Pentacam测量准分子激光原位角膜磨镶术后前房形态的研究

目的探讨准分子激光原位角膜磨镶术（LASIK）对近视眼前房形态的影响。方法随机选取接受LASIK的近视患者44例（87只眼）,分别于术前、术后1个月和术后3个月应用Pentacam眼前节分析系统测量患眼中央前房深度、前房角、前房容积、角膜后表面曲率、角膜后表面曲率半径等指标,并对测量结果进行统计学分析。结果LASIK术后3个月内,中央前房深度和前房容积较术前显著减小,180°前房角、360°前房角、角膜后表面曲率和角膜后表面曲率半径较术前无显著差异。结论LASIK术后中央前房深度变浅,前房容积变小,而周边前房形态无显著变化,可能与LASIK手术前后患眼视近时调节引起晶状体前移量不同有关。     

Orbscan角膜地形图系统测量误差的分析

目的：探讨Orbscan角膜地形图系统（Orbscan系统）的测量误差及其影响因素,为临床使用提供依据。方法：使用Orbscan系统和A超仪,测量200例（400只眼）行准分子激光原位角膜磨镶术（laser in situ keratomileusis,LASIK）患者和50例（100只眼）行准分子激光屈光性角膜切削术（photorefractive keratectomy,PRK）患者手术前、后的角膜厚度和中央前房深度;分别于PRK和LASIK手术前、后使用Orbscan系统测量患者的角膜后表面屈光力,并对测量值进行分析比较。结果：Orbscan系统测量的角膜厚度值LASIK和PRK术前低于A超仪的测量值,差值为18.83-24.29μm;LASIK和PRK术后与A超仪测量值的差值为56.32-139.52μm,明显高于术前。LASIK和PRK手术前、后Orbscan系统测量的中央前房深度值与A超仪测量值的差值为0.16-0.25mm,无临床意义。LASIK手术前、后Orbscan系统测量的角膜后表面屈光力差值约为-0.60D;PRK手术前、后Orbscan系统测量的角膜后表面屈光力差值低度组为-0.51D,中度组为-1.12D。结论：Orbscan系统测量值的精确性尚待进一步提高;LASIK和PRK术后角膜雾状混浊和角膜前表面屈光力的改变是导致Orbscan系统测量误差较大的主要原因;Orbscan系统的测量误差是临床工作不可忽视的重要问题。     

LASIK术后角膜后表面稳定性分析

目的:探讨近视眼准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)对角膜后表面稳定性的影响。方法:采用Orbscan-Ⅱz及Pentacam眼前节分析仪测量近视眼LASIK手术前、手术后1wk;1,3,6mo的角膜后表面高度,统计分析其术前、术后变化情况。结果:Orbscan-Ⅱz测量发现LASIK术后角膜后表面向前膨隆(P=0.000),且与术前近视度数、中央角膜厚度呈负相关(r=-0.403,P=0.001;r=-0.349,P=0.004)和切屑深度呈正相关(r=0.411,P=0.001)。Pentacam测量结果显示LASIK术后角膜后表面并未发生前移或后移(P>0.05)。结论:LASIK术后角膜后表面并未发生前凸等改变,Orbscan-Ⅱz眼前节分析系统测量结果显示的LASIK术后角膜后表面前凸可能是因为LASIK手术改变了角膜对Orbscan检查设备成像系统的放大效应。     

