角膜波前引导的LASIK治疗低中度近视角膜高阶像差的临床观察

目的:比较角膜波前像差引导下的准分子激光原位角膜磨镶术(laser in situkeratomileusi,LASIK)和常规的LASIK对低中度近视角膜高阶像差的影响。方法:采用前瞻性非随机对比研究,选取6mo内连续的低中度近视患者32例58眼实施常规LASIK(A组,其中低度近视24眼,中度近视34眼),34例52眼实施角膜波前引导下的个性化LASIK(B组,其中低度近视23眼,中度近视29眼)。所有手术均使用德国Schwind公司Esiris第九代准分子激光治疗仪和Carriazo Pendular钟摆式角膜板层刀,使用4.2.0版本的Optikon keratron Scout2000角膜地形图对两组患者在术前和术后3mo进行6mm瞳孔直径时角膜高阶像差检查。结果:两组病例角膜球差和均方根均高于术前。A组低度近视术后高阶像差增加量依次为均方根0.236μm、彗差0.146μm、球差0.139μm和三叶差0.054μm,中度近视高阶像差增加量依次为均方根0.367μm、球差0.284μm、彗差0.177μm和三叶差0.021μm。B组低度近视高阶像差增加量依次为球差0.127μm、均方根0.088μm、三叶差0.051μm、和彗差0.042μm,中度近视高阶像差增加量依次为均方根0.175μm、球差0.162μm、彗差0.027μm和三叶差0.024μm;两组病例术后3mo裸眼视力非常接近.同样条件下低中度近视角膜波前像差引导下的个性化LASIK切削的深度较常规LASIK深。结论:角膜波前像差引导下的低中度近视LASIK较常规LASIK角膜高阶像差影响少。     

波前像差引导的个体化切削技术在LASEK术中应用的研究

目的:探讨波前像差引导的个体化切削技术对LASEK患者术后高阶像差的影响。方法:将均方根(RMS)值>0.3的不适合做LASIK术的近视患者40例80眼随机分为2组。其中1组20例40眼行普通LASEK术,另1组20例40眼应用波前像差引导的个体化切削程序(Zyoptix)进行LASEK术;所有术眼术前及术后1,3mo行像差测量。结果:术前两组高阶像差,彗差,球差相比无统计学意义(P>0.05),在6mm的瞳孔直径下,术后1mo两组高阶像差,彗差,球差较术前增加,个体化切削组高阶像差,彗差,球差增加幅度低于常规组,有统计学意义(P<0.05),术后3mo时,总体高阶像差,彗差,球差较1mo时有所下降,个体化组增加幅度仍小于普通组。结论:Zyoptix波前引导LASEK术后高阶像差增加幅度小于普通LASEK术。     

常规LASIK与波前像差引导的LASIK治疗中高度近视散光的对比研究

目的 比较常规准分子激光原位角膜磨镶术（简称常规LASIK）和波前像差引导的个体化LISIK（简称波前像差引导LASIK）矫正中高度近视散光后的视觉质量.方法 随机选取2011年1月至2012年12月在我院行准分子激光手术者,其中散光度数≥-2.00 DC作为入选对象共82例（163只眼）.其中选择行波前像差引导的LASIK术者42例（83只眼）,散光（-3.55±1.09） DC;接受常规LASIK术者40例（80只眼）,散光（-3.47±1.23） DC.所有患者术前与术后7 d、1个月、6个月分别进行视力、角膜地形图、波前像差的检查和视疲劳满意度调查,比较两组的差别.结果 （1）术后7 d、1个月、6个月波前像差引导的LASIK术者视力分别优于常规LASIK术者（P＜0.05）.（2）角膜地形图查残余角膜散光度：波前像差组7 d、1个月、6个月分别为（-0.35±0.24） DC、（-0.42±0.13） DC、（-0.51±0.19） DC;常规组7 d、1个月、6个月分别为（-0.75±0.28） DC、（-0.92±0.23） DC、（-1.21±0.21） DC,两组差异有统计学意义（P＜0.05）.（3）波前像差组和常规组高阶像差均呈增加趋势,以彗差和球差增加为主.波前像差组在总高阶像差（HOAROM）、30°三叶草（Z6）、垂直彗差（Z7）和水平彗差（Z8）高阶像差的改变显著优于常规组（P＜0.05）.（4）视疲劳满意度调查：波前像差组明显优于常规组.结论 波前像差引导的个性化LASIK较常规LASIK能更好地矫正中高度近视散光,使患者术后角膜残余散光更少,高阶像差的增加更少,视力恢复更理想,视觉质量更佳,患者的满意度更好.     

