准分子激光前弹力层下角膜磨镶术前后散射特征及相关因素分析

目的研究准分子激光前弹力层下角膜磨镶术（SBK）矫正屈光不正手术前后的散射特征．并分析其相关因素。方法前瞻性临床研究。行SBK手术的近视及近视散光患者46例（92眼）,男29例,女17例,年龄18-39岁,平均（24．0±5．4）岁;等效球镜度为-4．75--11．13D,平均（-6．70±1．50）D;散光度为0-2．50D,平均（0．68±0．58）D。手术前,采用Pentacam眼前节分析仪测量平均曲率值、角膜中央厚度等。手术前及手术后第1天、第1周、第1个月,应用C-Quant散射光计量仪测量患者的散射值。对所得数据分别应用重复测量的方差分析、配对t检验及Pearson相关进行分析。结果SBK手术前眼内散射光计量值平均为0．90±0．13,手术后第1天、第1周、第1个月眼内散射光计量值分别为0．96±0．13、0．98±0．10、0．99±0．09,与术前比较,术后各个随访时间点散射均增加（F=24．94,P〈0．05）。经Pearson相关分析。手术前散射光计量值与等效球镜度、平均曲率值、角膜中央厚度的相关性无统计学意义;手术后各时间点散射光计量值增加量与术前散射光计量值水平呈负相关（r=-0．47、-0．67、-O．78,P均〈0．05）,与术前等效球镜度、切削深度的相关性无统计学意义。结论SBK术后早期散射增加可能是影响视觉质量的因素之一,术前散射光计量值愈低的患者术后增加量愈明显。     

角膜塑形术后角膜生物力学属性研究

【摘要】 目的 观察角膜塑形术后1天角膜形态变化和角膜生物力学变化。设计 前瞻性病例系列。 研究对象 等效球镜度-1.50~-6.00 D的青少年近视患者15例（30眼）。方法 双眼配戴夜戴型角膜 塑形镜,配戴前、配戴一夜摘镜时和摘镜后4小时分别测量等效球镜度、Pentacam分析系统测量角 膜平坦、陡峭K值和中央角膜厚度,眼反应分析仪测量角膜生物力学特性。主要指标 等效球镜度, 角膜曲率,中央角膜厚度,角膜黏滞性CH值,角膜阻力因子CRF值。结果 配戴角膜塑形镜一夜后等 球镜效度由配戴前（-3.72±1.82） D下降到（-2.12±1.93） D,角膜曲率平坦K1值从（41.95± 1.12） D下降到（41.22±1.34） D,摘镜4小时后等效球镜度回升到（-2.59±1.98）D,角膜曲率 平坦K1值回升到（41.44±40.10） D。中央角膜厚度在配戴一夜后由（535.9±34.5）μm增加到（ 553.3±36.6）μm（P=0.000）,摘镜4小时恢复至（535.0±40.3）μm。配戴一夜后CRF值由 （10.0±1.4）mm Hg升高至（10.7±1.5）mm Hg（P=0.037）。CH值由（10.6±1.4）mm Hg略有升 高至（10.7±1.3） mm Hg（P=0.208）。摘镜后4小时,与刚摘镜时比CRF值回降至（9.6±1.2）mm Hg（P=0.000）,与配戴前比差异无统计学意义（P=0.148）。CH与配戴后的差异无统计学意义 （P=0.163）。结论 配戴角膜塑形镜后1天角膜生物力学随角膜形态变化而改变,角膜生物力学测 量可作为配戴角膜塑形镜后角膜微观结构变化的一种观察手段。（眼科, 2012, 21： 381-383）     

SMILE术后散射的变化特征及相关影响因素

目的探讨SMILE术后眼内散射的变化,并对其相关影响因素进行分析。方法前瞻性病例研究。选取拟行SMILE手术的近视及近视散光患者67例（67眼）,应用C-quant散射仪分别测量患者手术前、术后1周、术后1个月、术后3个月及术后6个月眼内散射光计量值,并与年龄、球镜度、等效球镜度、CCT、角膜平均曲率值（Km）、角膜曲率半径等做相关分析,同时采用Pearson相关分析术后散射光计量值变化与角膜帽直径、小切口大小、切削深度、切削比、剩余角膜厚度（RBT）、RBT／CCT、能量等关系。结果SMILE手术前、术后1周、术后1个月、术后3个月、术后6个月的散射光计量值分别为0．93±0．16、0．97±0．14、0．94±0．17、0．94±0．17、0．90±0．17,术后1周散射光计量值较术前稍增加,但差异无统计学意义,各时间点散射光计量值比较差异无统计学意义（F=2．253,P〉0．05）;术后散射光计量值的变化与术中相关参数无明显相关性,仅在术后3个月散射光计量值与切口大小呈较弱正相关（r=0．356,P〈0．01）。结论SMILE术后散射光计量值较术前虽有变化,但变化不明显。术后由散射变化造成视觉质量下降的可能性较小。     

