IOLMaster生物测量精确性和可重复性研究

er与接触式A超均可用于眼前节参数的生物测量,两者的相关性好.但基于光学原理的IOLMaster具有良好的精确性和可重复性,具有较好的临床应用前景.     

Optic capture of the AcrySof intraocular lens in pediatric cataract surgery.

PURPOSE: To assess the results of acrylic intraocular lens (IOL) optic capture in children with cataract. SETTING: Department of Ophthalmology, Hospital de Clínicas José de San Martín, and Instituto de la Vision, School of Medicine, University of Buenos Aires, Argentina. METHODS: Eight children had cataract surgery. After lens and cortex aspiration, an AcrySof (Alcon) IOL was implanted in the bag. A primary posterior capsulorhexis was performed. The optic edges were slipped through the posterior capsule leaflets. Clarity of the visual axis, preoperative and postoperative best corrected visual acuities (BCVAs), and refraction were evaluated. RESULTS: The visual axis remained clear in all cases. No case required a secondary procedure. The mean preoperative BCVA was 0.06 +/- 0.06 (SD). Postoperatively, the mean BCVA was 0.88 +/- 0.11 and the mean spherical equivalent, +0.62 +/- 1.31. The mean follow-up was 28.9 +/- 5.3 months. CONCLUSION: Results show that the optic of an acrylic IOL may be captured through a posterior capsulorhexis in pediatric cataract surgery, combining the advantages of optic capture with a smaller incision and a decreased inflammatory response.     

Measuring corneal power for intraocular lens power calculation after refractive surgery. Comparison of methods

PURPOSE: To find a more accurate and predictable method for intraocular lens (IOL) power calculation in eyes after refractive surgery. SETTING: Department of Ophthalmology, Kangnam St. Mary's Hospital, Seoul, Korea. METHODS: The accuracy of the following methods for calculating IOL power in 132 eyes after PRK or LASIK was compared: manual keratometry, hard contact lens, refraction-derived keratometry at the corneal plane, and the refraction-derived keratometry at the spectacle plane. Based on this comparison, the IOL power was calculated in the 2 eyes of a patient using refraction-derived keratometry at the spectacle plane with the SRK II formula. Cataract surgery with IOL implantation was then performed. RESULTS: The largest corneal power values were obtained using a manual keratometer and the smallest using refraction-derived keratometry at the spectacle plane (P <.001). In the patient having cataract surgery with IOL implantation, near target refraction was achieved with minimal error in IOL power. CONCLUSIONS: If the corneal power is known before refractive surgery, the use of the smallest value of those obtained using refraction-derived keratometry and the hard contact lens method is recommended. However, if the corneal power before refractive surgery is unknown, the use of the hard contact lens method is recommended.     

IOL-Master的临床应用观察

目的:比较Zeiss IOL-Master与传统超声生物测量在人工晶状体测量中的准确性,并探讨不同测量方法的临床应用特点。方法:分析2007-11/2008-01在我院行白内障摘除及人工晶状体植入术的患者91例147眼,根据眼轴长度(L)分别分为五组(L≤22mm,22mm28mm),术前分别用ZeissIOL-Master,超声生物测量仪及角膜曲率计测量眼轴长度,角膜曲率和计算人工晶状体度数,并将结果进行比较。结果:用ZeissIOL-Master和超声生物测量仪测得的眼轴长度:L≤22mm组分别为21.69±0.298mm和21.97±0.623mm(P>0.05);22mm0.05);24.5mm0.05);26mm0.05);L>28mm组分别为31.59±1.852mm和31.22±1.718mm(P>0.05)。两种方法测得的眼轴长度在各组间无显著差异性。用IOL-Master和超声生物测量仪测得的各组的人工晶状体度数:L≤22mm组分别为23.73±1.29D和22.94±1.44D(P>0.05);22mm0.05);24.5mm0.05);L>28mm组分别为-4.28±4.52D和-3.53±4.76D(P>0.05),显示各组间无显著性差异。IOLMaster和角膜曲率计检测到的角膜曲率分别为43.65±1.62和43.70±1.71,两者比较无显著差异(P>0.05)。结论:IOL-Master用于人工晶状体度数的测量具有非接触、精确性高、操作简单、安全可靠和患者容易接受的特点。而传统的超声生物测量要接触患者角膜,对操作者的手法及患者的配合程度要求较高,但在屈光间质混浊明显的患眼测量中则明显较IOL-Master更为准确,因此临床上应根据个体情况选择不同的测量方法及计算公式以获得准确地人工晶状体度数。     