LASIK术后出现视觉不良症状者的高阶像差分析

目的分析经传统准分子激光原位角膜磨镶术（LASIK）或者波前像差引导的LASIK术后患者中（除外过矫、欠矫和眼部疾患导致的视力下降）,出现视觉不良症状者的高阶像差分布特征。方法回顾性病例对照研究。本研究回顾了北京军区总医院2006年1月1日至2010年3月31日期间经初次LASIK术后（包括传统组和波前像差引导组）,除外过矫、欠矫和眼表及眼内疾患导致的视力下降,出现重影和星芒等视觉症状患者总40例（48眼）,传统LASIK组18例（23眼）,波前像差引导的LASIK组22例（25眼）。两组患者术后均复诊3个月以上,屈光度稳定在±1．00D以内。所有患者采用WaveScan3．62版波前像差仪,在自然瞳孔下行波前像差检查,提取4mm瞳孔直径高阶像差结果。采用配对样本t检验、配对样本秩和检验、独立样本t检验、独立样本秩和检验及卡方检验对数据进行比较。结果波前像差引导LASIK组高阶像差手术前后比较差异均有统计学意义：总高阶像差均方根（RMS）值术后增加了1．18倍（t=-11．485,P〈0．01）;三阶像差RMS值术后增长了1．25倍（Z=-6．125,P〈0．01）;四阶像差RMS值术后增长了0．93倍（Z=-6．154,P〈0．01）;五阶像差增长了1．35倍（Z=-6．154,P〈0．01）;六阶像差增长了1．14倍（t=-21．080,P〈0．01）。垂直彗差增加了1．43倍（Z=-6．154,P〈0．01）、水平彗差增加了93％（Z=-6．154,P〈0．01）、球差增加了89％（f=-19．659,P〈0．01）。但术后30度三叶草仅增加了5％（Z=-6．154,P〈0．01）、0度三叶草增加了35％（Z=-6．154,P〈0．01）。波前像差引导组术后与传统组术后的比较：总高阶像差、三阶像差、四阶像差、垂直彗差、水平彗差、球差、30度三叶草和0度三叶草比较差异无统计学意义。但两组术后五阶像差陆-2．033,P=0．042）、六阶像差（Z--2．631,P=-0．009）比较差异有统计学意义。另外,两种LASIK术后总高阶像差中,三阶像差所占的比重最大,四阶像差占总高阶像差比例居于第二位。两组比较差异无统计学意义。但两组的五阶像差占总高阶像差比例（Z=-2．053,P=0．040）和六阶像差占总高阶像差比例（Z=-2．012,P=0．044）差异有统计学意义。波前引导组手术前后彗差占三阶像差的56％左右,球差占四阶像差的78％左右,手术前后保持稳定;但三叶草占三阶像差的比例由术前的43％降至术后的36％,手术前后比较差异有统计学意义（t=2．285,P=0．027）。主导像差分布：波前引导组术后垂直彗差为44％、水平彗差为12％、球差为40％,与术前差异有统计学意义（X^2=7．891,P=0．048）。传统组术后垂直彗差占30％、水平彗差占34％、球差为21％,与波前引导组比较差异无统计学意义。结论LASIK术后出现的视觉主诉与高阶像差均方根值增加密切相关。此类患者术后总高阶像差和各类高阶像差的均方根值较术前普遍增加1倍左右（三叶草像差增长较少）。总高阶像差中以三阶像差和四阶像差为主,其中三阶彗差和四阶球差所占的比重最大,三叶草像差所占的比重较小且手术前后有变化。传统LASIK对五阶像差和六阶像差的消融要优于波前像差引导LASIK。LASIK术后的视觉质量下降患者的主导像差类型以彗差和球差居多。     