有晶状体眼人工晶状体植入术后拱高及其影响因素研究

目的:探讨有晶状体眼人工晶状体(V4c型ICL)植入术后拱高的变化及其影响因素。方法:回顾性分析山西省眼科医院2015年7月至2018年12月中度及高度近视行V4c型ICL植入术60例(118只眼)的临床资料。术眼屈光状态为等效球镜度(-11.26±3.87)D。观察术后拱高随时间的变化趋势及可能的影响因素,并对比由Orbscan、IOLMaster、Pentacam及UBM所测得的角膜直径及前房深度的一致性。结果:眼前段OCT测量术后1 d、1、3、6及12个月拱高依次为:(0.635±0.201)mm、(0.608±0.194)mm、(0.581±0.195)mm、(0.597±0.171)mm及(0.495±0.158)mm。术后拱高与年龄呈负相关(r=-0.266,P=0.004),与角膜厚度呈负相关(r=-0.241,P=0.009),与前房深度、ICL直径、角膜直径及眼轴长度呈正相关(r=0.529、0.583、0.405及0.314,均P<0.05),与性别、术前眼的屈光状态、是否植入散光矫正型ICL、角膜曲率及是否伴随睫状体囊肿均无相关(P>0.05)。OrbscanⅡ及Pentacam术前测量角膜直径的一致性好,OrbscanⅡ、Pentacam及UBM术前测量前房深度可互相参考。结论:V4c型ICL植入术矫正中度及高度近视效果良好,拱高是术后安全的重要因素,术前精确的生物测量及术后定期的随访观察是关键。     

Orbscan-Ⅱ测量准分子激光原位角膜磨镶术前术后眼前节参数的改变

目的利用Orbscan-Ⅱ测量准分子激光原位角膜磨镶术(laser in situ reratomileusis,LASIK)术前术后眼前节参数的改变,探讨Orbscan-Ⅱ在LASIK术后测量不同屈光度近视的眼前节参数中可能存在的误差。方法应用Orb-scan-Ⅱ角膜地形图系统对进行LASIK术的48例88眼于术前、术后第1个月测量角膜厚度和前房深度,术前根据屈光度分组:Ⅰ组-2.00～-6.00D,Ⅱ组-6.25～-12.50D。分别比较各组术前理论预测术后角膜最薄点厚度值和术后实际测量值、术前术后中央前房深度测量值之间的差异。结果Ⅰ组术前理论预测术后角膜最薄点厚度与术后实际测量角膜最薄点厚度比较,差异无统计学意义(P>0.05)。Ⅱ组术前理论预测术后角膜最薄点厚度与术后实际测量角膜最薄点厚度比较,差异有统计学意义(P<0.05),术后实际测量值小于术前理论预测值。两组术前术后测量中央前房深度值比较,差异有统计学意义(P<0.05),术后测量值小于术前测量值。结论Orbscan-Ⅱ对术后角膜厚度及前房深度的测量存在误差,术后角膜后表面前凸、角膜水肿混浊、调节的增加等是影响其准确性的可能因素。     

Pentacam测量近视眼角膜厚度和前房深度

目的:比较Pentacam三维眼前节分析仪测量中央角膜厚度、前房深度与A型超声测量的差异,以评价Pentacam在眼前节参数测量中的准确性。方法:分别使用Pentacam眼前节分析仪和A型超声角膜测厚仪测量82例164眼近视患者的中央角膜厚度和前房深度,对两种方法的测量结果进行比较,并与眼压及眼轴长度进行了相关分析。结果:Pentacam眼前节分析仪测得中央角膜厚度和前房深度分别为524±0.037μm,3.26±0.25mm。A型超声角膜测厚仪测得值分别为521±0.036μm,3.36±0.53mm。两种测量结果比较中央角膜厚度和前房深度差异均有统计学意义(P<0.01,P<0.05)。光学法测量的中央角膜厚度值较超声法平均大3μm。超声法所测前房深度值较光学法平均大0.1mm。两种方法测量的角膜厚度与眼压及前房深度与眼轴长度均呈正相关(P<0.01)。结论:Pentacam三维眼前节分析仪测量屈光不正患者的中央角膜厚度和前房深度与A型超声测量结果存在一定差异。     

晶状体超声乳化术前前房空间与术后角膜内皮变化相关性研究

目的探讨晶状体超声乳化术前前房空间状态与术后角膜内皮细胞变化之间的相关性。方法对19例(20眼)老年性白内障行晶状体超声乳化吸出人工晶状体植入术。术前以OrbscanⅡ测定前房容积、前房深度,使用A超测定眼轴长度,并分别于术前和术后1周使用非接触型角膜内皮显微镜观察中部角膜内皮细胞的密度变化。结果术前的平均前房容积为(158.66±29.14)mm3,前房深度为(2.69±0.41)mm。眼轴长度为(23.79±2.43)mm。术后1周平均中部角膜内皮细胞损失率为31.27%±16.11%;术前的前房容积与术后1周角膜内皮细胞损失率呈显著负相关(r=-0.726,P<0.001),前房深度与术后1周角膜内皮细胞损失率亦呈显著负相关(r=-0.764,P<0.001);术前的眼轴长度与角膜内皮细胞损失率(r=-0.123,P=0.606)之间无相关性。结论晶状体超声乳化人工晶状体植入术后损伤术眼的角膜内皮细胞,术前前房空间状态的测定为临床评估预后提供重要参考。     