飞秒激光制瓣LASIK矫正近视合并高度散光短期疗效观察

目的评价飞秒激光制瓣LASIK矫正近视合并高度散光的短期疗效。方法回顾性病例研究。收集接受飞秒激光制瓣LASIK的高度散光患者53例（76眼）（柱镜≥-2.0 D）,所有患者均有完整的术前检查和术后3个月的检查结果,将术前和术后的屈光度转化为屈光度的极值参数,对相关指标进行计算分析和评估,数据分析采用配对t检验和线性回归分析。结果术后3个月平均球镜度为（+0.37±0.50）D,平均柱镜度为（-0.57±0.44）D。等效球镜度和术前预留等效球镜度之间的偏差是（+0.18±0.48）D,散光欠矫了（0.30±0.43）D（t=6.17,P<0.01）,手术诱发的平均柱镜旋转量是（0.09±0.34）D（t=2.22,P<0.05）,预期矫正等效球镜度和实际矫正等效球镜度之间显著相关（R2=0.96）。结论飞秒激光制瓣LASIK矫正近视合并高度散光的短期疗效确切,预测性好,但散光有轻度的欠矫,柱镜发生了轻微的逆时针旋转。     

LASIK治疗近视术后影响角膜非球面指数变化相关因素分析

背景 准分子激光角膜原位磨镶术（LASIK）治疗近视会改变角膜的非球面形态,进而对患者术后的视觉质量造成一定影响,但手术治疗参数,如切削深度、治疗光区直径如何影响角膜非球面形态目前国内外报道较少. 目的 探讨LASIK治疗近视术中所需切削深度及治疗光区直径大小等手术参数对角膜非球面性变化的影响.方法 采用前瞻性横断面研究方法.收集2011年3-7月在山东中医药大学附属眼科医院行飞秒制瓣LASIK治疗的近视患者89例175眼,术前等效球镜度为（-5.93±1.98）D,术前最佳矫正视力（BCVA）≥1.0.采用Orbscan-IIz角膜地形图检测患者术前和术后6个月时角膜中央6.0 mm区非球面指数（Q值）,记录每例手术治疗光区直径和切削深度,采用自身对照法比较手术前后术眼的视力和等效球镜变化,采用多元逐级回归分析法探讨切削深度和治疗光区直径与LASIK手术前后Q值变化的关系. 结果 所有术眼的术前平均球镜度为（-5.57±1.89）D,柱镜度（-0.71 ±0.55）D,等效球镜度为（-5.93±1.98）D;术后6个月的平均球镜度为（-0.25±0.30）D.平均柱镜度为（-0.14±0.22）D,平均等效球镜度为（-0.32±0.37）D,与术前比较差异均有统计学意义（=-32.39、-23.91、-35.18,均P＜0.01）.术眼术前和术后6个月角膜中央6.0mm区域Q值分别为-0.13±0.09（-0.47～0.08）和1.09±0.54（0.22～2.51）,术后Q值明显大于术前,差异有统计学意义（t=29.37,P＜0.01）.所有术眼手术切削深度平均为（95±28） μm;治疗光区直径平均为（6.32±0.26） mm.切削深度和治疗光区直径对术后Q值变化量（△Q）的多元回归公式为AQ=1.517＋0.015＆#215;切削深度-0.3＆#215;治疗光区直径,切削深度与△Q呈线性正相关（β=0.803）,而治疗光区直径与△Q呈线性负相关（β=-0.149）.结论 LASIK治疗近视术后角膜Q值有正性增大趋势,增加手术的切削深度和减小治疗光区直径可导致角膜Q值增加.     