飞秒激光制瓣LASIK联合波前优化治疗近视及散光术后的角膜像差

目的 研究飞秒激光制瓣LASIK（飞秒LASIK）联合波前优化治疗近视及散光术后角膜像差的特性.方法 回顾性研究.行飞秒LASIK手术的近视及近视散光患者30例（30眼）,平均年龄（20.9±2.8）岁;术前平均等效球镜度（-6.48±1.61）D.应用Pentacam眼前节分析仪测量角膜前表面6、7、8、9 mm直径下的Q值,采用Keratron角膜波前像差分析仪测量6 mm瞳孔直径下角膜波前像差.随访时间为术后3个月,手术前后数据采用配对t检验,采用Pearson相关分析角膜像差、Q值与其他参数的相关性.结果 6 mm瞳孔直径下角膜高阶像差、总球差、总彗差、水平彗差、垂直彗差、初级球差、x-向次级像散、次级水平彗差、次级垂直彗差、次级球差均较术前增加,差异有统计学意义（t=-8.254、-7.385、-6.108、-5.651、-2.195、-7.565、-4.628、-2.974、-2.748、-7.068,P＜0.05）.角膜前表面4个直径范围内Q值均较术前增加,差异有统计学意义（t=16.999、-19.208、-21.502、-22.197,P＜0.05）.6 mm瞳孔直径下手术前后Q值变化量（△Q6mm）与高阶像差变化量、总球差变化量、初级球差变化量、总彗差变化量呈正相关（r=0.736、0.792、0.788、0.383,P＜0.05）,△Q6mm与总三叶草变化量、次级球差变化量无相关性（r=0.099、-0.348,P＞0.05）.结论 飞秒LASIK联合波前优化治疗近视及近视散光是安全、有效的,但术后角膜高阶像差仍有显著增加.     

高度近视Zyoptix-LASIK和Artisan有晶状体眼人工晶状体植入术对视觉质量的影响

目的探讨高度近视Zyoptix-LASIK和有晶状体眼Artisan人工晶状体（IOL）植入术后高阶像差和对比敏感度的差异。方法按照术眼中央角膜厚度是否能够满足准分子激光角膜原位磨镶术（LASIK）的条件,将术眼分为LASIK组和ArtisanIOL组。LASIK组15例30眼接受波前像差引导的个体化LASIK,平均年龄27.6岁,屈光度-7.0～-12.0D平均等效球镜（-9.16±1.15）D;ArtisanIOL组17例30眼接受虹膜固定性有晶状体眼ArtisanIOL植入术,平均年龄29.1岁,屈光度-8.0～-14.0D平均等效球镜（-11.51±1.62）D。对比2组术后视力、最佳矫正视力、瞳孔大小、屈光状态、高阶像差、明光、暗光、暗光眩光条件下的对比敏感度等指标。高阶像差值以均方根（RMS）表示,测量总高阶像差（RMSh）、3阶X轴彗差（RMS3x）、3阶Y轴彗差（RMS3y）、4阶球差（RMS4s）及4阶像差（RMS4g）。结果术前2组间年龄和高阶像差的差异均无统计学意义（P〉0.05）。术后ArtisanIOL组的高阶像差低于LASIK组,其中2组间RMSh、RMS3x和RMS4g的差异均有统计学意义（P〈0.05）。术后2组高阶像差与术前相比均增高,但ArtisanIOL组手术前后RMS3x的差异无统计学意义（P=0.793）。ArtisanIOL组在明光、暗光、暗光眩光条件下各空间频率的对比敏感度均高于LASIK组,暗光条件下3、6、12cpd空间频率间的差异有统计学意义（P〈0.05）。结论与个体化LASIK相比,高度近视有晶状体眼植入ArtisanIOL后高阶像差的增加较少,且其暗光下中高空间频率对比敏感度优于LASIK。     

