的探讨可调节人工晶状体矫治老视的可行性。方法均为要求阅读时不配戴凸透镜的老视患者,同时伴有不同程度的晶状体浑浊,共31例（62只眼）。均常规行白内障超声乳化吸出联合囊袋内植入后房型Tetraflex可调节人工晶状体。记录术后裸眼远视力、裸眼近视力、矫正远视力下的近视力、调节幅度、脱镜率、满意度等。术后随访6个月,并与植入Akros单焦点人工晶状体30例（60只眼）进行比较。结果在随访期内,术后3个月两组的裸眼远视力无统计学差异（t=0．366,P〉0．05）,两组的裸眼近视力和矫正远视力下的近视力均有统计学差异（t=10．074,t=9．966,P〈0．05）。术后1周、3个月、6个月的调节幅度,两组之间均有统计学差异（t=28．875,t=31．007,t=30．227,P〈0．05）。术后6个月视近时的脱镜率和对疗效的满意度,两组之间均有统计学差异（Z=-4．901,Z=-5．974,Z=-9．282,P〈0．05）。结论Tetranex可调节人工晶状体具有一定的调节能力,可以为患者提供良好的近视力,同时术后远视力和中距离视力也有所改善。     

Changes of the accommodative amplitude and the anterior chamber depth after implantation of an accommodative intraocular lens

Background

Modern cataract surgery is interested in recovery of the accommodative power. This investigation aimed at determining pseudophakic accommodation in subjects implanted with the accommodative Human Optics 1 CU intraocular lens after drug-induced ciliary muscle stimulation by measuring the objective refraction and the changes in anterior chamber depth in comparison with a PMMA intraocular lens with rigid haptics.

Methods

The studied sample involved 30 eyes of 30 patients undergoing cataract surgery due to age-related cataract. Patients were between 50 and 77 years of age (67.71±8.0). No randomization was performed. The 1 CU accommodative intraocular lens and the PMMA intraocular lens were implanted in 15 eyes of patients with an expected visual acuity of at least 0.7. Objective refraction under pilocarpine-stimulated ciliary muscle contraction was determined with a Hartinger coincidence refractometer. The anterior chamber depth was measured with Jäger’s Haag–Streit slit-lamp attachment. The accommodative amplitude and the anterior chamber flattening were calculated from the measured values.

Results

Twelve weeks after surgery the average accommodative amplitude in eyes with a 1 CU intraocular lens calculated from the refractive change under drug-induced stimulation was 0.48±0.36 D (with a maximum of 1.25 D). The measured change of anterior chamber depth under drug-induced stimulation was 0.3±0.32 mm (at a maximum of 0.9 mm). In the reference group with PMMA lenses, the mean accommodative amplitude derived from the refractive changes under drug-induced stimulation was 0.34±0.27 D (at a maximum of 0.85 D). The measured change in anterior chamber depth under drug-induced stimulation was 0.18±0.09 mm (at a maximum of 0.31 mm). No statistically significant differences were found between the two groups of lenses concerning change in anterior chamber depth and accommodative amplitude.

Conclusions

This investigations indicate a mean anterior 1 CU shift of only 0.32 mm and a maximum of 0.9 mm. The accommodative amplitudes measured with the Hartinger coincidence refractometer (mean value 0.47 D) correspond to these values. Similar conclusions may be drawn from existing investigative results of the reference group, which are on the same order of magnitude as those of the 1 CU group. Objective accommodation measurements are needed to evaluate commercially available accommodative intraocular lenses in a scientifically satisfactory manner. Objectively measurable parameters include changes of the anterior chamber depth as well as refraction, as determined for instance by coincidence refractometry and streak retinoscopy. Future studies should also consider the IOL properties, astigmatism, and pupillary diameter. This is the only way to identify pseudoaccommodation and a decisive factor for further development of accommodative artificial lenses.     

双元件可调节人工晶状体设计

目的：设计一种新的双元件可调节人工晶状体,并对其成像质量进行评估。方法：通过光学设计软 件Zemax,建立新设计的双元件可调节人工晶状体和人眼模型,模拟仿真其在不同视距下（L=6 m、 L=70 cm、L=40 cm以及L=25 cm）的成像结果,得到空间频率为100 cycles/mm时的调制传递函数 （MTF）值。与Simonov等研究结果进行对比分析,同时分析仿真结果是否满足人工晶状体植入光学 特性和测试标准。结果：通过光学设计软件模拟仿真新设计的双元件可调节人工晶状体眼模型,其 结果显示无论α=0°还是α=5°,瞳孔大小为3 mm时,单色光（λ=0.546 μm）空间频率100 cycles/mm 对应的MTF值均大于0.43,满足人工晶状体植入光学特性和测试标准。在α=0°时,仿真结果相较 于Simonov等研究结果有较大提升;在α=5°时,无明显提升。结论：本研究设计的双元件可调节人 工晶状体仿真结果满足人工晶状体植入光学特性和测试标准要求,相较于Simonov的研究结果,其 整体性能有所提升。     

Sarfarazi dual optic accommodative intraocular lens

The Sarfarazi accommodative intraocular lens, currently in clinical studies, is a single continuous silicon accommodative lens with dual optics and three haptics that mimic the action of the natural lens by using the contraction and relaxation of ciliary muscles. The lenses have been implanted in the eyes of patients. There have been no surgical or patient complications related to the lens, and its safety has been clearly demonstrated. Patient acceptance of the lens is excellent. Clinical enrollment will continue to expand.