Optimising biometry for best outcomes in cataract surgery

Biometry has become one of the most important steps in modern cataract surgery and, according to the Royal College of Ophthalmologists Cataract Surgery Guidelines, what matters most is achieving excellent results. This paper is aimed at the NHS cataract surgeon and intends to be a critical review of the recent literature on biometry for cataract surgery, summarising the evidence for current best practice standards and available practical strategies for improving outcomes for patients. With modern optical biometry for the majority of patients, informed formula choice and intraocular lens (IOL) constant optimisation outcomes of more than 90% within ±1 D and more than 60% within ±0.5 D of target are achievable. There are a number of strategies available to surgeons wishing to exceed these outcomes, the most promising of which are the use of strict-tolerance IOLs and second eye prediction refinement.     

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.     

Accuracy of intraocular lens power calculation in paediatric cataract surgery

AIMS: To determine the accuracy of intraocular lens (IOL) power calculation in a group of pseudophakic children. METHODS: A retrospective analysis of biometric and refractive data was performed on 52 eyes of 40 infants and children, who successfully underwent cataract extraction and IOL implantation. The following parameters were included: age at the time of surgery, keratometry, axial length, estimated refraction, and the power of IOL implanted. The postoperative refractive outcome was taken as the spherical equivalent of the refraction at 3 months after surgery. The prediction error was taken as the absolute difference between the estimated and actual postoperative refraction. The data were analysed to assess the effects of age at the time of surgery, keratometry, and axial length on the accuracy of calculation of IOL power. RESULTS: For the overall group the mean and median prediction errors were 1.40 D and 0.84 D (SD 1.60). The mean and median prediction errors in eyes with axial lengths > or =20 mm were 1.07 D and 0.71 D (SD 0.98) and in eyes <20 mm were 2.63 D and 2.61 D (SD 2.65). The mean and median prediction errors in eyes in children aged > or =36 months were 1.06 D and 0.68 D (SD 1.02) and in children aged <36 months was 2.56 D and 2.29 D (SD 2.50). The differences between the prediction errors for both axial length and age were statistically significant (p<0.05). CONCLUSIONS: For the overall group IOL power calculation is satisfactory. In eyes with axial lengths less than 20 mm and in children less than 36 months of age larger errors can arise. This study demonstrates the need for an IOL formula specifically designed for paediatric use.     

青光眼患者白内障手术人工晶状体计算公式的选择

青光眼与白内障是导致失明的主要原因,手术是重要的治疗方式。青光眼患者具有高眼压、浅前房及短眼轴等临床特征,小梁切除术等抗青光眼术后眼部结构常发生改变。这些变化也导致了抗青光眼术后行白内障手术或青白联合手术与单纯白内障手术在人工晶状体(intraocular lens, IOL)屈光度计算准确性方面存在差异。同时青光眼患者自身的临床特征与抗青光眼手术造成的结构改变对于IOL屈光度预测准确性、屈光漂移的类型等方面的影响也表现出差异。本文就青光眼或抗青光眼术后患者行白内障手术或青白联合手术时屈光误差(refractive error, RE)产生的原因、屈光漂移特征及选择最合适IOL计算公式的最新研究进展进行综述。     

Biometric calculation of intraocular lens power for cataract surgery following pupil dilatation

Background: The ability to perform biometry accurately on a dilated pupil can greatly facilitate the efficiency of a cataract service as it can be done on the day of surgery. The purpose of this study was to assess the repeatability of axial length (AL) calculations in undilated pupils and measure the difference in predicted and actual refractive outcomes in dilated pupils compared with undilated pupils. Methods: First, intraobserver repeatability was assessed by taking two consecutive recordings of AL using applanation A‐scan ultrasonography in undilated pupils in 21 eyes. The mean AL for each eye was compared with a measurement made following pupil dilatation. Second, we audited the mean spherical equivalent refractive errors following routine cataract surgery in 38 patients with undilated pupils and 36 patients with dilated pupils. Results: The mean difference in intraobserver measurements was ?0.05 mm (standard deviation [SD] 0.15) with pupils undilated. Following pupil dilatation, the mean dilated AL differed from the mean undilated AL reading by only 0.03 mm (P > 0.05). The mean differences between planned and actual refractive error were 0.71D (SD 0.54) and 0.55D (SD 0.41) in dilated and undilated patients, respectively. This was not statistically significant (P > 0.05). The range of differences between target and actual refraction was ?1.45D to 2.70D for undilated patients and ?1.88D to 1.18D in dilated patients. Conclusion: Although there was a greater spread of postoperative refractive errors in the dilated group, there were no statistically or clinically significant differences in postoperative refractive errors between the two categories of patients. Our study shows that applanation biometry may be safely performed for the purpose of cataract surgery after pupil dilatation.     