FEMTO LDV飞秒激光制瓣LASIK术后像差的改变

目的 对比飞秒激光及机械微型角膜刀制瓣行准分子激光原位角膜磨镶术(LASIK)后眼球像差的变化.方法 选取接受FEMTO LDV飞秒激光制瓣患者38例(76眼)为试验组,同期接受Hansatome微型角膜刀制瓣患者35例(70眼)为对照组,制瓣后均行波前像差引导的准分子激光切削术.对2组波前像差进行比较.随访时间为3个月.结果 试验组术后3个月时75眼(99%)达到或超过最佳矫正视力,与对照组66眼(94%)比较差异无统计学意义(P>0.05).整体高阶像差试验组术后较术前无差异,对照组术后1周(0.52±0.30)μm、1个月(0.81±0.15)μm时较术前增加.同时术后各期2组间的差异均有统计学意义(均为P<0.05).2组的球差均较术前增加,对照组球差的增加量高于试验组.垂直彗差试验组术后无明显变化,对照组较术前增加(P<0.05).水平彗差2组均较术前增加(均为P<0.05).结论 飞秒激光制瓣LASIK可减少术后高阶像差的增加.     

近视眼患者角膜高阶像差分布及LASIK和波前像差引导的优化LASIK术后高阶像差变化的研究

目的比较常规准分子激光原位角膜磨镶术（laserin situ keratomileusis,LASIK）和角膜波前像差引导的优化屈光角膜切削术（optimized refractive keratomy,ORK）后近视眼患者视力及角膜前表面高阶像差的变化,探讨角膜波前像差引导的优化准分子激光原位角膜磨镶术（ORK-LASIK）的安全性和有效性。方法选取拟做LASIK手术的近视眼患者396例733眼,按球镜屈光度分成低度（≤-3.00D）、中度（-3.00～-6.00D）和高度（-6.00～-12.00D）3组,每组柱镜度数均小于-2.50D,各组再随机分成2组,一组行常规LASIK手术,另一组行ORK-LASIK。手术切削区直径为6.0～7.0mm。角膜波前像差分析为6mm瞳孔直径。术后随访6个月,检查裸眼视力及角膜地形图并进行波前像差分析。结果成人近视眼角膜前表面波前像差在6mm瞳孔直径以3阶和4阶为主,占90%,在3阶和4阶中又以彗差和球差为主,分别占角膜全部像差的27.7%和28.4%;球差和球镜度数呈负相关（r=-0.501,P〈0.05）,其他高阶像差和球镜度数无关。但在-6.00D以上的近视眼中,彗差和次级彗差均和球镜度数有关（F=8.808,7.123,P〈0.04,0.01）。角膜前表面各高阶像差均和年龄及性别无关。LASIK和ORK-LASIK2组比较,术后6个月时,低度和高度组2组的裸眼视力均达到术前矫正视力,差异无统计学意义（P〉0.05）;在中度组,ORK-LASIK组视力明显好于LASIK组,2组差异有统计学意义（P〈0.05）。术后6个月时,角膜前表面的球差、彗差和总高阶像差均较术前增加,和术前比较差异有统计学意义（P〈0.05）。在低度组,ORK-LASIK组和LASIK组比较角膜彗差和球差2组间差异无统计学意义（P〉0.05）;中、高度组ORK-LASIK组角膜彗差和球差较LASIK组明显下降,差异有统计学意义（P〈0.05）。结论角膜波前像差引导的ORK-LASIK手术能有效地矫正近视和散光,提高中度近视患者的视力,降低中、高度组术后彗差和球差,手术效果稳定、安全。     