RGPCL控制青少年近视合并高度散光的远期效果

 目的 探讨硬性透气性角膜接触镜（RGPCL）控制青少年近视合并高度散光的远期效果。 设计 回顾性病例系列。 研究对象　戴用RGPCL随诊5年的近视合并高度散光（≥-2.50 D）患者48例（69眼）,平均年龄（15.2±1.5）岁;戴用框架眼镜随诊5年的近视合并高度散光（≥-2.50 D）患者51例（102眼）,平均年龄（15.3±1.6）岁。方法 两组患者配镜前后均经复方托呲卡胺散瞳验光。检查二种矫正方法组患者的矫正视力,电脑验光仪检测角膜水平曲率半径、垂直曲率半径和平均曲率半径。两组患者连续5年观察上述数据变化,并对初诊时及第5年随诊的结果进行统计分析。主要指标  球镜度、柱镜度、戴镜视力、角膜水平曲率半径值、角膜垂直曲率半径值、角膜平均曲率半径值。结果 第5年时,RGPCL组和框架组最佳矫正视力分别为（0.99±0.41）和（0.74±0.13）。第5年与初诊时比较,RGPCL组和框架组球镜度分别增加（0.623±1.067）D、（2.018±1.461）D,两组比较差异有统计学意义（P =0.000）;RGPCL组柱镜度减少（0.696±0.694）D,框架组柱镜度增加（0.417±0.574）D,两组比较差异有统计学意义（P=0.000）。RGPCL组戴镜5年后角膜水平曲率半径、角膜垂直曲率半径、角膜平均曲率半径平均增加量分别为（0.046±0.106）mm、（0.189±0.184）mm、（0.119±0.131）mm。 结论  5年的随访结果显示,硬性透气性角膜接触镜对青少年近视合并高度散光患者的近视、散光发展有一定的控制作用。（眼科,2016, 25：93-97）     

应用准分子激光仪测量角膜屈光手术中静态和动态眼球旋转

目的探讨角膜屈光手术中静态眼球旋转（SCC）和动态眼球旋转（DCC）的方向和程度。方法回顾性病例研究。选择2013年5-7月接受个体化角膜屈光手术的患者144例（281眼）,术中应用阿玛仕准分子激光仪（型号500）进行激光切削,测量并比较按性别、眼别、手术方式、术前等效球镜度分组后组间的SCC及DCC差异。计数资料采用卡方检验,计量资料采用成组设计t检验进行分析。结果平均SCC为3.34°±2.57°（0°~12°）。SCC成功率66.55%,飞秒LASIK手术（100例195眼）和Trans PRK手术（44例86眼）的SCC成功率分别为57.44%和87.21%,差异有统计学意义（χ2=23.76,P<0.01）。SCC成功的右眼中,60%发生逆时针旋转,SCC成功的左眼中,50%发生逆时针旋转。测得术中平均DCC幅度为2.30°±1.42°（0.00°~7.80°）。接受飞秒LASIK手术的患眼,平均DCC幅度为2.05°±1.26°,接受Trans PRK手术的患眼为2.88°±1.59°,差异有统计学意义（t=4.33,P<0.01）。术前等效球镜度≥-5.00 D的患眼,平均DCC幅度为2.51°±1.51°,术前等效球镜度<-5.00 D的患眼为2.00°±1.23°,差异有统计学意义（t=3.07,P<0.01）。结论角膜屈光手术过程中,眼球会发生旋转。阿玛仕准分子激光仪能够准确有效地测量静态及动态眼球旋转,并进行补偿。     

LASIK术后5年结果分析

目的 评价准分子激光原位角膜磨镶术（LASIK）治疗近视眼的远期疗效。方法 回顾性系列病例研究。选取LASIK术后随访≥5年资料完整者68例（125眼）,根据术前等效球镜度分为低中度近视组76眼,等效球镜度-0.75～-6.00（-3.79±1.41）D;高度近视组49眼,等效球镜度-6.12～-13.25（-8.13±1.35）D。术后1个月、6个月、1年、5年检查裸眼视力（UCVA）、最佳矫正视力（BCVA）、裂隙灯、角膜地形图和眼底情况,最后一次复查填写满意程度问卷调查表。对数据进行χ2检验、配对样本t检验。结果 低中度近视组和高度近视组术后5年裸眼视力≥0.5的比例分别为100%和96%;术后5年等效球镜度在±1.00 D范围的比例分别为93%和84%;术后最后一次复查最佳矫正视力没有变化或增加的占82%眼（103/125）;术后5年等效球镜度分别为（-0.02±0.65）D和（-0.33±0.80）D,与术后1年比较差异均无统计学意义;1眼术中发生部分游离瓣,1眼术后发生上皮植入,8眼进行了增效手术;两组术后1~5年间均没有出现与手术相关的并发症,患者的满意程度较高。结论 LASIK手术治疗近视术后5年有较好的有效性、安全性和满意度,手术并发症少,术后5年屈光度稳定,远期没有手术相关的并发症发生。     

