高度近视薄角膜患者LASIK术后3a疗效观察

目的:通过研究角膜相对较薄的高度近视患者LASIK术后的远期效果,进一步探讨LASIK术中保留角膜基质床厚度与术后疗效的关系,以及可能影响术后屈光回退的因素.方法:选2001-01/2002-10在我院行LASIK手术的高度近视相对薄角膜患者21例39眼,查术后3a的视力、眼压、屈光状态、角膜曲率及中央角膜厚度,并与术前及术后早期数据进行统计学比较分析.结果:术后3a无1例出现继发圆锥角膜改变,术后视力0.8以上25眼,占64%,术后视力与术前最佳矫正视力间呈低度正相关.术后3a与早期视力无显著性差异,但屈光与角膜曲率有明显增加.术后3a屈光回退量≥1.00D30眼,占77%,屈光回退量与术前屈光度呈负相关,与患者年龄、术后角膜曲率的改变和实际角膜厚度与预留角膜厚度的差值呈正相关.结论:高度近视薄角膜患者LASIK术后的远期稳定性较低,可预测性较差,术后屈光回退可能与术前屈光、年龄、角膜厚度和曲率的改变有关.本组患者今后是否会继发圆锥角膜的改变仍需进一步观察研究.     

Laser in situ keratomileusis for residual myopia after primary LASIK

PURPOSE: To analyze the results of secondary laser in situ keratomileusis (LASIK) for residual myopia after primary LASIK. SETTING: Dr. Agarwal's Eye Hospital, Chennai, India. METHODS: A retrospective study of 50 eyes of 29 patients who had a secondary LASIK procedure was carried out. After a mean follow-up of 5.84 months +/- 3.24 (SD) after the primary procedure, the mean myopic residual refraction was -4.30 +/- 1.83 diopters (D). In 10 eyes, the primary corneal flap was lifted by blunt dissection. In 40 eyes, the flap was made with a second cut. The secondary LASIK was performed using the Chiron Technolas Keracor 217 excimer laser and the Automated Corneal Shaper microkeratome (Bausch & Lomb). RESULTS: The mean follow-up was 16.58 +/- 3.06 months. At 12 months, the mean spherical equivalent was -0.45 +/- 0.68 D (P <.05). Thirty-one eyes were emmetropic, 13 eyes were within +/-1.00 D of emmetropia, and 5 eyes were within +/-2.00 D. The mean uncorrected visual acuity improved from 20/80 (range 20/60 to 20/200) to 20/40 (range 20/20 to 20/200) (P <.005). Seventeen eyes gained 1 line of best spectacle-corrected visual acuity; 1 eye lost 1 line because of a decentered ablation with an induced postoperative astigmatism of -3.50 D cylinder. No sight-threatening complications such as a free cap, flap irregularity, corneal ectasia, or retinal complication occurred postoperatively. Epithelial ingrowth developed in 5 eyes and corneal thinning, in 1 eye. Three eyes had night glare. CONCLUSION: Secondary LASIK was a safe, stable, and effective method for the treatment of residual myopia after primary LASIK.     

Errors of residual stromal thickness estimation in LASIK.

BACKGROUND AND OBJECTIVE: To investigate inaccuracy and variability in residual stromal thickness estimation in LASIK by pachymetry and measurements of corneal thickness, flap thickness, and ablation depth. PATIENTS AND METHODS: In 73 eyes of 37 patients, preoperative and postoperative corneal thicknesses were obtained with slit-scanning elevation topography and the ultrasound pachymeter. LASIK was performed and corneal flaps were created with a microkeratome. Flap thickness and ablation depth (expected and achieved) were calculated. Residual stromal thickness estimation error was analyzed. RESULTS: The mean preoperative corneal thicknesses were 559.58 +/- 23.47 and 554.92 +/- 29.95 microm for the ultrasound pachymeter and slit-scanning elevation topography, respectively. Measurement differences ranged from -36 to 30 microm. With the pachymeter, calculated mean flap thickness was 139.58 +/- 17.59 microm. With this device, predicted ablation depth differed from achieved depth by 20% or more in approximately one-third (30.14%) of treated patients; ablation differences ranged from 10.0% to 19.99% in 37% of patients and 1.00% to 9.99% in 31.5% of patients. CONCLUSION: Imprecision of microkeratome cuts, preoperative corneal pachymetry, and laser ablation depth have a significant impact on the inaccuracy of residual stromal thickness prediction. Especially in patients with borderline corneal thickness, intraoperative pachymetry measurements and a residual stromal thickness higher than the safety margin of 250 microm are recommended to minimize iatrogenic ectasia.     