Q值优化非球面切削矫正高度近视的远期高阶像差观察

目的观察Q值优化的非球面切削准分子激光手术矫正高度近视的远期Q值和高阶像差变化。方法回顾性分析2007年在上海交通大学附属第六人民医院眼科行Q值引导的个体化切削（F—CAT）准分子激光手术的高度近视患者35例（70眼）,其中行准分子激光原位角膜磨镶术（LASIK117例（34眼）,准分子激光上皮瓣下角膜磨镶术（LASEK）18例（36眼）,观察并用配对≠检验比较两种手术方式术前、术后远期角膜Q值和高阶像差的变化,采用独立样本t检验比较两组间各项指标的差异,采用Pearson相关和线性回归分析术后高阶像差的相关影响因素。结果术后3年,所有患者裸眼视力〉10．8,LASIK组和LASEK组安全性指数均〉1,有效性指数均接近1。两组Q值与术前相比,均从负值变为正值。术后总高阶像差均比术前增加,差异有统计学意义（t=-3．90、-6．75,P〈0．01）。术后LASIK组和LASEK组三阶像差均方根（RMS）值（t=-3．50、-5．22）、四阶像差RMS值（t=-6．79、-10．14）、垂直彗差RMS值（t=5．73、-5．50）、球差RMS值（t=-8．57、-13．79）均比术前增加（P〈0．01）,两组间垂直彗差,球差差异均无统计学意义;水平彗差与术前相比差异无统计学意义。术后总高阶像差RMS值（R^2=372,F=16．96,P〈0．01）和术后球差RMS值（R^2=0．224,F=10．93,P〈0．01）与术前等效球镜度、手术光学区大小相关。术后垂直彗差与术前等效球镜度、手术目标Q值相关（R^2=0．224,F=10．93,P〈0．01）。结论Q值引导LASIK和LASEK矫正高度近视手术远期安全、有效。IASIK和LASEK术后Q值均由负值变为正值,远期高阶像差和球差增加。垂直彗差的增加可能与手术瓣蒂位置有关。术后高阶像差与患者术前屈光度、手术方式及光学区相关。     

不同方式角膜准分子激光手术对人眼波前像差的影响

目的研究不同方式的角膜准分子激光手术(LASIK、LASEK)对术后高阶像差的影响。设计病例对照研究。研究对象行LASIK及LASEK患者各22例(各43眼)。方法对行LASIK或LASEK的患者术前、术后1、3、6个月进行波前像差检查。主要指标视力、屈光、波前像差的变化。结果两种手术方式的术后视力与等效球镜度相近。6mm瞳孔直径下,术后1个月时,总波前像差的RMS值比术前减少61%,高阶像差增加110%。术后高阶像差的主要成分大部分增加;其中,球差增加最大,1个月时比术前增加285%。术后1、3个月,LASIK术式组高阶像差RMS值稍低于LASEK术式组;术后6个月,LASIK术式组高阶像差RMS值稍高于LASEK术式组(P>0.05)。其中,两组的三阶彗差、三叶草、球差RMS值改变无统计学意义(P>0.05)。结论LASIK与LASEK患者术后视力与屈光结果相近。术后总波前像差和低阶像差降低,高阶像差增加。不同手术方式对术后高阶像差无显著性影响。(眼科,2006,15:191-194)     

Q值引导与波前引导的LASIK治疗近视的初步研究

目的:观察Q值引导与波前引导的LASIK治疗近视的疗效。方法:接受非球面切削与波前引导的LASIK治疗26例患者(52眼),每名患者的1眼使用Q值引导的切削,另1眼使用波前引导的个性化切削进行LASIK手术,分析2组的治疗效果。结果:术后3mo,2组手术眼视力矫正均满意,其间屈光度无差别(P>0.05);Q值引导组与波前引导组比较其术后角膜更倾向于长椭球形,Q值(0.24±0.32)低于波前引导组Q值(0.53±0.41)(P<0.01),当瞳孔直径为6mm时,两组术后高阶像差RMS均有增加,Q值引导组术后球差增加的幅度小于波前引导组,而彗差增加的幅度大于波前引导组。术后眩光发生率两组无显著性差异(P>0.05)。结论:使用Q值引导与波前引导的LASIK治疗近视及近视散光均是安全有效的,但仍存在不足,需要进一步改进、优化或整合。     

Conservation of corneal tissue with wavefront-guided laser in situ keratomileusis

