Laser subepithelial keratomileusis for low to moderate myopia: 6-month follow-up

PURPOSE: To examine the effectiveness, safety, and stability of laser subepithelial keratomileusis (LASEK), a modified photorefractive keratectomy for low to moderate myopia. METHODS: This study evaluated the results of LASEK in 48 myopic patients (84 eyes) with a consecutive 6-month follow-up period. Preoperative myopia ranged from 3.25 to 7.00 diopters (D). Uncorrected and corrected visual acuity, manifest refraction, epithelial healing time, postoperative pain, subepithelial corneal haze, and complications were examined. RESULTS: Uncorrected visual acuity of 20/30 or better was achieved in 78.6% of eyes at 1 week and in 96.4% at 6 months after surgery. A mean refraction of within +/-0.50 D was measured in 42 eyes (50.0%) and +/-1.0 D in 79 eyes (94.0%) at 6 months. The epithelial healing time was 3.68 +/- 0.69 days (range, 3-6 days) and postoperative pain scores were 1.49 +/- 0.65. The subepithelial corneal haze scores were 0.56 +/- 0.34 and 0.16 +/- 0.25 at 1 and 6 months, respectively. As for complications, alcohol leakage during surgery occurred in 3 eyes, incomplete epithelial detachment in 3 eyes, contact lens intolerance in 5 eyes and steroid-induced elevated intraocular pressure (>21 mm Hg) in 1 eye. CONCLUSIONS: LASEK is an effective and safe procedure for low to moderate myopia. It can be considered an alternate type of refractive surgery for correction of low to moderate myopia.     

Laser epithelial keratomileusis for myopia

PURPOSE: To describe a new technique for excimer laser corneal surgery: laser epithelial keratomileusis (LASEK). METHODS: We report 76 eyes with spherical equivalent refractive myopia ranging from -8.00 to -22.00 D (mean -11.00 +/- 3.00 D). Using ethanol applied over an 8.5-mm-diameter area for 20 seconds, the epithelium was detached and photorefractive keratectomy (PRK) was performed. The epithelium was reapplied to the ocular surface and covered with a therapeutic soft contact lens. Treatments were carried out with the Nidek EC-5000 excimer laser. RESULTS: At a mean of 803 days after LASEK, mean spherical equivalent refraction was -1.80 +/- 2.40 D (range -9.27 to +2.00 D). Stability was reached in approximately 60 days. Fifty-nine percent of the epithelial flaps were easy to detach intact during surgery and 62.7% of patients reported no postoperative pain. Eighty-four percent of eyes had the therapeutic bandage lens removed by the fourth postoperative day. Twelve percent of eyes had incomplete epithelial flap removal. Epithelium can fall off the cornea during the healing phase. No significant subepithelial haze was seen in 95% of eyes. CONCLUSION: With LASEK, it may be possible to treat a larger diameter ablation zone in thinner corneas without the problems of a LASIK stromal flap and with less postoperative pain than PRK, with minimal subepithelial haze.     

Comparison of laser epithelial keratomileusis and photorefractive keratectomy for low to moderate myopia

PURPOSE: To compare the effectiveness, safety, and stability of laser epithelial keratomileusis (LASEK), a modified photorefractive keratectomy (PRK) technique, with those of conventional PRK for low to moderate myopia. SETTING: Department of Ophthalmology, Yonsei University School of Medicine, Seoul, Korea. METHODS: In this prospective study, 27 patients with a manifest refraction of -3.00 to -6.50 diopters were treated and followed for 3 months. In each case, PRK was performed in 1 eye and LASEK in the other eye. The first eye treated and the surgical method used in the first eye were randomized. Postoperative pain, epithelial healing time, uncorrected visual acuity (UCVA), manifest refraction, corneal haze, and surgical preference were examined in PRK- and LASEK-treated eyes. RESULTS: During the 3 month follow-up, there were no significant between-eye differences in epithelial healing time, UCVA, or refractive error. However, LASEK-treated eyes had lower postoperative pain scores (P =.047) and corneal haze scores (1 month; P =.02) than PRK-treated eyes. Seventeen patients (63%) preferred the LASEK procedure. CONCLUSIONS: Laser epithelial keratomileusis safely and effectively treated eyes with low to moderate myopia. It reduced the incidence of significant postoperative pain and corneal haze and may prevent the flap- and interface-related problems of laser in situ keratomileusis.     