Comparison of the Zeiss IOLMaster and applanation A-scan ultrasound: biometry for intraocular lens calculation

Purpose: A comparison of axial length estimates using applanation A‐scan ultrasound and the Zeiss IOLMaster was conducted. The accuracy in predicting postoperative refraction determined by each method was also compared. Methods: A cross‐sectional study was performed on 51 eyes in 46 patients presenting to clinical practice for cataract surgery assessment. Preoperative measurement of axial length was performed with applanation ultrasound and the IOLMaster. The IOLMaster measurements were used to determine the intraocular lens power based on the SRK/T formula. Postoperative refractive outcomes were obtained and spherical equivalent calculated and compared to the predicted refractive error with each biometric method. Results: On average the axial lengths measured by the IOLMaster were longer by 0.15 mm compared to ultrasound biometry (P < 0.01). Using the IOLMaster over applanation ultrasound biometry significantly improved the postoperative refractive outcome from 0.65 D to 0.42 D (P = 0.011). Conclusions: The IOLMaster provides an accurate axial length measurement and results in accurate intraocular lens power calculation based on the SRK/T formula. It is quick and easy to use and provides a non‐contact technique with no risk of infection or corneal abrasion.     

白内障术前测算人工晶状体屈光度不同方法的对比研究

目的对比研究光学低相干反射生物测量仪（Lenstar LS900）、光学相干生物测量仪（IOL Master）及A型超声扫描3种方法测量眼轴、前房深度及计算所需IOL屈光度,比较3种方法所测数据之间的差异。方法应用LenstarLS900、IOLMaster及A型超声扫描仪分别对50例（80眼）白内障患眼进行眼轴及前房深度测量;利用3种设备分别计算所需IOL屈光度,均选用SRK／T计算公式和SA60AT（Alcon）人工晶状体,在确定同一度数的前提下比较目标屈光度的差异。结果Len-star LS900、IOL Master及A超测量眼轴长度及前房深度,三者所测的数据之间差异无统计学意义,具有良好的相关性。Lenstar LS900和IOL Master所获得的术后目标值差异无统计学意义（P〉0．05）,而B超所获得的术后目标值与另二者获得的结果差异有统计学意义（P〈0．05）。Bland—Ahman分析显示,3种设备获得的目标屈光值具有良好的一致性,尤其是Lenstar LS900和IOL Master之间。结论在白内障患眼的生物测量中,Lenstar LS900、IOL Master和A超有良好的一致性。同时,Lenstar LS900还可以快速、准确的为白内障和屈光医生提供更多眼生物信息。     

Phaco+IOL手术前后眼球生物测定值对比观察

目的:通过对白内障患者行Phaco+IOL手术前后A超和IOL-Master的眼球生物测定值的动态对比观察,经统计分析其临床意义。方法:连续动态观察本院固定手术(Phaco+IOL术)患者70例84眼。采用A超和IOL-Master分别对术前、术后14d患者眼球生物值测定,包括:眼轴长度、前房深度、晶状体厚度、玻璃体腔深度。并对手术前后患者坐、卧位的眼球生物值进行对比观测,分别对各项生物测定值进行统计学分析。结果:(1)前房深度:术后比术前前房平均加深28.41%,前房深度加深改变与晶状体厚度呈正相关(r=0.396,P=0.002,n=58),进行线性模拟表示:前房加深深度=0.445×晶状体厚度-1.207;(2)A超测定手术前后坐、卧位前房深度的差异无统计学意义(P=0.264,n=57;P=0.663,n=44);(3)A超、IOL-Master术前前房深度测定有显著统计学意义(P<0.01,n=29),A超测得均值为:2.75±0.57mm,Master测得均值为:2.96±0.61mm,差值为:-0.21±0.29mm,两者差值的95%CI为:(-0.32～0.10mm);(4)A超、IOL-Master术后前房深度测定有显著统计学意义(P=0.002,n=41),A超测得均值为:3.46±0.46mm,Master测得均值为:3.79±0.65mm,差值为:-0.33±0.63mm,两者差值的95%CI为:(-0.53～0.14mm);(5)A超测定手术前后前房深度改变与IOL-Master手术前后前房深度改变的差异无统计学意义(P=0.619,n=19)。眼轴:(1)A超测定手术前后眼轴长度无统计学差异(P=0.079,n=58);(2)术前、术后A超坐、卧位测定眼轴长度无统计学意义(P=0.934,n=57;P=0.196,n=44);(3)A超、IOL-Master术前、术后眼轴长度测定均没有统计学意义(P=0.175,n=17;P=0.248,n=31)。结论:Phaco+IOL患者手术前后前房深度改变显著且与晶状体厚度呈正相关,术后比术前前房平均加深28.41%;除前房深度外,常规A超眼球生物测定值与IOL-Master眼球生物测定值相一致。另外,患者的体位对A超测定结果基本无影响。     