PURPOSE: To determine whether corneal tissue can be conserved with wavefront-guided ablation compared to conventional surgery with a larger ablation zone for attempted prevention of glare and halo. SETTING: Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Korea. METHODS: This prospective study was composed of 2 parts: First, 40 eyes of 20 patients were studied to determine whether a larger optical ablation could be beneficial in prevention of glare after conventional laser in situ keratomileusis (LASIK) surgery. One eye in each patient was treated with a 6.00 mm optical zone, and the other with a 6.25 mm optical zone. Second, 20 eyes of 10 patients with a higher-order root mean square (RMS) value of 0.3 or greater were evaluated to learn whether a wavefront-guided ablation could be as effective as a larger conventional optical ablation. One eye in each patient was treated by conventional LASIK surgery with a 6.25 mm optical zone, and the other eye was treated by wavefront-guided LASIK surgery with a 6.00 mm optical zone. All patients were analyzed with a WASCA analyzer (Carl Zeiss Meditec) preoperatively, and 1 month and 3 months after surgery. RESULTS: Higher-order aberrations including coma, spherical aberration, and higher-order RMS were statistically significantly increased after conventional surgery with both a 6.00 mm and 6.25 mm optical zone. High-order aberrations including comaer- and spherical aberration after conventional surgery with 6.25 mm zone were statistically significantly increased. However, coma and higher-order RMS did not show a statistically significant increase between pre-LASIK and post-LASIK in wavefront-ablated eyes with a 6.00 mm optical zone. CONCLUSION: Wavefront ablation showed less increase of coma and higher-order RMS regardless of a smaller optical zone. This finding might provide a clinical clue for an advantage of wavefront-guided ablation from the standpoint of corneal tissue conservation.     

配戴角膜塑形镜后偏心对人眼高阶像差的动态影响

目的观察分析配戴角膜塑形镜后角膜光学压平区偏中心状态及不同瞳孔直径下人眼高阶像差的动态变化，探索偏心性质和程度对视觉的影响。方法前瞻性临床研究。30例年龄为（23．6-2．3）岁的中低度近视患者配戴夜戴型角膜塑形镜，等效球镜度为-0．75—．4．00D，平均（-2．61±0．83）D。在戴镜前和戴镜后1周、1个月、3个月分别检测角膜地形图，检测波前像差（在自然瞳孔下检查，分别提取3mm和6mm瞳孔直径下的全眼高阶像差结果），并通过分析戴镜后的角膜地形图形态，测量出角膜塑形镜压平区中心相对于瞳孔中心的偏心量（包括偏心距离和角度），只取右眼数据进行研究。采用Pearson相关性分析、重复测量资料方差分析对数据进行分析。结果配戴角膜塑形镜后1周、1个月、3个月时的平均偏心距离分别为（0．53±0．26）mm、（0．54±0．32）mm和（0．60±0．35）mm，偏心的方向主要集中于颞上方，偏心距离和角度在戴后3个时间点之间差异无统计学意义：戴后各时间点，偏心距离与戴前等效球镜度、初始散光量均不相关。在3mm与6mm瞳孔直径下，总高阶像差、总三阶像差、总四阶像差、总彗差（包括垂直彗差和水平彗差）、总三叶草和球差均方根值在戴后1周、1个月、3个月时均比戴前有明显增加，但各项像差在戴后各时间点之间差异均无统计学意义：在戴后的各个时间点，6mm瞳孔直径的像差结果都较3mm时大。戴后不同瞳孑L直径下，垂直或水平偏心距离与相应方向彗差在戴后各时间点均呈正相关；而总偏心距离与总高阶像差、总三阶像差、总四阶像差、总彗差、总三叶草和球差在戴后各时间点均不相关。结论配戴角膜塑形镜后偏心客观存在，程度较小并在1周后稳定；术后偏心会造成人眼高阶像差显著增加。     

近视LASIK手术后高阶像差的改变

目的分析LASIK手术对高阶像差的影响，分析IASIK术的近视屈光度与LASIK术后眼的高阶像差的关系。方法采用WASCA波前像差仪测量150眼LASIK术前及术后1月及3月瞳孔直径分别为小瞳孔（3mm）及人瞳孔（6．25mm）时的总高阶像差的均方根及第三和第四阶像差的Zemike系数，并计算出球差、慧差、第三及第四阶像差的均方根。对结果进行方差分析和直线相关分析。结果LASIK术后，大瞳孔直径和小瞳孔直径下高阶像差均明显增高。无论瞳孔人小．术后3月较1月时高阶像差均轻微下降。人瞳孔直径下，光区直径为6．25mm时，术后球差、第四阶像差和总高阶像差与术前屈光度存在正相关。结论IASIK术后，高阶像差明显增高，尤以球差最明显。术前屈光度越高，手术所导致的高阶像差也越大，屈光度过高的近视眼不宜采用波前像差引导的个体化屈光手术。     