A control-matched comparison of laser epithelial keratomileusis and laser in situ keratomileusis for low to moderate myopia

PURPOSE: To compare the visual and refractive outcomes of laser epithelial keratomileusis (LASEK) and laser in situ keratomileusis (LASIK) for the treatment of low to moderate myopia. DESIGN: Retrospective, nonrandomized, control-matched study. METHODS: The charts of 2257 eyes that underwent LASEK or LASIK treatment were reviewed. Patients who were 21 years of age or older having between -0.75 and -6.00 diopters (D) of myopia with up to -2.25 D of astigmatism were included. One hundred twenty-two LASEK-treated eyes were matched with 122 LASIK-treated eyes having preoperative spheres, cylinders, and spherical equivalent (SE) within +/-0.50 D. Both groups had similar preoperative best spectacle-corrected visual acuity (BSCVA), laser platform, and follow-up durations. Outcome measures were visual and refractive results. RESULTS: Preoperatively, the mean SE was -3.50 +/- 1.40 D for LASEK and -3.50 +/- 1.42 D for LASIK (P = .59). Postoperatively, the mean logarithm of minimum angle of resolution (logMAR) uncorrected visual acuity (UCVA) was 0.01 +/- 0.08 (20/21) for LASEK and 0.06 +/- 0.12 (20/23) for LASIK; the mean SE was -0.15 +/- 0.40 D for LASEK and -0.37 +/- 0.45 D for LASIK; and the mean logMAR of BSCVA was -0.03 +/- 0.06 (20/19) for LASEK and -0.02 +/- 0.05 (20/19) for LASIK. No eye lost 2 or more lines of BSCVA in both groups. CONCLUSIONS: Slight differences in the visual and refractive results between LASEK and LASIK were observed, despite the use of the same nomogram. Both procedures were safe, effective, and predictable. Nomogram adjustment may be necessary for LASIK surgeons adopting surface ablation.     

WG-LASIK与WG-LASEK治疗中低度近视的临床疗效比较

目的:比较波前像差引导的准分子激光原位磨镶术(wave-front-guided LASIK,WG-LASIK)与波前像差引导的准分子激光上皮瓣下磨镶术(wavefront-guided LASEK,WG-LASEK)治疗中低度近视的疗效。方法:80例患者(160眼)随机分为WG-LASIK组和WG-LASEK组,每组40例(80眼)。术后随访观察上皮愈合时间与疼痛情况,术后2wk;1,2,3,6mo;1a时术后裸眼视力、屈光度数、角膜上皮下雾状混浊(Haze)和高阶像差。术后3,6mo时做视觉质量问卷调查。结果:两组术后眼痛程度,上皮愈合时间,屈光度数及角膜Haze无显著性差异。两组裸眼视力、暗视瞳孔下高阶像差的均方根值有显著性差异,且时间曲线不相同。结论:WG-LASIK与WG-LASEK矫正中低度近视均能取得较好的临床效果,用来矫正中低度近视是安全,有效的。术后裸眼视力、视觉成像质量及视力稳定程度方面,WG-LASEK更优于WG-LASIK。     