准分子激光原位角膜磨镶术后角膜基质床厚度安全值分析

目的　探讨准分子激光原位角膜磨镶术 (LASIK)后残留角膜基质床厚度的安全值及术后角膜后表面曲率的稳定时间。方法　于 2 0 0 0年接受LASIK的患者中随机抽取 117例 (2 2 7只眼 ) ,对其术前及术后 1个月、3个月、6个月、1年、2年的OrbscanⅡ角膜后表面曲率检测结果进行比较分析。结果　LASIK术后早期角膜后表面中央均有不同程度向前膨隆 ,角膜基质床越薄者 (<30 0 μm)前膨趋势越明显 ,角膜基质床越厚者 1年内角膜后表面曲率稳定或回复越明显。所有病例的角膜后表面曲率在术后 2年与 1年的比较中差异均无显著意义 (P >0 0 5 )。结论　LASIK术后早期角膜后表面前膨增加 ,术中残留角膜基质床厚度 >30 0 μm更安全。术后 1年角膜状态稳定 ,无前膨增加趋势。 (中华眼科杂志 ,2 0 0 4 ,4 0 :74 1 74 4 )     

马来酸噻吗洛尔滴眼液对高度近视眼LASIK术后近视回退的影响

目的探讨马来酸噻吗洛尔滴眼液在防治高度近视眼准分子激光原位角膜磨镶术(1aser in situ keratomileusis,LASIK)后屈光回退中的作用。方法选取接受LASIK治疗的高度近视眼患者术后第1天主觉验光等效球镜屈光度在0～-0.75D患者78例(78眼),随机分为研究组39例(39眼)和对照组39例(39眼)。对照组术后常规应用抗生素滴眼液滴眼10d和皮质类固醇滴眼液滴眼1个月。研究组术后除常规用药外,术后第1天增加使用马来酸噻吗洛尔滴眼液每天2次滴眼1个月。术前、术后10d、1个月、3个月进行眼压和主觉验光检查,OrbscanⅡ测量角膜后表面前移量(Diff差值)。结果研究组术后10d、1个月、3个月眼压分别为(9.61±2.90)mmHg(1kPa=7.5mmHg)、(9.97±2.50)mmHg、(10.61±2.90)mmHg,与对照组比较[(11.69±2.60)mmHg、(11.99±3.07)mmHg、(10.92±2.65)mmHg],术后10d、1个月差异均有统计学意义(均为P<0.05),术后3个月差异无统计学意义(P>0.05)。研究组术后10d、1个月和3个月角膜后表面Diff差值分别是(9.56±6.66)μm、(10.72±6.70)μm和(14.11±4.66)μm,对照组分别为(19.57±7.76)μm、(20.24±7.37)μm和(20.10±6.98)μm,两组比较差异有显著统计学意义(F=34.236,P=0.000);两组术后同时间点Diff差值比较,差异均有统计学意义(均为P<0.05)。研究组术后10d、1个月和3个月时等效球镜屈光度分别为(-0.46±0.28)D、(-0.61±0.34)D和(-0.75±0.21)D,对照组分别为(-0.67±0.23)D、(-0.93±0.23)D和(-1.05±0.29)D,两组术后同时间点比较差异均有统计学意义(均为P<0.05)。结论高度近视眼LASIK术后早期应用马来酸噻吗洛尔滴眼液能阻滞角膜后表面前移,降低近视屈光度,是预防高度近视眼LASIK术后屈光回退的一种有效方法。     

Central corneal thickness in high myopia

PURPOSE: To examine if central corneal thickness (CCT) is different in emmetropia and high myopia. METHODS: 57 emmetropic subjects (0 to + 1.5 D) and 48 high myopes (all more than - 6 D in spherical equivalent refraction) were studied. CCT was measured by a Haag-Streit Optical Low-Coherence Reflectometry (OLCR) pachymeter, a recently developed high precision pachymeter with a standard deviation (SD) for repeated measurements of 1 microm. RESULTS: Mean CCT for the emmetropic group was 538.6 microm (SD = 32.1), and for the myopic group 527.7 microm (SD = 35.0). Neither the mean CCT nor the variance from the two groups showed a statistically significant different (p > 0.05). CONCLUSION: CCT is not systematically altered in myopia. The process by which the myopia progresses does not to a measurable degree influence the central cornea.     