SMILE术后眼前节结构变化及其影响因素

目的: 观察飞秒激光小切口角膜基质透镜取出术(SMILE)术后1年内眼前节结构的变化, 并分析其影响因素。方法: 前瞻性非随机自身对照研究。连续性收集2019年1月至2021年10月在台州市立医院眼科中心接受SMILE手术矫正近视的患者29例(58眼)。采用Oculyzer眼前节分析系统测量术前、术后1个月及1年的中央角膜后表面曲率(PCC)、中央角膜后表面高度(PCE), 2、4、6 mm处的角膜后表面平均高度(PME)、中央前房深度(ACD)、前房容积(ACV)。采用Lenstar生物测量仪测量术前、术后1个月及1年的眼轴长度(AL)、中央角膜厚度(CCT)、中央ACD、晶状体厚度(LT)。应用重复测量方差分析比较患者术前、术后1个月及1年眼前节各参数的变化, Pearson相关分析中央ACD变化值与角膜、晶状体等参数的相关性。结果: 与术前相比, SMILE术后1个月、1年Oculyzer测得的中央PCC、中央PCE, 2、4、6 mm处的角膜PME变化差异均无统计学意义(均P>0.05), 中央ACD变浅(均P<0.001), ACV变小(P=0.001, P<...     

原发性闭角型青光眼生物解剖结构差异的研究

目的探讨原发性急性闭角型青光眼术前术后与正常眼的解剖结构差异。方法使用A超对30例（60只眼）原发性急性闭角型青光眼（AACG）术前术后及对照组30例（60只眼）正常眼的解剖结构（包括前房深度、晶状体厚度、玻璃体腔长度、眼轴长度）和角膜直径进行测量,同时计算相对晶状体位置及晶状体厚度／眼轴长度系数,各项均值进行对比分析（t检验）。结果AACG术前术后与正常眼相比,前房浅、晶状体厚、眼轴短、相对晶状体位置前移、晶状体厚度／眼轴长度系数大,角膜横径较小,以上差异均有显著性（P〈0．05）。结论AACG以浅前房、厚晶状体、眼轴短、角膜横径较小等特点。相对晶状体位置及晶状体厚度／眼轴长度系数可作为AACG早期诊断的指标之     

高度近视白内障患者手术前后眼生物测量参数相关性分析

目的：对高度近视白内障患者手术前后眼生物测量参数进行分析,为高度近视白内障的人工晶状体屈光度计算公式提供参考。

方法：选取2011-01/2017-05我院收治的152眼高度近视白内障患者,所有患眼眼轴≥26mm,测量白内障手术前眼轴长度、角膜曲率、前房深度、晶状体厚度,以及手术后3mo角膜曲率、前房深度。分析各参数之间相互关系,并对术后前房深度进行多元线性回归分析。

结果：术前眼轴长度与术前角膜曲率、晶状体厚度呈正相关(r=0.236、0.216,P<0.05)。术前眼轴长度与术前前房深度无相关关系(P>0.05)。术前前房深度与术前角膜曲率无相关关系(P>0.05)。术前前房深度与术前晶状体厚度呈负相关关系(r=-0.513,P<0.05)。术后前房深度与术前眼轴长度、术前前房深度、术前角膜曲率、术后角膜曲率呈正相关关系(r=0.374、0.364、0.333、0.356,P<0.05)。术后前房深度与术前晶状体厚度无相关关系(P>0.05)。术后前房深度的多元线性回归方程为：术后前房深度=-2.592+0.091×术前眼轴长度+0.078×术前角膜曲率+0.491×术前前房深度。