Laser epithelial keratomileusis for myopia with the autonomous laser

PURPOSE: To describe the refractive outcome, objective clinical data, and subjective patient experiences after laser epithelial keratomileusis (LASEK) at 1, 3, and 6 months after surgery. METHODS: This was a retrospective, nonrandomized, comparative study of 58 LASEK-treated eyes (36 patients) with myopia (with and without astigmatism) between -1.50 and -14.75 D (mean -7.80 +/- 2.90 D, median -7.90 D). Refractive surgery was performed using the Alcon Summit Autonomous LADAR Vision excimer laser. Manifest refraction, best-spectacle and uncorrected Snellen visual acuity, stability of refraction, and corneal haze were evaluated before surgery and up to 6 months after surgery. A group of randomly selected LASIK-treated eyes were compared at each time point. RESULTS: Patients who opted for monovision (n=12) were excluded. In the emmetropia targeted eyes (n=46), 45%, 83%, 85%, and 89% achieved 20/40 or better uncorrected Snellen visual acuity (UCVA) at 1 day, 1 week, 2 weeks, and 1 month respectively. At 6 months, 73% (n=28) of eyes treated achieved UCVA 20/20 with 97% achieving 20/40 or better (mean, -0.51 D). At 3 and 6 months, 71% (n=46) and 68% (n=28) were within +/- 0.50 D of emmetropia. The percentage of eyes that achieved UCVA 20/40 or better at 6 months was 97% (n=28). Visually significant corneal haze was evident in two LASEK-treated patients (four eyes) at 6 months. No eyes lost two or more lines of best spectacle-corrected Snellen visual acuity. CONCLUSIONS: Preliminary data suggest that LASEK appears to be a safe, effective, and comparable alternative to LASIK, even for higher amounts of myopia. A prospective, randomized clinical trial is needed to better define the role of LASEK as it compares to other refractive procedures, specifically LASIK and PRK.     

激光角膜上皮瓣下磨镶术和激光原位角膜磨镶术治疗中高度近视的对比研究

目的比较激光角膜瓣下磨镶术(LASEK)和激光原位角膜磨镶术(LASIK)治疗中高度近视的临床效果. 方法中高度近视患者198例(394只眼).其中LASEK手术治疗93例(184只眼), LASIK手术治疗105例(210只眼). 结果术后1天,LASIK 组28 %裸眼视力达到1.0,LASEK组无1例裸眼视力达到1.0.术后1周、1、3、6月裸眼视力大于或等于1.0者,两组比较差异无显著性 (P=0.36,P=0.58,P=0.44,P=0.64).角膜地形图分析平均角膜中央屈光力与周边屈光力的差异,LASEK组(0.69)明显小于LASIK组(2.62).结论 LASEK手术矫正中高度近视均有良好的治疗效果,是一种安全、有效、预测性好的屈光手术.     

中低度近视LASEK术后角膜地形图分析

目的　探讨中低度近视准分子激光上皮瓣下角膜磨镶术 (LASEK)后的角膜地形图变化。方法　中低度近视LASEK术 40例 (80眼 ) ,术前及术后 1、3、6月行角膜地形图检查 ,与综合验光结果进行相关分析。结果　LASEK术后 6月裸眼视力≥ 0 .6者占 10 0 .0 0 % ,其中≥ 1.0者占 97.5 0 %。 80眼术前角膜地形图表现最多者为对称领结形 ,依次为非对称领结形 ,圆形 ,椭圆形及不规则形。术后 6月检查时角膜地形图主要表现为圆形或椭圆形 (75 .0 0 % ) ,肾形 (2 1.2 5 % )及半环形 (3 .75 % )。LASEK术后 (SAI)、SimK等效值和SimK的差值较术前变化显著 (P <0 .0 5 ) ,SRI改变则不显著。结论　LASEK治疗中低度近视疗效佳。角膜地形图的定量分析对术后角膜表面球面性状的评价、手术设计的改进和疗效的预测具有重要意义。     

准分子激光上皮下角膜磨镶术治疗中高度近视的效果分析

目的探讨准分子激光上皮下角膜磨镶术（LASEK）治疗中高度近视的疗效。方法40例（79眼）行LASEK,屈光度-3．50D～-15．00D,平均-8．50D;随访6个月,观察早期眼部症状、视力、眼压、屈光状态、雾状角膜浑浊（haze）程度及屈光回退等情况。结果LASEK术后早期眼部刺激症状较重;术后角膜上皮愈合时间为3～7d,平均为5d;术后2周裸眼视力（UCVA）〉0．5者71眼（89．87％）,术后6个月UCVA等于或优于术前最佳矫正视力（BCVA）者74眼（93．67％）;术后6个月发生（haze）：0级76眼（96．20％）;0．5级2眼（2．53％）;2级1眼（1．27％）;无1级及2级以上haze。结论LASEK治疗中高度近视有一定的疗效,但手术后早期跟部刺激症状重,视力恢复慢,haze和屈光回退有待观察与研究。     