地形图引导的经上皮准分子激光屈光性角膜切削术治疗穿透性角膜移植术后散光

目的评价地形图引导的经上皮准分子激光屈光性角膜切削术（T-PRK）治疗穿透性角膜移植（PKP）术后高度散光及不规则散光的安全性和有效性。方法非随机、回顾性研究。收集PKP术后因高度散光或不规则散光而接受地形图引导的T-PRK治疗的患者18例（20眼）。记录并分析术前及进行本研究时末次随访的裸眼视力（UDVA）、最佳矫正视力（CDVA）、屈光状态、角膜地形图及视觉症状变化等,应用秩和检验对视力、屈光状态、角膜地形图变化进行比较。结果术后平均随访（12.15±2.06）个月。平均logMAR UDVA由1.36±0.42提高到0.65±0.40（Z=-3.727,P＜0.01）;平均CDVA由0.34±0.22提高到0.17±0.14（Z=-3.607,P＜0.01）,10眼CDVA提高≥2行。术后平均球镜度由（1.48±3.14）D下降到（-0.19±2.11）D （Z=-2.373,P＜0.05）;术后平均柱镜度由（-7.81±3.43）D下降到（-3.06±1.99）D （Z=-3.792,P＜0.01）;术后平均等效球镜矫正度（术后实际值与术前目标值之差）为（-1.72±2.55）D,其中3眼在目标值±0.50 D范围内,9眼在目标值±1.00 D范围内。平均角膜不规则指数由（66.33±22.03）μm 降低为（59.11±14.66）μm（Z=-0.831,P＞0.05）,而平均角膜正交曲率不对称性由（8.96±4.36）D降低为（7.44±3.56）D （Z=-2.576,P＜0.05）。患者术后视觉症状均不同程度好转,无一症状恶化。结论地形图引导的T-PRK是治疗PKP术后高度散光及不规则散光的一种安全、有效的方法。     

角膜塑形镜的临床疗效及安全性

目的观察角膜塑形镜矫正青少年儿童近视的疗效,探讨角膜塑形镜对近视进展控制的临床效果,并观察其安全性。方法回顾性病例分析。选取2011-2012年间在上海瑞视维景眼科门诊部验配角膜塑形镜的近视青少年儿童58例,均以左眼作为研究对象,年龄（11.1±2.0）岁,平均等效球镜度（SE）（-3.68±1.36）D。选用Boston EqualensⅡ和Boston XO 2种不同材料角膜塑形镜,按照所验配的角膜塑形镜材料为A组（38例）和B组（20例）,再以-3.00 D为界分为低度近视组（19例）和中度近视组（39例）,患者连续配戴角膜塑形镜2年后停戴4周复诊,分别比较戴镜2年前后的SE、眼轴长度、角膜内皮细胞计数、中央角膜厚度、角膜平坦曲率值、角膜陡峭曲率值和角膜散光。采用独立样本t检验,符号秩和检验,Pearson相关分析等进行数据分析。结果配戴角膜塑形镜的患者在戴镜2年后均有近视度数加深[（-0.35±0.64）D,t=4.132,P<0.01],眼轴长度增加[（0.33±0.33）mm,t=4.411,P<0.01],角膜平坦曲率值减少[（-0.33±0.25）D,t=10.001,P<0.01]和角膜散光增加[（-0.34±0.38）D,t=6.873,P<0.01];但A组与B组之间的差异无统计学意义。低度近视组的SE、眼轴长度和角膜散光改变量分别为（-0.70±0.68）D,（0.47±0.36）mm,（-0.54±0.37）D,均高于中度近视组的改变量[（-0.17±0.54）D,（0.26±0.29）mm,-0.25（-1.00,0.25）D],差异均有统计学意义（t=3.193、-2.384,Z=-2.598,P＜0.01）。结论青少年儿童配戴角膜塑形镜2年后仍有少量近视进展和眼轴增长,并且中度近视的近视增加量可能低于低度近视者。     

Correlation among refractive, keratometric and topographic astigmatism after myopic photorefractive keratectomy