Keratectasia after laser in situ keratomileusis (LASIK): evaluation of the calculated residual stromal bed thickness

PURPOSE: To report corneal histopathology associated with keratectasia after laser in situ keratomileusis (LASIK) and to evaluate the thickness of the calculated residual stromal bed in two cases and those in the literature. DESIGN: Interventional case reports. METHODS: Three eyes of two patients developed keratectasia after LASIK. Corneal specimens after penetrating keratoplasty in one eye of each patient were studied histopathologically, and the residual stromal bed was directly measured. For comparison, residual stromal bed thicknesses were calculated from published cases of keratectasia. RESULTS: Two eyes of a 26-year-old woman and one eye of a 22-year-old woman developed keratectasia after LASIK. Calculated residual stromal bed thicknesses were 210, 213, and 261 microm. Histologic sections revealed focal scarring in the flap plane. The cornea specimens measured 75 and 118 microm thinner than calculated values immediately after LASIK. Transmission electron microscopy of one case revealed an average lamellar thickness of 0.94 microm. In 28 (49%) of 57 previous cases of keratectasia, the calculated residual stromal bed thicknesses were greater than 250 microm. CONCLUSIONS: Both the flap and the stromal bed of the cornea may thin after LASIK. A residual stromal bed thickness of 250 microm does not preclude the development of keratectasia after LASIK.     

准分子激光角膜上皮瓣下磨镶术治疗准分子激光原位角膜磨镶术后残留近视及散光

目的探讨准分子激光角膜上皮瓣下磨镶术(LASEK)治疗准分子激光原位角膜磨镶术(LASIK)后残留近视及散光的疗效。方法对我院自2000年4月至2004年1月间用LASEK治疗LASIK术后残留近视及散光患者34例(66只眼)进行随访,观察术后症状、角膜上皮瓣愈合时间、视力、屈光度数、波阵面像差及角膜上皮下雾状混浊(haze)形成情况。随访时间平均13.2个月。结果34例(66只眼)平均等效球镜为(-3.20±0.32)D,所有患者均一次完成手术,有3只眼上皮瓣周边部有破损,其余完好。术后1d上皮瓣基本透明者55只眼,11只眼有轻度的水肿。取镜时间平均为(3.35±0.49)d。术后3个月有56只眼(85%)屈光度数介于±0.50D之间,64只眼(97%)屈光度数介于±1.00D之间。有3只眼最佳矫正视力较术前提高1行,2只眼提高2行,无最佳矫正视力下降者。术后3个月高阶像差较术前增大。术后3个月haze0.5级者10只眼(15%),1级者2只眼(3%)。结论LASEK治疗LASIK术后残留近视及散光的预测性好,疗效确定,安全可靠。(中华眼科杂志,2005,41:981-985)     

LASIK矫治儿童高度复性近视散光性屈光参差

目的　评价LASIK联合散光MASK盘 (M盘 )矫治儿童高度复性近视散光性屈光参差的安全性、有效性、可预测性和稳定性。方法　使用Summit公司的SVSApexPlus准分子激光系统、MASK盘 (M盘 )及Moria公司的板层刀 ,对 2 1例 7～ 1 5岁患儿 2 3只高度复性近视散光性屈光参差眼行LASIK手术 ,术后托百士、艾氟龙眼液点眼。随访时间 1 2个月。结果　术前球镜均值 :-9 1 0± 3 3 7DS ( -4 5 0～ -1 7 2 5DS) ,柱镜均值 :-2 3 7± 0 47DC ( -1 2 5～ -4 5 0DC)。裸眼视力均值 :0 0 7± 0 0 4( 0 0 4～ 0 1 ) ,矫正视力均值 :0 5 1± 0 3 1 ( 0 1～ 1 0 )。术后 1 2月球镜均值 :-1 1 0± 1 1 5DS ( +0 5 0～ -3 2 5DS) ,柱镜均值 :-0 1 0± 0 1 4DC ( +0 2 5～ -1 2 5DC)。裸眼视力均值 :0 5 8± 0 41 ( 0 2～ 1 0 ) ,矫正视力均值 :0 67± 0 40 ( 0 3～ 1 2 )。结论　LASIK矫治儿童高度复性近视散光性屈光参差是安全、有效的 ,且可预测性及稳定性均较好。这一手术的开展为不能耐受戴镜的高度复性近视散光性屈光参差眼提供了一种有效的矫治手段。     