准分子激光原位角膜磨镶术治疗中低度近视的临床研究

目的评估准分子激光原位角膜磨镶术（LASIK）治疗中低度近视的安全性、有效性、稳定性及预测性。方法采用SCMD气动式角膜切割刀及SCHWINDKERATOM－F型准分子激光系统，对中低度近视（等值球镜-2．00D～6．00D，平均－4．61±0．98D）41例74只眼行LASIK手术，术后随访观察6个月以上。结果术后自觉症状轻微，无角膜雾状混浊及眼压升高。术后第1天即可获良好的裸眼视力，屈光度在术后1个月基本趋于稳定。术后6个月裸眼视力≥1．0者达94．6％，屈光度在±1．00D以内的达89．2％．在±0．50D以内的达62．2％，所有术眼的矫正视力均≥1．0。结论LASIK对于治疗中低度近视有很好的疗效，无明显并发症，对于远期结果尚需进一步观察。     

准分子激光上皮下角膜磨镶术治疗近视

目的 :研究保留角膜上皮的准分子激光上皮下角膜磨镶术治疗近视早期临床疗效。方法 :2 0例 3 7眼术前近视屈光度平均 -2 48± 1 14D (-1 2 5～ -8 0D) ,采用 2 3 %酒精浸泡 3 0秒制作角膜上皮瓣 ,激光切削采用Chiron117准分子激光系统。结果 :术后平均视力 :1周 0 92± 0 14 ,1月 1 2 8± 0 2 0 ,3月 1 2 5± 0 18。术后 3月角膜Haze 0级 2 8眼 ,0 5级 9眼。术后第 1天疼痛分级 :0级 12眼 (3 2 4% ) ,Ⅰ级 18眼 (4 8 2 % )、 >Ⅰ级 7眼 (19 4% )。结论 :准分子激光上皮下角膜磨镶术术后疼痛症状、角膜Haze明显减轻 ,但是疗效还需要长期观察及与PRK对比研究     

准分子激光上皮瓣下角膜磨镶术治疗近视散光

目的　探讨准分子激光上皮瓣下角膜磨镶术 (LaserSubepithelialKeratomileusis ,LASEK)治疗近视散光的疗效。方法　 2 2 5例 42 3眼行LASEK术 ,术前裸眼视力 (UncorrectedVisualAcuity ,UCVA) 0 0 1～ 0 8,平均 0 2± 0 16,最佳矫正视力 (BestCorrectedVisualAcuity ,BCVA )0 5～ 1 5 ,平均 1 14± 0 18。术前近视度数 -0 2 5～ -10 75D ,平均 -4 2 2± -1 88D ,散光度数 -0 2 5～ -5 0 0D ,平均 -1 0 4± -0 74D。随访 3～ 12月。结果　术后裸眼视力 0 2～ 1 5 ,平均 1 0 6± 0 18。术后 3 89眼 ( 92 % )有轻度不适。术后 2 1眼出现haze ,0 5级 15眼 ,1 0级 4眼 ,2 0级 2眼。结论　LASEK兼具了PRK和LASIK的优点 ,无严重并发症 ,手术预测性好 ,是一种安全、有效的屈光手术     

弃瓣和常规Epi-LASIK术矫正中低度近视临床观察

目的:比较弃瓣和常规机械法准分子激光角膜上皮瓣下磨镶术(epipolis laser in situkeratom ileusis,Epi-LASIK)手术矫正近视临床效果。方法:对38例72眼患者,低度近视行弃瓣(A组)和常规Epi-LASIK手术(B组)并随诊2a,比较两种手术方式早期临床反应,中、后期视力、haze、屈光度变化。结果:A,B两组手术均顺利;术后A组刺激症状轻于B组,差异有统计学意义;术后第2d:A组角膜透明眼数较B组多,差异有统计学意义;A,B两组术后7d;1mo视力比较差异有统计学意义,3,12,24mo比较差异无统计学意义;术后1moA,B两组屈光度比较差异有统计学意义,3,12,24mo比较差异无统计学意义;术后各时间两组haze差异无统计学意义。结论:Epi-LASIK、弃瓣Epi-LASIK在矫正中、低度近视安全、有效、稳定性好、可预测性好;弃瓣Epi-LASIK早期有效视力恢复方面、减轻术后不适感具有优越性。     