Aberrations induced in wavefront-guided laser refractive surgery due to shifts between natural and dilated pupil center locations

PURPOSE: To determine the aberrations induced in wavefront-guided laser refractive surgery due to shifts in pupil center location from when aberrations are measured preoperatively (over a dilated pupil) to when they are corrected surgically (over a natural pupil). SETTING: Center for Visual Science and Department of Ophthalmology, University of Rochester, Rochester, New York, USA. METHODS: Shifts in pupil center were measured between dilated phenylephrine hydrochloride (Neo-Synephrine [2.5%]) and nonpharmacological mesopic conditions in 65 myopic eyes treated with wavefront-guided laser in situ keratomileusis (Technolas 217z, Bausch & Lomb). Each patient's preoperative and 6-month postoperative wave aberrations were measured over the dilated pupil. Aberrations theoretically induced by decentration of a wavefront-guided ablation were calculated and compared with those measured 6 months postoperatively (6.0 mm pupil). RESULTS: The mean magnitude of pupil center shift was 0.29 mm +/- 0.141 (SD) and usually occurred in the inferonasal direction as the pupil dilated. Depending on the magnitude of shift, the fraction of the higher-order postoperative root-mean-square wavefront error that could be due theoretically to pupil center decentrations was highly variable (mean 0.26 +/- 0.20 mm). There was little correlation between the calculated and 6-month postoperative wavefronts, most likely because pupil center decentrations are only 1 of several potential sources of postoperative aberrations. CONCLUSIONS: Measuring aberrations over a Neo-Synephrine-dilated pupil and treating them over an undilated pupil typically resulted in a shift of the wavefront-guided ablation in the superotemporal direction and an induction of higher-order aberrations. Methods referencing the aberration measurement and treatment with respect to a fixed feature on the eye will reduce the potential for inducing aberrations due to shifts in pupil center.     

LASIK术后眼高阶像差和角膜非球面系数Q值的变化

目的:观察2mm小光斑飞点扫描伴主动眼球跟踪系统的激光机行常规LASIK术后,眼高阶像差和角膜非球面系数Q值的改变,同时观察术后不同瞳孔直径下眼高阶像差的变化。方法:近视患者33例60眼均接受常规LASIK手术,术前和术后3mo分别检查记录5mm和6mm瞳孔直径下总高阶像差、三阶彗差、四阶球差和角膜前表面非球面系数Q值,并进行统计学分析。结果:LASIK术后,5mm和6mm瞳孔直径下各高阶像差均较术前显著增加,其中四阶球差增加最为显著;术后水平彗差比垂直彗差增加显著;术前术后6mm直径下高阶像差均较5mm直径下显著增大;LASIK术后角膜非球面系数Q值向正值方向明显变化,差异具有显著性。结论:近视眼常规LASIK术后,各项高阶像差明显增大,其中球差增大最为显著。手术前后6mm瞳孔直径下高阶像差均比5mm瞳孔直径下高阶像差明显增大。术后角膜表面非球面系数Q值由负值变为正值,且增大显著。     

Comparison of corneal aberration changes after laser in situ keratomileusis performed with mechanical microkeratome and IntraLase femtosecond laser: 1-year follow-up

PURPOSE: To compare corneal aberration changes 1 year after myopic laser in situ keratomileusis (LASIK) performed with a mechanical microkeratome and IntraLase femtosecond laser. METHODS: Twenty four eyes of 15 patients underwent LASIK with the Hansatome microkeratome, and 23 eyes of 13 patients underwent LASIK with the IntraLase femtosecond laser. A standard ablation was performed with the Bausch & Lomb Technolas 217 excimer laser. Topography data were used to calculate corneal aberrations with a 3.0 mm and 5.00 mm pupil, before and 12 months after surgery. The increasing factor (IF), defined as the ratio between the postoperative and preoperative mean value of the optical aberration, was calculated. The method of Mulhern et al was used to evaluate the centration of ablation. The comalike aberration was correlated with the decentration of ablation. The Student t test was used for the statistical anaylsis. RESULTS: The postoperative mean decentration of ablation was <0.5 mm. The comalike aberration appeared to be positively correlated with the decentration of ablation in both groups with a 5.0-mm pupil (P < 0.05). With a 3.00-mm pupil, the comalike aberration changed in the Hansatome group, whereas with a 5.00-mm pupil, all aberrations statistically significantly changed in both groups (P < 0.05). The IF similarly increased in 2 groups for spherical-like aberration, whereas IF greatly increased for total and comalike aberrations in the Hansatome group. CONCLUSIONS: Wavefront corneal aberrations change significantly 1 year after myopic LASIK performed with the Hansatome microkeratome as well as with IntraLase femtosecond lasers. Both of the procedures induce higher-order aberrations in the anterior corneal surface, but the amount of comalike aberration increases more with the Hansatome mechanical microkeratome.     

