LASIK与LASEK术后角膜神经损伤和修复的实验研究

目的 比较兔眼LASIK与LASEK两种准分子激光手术后角膜神经损伤和再生修复情况.方法 选用健康、纯种新西兰白兔30只,随机分为6组,每组5只,1组为正常对照组,其余5组为实验组,实验组白兔一眼行LASIK手术;另一眼行LASEK手术.术后1、7 d,1、3、6m取兔角膜行氯化金染色,光镜下观察LASIK与LASEK术后角膜神经损伤及修复情况.结果 LASIK与LASEK手术后不同时期角膜神经损伤和再生修复有明显差异.结论 LASIK术后角膜神经损伤的程度比LASEK重,角膜神经再生修复速度慢.     

高度近视LASIK与LASEK术后角膜地形图的变化

目的分析高度近视LASIK与LASEK术后角膜地形图的变化,评价LASEK治疗高度近视的效果。方法选取接受准分子激光高度近视矫正术的连续性病例68例（125眼）。术前等效球镜值为-6．00D～-12．00D,平均（-8．91±2．12）D。按手术方式分为两组：LASEK组和LASIK组。比较术前、术后1个月、3个月和6个月患者角膜地形图的变化。结果两组术前角膜地形冈均以不对称领结型为主,LASEK组为55．6％,LASIK组为54．7％,两组差异无统计学意义（P〉0．05）;术后6月,两组均以平滑型为主,LASEK组为79．2％,LASIK组为83．0％,两组均无偏中心切削或中央岛型,两组差异无统计学意义（P〉0．05）。随着时间的推移,两组中的半环型均向平滑型转变。术后1个月、3个月、6个月与术前相比,两组模拟角膜镜度数（simk）的等效值、Simk差值明显减小,角膜不规则指数（CIM）明显增高,角膜形态因子（SF）向负值改变,其差异有统计学意义（P〈0．05）。术后1个月,LASEK组CIM值、Simk差值、SF绝对值均高于LASIK组,两组差异有统计学意义（P〈0．05）。术后3个月和6个月LASEK组CIM值低于LASIK组,两组差异有统计学意义（P〈0．05）,而Simk差值、Simk等效值及SF绝对值与LASIK组相比,差异无统计学意义（P〉0．05）。结论LASEK治疗高度、超高度近视术后角膜地形网形态较LASIK平整、规则。远期效果有待进一步观察。     

Excimer laser surface ablation – a review

Corneal surface laser ablation procedures for the correction of refractive error have enjoyed a resurgence of interest, especially in patients with a possible increased risk of complications after lamellar surgery. Improvements in the understanding of corneal biomechanical changes, the modulation of wound healing, laser technology including ablation profiles and different methods for epithelial removal have widened the scope for surface ablation. This article discusses photorefractive keratectomy, trans‐epithelial photorefractive keratectomy, laser‐assisted sub‐epithelial keratomileusis and epithelial‐laser‐assisted in situ keratomileusis.     

Laser epithelial keratomileusis in 2010 – a review

Photorefractive keratectomy, laser epithelial keratomileusis (LASEK) and Epi‐LASIK are all variants of a similar type refractive surgery involving laser on the surface of the cornea and differ mainly in management of the epithelium. Although laser in situ keratomileusis (LASIK) is currently the most popular form of refractive surgery, LASEK is the procedure of choice in some patients. We highlight potential complications of LASEK and how these may be managed. Following laser refractive surgery, corneal thickness is reduced, which has implications for intraocular pressure measurement and glaucoma screening and management. This is particularly important following surface laser procedures where no evidence of previous surgery may be visible. In the event that cataract surgery is required at a later date, correct calculation of the appropriate intraocular lens power can be difficult and it thus important that patients are given their preoperative keratometry readings and refraction. Compared with LASIK patients, those who undergo LASEK are considered to be at lower risk of corneal ectasia. Improved understanding of wound healing post LASEK and better postoperative pain management are ongoing challenges.     