Wavefront-guided versus standard laser in situ keratomileusis to correct low to moderate myopia

To evaluate the 6-month refractive outcomes of wavefront-guided laser in situ keratomileusis (LASIK) (Zyoptix, Bausch & Lomb) versus standard LASIK (PlanoScan, Bausch & Lomb).Department of Ophthalmology, University Hospital Maastricht, Maastricht, The Netherlands.In a prospective randomized study, 12 patients with myopia had Zyoptix wavefront-guided LASIK in 1 eye and PlanoScan LASIK in the contralateral eye. The safety, efficacy, predictability, stability, optical zone size, and ablation depth were evaluated.The mean preoperative spherical equivalent (SE) of the subjective manifest refraction was -3.88 diopters (D) +/- 1.92 (SD) (Zyoptix) and -4.35 +/- 2.11 D (PlanoScan). Six months postoperatively, 8% of PlanoScan patients and 16% of Zyoptix patients gained at least 2 lines of best corrected visual acuity; the safety index was 1.12 in the Zyoptix group and 1.08 in the PlanoScan group. An SE of +/-1.00 D and +/-0.50 D was achieved by 100% and 92%, respectively, in both groups. There were 2 undercorrections in the Zyoptix group and 1 undercorrection in the PlanoScan group. In the Zyoptix group, 100% had a UCVA of 20/40 and 67% of 20/20 and in the PlanoScan group, 100% and 83%, respectively. The efficacy index was 0.87 and 0.93 in the Zyoptix group and PlanoScan group, respectively. The mean optical zone 6 months postoperatively was 6.16 +/- 0.34 mm in the PlanoScan group and 6.23 +/- 0.41 mm in the Zyoptix group (P =.67). The ablation depth per diopter of defocus equivalent was 13.5 +/- 4.6 microm/D and 8.6 +/- 4.4 microm/D, respectively (P =.01).An excellent safety index was achieved with the Zyoptix and PlanoScan treatments. The efficacy index was marginally lower for Zyoptix treatments as a result of 2 undercorrections. The ablation depth in the Zyoptix group per diopter of defocus equivalent was significantly lower than in the PlanoScan group. Further refinements in defining the ablation algorithms may increase the efficacy index.     

Laser in situ keratomileusis with a scanning excimer laser for the correction of low to moderate myopia with and without astigmatism

PURPOSE: To evaluate the safety and effectiveness of and patient satisfaction with laser in situ keratomileusis (LASIK) performed with a scanning excimer laser by experienced surgeons to correct low and moderate levels of myopia and astigmatism. SETTING: Clinique Laservue, Montreal, Quebec, Canada. METHODS: A consecutive series of 125 patients (236 eyes) with myopia of -0.5 to -7.0 diopters (D) and cylinder less than 2.5 D were enrolled in this single-center prospective clinical trial. The patients were treated with LASIK and followed for 6 months. The System-ALK Automated Corneal Shaper microkeratome (Bausch & Lomb Surgical) with a 180 microm thickness plate and the Technolas 217 excimer laser (Bausch & Lomb Surgical) with PlanoScan software for the stromal ablation were used in all procedures. Since this version of PlanoScan tended to undercorrect, a mean of 14.7% was added to the standard nomogram. Patient satisfaction was assessed by questionnaires administered preoperatively and 1 and 6 months postoperatively. Retreatments for enhancement were not performed during the 6-month follow-up. RESULTS: Six months after LASIK (86.4% follow-up), the mean postoperative manifest spherical equivalent was +0.02 D +/- 0.64 (SD) compared with a preoperative mean of -4.01 +/- 1.59 D. The uncorrected visual acuity was 20/40 or better in 94.6% of eyes and 20/20 or better in 81.9%. A total of 91.2% were within +/-1.0 D of emmetropia and 73.0% were within +/-0.5 D. Only 2 eyes were overcorrected by >1.0 D. Of the eyes with astigmatic myopia, 86.8% were within +/-1.0 D of the intended cylinder correction (by vector analysis) and 73.0% were within +/-0.5 D. The refractions were generally stable after 1 month, and the change in refraction between postoperative examinations was within +/-0.5 D in 88.0% of eyes. A 1-line decrease in best spectacle-corrected visual acuity was seen in 11.3% of eyes, and no eye lost more than 1 line. An increase of 1 or 2 lines was seen in 45.1%. No intraoperative problems occurred, and the interface was clear in all eyes. At 6 months, most symptoms present significantly more frequently than preoperatively were "mild"; none were "marked" or "severe." A total of 90.5% of eyes were reported with marked to extreme improvement in the overall quality of vision, and 99.0% of patients said they would choose LASIK surgery again. CONCLUSIONS: Mild to moderate myopia, with and without astigmatism, was corrected safely, effectively, and predictably with a high degree of patient satisfaction using LASIK with a scanning excimer laser and the System-ALK Automated Corneal Shaper.     