BACKGROUND: Photorefrative keratectomy can be used to flatten the curvature of the anterior cornea and reduce the myopic refraction of the eye. This leads to unphysiological topographical changes of the cornea and may alter the conditions for examinations of corneal surface topography. The purpose of this study was to check for mutual agreement of three different methods of assessment of astigmatism before and after myopic photorefractive keratectomy (PRK). PATIENTS AND METHODS: Forty-seven eyes of 28 patients (age 32.7+/-6.6 years) following PRK using an 193-nm excimer laser were included in this study. 37 eyes were treated for pure myopia (-4.9+/-2.4 D) and 10 eyes for myopic astigmatism (sphere -2.0 to -7.0 D, cylinder -1.0 to -3.0 D). Preoperatively and at 18 months postoperatively, subjective refractometry, keratometry and topography analysis were performed. The axes of topographic and keratometric cylinder were standardized periodically (180 degrees) with respect to the refractive cylinder axis. RESULTS: Pre- and postoperatively, the absolute astigmatism values correlated highly significantly between all three methods (P< or =0.001). The mean refractive cylinder was 0.65+/-0.61 D preoperatively and 0.46+/-0.41 D postoperatively (P=0.2). The mean keratometric astigmatism was 1.14+/-0.64 D before and 0.94+/-0.50 D after PRK treatment (P=0.2). Among the three methods, the mean topographic astigmatism was the highest (P<0.001) preoperatively (1.31+/-0.56 D) and postoperatively (1.21+/-0.52 D) (P=0.3). In eyes treated for pure myopia, no difference between pre- and postoperative refractive, keratometric and topographic astigmatism was detected (P>0.5). The axes of both topographic and keratometric astigmatism correlated highly significantly with the refractive cylinder axis (R> or =30.9, P<0.0001). CONCLUSION: Up to 2 years after myopic PRK, the difference between refractive and keratometric astigmatism does not differ from the preoperative value, indicating an even corneal surface. The absolute astigmatism values and the cylinder axis correlated well between subjective and objective methods of astigmatism assessment. Thus, objective measurements may be helpful in determining the cylinder component of best spectacle correction after PRK. However, topographic analysis overestimates astigmatism values systematically before and after PRK.     

前弹力层下激光角膜磨镶术中负压吸引圆环与椭圆环对角膜散光的影响

目的 探讨前弹力层下激光角膜磨镶术(SBK)手术中运用负压吸引圆环与椭圆环对患者术后角膜散光的影响.方法 回顾性病例对照研究.收集2011年3月在四川大学华西医院近视激光中心行SBK患者51例(102眼),在制作角膜瓣时,分别采用圆环和椭圆环,其中圆环组23例,椭圆环组25例,另外3例左右眼分别使用圆环与椭圆环,圆环眼纳入圆环组,椭圆环眼纳入椭圆环组.OrbscanⅡ角膜地形图检查患者术前、术后水平及垂直方向角膜曲率,并计算患者术前、术后散光值.采用独立样本t检验进行统计分析.结果 术后1周,圆环组角膜散光值为(-0.84±0.71)D,椭圆环组角膜散光值为(-0.90±0.54)D,两组之间差异无统计学意义.排除术中矫正散光值的影响,术前与术后1周角膜散光值差值椭圆环组为(0.58±0.77)D,圆环组为(0.57±0.76)D,两组差异无统计学意义.所有病例术中术后均未出现游离瓣、不全瓣、纽扣瓣等角膜瓣并发症,术后角膜愈合过程也未出现层间异物、瓣溶解、感染等严重影响视力的并发症.结论 相对传统负压吸引圆环来说,SBK手术中负压吸引椭圆环不会引起角膜散光值增加或降低.     