结论：通过测量术前眼轴长度、角膜曲率、前房深度,利用术后前房深度多元回归方程,可以计算出术后前房深度,从而为高度近视白内障患者术后人工晶状体屈光度计算公式提供参考。     

Analysis of changes in crystalline lens thickness and its refractive power after laser in situ keratomileusis

AIM: To evaluate changes in the anterior chamber depth (ACD), crystalline lens thickness (LT) and its refractive power after laser in situ keratomileusis (LASIK). METHODS: In all cases, the preoperative and postoperative central ACD which were measured with Pentacam, Orbscan, IOL-Master and A-scan ultrasonography, central corneal true net power which was measured with the Pentacam, Orbscan and IOL-Master, axial length (AL) which was measured with IOL-Master and LT which was measured with the A-scan ultrasonography were compared using the paired sample t test. Ocular refractive errors and lens refractive power at corneal plane were calculated and their correlations were also evaluated before and after LASIK. RESULTS: At 1 week after LASIK, LT and crystalline lens refractive power at corneal plane (Dlens) which were associated with the IOL-Master and Pentacam increased significantly (P≤0.005), ACD decreased significantly (P≤0.001), but no significant increase was observed in the Dlens which was associated with the Orbscan (P=0.261). Significant correlations between the changes in the ocular refractive errors and Dlens which were associated with the Pentacam were observed at 1 week and 6 months after LASIK (P=0.028; P=0.001). CONCLUSION: LT increased significantly after LASIK, and this might partially lead to ACD decrease, Dlens increase and a small quantity of myopic regression.     

Central corneal thickness measurements by ultrasound, Orbscan II, and Visante OCT after LASIK for myopia

PURPOSE: To compare central corneal thickness measurements obtained with Orbscan II scanning slit topography, Visante optical coherence tomography (OCT), and ultrasound pachymetry in myopic eyes after LASIK. METHODS: This retrospective study included 34 consecutive patients (68 eyes) who underwent LASIK for the correction of myopia. Six months after surgery, central corneal thickness measurements were obtained using ultrasound pachymetry, Orbscan scanning slit topography, and Visante OCT. Data were analyzed using paired sample t test, Bland and Altman plot, and linear regression. RESULTS: Average postoperative central corneal thickness was 436.65+/-43.82 microm for ultrasound pachymetry, 422.84+/-51.04 microm for Orbscan (0.89 acoustic equivalent correction factor), and 422.26+/-42.46 microm for Visante. Compared to the ultrasound measurement, Orbscan and Visante measurements significantly underestimated the corneal thickness by 13.81+/-17.34 microm (P<.01) and 14.38+/-10.13 microm (P<.01), respectively. CONCLUSIONS: Both Orbscan and Visante OCT underestimated central corneal thickness compared to ultrasound pachymetry 6 months after LASIK, although measurements obtained with Visante OCT had better agreement and correlation with ultrasound pachymetry than with Orbscan.     