Lenstar LS900与A超测算白内障患者人工晶状体度数对比研究

目的 评估及比较A超、Lenstar LS900光学生物测量白内障患者眼轴长度、前房深度、人工晶状体度数的差异.方法 分析2011年3月行白内障超声乳化摘除及人工晶状体植入术的白内障患者50例(80只眼),分别用接触式A超和Lenstar LS900光学生物测量两种方法测量眼轴长度及前房深度差异.选用SRK/T公式及SA60AT (Alcon)人工晶状体常数计算人工晶状体度数,在确定同一度数的前提下比较目标屈光度的差异.结果 Lenstar LS900及A超测量眼轴长度及前房深度之间差异无统计学意义,具有良好的相关性.Bland-Altman分析显示,两种设备获得的人工晶状体目标屈光值具有良好的一致性.结论 Lenstar LS900及A超对白内障术前生物测量结果准确,可靠,可用于白内障术前检查.同时,Lenstar LS900能测量角膜厚度,前房深度、晶状体厚度,视网膜厚度和瞳孔大小等参数,对白内障及屈光性手术的能提供更多生物信息.     

Comparison of immersion ultrasound biometry and partial coherence interferometry for intraocular lens calculation according to Haigis

Background: The precision of intraocular lens (IOL) calculation is essentially determined by the accuracy of the measurement of axial length. In addition to classical ultrasound biometry, partial coherence interferometry serves as a new optical method for axial length determination. A functional prototype from Carl Zeiss Jena implementing this principle was compared with immersion ultrasound biometry in our laboratory. Patients and methods: In 108 patients attending the biometry laboratory for planning of cataract surgery, axial lengths were additionally measured optically. Whereas surgical decisions were based on ultrasound data, we used postoperative refraction measurements to calculate retrospectively what results would have been obtained if optical axial length data had been used for IOL calculation. For the translation of optical to geometrical lengths, five different conversion formulas were used, among them the relation which is built into the Zeiss IOLMaster. IOL calculation was carried out according to Haigis with and without optimization of constants. Results: On the basis of ultrasound immersion data from our Grieshaber Biometric System (GBS), postoperative refraction after implantation of a Rayner IOL type 755U was predicted correctly within ±1 D in 85.7% and within ±2 D in 99% of all cases. An analogous result was achieved with optical axial length data after suitable transformation of optical path lengths into geometrical distances. Conclusions: Partial coherence interferometry is a non- contact, user- and patient-friendly method for axial length determination and IOL planning with an accuracy comparable to that of high-precision immersion ultrasound. Received: 8 March 2000 Revised: 22 May 2000 Accepted: 8 June 2000     

Comparison of optical low-coherence reflectometry and applanation ultrasound biometry on intraocular lens power calculation

Background

The aim of the study was to determine whether the innovative non-contact optical low-coherence reflectometry method utilized by the Lenstar LS 900® agrees sufficiently with applanation ultrasound A-scan technique in routine biometric measurement and intraocular lens power calculation to replace it.

Methods

Twenty-two patients hospitalized at our eye clinic undergoing cataract surgery were assigned to have five consecutive measurements of axial length by two examiners in a single session using applanation ultrasound and the Lenstar. The applanation ultrasound intraocular lens power calculation was based on automated keratometry and applanation ultrasound axial length measurements. The Lenstar intraocular lens power calculation was based on its measurement of keratometry and axial length. Bland–Altman analysis was used to assess interobserver repeatability of applanation ultrasound and the Lenstar as well as agreement between the Lenstar and applanation ultrasound for axial length measurement and intraocular lens power calculation.

Results

Thirty-two eyes of 22 patients were analyzed. In 95% of the observations, predicted refractive error corresponded to –0.26?±?0.62 D and 0.01?±?0.20 D obtained with applanation ultrasound and the Lenstar, respectively.