LASEK、PRK和LASIK治疗中低度近视的比较

目的对比分析准分子激光上皮下角膜磨镶术(LASEK)、碰光性角膜切削术(PRK)、激光原位角膜磨镶术(LASIK)治疗中低度近视临床疗效。方法LASEK组58例(112眼)随访3-9月,PRK、LASIK组各120眼随访1a以上,观察分析术后疼痛症状,裸眼视力及角膜混浊情况。结果术后1d出现疼痛症状:LASEK组:81眼(72.3％),PRK组120 眼(100.0％),LASIK组13眼(10.8％);术后3d裸眼视力≥0.8:LASEK组24眼(21.4％),PRK组27眼(22.5％),LASIK组113 眼(94.2％);术后3月存在角膜Haze:LASEK组31眼(27.6％)、PRK组94眼(78.3％),LASIK组0眼。结论LASEK后疼痛症状、角膜Haze明显减轻,疗效优于PRK;LASEK与LASIK相比没有角膜瓣相关并发症,早期视力恢复较慢。     

改良LASEK治疗中高度近视临床分析

目的探讨应用改良的上皮瓣制作方法施行准分子激光角膜上皮瓣下磨镶术（LASEK）治疗中度和高度近视的方法及临床结果分析。方法中度和高度近视368例（730眼），应用改良的上皮瓣制作方法一撕囊法。施行LASEK，观察术后上皮瓣的活性、症状、视力、屈光度、上皮下雾状浑浊（haze）发生率及屈光回退发生率。结果术后1～3天角膜透明、上皮完整、角膜瓣周缘吻合良好；术后屈光度及裸眼视力均在6月内趋于稳定；屈光回退于术后6月有35眼（4．79％），术后1年有36眼占（4．93％）；术后haze2周有206眼（28．20％），6月有85眼（11.59％）。结论改良的LASEK治疗中度及高度近视疗效确切而安全，上皮瓣存活良好，能降低haze及屈光回退的发生。     

Comparison of two procedures: photorefractive keratectomy versus laser in situ keratomileusis for low to moderate myopia

PURPOSE: A prospective study was conducted to compare the effectiveness, safety, and stability of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for correction of low to moderate myopia. METHODS: Forty-five patients with a manifest refraction (PRK, -4.54 +/- 0.80; LASIK, -4.82 +/- 1.10) from -1.50 to -6.00 diopters (D) were treated and followed-up for 6 months. In each case, 1 eye received PRK and the other LASIK. The first eye treated, and the surgical method used in the first eye, were randomized. Uncorrected and corrected visual acuity, manifest refraction, corneal haze, and topographic analysis of ablation decentration were examined. RESULTS: The uncorrected visual acuity was 20/20 or better in 35 PRK eyes (77.8%) and 28 LASIK eyes (62.2%) at 6 months (P =.107). At 6 months, 28 eyes (62.2%) that received PRK showed a spherical equivalent of within +/-0.5 D as compared with 24 eyes (53.4%) that received LASIK (P =.393). The amount of ablation decentration was 0.37 +/- 0.25 mm in PRK eyes and 0.49 +/- 0.38 mm in LASIK eyes at 3 months (P =.36). CONCLUSIONS: In our study, PRK and LASIK were found to be similarly effective and predictive of correction in low to moderate myopia. PRK has the advantage of less ablation decentration and is safer than LASIK, so we recommend PRK for eyes with low to moderate myopia.