近视患者准分子激光原位角膜磨镶术前后OrbscanⅡ观察

目的探讨近视眼准分子激光原位角膜磨镶术（LASIK）后OrbscanⅡ的动态变化及影响角膜后表面前突出度的主要因素。方法216例（230只眼）近视患者,根据等效球镜屈光度分为4组,Ⅰ组：-1．25～-3．00D;Ⅱ组：-3．13～-5．75D;Ⅱ组：-6．00～-8．88D;Ⅳ组：-9．00～-15．75D,采用OrbscanⅡ角膜地形图系统分别于术前、术后1个月、3个月进行检测,取角膜厚度图、角膜后表面地形图进行动态对比分析。结果预留角膜最薄处厚度,角膜后表面屈光力及角膜后表面顶点距理想球面的距离（Diff值）,术后较术前明显改变,术前与术后1个月相比,差异有统计学意义（t=22．79,-20．63,-15.90;P〈0．05）。术前与术后3个月相比,差异有统计学意义（t=17．87,-17．98,-27．26;P〈0．05）,表现为角膜变薄,后表面屈光力及Diff值增加,术后同一时间段不同组间比较差异有统计学意义（术后1个月F=61．92,4．74,7．28;P〈0．05。术后3个月F=64．16,5．12,21．83;P〈0．05）,不同时间段同一组间比较差异无统计学意义（P〉0．05）。术后角膜最薄处厚度较术前预留最薄角膜厚度在不同组间比较差异有统计学意义（P〈0．01）,术前角膜后表面Diff值（Y）与术前角膜最薄处厚度（X1）、角膜中央厚度（X2）、角膜横径（X3）、眼轴长度（X4）建立多元线性回归方程为Y=0．0941-0．00053X1-0．000471X2-0．0063X3＋0．00122以（F=13．48,P〈0．01）。术后3个月与1个月角膜后表面Diff值的差值（Y）与术后3个月与1个月角膜最薄处厚度差值（X1）、术前眼压（X2）、术后3个月与1个月角膜后表面屈光力差值（X3）建立多元线性回归方程为Y=-0．027-0．00078X1＋0．00201X2-0．0055X3（F=21．81,P〈0．01）。结论OrbscanⅡ对近视眼LASIK术前患者的筛选及术后监测评估具有重要的临床意义,但角膜测厚功能在高度近视眼LASIK术后准确性差,不宜作为再次手术的筛选标准;影响近视眼术前角膜后表面前突出度变化的主要因素为角膜厚度、角膜横径与眼轴长度;影响术后3个月与1个月前突出度变化值的主要因素为术后3个月与1个月角膜最薄处厚度差值,角膜后表面屈光力差值及术前眼压。这些影响因素应作为术前筛选病例的参考指标。     

Flap thickness reproducibility in laser in situ keratomileusis with a femtosecond laser: optical coherence tomography measurement

PURPOSE: To compare ultrasound (US) pachymetry, Orbscan, and optical coherence tomography (OCT) measurements of the central corneal thickness (CCT) before laser in situ keratomileusis (LASIK) and evaluate the reproducibility of flaps created with the IntraLase femtosecond laser (IntraLase, Inc.) using OCT. SETTING: Department of Ophthalmology, IIsan Paik Hospital, Goyang, Korea. METHODS: Central corneal thickness was measured using OCT, US pachymetry, and Orbscan in 59 eyes of 30 patients before femtosecond laser LASIK. The postoperative corneal flap thickness, measured using OCT, was compared with the preoperative intended thickness. RESULTS: Optical coherence tomography, US pachymetry, and Orbscan measurements provided similar CCT values (P>.05). Corneal thickness values obtained using US or Orbscan correlated well with those obtained by OCT, with the correlation coefficient ranging from 0.804 to 0.889 (P<.05). The OCT measurements showed no significant difference between the postoperative flap thickness and the intended flap thickness (P>.05). CONCLUSIONS: Optical coherence tomography was comparable to US pachymetry and Orbscan in cornea thickness measurement. Optical coherence tomography was easy and relatively accurate to use preoperatively and in the early postoperative period. The femtosecond laser created highly reproducible flaps that corresponded with the preoperative intended thickness.     

眼前节相干光断层扫描仪与Orbscan Ⅱ及超声法眼前节生物测量对比研究

目的 比较眼前节相干光断层扫描仪(AS-OCT)与Orbscan Ⅱ以及超声法眼的节生物测量结果,为临床应用提供参考:方法对33例(66只眼)近视眼患者分别行AS-OCT,Orbscan Ⅱ以及A型超声测量仪(DGH550和DGH4000)进行眼前节生物测量,获取角膜中央厚度(CCT),前房深度(ACD),角膜直径,瞳孔直径以及前房角度数,进行对比分析.结果 AS-OCT,Orbscan Ⅱ以及超声法测量CCT分别为(532.32±35.26)μm.(538.45±38.31)μm,(555.82±37.63)μm,两两比较各组差异均有统计学意义(P<0.01).相关性分析显示三种方法中两两间均呈正相关,相关系数r=0.92、0.91、0.95;ACD分别为(3.19±0.21)mm,(3.08±0.24)mm,和(3.27±0.23)mm,两两间差异也均有统计学意义(P<0.01). OCT法测量瞳孔直径为(5.5±0.93)mm,Orbscan法测量结果为(4.5±0.75)mm,二者相差(-1.00±0.68)mm.差异有统计学意义(t=11.95,P=0.000),95%置信区间(0.84,1.17). OCT测量房角度数均大于Orbscan测量结果,在180度二者相差1.58度,差异无统计学意义(t=1.58,P=0.119),在0度相差2.89度,差异有统计学意义(t=2.89,P=0.005).结论 AS-OCT测量角膜中央厚度较Orbscan Ⅱ以及超声法测量结果薄,前房深度较Orbscan结果深,更接近于超声测量结果.房角角度测量结果与Orbscan结果近似,且能直观显示房角结构;眼前节OCT快速,非接触,在眼前节生物测量有广泛的应用前景.     