Conclusions

Based on excellent repeatability of the Lenstar and acceptable repeatability of applanation ultrasound, two techniques may be used interchangeably. The predicted refractive error of ±0.20 D in 95% of the observations has never been achieved. Optical low-coherence reflectometry might become a new standard method for biometric measurement needed for intraocular lens-power calculation in patients with cataract.

     

眼压对青光眼—白内障联合术患者人工晶状体计算公式选择的影响

目的　探讨眼压对青光眼—白内障联合术患者人工晶状体计算公式选择的影响,为临床上避免屈光误差（refractive error,RE）提供参考依据。方法　选取2014年5月至2017年4月在我院行白内障超声乳化吸出并人工晶状体植入联合复合式小梁切除术的原发性闭角型青光眼（primary angle-closure glaucoma,PACG）合并白内障患者72例（80眼）,依术前平均眼压将测试眼分为两组:正常眼压组（10～21 mmHg,1 kPa=7.5 mmHg）和高眼压组（＞21 mmHg）,分别为28眼和52眼。比较各组内术后3个月验光所得实际等效球镜度与术前人工晶状体 Master中 4种人工晶状体计算公式（SRK/T、Holladay1、Hoffer Q及Haigis）相应预测等效球镜度的差异。定义实际等效球镜度减去预测等效球镜度即为RE,当RE＜0时为屈光近视漂移,而RE＞0则为屈光远视漂移,RE取绝对值为绝对屈光误差（absolute refractive error,ARE）,评估眼压对各公式术后ARE及RE的影响。术后随访6个月。结果　全部患者术后3个月眼压较术前下降明显,差异有统计学意义（t=9.96,P=0.000）,且眼压降低幅度与术前平均眼压呈正相关（r=0.974,P=0.000）。正常眼压组SRK/T、Holladay1、Hoffer Q、Haigis公式ARE的中位数差异有统计学意义（P=0.008）;高眼压组各公式ARE的中位数差异亦有统计学意义（P=0.004）。正常眼压组和高眼压组远视漂移时SRK/T、Holladay1、Hoffer Q、Haigis公式RE总体差异均无统计学意义（P=0.633、0.422）。正常眼压组近视漂移时各公式RE间总体差异有统计学意义（P=0.000）,经LSD两两比较,SRK/T公式较其他公式的RE小（均为P<0.01）,Haigis公式较其他公式的RE大（均为P<0.05）,其他各公式RE差异均无统计学意义（均为P＞0.05）。而高眼压组近视漂移时各公式RE总体差异亦有统计学意义（F=6.757,P=0.000）,经LSD两两比较,Hoffer Q公式RE较其他公式的小（均为P<0.01）,其他各公式RE差异均无统计学意义（均为P＞0.05）。结论　青光眼—白内障联合术可提高患者视力并改善眼压,术后眼压降低幅度与术前平均眼压呈明显正相关。计算青光眼—白内障联合术人工晶状体度数时,术前平均眼压正常者应选SRK/T公式较为准确,而术前平均眼压高时Hoffer Q公式更合适。     

Broken intraocular lens during cataract surgery.

A case of planned routine extracapsular cataract extraction is described where surgery was complicated peroperatively by fracture of the posterior chamber lens implant. The technique of lens implantation is discussed.     

Comparison of wavefront aberration after cataract surgery with acrylic intraocular lens implantation

PURPOSE: To compare aberration changes in pseudophakic eyes with 3 types of acrylic intraocular lenses (IOLs) and in normal phakic eyes. SETTING: Department of Ophthalmology, Asan Medical Center, Seoul, Korea. METHODS: This single-center prospective study comprised 51 cataract patients who had cataract surgery and 12 phakic eyes. Fourteen eyes received an AcrySof MA60BM (Alcon), 18 eyes received a Sensar AR40 (AMO), and 19 eyes, a Corneal ACR6D (Corneal Laboratoire). One month after cataract surgery, aberrations in the eyes were measured using a Hartmann-Shack-type aberrometer. The same measurements were done in the 12 age-matched normal phakic eyes. Individual Zernike polynomials and the root-mean-square (RMS) 3rd- and 4th-order aberrations in the 2 groups were compared. The total RMS value was also compared. RESULTS: The RMS value of the 3rd- and 4th-order aberrations did not differ significantly between groups, nor did the total RMS value. In all IOL groups, an individual Zernike coefficient (C3(3), triangular astigmatism with base on the y-axis) was significantly different than that in the normal phakic group. CONCLUSION: There was no statistically significant difference in overall higher-order aberrations between normal eyes and eyes implanted with 3 types of acrylic IOLs.