Wavefront aberration outcomes of LASIK for high myopia and high hyperopia

PURPOSE: To determine the higher order aberrations at the corneal first surface after conventional LASIK for high myopia and high hyperopia. METHODS: This was a retrospective study using a convenience sample with subjects divided into five groups by level of refractive correction. Group 1 were normals, having no eye disease or previous surgery, but may have had refractive error. Group 2 had low myopia (-1.00 to -5.87 D), group 3 high myopia (> 6.00 D), group 4 low hyperopia (+1.00 to +3.87 D), and group 5 high hyperopia (> 4.00 D). LASIK was performed using a Technolas 217 laser. Corneal topography was taken with Orbscan II, and Placido data exported to VOLPro software v6.71. Wavefront aberrations were determined for a 6.0-mm pupil. RESULTS: The study included 264 subjects-group 1 (normal), n=204; group 2 (low myopia), n=20; group 3 (high myopia), n=20; group 4 (low hyperopia), n=10; and group 5 (high hyperopia), n=10. The spherical equivalent refractive error corrected (mean +/-SD) was 0.00 +/- 0.00 D in group 1, -3.92 +/- 1.47 D in group 2, -9.53 +/- 2.06 D in group 3, +2.49 +/- 0.51 D in group 4, and +5.54 +/- 1.22 D in group 5. The total higher order root-mean-square (RMS) wavefront aberration was 0.38 +/- 0.07 microm in group 1, 0.69 +/- 0.22 microm in group 2, 1.36 +/- 1.79 microm in group 3, 0.64 +/- 0.34 microm in group 4, and 1.76 +/- 0.54 microm in group 5. Spherical aberration was 0.25 +/- 0.06 mcirom in group 1, 0.45 +/- 0.11 microm in group 2, 0.64 +/- 0.29 microm in group 3, -0.11 +/- 0.15 microm in group 4, and -0.56 +/- 0.22 microm in group 5. The refractive correction (Rx) was highly correlated to total higher order RMS for myopic correction higher order RMS = 0.38 - 0.07 Rx, R2=0.52, and for hyperopic correction higher order RMS = 0.18 + 0.28 Rx, R2 = 0.75. CONCLUSIONS: Conventional LASIK increases all corneal higher order aberrations with induced aberrations increasing with the magnitude of refractive correction. High refractive corrections, both myopic (>6.00 D) and hyperopic (>5.00 D), can lead to very high levels of corneal higher order aberrations.     

近视眼LASIK后黄斑区视网膜厚度变化的研究

目的 探讨准分子激光角膜原位磨镶术（exdmer laser insitu keratomileusis LASIK）对近视眼黄斑区视网膜厚度的影响及其影响因素。方法 随机选择接受LASIK手术矫正视力≥1．0近视眼患者25例49眼，根据术前屈光度数分为二组：中轻度近视组：≤6．00D，17眼；高度近视组：＞6．00D，32眼。采用Zeiss-Humphrey光学相干断层成像仪（Optical Coherence Tomography OCT）第三代观察近视眼LASIK术前，术后1d、3d、1w、1m眼底黄斑区变化，并测量以黄斑中心凹为中心3mm半径内的视网膜平均厚度，以地形图分9个区域显示。结果 25例49眼近视患者LASIK术后1d、3d黄斑中心凹（A1）视网膜平均厚度同术前比较有增加，差别具有统计学意义（P＜0．05；P＜0．01），近视眼术后1w、1m黄斑中心凹视网膜平均厚度同术前比较差别无统计学意义（P＞0．05）：除黄斑中心凹（A1区）外的近视眼黄斑部各区（A2-A9）视网膜平均厚度术后同术前比较差别无统计学意义（P＞0．05）。高度近视眼组术后1d、3d、1w黄斑中心凹（A1区）视网膜平均厚度均高于术前，差异具有统计学意义（P＜0．05；P＜0．01；P＜0．05），高度近视眼组术后1m黄斑中心凹视网膜平均厚度同术前比较差异无统计学意义（P＞0．05）；中轻度近视组术后观察各时期与术前比较差异无统计学意义（P＞0．05）。高度近视眼LASIK术后黄斑中心凹视网膜平均厚度的增加与术前屈光状态、激光切削时间呈正相关。结论 近视眼LASIK术后出现的黄斑中心凹视网膜水肿主要发生在高度近视眼，与术前屈光度数大、激光切削时间长有关。高度近视眼LASIK术后出现的黄斑中心凹水肿是轻微的，可逆的，未影响视力，在1m内消退。     