Pachymetry assessment with Orbscan II in postoperative patients with myopic LASIK

PURPOSE: To compare central corneal thickness after LASIK for myopia, using ultrasonic pachymetry and Orbscan II measurements, and to evaluate changes in these measurements over time. METHODS: Central corneal thickness measurements obtained by ultrasonic pachymetry and Orbscan II (Bausch and Lomb, Rochester, NY) in patients who underwent myopic LASIK between July 2002 and May 2003 were analyzed. The two measurements were assessed preoperatively and postoperatively at 1 day and 1, 3, 6, and 12 months. RESULTS: In 237 eyes, using the correction factor 0.93, no significant difference was noted in the preoperative central corneal thickness measured by ultrasonic pachymetry (561.89 +/- 28.66 microm) and Orbscan pachymetry (562.28 +/- 28.18 microm) (P =.713). Postoperatively, the difference was statistically significant at day 1 and 1, 3, and 6 months (P < .001), but was not significant at 12 months (P = .130). CONCLUSIONS: Orbscan II measurements of central corneal thickness after myopic LASIK are less than those measured by ultrasonic pachymetry; however, this difference decreases with time and may not be significant after 1 year.     

A five-year follow-up study of posterior corneal curvature and central corneal thickness after LASIK using OrbscanⅡ

Objective To study the long-term （five-year follow-up） changes in posterior corneal curvature and central corneal thickness by using the OrbscanⅡ topographer in patients who had undergone laser in situ keratomileusis （LASIK） for myopia. Methods Forty-eight eyes of 48 patients who had undergone LASIK for myopia were included in a retrospective observational case series study. The mean preoperative refractive error was -6.25±2.87 D. The preoperative and postoperative changes in the posterior corneal curvature and central corneal thickness of each eye were measured by OrbscanⅡ. The posterior corneal curvature was obtained from the central 6mm zone of the OrbscanⅡ. The postoperative follow-up period was at 1， 3， 6， 9， 12， 24， 36 and 60 months. Using SPSS 16.0 software， a comparison of the least-significant difference （LSD） pairwise was used to analyze the difference in the posterior corneal curvature and central corneal thickness at each follow-up visit. Results ①The posterior corneal curvature was higher in the 1st month postoperatively compared to preoperative curvature （t=8.211， P<0.01）. There was no statistically significant difference for the change in posterior corneal curvature from the 1st month to the 9th month （P>0.05）. The posterior corneal curvature slowly decreased over time from the 9th month to the 24th month （the values of t were -4.640 and -2.659， the values of P were <0.001 and 0.014）. The posterior corneal curvature did not become stable until after the 24th month （P>0.05）. ②The central corneal thickness was lower in the 1st month postoperatively than preoperative thickness （t=10.08， P<0.01）. The central corneal thickness slowly increased over time from the 1st month to the 9th month （the values of t were -5.402， -4.428 and -2.334， the values of P were <0.001， <0.001 and 0.027）. The central corneal thickness did not become stable until after the 9th month （P>0.05）.③The posterior corneal curvature was correlated with corneal thickness （r=-0.703， P<0.01）. Conclusion The posterior corneal curvature and the central corneal thickness both increase shortly after LASIK surgery and stabilize after this initial period. There is a negative correlation between posterior corneal curvature and central corneal thickness.     