角膜地形图引导的FS-LASIK治疗近视及散光的视觉质量评估

观察和评价角膜地形图引导的飞秒激光制瓣准分子激光原位角膜磨镶术（FS-LASIK）治疗近视及散光术后视觉质量的变化。方法：前瞻性研究。选取2017年6-10月在湖南省人民医院眼视光中心就诊的40例（68眼）近视或近视散光患者，分为中高散光组（32眼，散光度>1.0 D）和低散光组（36眼，散光度≤1.0 D），均采用角膜地形图引导的FS-LASIK。记录术前及术后3个月的裸眼视力（UCVA）、最佳矫正视力（BCVA）、屈光度、角膜总高阶像差、角膜球差、角膜彗差、调制传递函数截止频率（MTF cutoff）及客观散射指数（OSI）。手术前后各参数的变化情况比较采用配对t检验分析，组间数据采用独立样本t检验进行比较。结果：术后3个月100%的眼UCVA达到术前BCVA，患者术后3个月UCVA（LogMAR）为-0.10±0.07，较术前BCVA（LogMAR）（-0.02±0.07）明显提高，差异具有统计学意义（t=-8.714，P<0.001）。术后3个月等效球镜度（SE）在±0.50以内的比例为94%；残余散光度为（0.40±0.17）D。术后3个月彗差、OSI较术前降低，MTF cutoff较术前增加，差异均有统计学意义（t=1.757、-2.935、4.243，P<0.05）；术后3个月中高散光组与低散光组的UCVA、彗差、 MTF均较术前有所改善，但2组差异无统计学意义。结论：角膜地形图引导的FS-LASIK能有效改善近视及散光患者术后的视觉质量。     

准分子激光角膜屈光手术后角膜后表面非球面性变化的研究

目的 探讨准分子激光角膜屈光手术对角膜后表面不同范围非球面性(Q值)的影响.方法 前瞻性研究.对115例(115只眼)近视及近视散光患者行常规角膜屈光手术(其中包括LASIK手术59只眼,EPI-LASIK手术56只眼),术前近视球镜度-2.25～-7.75 D,柱镜度-0.50～-2.00 D.手术前及手术后1个月、6个月应用Pentacam眼前节分析系统对患者角膜后表面6、7、8、9 mm等直径下的Q值进行测量,研究手术前及手术后Q值的变化规律并分析其与其他变量之间的相关性.结果 手术前115只眼角膜后表面4个直径下的Q值分别为0.08±0.16,-0.05±0.13,-0.15±0.12以及-0.26±0.11.手术后1个月.LASIK与EPI-LASIK均引起角膜后表面的Q值往正向变化,其中6、7、8 mm范围内Q值的变化较手术前差异均有统计学意义(LASIK:t6mm=-2.076,P=0.042;t7mm=-2.873,P=0.006;t8mm=-2.180,P=0.033;EPI-LASIK:t6mm=-2.859,P=0.006;t7mm=-3.901,P=0,000;t8mm=-3.510,P=0.001).手术后6个月,除LASIK组9 mm直径区域Q值变化与手术前比较差异有统计学意义外(t=2.649,P=0.011),其余后表面Q值与手术前差异均无统计学意义(P＞0.05).非球面性变化量与等效球镜度、角膜厚度、切削深度等参数均无明显相关.结论 近视眼角膜后表面呈长椭圆形,越靠近周边区域Q值越负;角膜屈光手术后早期会影响角膜后表面的非球面特性,较手术前变扁平,但是随着时间的延长这种变化可以恢复至手术前水平.

Abstract：

Objective To investigate the changes of the asphericity (Q-value) of the posterior corneal surface with different corneal diameters after corneal refractive surgery. Methods One hundred and fifteen myopic eyes of 115 subjects undertaken corneal refractive surgery (59 LASIK and 56 EPI-LASIK)were enrolled in this prospective study. The Q-value of the posterior corneal surface for patients with different corneal diameters (6, 7, 8 and 9 mm ) was measured with Pentacam pre-and post-operatively. The correlations between Q-value, Q change (△Q), and the mean preoperative spherical equivalent refraction (SE), central corneal thickness (CCT), central ablation depth (AD) and AD/CCT were investigated.Results The mean Q-value of the posterior corneal surface in 115 preoperative eyes with corneal diameters at 6, 7, 8 and 9mm was 0.08±0.16,-0.05±0.13,-0.15±0.12 and-0.26±0.11, respectively.The Q-value had a statistically significant positive shift 1 month after surgery in eyes with 6, 7 and 8 mm corneal diameters ( LASIK: t6mm=-2.076, P=0.042; t7mm=-2.873, P=0.006; t8mm=-2.180, P=0.033;EPI-LASIK:t6mm=-2.859,P=0.006;t7mm=-3.901,P=0.000;t8mm=-3.510,P=0.001 ).The mean Q-value diminished significantly 6 months compared to I month after surgery, and had an obvious tendency back to its preoperative level. No statistically significant correlation between Q and SE or CCI was found in the preoperative eyes. Also, no correlation between △Q and SE, CCT, AD and AD/CCT was found after surgery. Conclusions The shape of the posterior corneal surface in myopic eyes was more prolate as corneal diameter increased, which was similar to the anterior corneal surface. The posterior corneal surface showed central flattening and peripheral steepening (oblate shift) at early stage either post-LASIK or post-EPI-LASIK, and then returned to its original state over time.     