未行准分子激光上皮瓣下角膜磨镶术的原因分析

目的探讨已行术前检查的近视患者未实施准分子激光上皮瓣下角膜磨镶术（LASEK）的具体原因。方法对78例患者经术前系统检查以及术前谈话后未实施手术的原因进行了分析。结果78例中角膜屈光力较高16例（20．51％）;圆锥角膜2例（2．56％）;最佳矫正视力〈0．5的13例22眼（16．67％）;对手术有顾虑12例（15．38％）;眼底病变10例（12．82％）;角膜厚度不足8例（10．26％）;眼压高7例（8．97％）;对疼痛恐惧6例（7．69％）;度数不稳定4例（5．13％）。结论LASEK是一种选择性手术,必须进行严格的术前检查和医患沟通,严格掌握手术的适应证和禁忌证。     

去上皮瓣的Epi-LASIK和LASEK矫治近视的临床疗效

目的 探讨去除或保留上皮瓣对机械法LASIK(epipolis LASIK,Epi-LASIK)和LASEK治疗近视的临床疗效影响.方法 将42例(84眼)接受Epi-LASIK的患者随机分为留瓣组(22例44眼)和去瓣组(20例40眼);将46例(92眼)接受LASEK的患者亦随机分为留瓣组(23例46眼)和去瓣组(23例46眼).定期随访观察4组患者术后疼痛、角膜上皮愈合时间、视力、屈光状态及haze情况.结果 术后第1天2种术式中去瓣组与留瓣组之间疼痛程度差异无统计学意义(P>0.05),术后第3天、第5天2种术式中去瓣组疼痛程度明显轻于留瓣组(P<0.05);留瓣组之间和去瓣组之间疼痛程度差异无统计学意义(P>0.05).去瓣组角膜上皮愈合时间:Epi-LASIK术后为(2.64±0.61)d,LASEK术后为(2.75±0.82)d,留瓣组:Epi-LASIK术后为(4.53±1.03)d,LASEK术后为(4.59±1.16)d,各术式去瓣组与留瓣组比较差异均有统计学意义(P均<0.05);2种术式留瓣组之间和去瓣组之间比较差异无统计学意义(P均>0.05).2种术式术后视力、屈光状态及haze情况去瓣组与留瓣组之间比较差异均无统计学意义(P均>0.05);1个月时,haze眼数Epi-LASIK和LASEK留瓣组分别为1眼和2眼,去瓣组分别为2眼和3眼,去瓣组间和留瓣组间比较差异无统计学意义(P>0.05).结论 Epi-LASIK和LASEK矫治近视术中去除上皮瓣不影响临床疗效.而且能减轻患者术后疼痛,缩短上皮愈合时间.[眼科新进展2009;29(6):460-463]     

弃上皮瓣LASEK治疗近视的临床观察

目的 对比分析保留和去除上皮瓣的LASEK矫治近视的临床疗效.方法 33例(66眼)近视患者进行自身对照分析,激光切削后随机去除一眼的上皮瓣为Ⅰ组,另一眼保留上皮瓣为Ⅱ组.对比分析2组术后裸眼视力、最佳矫正视力、角膜上皮愈合时间、角膜上皮下雾状混浊(haze)程度以及眼部刺激症状.结果 术后6个月,2组裸眼视力在1.0以上者分别为30眼(90.9%)和28眼(84.8%),差异无统计学意义(X2=0.14,P=0.71);2组均无最佳矫正视力下降大于1行者.Ⅰ组角膜上皮愈合时间为(4.24±1.30)d,Ⅱ组为(4.67±1.02)d,差异有统计学意义(t=-2.23,P:0.03);2组haze的发生率分别为0.12%和0.09%(X2=0.00,P:1.00).结论 去除上皮瓣不影响LASEK的疗效,并且能减轻患者的眼部刺激症状,缩短上皮愈合时间.     