LASIK术后眼前节形态变化及相关影响因素分析

背景 准分子激光角膜原位磨镶术(LASIK)是矫正屈光不正的主要方式之一,术中角膜基质层切削、负压吸引等操作可能导致术后眼前节形态和结构的改变,这些改变对术眼会带来何种影响值得关注. 目的 探讨LASIK对眼前节形态变化的影响,并分析其原因. 方法 采用等距抽样方法选择2012年5月至2013年7月于重庆明达眼科接受LASIK患者31例59眼的临床资料进行回顾性分析,患者平均年龄为(24.52±8.41)岁,术眼平均等效球镜度为(-5.96±3.75)D.分别于LASIK术前及术后1、3、6个月采用Sirius眼前节分析仪测量前房角(ACA)、前房容积(ACV)、中央前房深度(ACD)等参数,采用A型超声测量晶状体厚度(LT).以角膜4 mm半径平面为界限将前房分为前、后2段,计算矢高段前房深度(Sag4mmACD)(即角膜后表面顶点至角膜4 mm半径平面高度)和残余前房深度(RACD)(即角膜4 mm半径平面至晶状体前表面高度).采用Pearson相关分析法评估ACD与RACD和LT之间的相关性.结果 术眼术前及术后1、3、6个月ACA、ACV、ACD、RACD和LT测量值的总体比较差异均有统计学意义(F=8.319,P＜0.05;F=11.596,P＜0.05;F=24.045,P＜0.01;F=16.087,P＜0.05;F=15.333,P＜0.01),术眼术后1～6个月ACA、ACV、ACD、RACD测量值较术前均明显减小,差异均有统计学意义(均P＜0.05),而Sag4mmACD值与术前比较差异无统计学意义(P＞0.05);术眼术后各时间点LT值较术前均明显增加,差异均有统计学意义(均P＜0.01).术前及术后1、3、6个月ACD与RACD均呈显著正相关(r=0.976、0.824、0.724、0.938,均P＜0.01);术后3个月和6个月术眼LT值与ACD值均呈明显负相关(r=-0.344,P＜0.01;r=-0.363,P＜0.01). 结论 近视眼LASIK术后ACD变浅,ACD变化区域主要为角膜4 mm半径平面至晶状体前表面,该变化可能与术后视近时调节力增强致LT增加使晶状体前表面前移有关.     

LASIK术后5年内角膜后表面曲率和中央角膜厚度变化

目的 采用OrbscanⅡ角膜地形图仪对准分子激光原位角膜磨镶术（LASIK）后角膜后表面曲率和中央角膜厚度进行5年随访测量,探索其变化规律。方法 回顾性系列病例研究。LASIK手术患者48例（48眼）,平均屈光度（-6.25±2.87）D。术前及术后1个月、3个月、6个月、9个月、1年、2年、3年、5年,采用OrbscanⅡ测量其角膜后表面曲率（中央6 mm区域）和角膜厚度。采用重复测量的方差分析和LSD法比较角膜后表面曲率和中央角膜厚度的变化,并对两者关系作Pearson相关分析。结果 ①角膜后表面曲率变化：术后1个月,角膜后表面曲率较术前升高（t=8.211,P<0.01）;术后1~9个月,数值无明显变化,前后差异无统计学意义;术后9个月至2年,角膜后表面曲率逐渐下降,前后比较差异有统计学意义（t=-4.640、-2.659,P均＜0.01）;2年后,角膜后表面曲率趋于稳定,前后差异均无统计学意义。②中央角膜厚度变化：术后1个月,中央角膜厚度较术前下降（t=10.08,P<0.01）;术后1~9个月,中央角膜厚度逐渐上升,前后差异有统计学意义（t=-5.402、-4.428、-2.334,P均＞0.05）;术后9个月,中央角膜厚度趋于稳定,前后差异无统计学意义。③LASIK术后角膜后表面曲率与中央角膜厚度呈负相关（r=-0.703,P<0.01）。结论 LASIK术后早期角膜后表面中央区前凸,中央角膜厚度增加,此后两者均趋于稳定。随访期内角膜后表面曲率与中央角膜厚度呈负相关。