准分子激光角膜屈光手术后散射的变化及其相关因素分析

目的 探讨眼内散射在机械法准分子激光上皮瓣下角膜磨镶术(Epi-LASIK)及准分子激光原位角膜磨镶术(LASIK)手术后的变化及相关因素分析.方法 病例系列研究.对87例(87只眼)近视及近视散光患者行Epi-LASIK(45只眼)或LASIK(42只眼),使用C-quant散射仪分别在手术前、手术后1、4、10个月测量散射光计量值.应用单因素方差分析及Pearson相关进行数据分析.结果 Epi-LASIK组及LASIK组手术前、手术后1、4、10个月眼内散射光计量值分别为(0.91±0.17)、(1.03±0.15)、(1.11±0.13)、(1.01±0.16)及(0.96±0.14)、(1.05±0.12)、(1.10±0.12)、(0.98±0.15),组间比较差异有统计学意义(F=12.29,8.11;P＜0.05);与手术前相比两组各时间段的变化量分别为(0.12±0.18)、(0.19±0.20)、(0.08±0.16)及(0.09 ±0.13)、(0.15±0.17)、(-0.01±0.17).Epi-LASIK组手术后4个月眼内散射光计量值与手术前屈光度、剩余基质床与中央最薄角膜厚度之比(RBT/CCT)、切削比有明显相关性(r=-0.344,-0.361,0.361;P＜0.05),LASIK组无明显相关性(r=0.186,0.162,-0.206;P＞0.05).Epi-LASIK组手术后1～4个月发生2级、1级、0.5级haze分别有1、2、4只眼,其4个月时眼内散射光计量值变化量分别为0.52,(0.37,0.42),(0.06,0.09,0.07,0.17).发生2级haze眼在haze消退后散射值变化量由4个月时的0.52降至10个月时的0.11.结论 Epi-LASIK及LASIK术后早期眼内散射光计量值较术前均增高,随时间延长有下降趋势.角膜伤口愈合反应可能是Epi-LASIK术后早期散射增加的主要因素,而LASIK 术后早期增加的主要原因可能是界面相关因素.Epi-LASIK术后轻度以上haze眼散射明显增加.

Abstract：

Objective To investigate the changes and relevant factors of forward scatter after Epipolis laser in situ keratomileusis (Epi-LASIK)and laser in situ keratomileusis (LASIK). Methods It was a prospective clinical comparative study. 45 patients (45 eyes) were scheduled for Epi-LASIK and 42patients (42 eyes) for LASIK. Straylight examinations were performed using the C-Quant straylight meter before and 1,4, 10 months after surgery. The data was analyzed for statistical significance by one-way ANOVA and the correlation was tested by Pearson' s test by using SPSS 13. 0 software. Results The straylight values were(0. 91 ±0. 17) , (1. 03 ±0. 15) ,(1. 11 ±0. 13) , ( 1. 01 ±0. 16) of Epi-LASIK group and (0.96±0. 14) ,(1. 05 ±0. 12) ,(1. 10 ±0. 12) ,(0. 98 ±0. 15) of LASIK group preoperatively and 1,4,10 months postoperatively respectively,which there were significant increase postoperatively in both groups (F = 12.29,8.11;P＜0.05). Compared with preoperative values, the changes in straylight values at 1, 4and 10 months postoperatively were (0. 12 ±0. 18) , (0. 19 ±0. 20) , (0. 08 ±0. 16) of Epi-LASIK group and (0.09 ± 0. 13 ) , ( 0. 15 ± 0. 17 ) , ( -0. 01 ± 0. 17 ) of LASIK group. In Epi-LASIK group, the preoperative refractive error, RBT/CCT, and ablation ratio have significant relevance with straylight values at 4 months postoperatively ( r = - 0. 344, - 0. 361 , 0. 361; P ＜ 0. 05 ) , no such correlation was found in LASIK group (r = 0. 186,0. 162,-0.206;P＞0. 05). For corneal haze which was found from 1 to4months after Epi-LASIK, grade 2, 1, 0. 5 appeared in 1, 2, 4 eyes respectively and the changes of straylight values were 0.52, (0.37, 0.42), (0.06, 0.09, 0.07, 0.17) at 4 months postoperatively. 10 months postoperatively, the increases of straylight values for the eye with grade 2 haze declined from 0. 52 to 0. 11after the haze disappeared. Conclusion Straylight values increase significantly at early time after EpiLASIK and LASIK, but decrease partially as time going. Corneal wound healing response may be the reasons induced the increases of light scatter after Epi-LASIK. For LASIK, flap interface factors may be the reasons.Corneal haze especially above mild grade, can affect the straylight obviously.     