LASIK与LASEK治疗高度近视的远期疗效比较

目的 评价LASIK与LASEK治疗高度近视的远期有效性与稳定性.方法 回顾生分析行LASIK的高度近视患者124例和行LASEK的高度近视患者204例的临床资料,随访观察12个月,对比2种术式术眼裸眼视力、疼痛程度及不适症状、等效球镜值以及角膜haze等情况.结果 术后第14天、1个月,LASIK组裸眼视力分别为0.90±0.18、0.98±0.20,LASEK组分别为0.67±0.22、0.79±0.18,2组比较差异均有显著统计学意义(均为P＜0.01);术后3个月、6个月、12个月,2组裸眼视力比较差异无统计学意义(P＞0.05).术后第14天、1个月、3个月,LASIK组等效球镜值分别为(0.58±0.26)D、(0.35±0.32)D、(-0.38±0.56)D,LASEK组分别为(1.68±0.56)D、(1.12±0.38)D、(0.75±0.65)D,2组比较差异均有显著统计学意义(均为P＜0.01);术后6个月、12个月,2组比较差异无统计学意义(P＞0.05).与LASEK相比,LASIK术后疼痛程度轻,haze发生率低.结论 LASIK、LASEK矫正高度近视远期具有相似的临床效果,2种术式对高度近视的矫正均有良好的稳定性.LASEK术后角膜刺激症状较LASIK重,术后haze不能完全避免,但其克服了LASIK因角膜瓣所带来的并发症,二者各有优劣.     

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.     

青少年高度近视眼的脉络膜厚度改变

目的 比较青少年高度近视眼与正常眼的脉络膜厚度的差异,分析脉络膜厚度变化与青少年高度近视的关系.方法 选取2014年2月至2014年8月在我院眼视光中心就诊和体检的青少年62例111眼,年龄为13～17 (14.34±2.74)岁.分为高度近视组32例57眼,正常对照组30例54眼,高度近视组屈光度(-6.85±1.14)D,眼轴(26.31±1.13)mm.正常对照组屈光度(-0.37±0.85)D,眼轴(23.91 ±0.64) mm.两组间的屈光度、眼轴差异均有统计学意义(P＜0.001).采用频域光学相干断层扫描的加强深度扫描技术对黄斑部进行0°扫描,测量黄斑中心凹下及由中心凹向鼻侧和颞侧3000 μm的脉络膜厚度值,共测量13个子午线,每个子午线间隔500 μm,比较两组间脉络膜厚度、屈光度和眼轴,分析脉络膜厚度变化与青少年高度近视的关系.结果 青少年高度近视组受检眼黄斑中心凹下脉络膜厚度值和黄斑部脉络膜平均厚度值分别为(220.4±49.6) μm和(209.9±62.8) μm,正常对照组分别为(347.4±63.6)μm和(295.1±71.2) μm,两组间差异均有统计学意义(t=-17.220,P=0.000;t-16.180,P=0.000).青少年高度近视组颞侧脉络膜最厚,中心凹下厚度次之,鼻侧最薄;而正常对照组以黄斑中心凹区域脉络膜最厚,其次为颞侧,鼻侧最薄.高度近视组受检眼各检测点脉络膜均薄于正常对照组.两组脉络膜厚度的差异黄斑中心凹区域较黄斑周边区域明显(P ＜0.001).结论 青少年高度近视患者脉络膜厚度较青少年正常眼明显变薄,以黄斑中心凹区域的差异显著.提示脉络膜的厚度改变可能在青少年高度近视眼的发生过程中发挥作用.     

LASIK单中心多区切削治疗高度近视

目的探讨如何改善LASIK治疗高度近视术后出现的屈光回退,眩光及暗适应下降。方法门诊随机抽取行LASIK手术高度近视86例(160眼)矫正视力≥0.8、屈光度在(-9.00 D~-14.00 D)者。分A、B两组,每组80眼。A组选择5.75 mm的切削直径。B组选择在相同切削量的基础上采用5.50 mm与6.50 mm相结合的多区切削。结果A组:裸眼视力≥0.8者68眼占85.00%,主诉有眩光者56眼占70.00%,暗适应下降76眼占95.00%,角膜厚度(390±30)μm,屈光度±0.75 D~-2.50 D,地形图均为正常负性形态。B组:裸视≥0.8者78眼占97.50%,主诉有眩光共6眼占7.50%,暗适应下降22眼占27.50%角膜厚度(410±30)μm,屈光度±0.50 D~-1.0 D,在形图均为正常负性形态。结论LASIK单中心、多区切削治疗高度近视,减少了屈光回退,降低了眩光和暗适应当的发生率,提高了术后的视觉质量。