Comparison of higher-order aberrations after wavefront-guided laser in situ keratomileusis and laser-assisted subepithelial keratectomy

PURPOSE: To compare the higher-order aberrations (HOAs) in 70 eyes (38 patients) that had wavefront-guided laser in situ keratomileusis (LASIK) with those in 70 eyes (40 patients) that had wavefront-guided laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia. SETTING: Department of Ophthalmology, Yonsei University College of Medicine, Myongdong Bal-geun sesang Eye Clinic, and Seran Eye Center, Seoul, Korea. METHODS: In a prospective study, 140 consecutive eyes of 78 patients were treated with wavefront-guided LASIK or LASEK according to the patient's choice after each procedure had been thoroughly explained. The patients were followed for 6 months. Best corrected visual acuity (BCVA), uncorrected visual acuity (UCVA), manifest refraction, and wavefront aberrations were measured at baseline and 1, 3, and 6 months after surgery. RESULTS: There were no significant differences in postoperative BCVA, UCVA, and manifest refraction between groups. The mean root-mean-square wavefront error of HOAs for a scotopic pupil in the wavefront-guided LASIK group was significantly smaller than that in the wavefront-guided LASEK group at 1 month. Analyzing individual Zernike coefficients, the spherical aberration and second coma were significantly smaller in the wavefront-guided LASIK group than in the wavefront-guided LASEK group at 1 month. This difference in HOAs between groups disappeared at 3 and 6 months. CONCLUSIONS: The HOAs in the scotopic condition were not different between the wavefront-guided LASIK and LASEK groups beginning 3 months after surgery. However, the HOAs in the LASIK and LASEK groups had a different time course, especially in the case of spherical aberration. This finding suggests that postoperative changes in aberration contribute to the final outcome of wavefront-guided ablation.     

准分子激光原位角膜磨镶术治疗近视后眼高阶像差变化的研究

目的探讨光学区大小对准分子激光原位角膜磨镶术（LASIK）治疗近视后眼高阶像差的影响。方法将接受LASIK治疗的近视者236例（461只眼）分为高、中、低度近视组,每组根据激光切削光学区直径不同（5．75、6．00、6．25和6．50mm）分为Ⅰ～Ⅳ亚组。术前和术后6个月用波阵面像差仪测量眼的像差。用方差分析和q检验分析手术前后各组内不同亚组间在瞳孔直径为4．00、5．00、6．00mm时眼总高阶像差、水平彗差、垂直彗差和球差的差异。结果术前各组内不同亚组间眼高阶像差差异无统计学意义（P〉0．05）。术后6个月,各组内不同亚组间眼总高阶像差和球差差异有统计学意义（P〈0．05）,较大光学区亚组低于较小光学区亚组。高度近视组在不同瞳孔直径时差异均有统计学意义（P〈0．05）,低度近视组在瞳孔直径为6．00mm时差异有统计学意义（P〈0．05）;瞳孔直径为6．00mm时,高度近视组各亚组间差异均有统计学意义（P〈0．05）,低度近视组在Ⅰ、Ⅳ亚组间差异有统计学意义（P〈0．05）。各组内不同亚组间水平彗差和垂直彗差差异均无统计学意义（P〉0．05）。结论光学区大小影响LASIK治疗近视后眼总高阶像差和球差,较大光学区组低于较小光学区组,在治疗高度近视时影响更加明显。