Photorefractive keratectomy with mitomycin C after deep anterior lamellar keratoplasty for keratoconus

PURPOSE: To evaluate the safety and efficacy of photorefractive keratectomy (PRK) with intraoperative mitomycin C (MMC) after deep anterior lamellar keratoplasty (DALK) for keratoconus. METHODS: This was a prospective, noncomparative single-surgeon study. Eyes with compound myopic astigmatism after DALK with a spherical equivalent (SE) between -3 and -10 D were treated by PRK. After ablation, MMC 0.2 mg/mL was placed on the stromal bed for 45 seconds. A 6% undercorrection was planned. RESULTS: The study was completed on 10 eyes of 10 patients. The preoperative mean SE was -4.98 +/- 1.75 (SD) D. At 10 months after surgery, the mean SE was 0.28 +/- 0.61 D, and the mean defocus equivalent was 1.08 +/- 0.58 D. Postoperatively, 9 eyes were within 2 D, 6 were within 1 D, and 1 eye was within 0.5 D of defocus equivalent. The preoperative mean best spectacle-corrected visual acuity (BSCVA) was 0.68 +/- 0.15 D, and at 10 months it was 0.78 +/- 0.13 D. The 95% confidence interval for the mean difference of pre- and postoperative BSCVA was 0.02-0.17 (P < 0.05). No lines of BSCVA were lost. The mean postoperative uncorrected visual acuity was 0.55 +/- 0.1. The safety index was 1.15, and the efficacy index was 0.81. Corneal haze was grade 0 in 8 eyes and grade 0.5 in 2 eyes. Mean epithelialization time was 4.1 +/- 0.99 days. Preoperative mean endothelial cell density was 2320 +/- 184 cells/mm(2), and at 10 months it was 2284 +/- 175 cells/mm(2). CONCLUSIONS: PRK with MMC can safely and effectively correct myopia and regular myopic astigmatism after DALK. Undercorrection should be planned to compensate for the overcorrecting effect of MMC.     

Straylight values 1 month after laser in situ keratomileusis and photorefractive keratectomy

PURPOSE: To compare straylight values before and 1 month after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). SETTING: Private practice refractive surgery center, Delft, The Netherlands. METHODS: In a prospective nonrandomized study, straylight values of 21 patients (42 eyes) were measured using the van den Berg straylight meter (third generation) during intake sessions at a refractive surgery clinic. Of the 21 patients, 12 were scheduled for LASIK (6 patients, 12 eyes) or PRK (6 patients, 12 eyes). At the 1-month follow-up visit, straylight values were measured again in the same manner and compared with the preoperative straylight values. RESULTS: Overall, there was no statistically significant increase in straylight values compared with the preoperative values 1 month after LASIK or PRK (P>.05). Individual straylight values increased in some cases, however, and the values correlated well with decreased quality of vision and changes in the eye examination. CONCLUSION: Straylight values 1 month after LASIK or PRK did not increase on average, although individual straylight values increased in some cases.     

Comparison of the keratometric corneal astigmatism and refractive astigmatism after phacoemulsification and foldable intraocular lens implantation

Here we aimed to define keratometric and refractive astigmatism in a series of patients who underwent phacoemulsification, using small corneal incision and implantation of foldable intraocular lenses. Furthermore, we compared keratometric astigmatism and refractive astigmatism of the patients both before and after surgery. We performed a follow-up study of patients with newly diagnosed cataract before and after phacoemulsification surgery. Eighty eyes from 78 patients with a mean age of 62.9?±?12.03 (32-86) years were studied. Thirty-nine (48.8?%) were male and 41(51.2?%) were female. All subjects underwent 3.5?mm corneal incision with the temporal (75 patients; 94?%) or superior (5 patients; 6?%) approach. The patients were followed for a mean of 74.21?±?71.25 (30-400) days. Patients had higher values of keratometric measurements after surgery compared to those before surgery [45.81?±?0.11 (45.06-45.94) vs. 45.2?±?0.20 (44.6-45.41)] (p?1 D difference in these measurements.