准分子激光角膜屈光手术后丝状角膜炎的临床分析及治疗

目的:观察准分子激光角膜屈光手术后丝状角膜炎的发病情况,总结采用唯地息凝胶治疗的效果,探讨其发病相关因素及防治方法。方法:所有患者2139眼,按术前有无角膜接触镜配戴史分为Ia组493眼(有角膜接触镜配戴史)与Ib组1646眼(无角膜接触镜配戴史),按术式分为IIa组1916眼(LASIK术后)与IIb组223眼(LASEK术后),比较其发病率,观察准分子激光角膜屈光手术后丝状角膜炎的发生情况,发病者迅速、足量使用唯地息凝胶治疗,观察其疗效,分析该病变的临床特征,相关发病因素及防治措施。结果:Ia组与Ib组术后丝状角膜炎发病率分别为3.45%和1.76%,两者有显著差异(P<0.05);IIa组与IIb组术后丝状角膜炎发病率分别为1.93%和4.04%,两者有显著差异(P<0.05)。唯地息凝胶治疗准分子激光角膜屈光手术后丝状角膜炎的平均疗程1.22±0.63d,随访6mo未见复发。结论:与准分子激光角膜屈光手术后丝状角膜炎发生的相关因素包括:术前配戴角膜接触镜继发干眼及眼表炎症、术中角膜损伤、术后角膜上皮愈合及术后用药等。唯地息凝胶治疗准分子激光角膜屈光手术后丝状角膜炎,疗程短、效果显著。     

准分子激光上皮瓣下角膜磨镶术和准分子激光角膜切削术的疗效比较

目的探讨准分子激光上皮瓣下角膜磨镶术(LASEK)矫治近视的优缺点.方法选择双眼近视程度相近患者46例92只眼,双眼同时手术,1只眼行准分子激光角膜切削术(PRK),另1只眼行准分子激光上皮瓣下角膜磨镶术(LASEK),进行前瞻性自身对照研究,术后随访6个月以上.结果两组术后疼痛程度无明显区别,角膜上皮下雾状混浊(Haze)的发生率在1、3个月时,LASEK组明显较PRK组少、程度轻,6个月时两组比较无明显区别;LASEK组的视力恢复较PRK组更快、更佳.结论准分子激光上皮瓣下角膜磨镶术治疗近视,安全、有效,其雾状混浊发生率低且程度轻,视力恢复更快更佳.     

Corneal hysteresis using the Reichert ocular response analyser: findings pre‐ and post‐LASIK and LASEK

Purpose: To evaluate and compare corneal hysteresis in patients prior to and following laser in situ keratomileusis (LASIK) and laser‐assisted subepithelial keratectomy (LASEK) using the Reichert ocular response analyser (ORA). Methods: Corneal hysteresis was recorded prior to and 3 months after corneal laser refractive surgery for myopia. Preoperative corneal hysteresis was correlated with age and preoperative central corneal thickness (CCT). Postoperative corneal hysteresis was correlated with postoperative CCT in both the LASIK and LASEK treatment groups. The correlations between postoperative change in hysteresis and stromal ablation depth, percentage of tissue ablated, optical zone and patient age were also examined. Results: A total of 84 eyes of 84 patients were involved in the study. LASIK was performed in 63 eyes and LASEK in 21. Mean preoperative corneal hysteresis of all eyes was 10.8 ± 1.5 mmHg. Mean age, preoperative CCT, corneal hysteresis and ablation profile were similar in both groups. A statistically significant decrease in hysteresis occurred following LASIK (p < 0.01) and LASEK (p < 0.01) with similar decrements observed in both treatment groups. A moderate correlation was found between postoperative hysteresis and postoperative CCT in LASIK (r = 0.7) and LASEK (r = 0.7) treated eyes. A weak correlation was found between postoperative decrease in hysteresis and the parameters examined. Conclusion: Corneal hysteresis decreased following LASIK and LASEK. Similar reductions occurred following both procedures, indicating that LASIK involving a thin 120‐μm flap did not induce additional biomechanical change. Postoperative reduction in hysteresis did not correlate with the amount or percentage of corneal tissue removed, nor with optical zone or patient age.