Prospective randomized comparison of wavefront-guided and conventional photorefractive keratectomy for myopia with the meditec MEL 70 laser

PURPOSE: To study refractive results and aberrometric changes in myopic patients treated with wavefront-guided photorefractive keratectomy (PRK) in comparison with standard PRK. METHODS: Sixty eyes of 60 patients with myopic astigmatism were randomly divided into two groups. Group 1 included 30 eyes (mean spherical equivalent refraction -4.39 +/- 1.31 D; range -2.50 to -6.50 D) treated with wavefront-guided PRK using the WASCA workstation and the Asclepion Meditec flying spot MEL 70 excimer laser. Group 2 had 30 eyes (mean spherical equivalent refraction -4.33 +/- 1.22 D; range -2.50 to -6.50 D) that underwent conventional PRK using the same laser, and served as the control group. Wavefront analysis of high order aberrations was performed before and 6 months after surgery. RESULTS: Postoperatively, wavefront error increased in both groups (5.0-mm wavefront aperture diameter). Six months after surgery, the eyes that received the WASCA ablation had a smaller increase in root-mean-square (RMS; 70% of increment) compared to the conventional PRK group (139% of increment) (P<.001). In the standard PRK group, all aberrations notably increased; in the wavefront-guided PRK group there was a smaller increase of trefoil and spherical aberrations (P<.001) and a decrease of coma aberrations (P<.001). The smaller increase of wavefront error in the wavefront-guided PRK group compared to the standard PRK group was more evident when preoperative RMS values were higher than 0.4 microm (P<.01). The visual parameters (spherical equivalent refraction, uncorrected and best spectacle-corrected visual acuity) did not show significant differences between the two groups. CONCLUSION: Wavefront-guided PRK induced a smaller increase of postoperative wavefront-error compared to conventional PRK, particularly in patients with higher preoperative higher order aberrations.     

MEL-80治疗近视的准分子激光上皮下角膜磨镶术效果评价

目的评价使用蔡司MEL-80准分子激光治疗仪施行准分子激光上皮下角膜磨镶术（1aser-assisted subepithe-lial keratomileusis，LASEK）治疗近视和近视散光的预测性、有效性、安全性和稳定性。方法回顾性分析使用MEL-80准分子激光治疗系统行LASEK治疗近视和近视散光的连续性病例76例（150眼），于术后第1天、第1、第3、第6和第12个月定期随访，检查裸眼视力，以显然主觉验光检查术后屈光状态及最佳矫正视力。结果术后第10天、第1、第3、第6和第12个月时，裸眼视力平均值分别为4．91±0．15、4．97±0．26、5．05±0．37、5．12±0、20、4．96±0．24。预测性：术前屈光度等效球镜值为（-6．25±1．25）D，术后第3、第6和第12个月分别降到（＋0．12±0．42）D、（-0．03±0．23）D、（-0．15±0．36）D，术后第3、第6和第12个月屈光度变化量在＋0．50D以内的比例分别为94．6％、96．0％、97．3％。术后第3、第6和第12个月离焦等效球镜值在±0．50D内的眼数分别为88．0％、96．0％、96．6％。有效性：术后第3个月，24．0％的眼裸眼视力（uncor-rected visual acuity,UCVA）≥5．1，94．6％的眼UCVA≥5．0，97.3％的眼UCVA≥4．9。术后第6个月，36．0％的眼UCVA≥5．1．96．0％的眼UCVA≥5．0，98．6％的眼UCVA≥4．9。术后第12个月，38．0％的眼UCVA≥5．1，98．0％的眼UCVA≥5．0，98．6％的眼UCVA≥4．9。安全性：术后第3、第6、第12个月，均无任何一眼最佳矫正视力（best spectacle corrected vision acuity，BSCVA）下降2行以上；分别有34．6％、34．6％和30．0％的眼BSCVA提高1行；16．0％、17．3％和14．6％的眼BSCVA提高2行。稳定性：术后第3、第6、第12个月显然验光值等效球镜平均值变化小于1．00D。结论使用MEL-80的LASEK治疗近视和近视散光有良好的预测性、有效性、安全性和稳定性。     

Correction of myopia by PRK method with the use of MEL 80 excimer laser--initial report

PURPOSE: The aim of this study was to evaluate the effectiveness of PRK procedure by estimation: changes of visual acuity, refractive errors, IOP, pachymetry, high order aberrations before and after surgery. MATERIAL AND METHODS: In the First Department and Clinic of Ophthalmology Medical School 22 patients went through ophthalmological examination for PRK procedure. In this study we used MEL 80 excimer laser. There were 13 women (15 eyes) and 5 men (7 eyes). The myopia was corrected from -1.75D till -6.5D. The patients were from 22 to 41 years of age. RESULTS: The correction for myopia by PRK method with MEL 80 excimer laser is effective and safe laser procedure. Stabilization of the refraction post photorefractive keratectomy was after 2 months and there was no increase of intraocular pressure in all cases. The procedure increased the high order aberrations.     

Photorefractive keratectomy using the meditec MEL 70 G-scan laser for hyperopia and hyperopic astigmatism

PURPOSE: To evaluate the results of photorefractive keratectomy (PRK) using Gaussian flying spot technology in the treatment of hyperopia and hyperopic astigmatism. METHODS: Two hundred eyes were evaluated with 12-month follow-up. An Asclepion-Meditec MEL 70 G-scan flying spot ArF excimer laser with a Gaussian scanner was used (6.0-mm treatment zone and 9.0-mm transition zone). Eyes were divided into four groups: Group 1 (spherical hyperopia up to +3.50 D and astigmatism less than 1.00 D, n=62); Group 2 (hyperopia up to +3.50 D and astigmatism of 1.00 D or more, n=44); Group 3 (hyperopia greater than +3.50 D and astigmatism less than 1.00 D, n=56); and Group 4 (hyperopia greater than +3.50 D and astigmatism of 1.00 D or more, n=38). RESULTS: In Group 1, 82.2% (51/62 eyes) were within +/-0.50 D of target refraction; 88.7% (55/62 eyes) had 20/20 or better uncorrected visual acuity; 1.6% (1/62 eye) lost two or more lines, 3.2% (2/62 eyes) gained two or more lines of spectacle-corrected visual acuity. In Group 2, 68.1% (30/44 eyes) were within +/-0.50 D; 77.2% (34/44 eyes) had 20/20 or better uncorrected visual acuity; 9.1% (4/44 eyes) lost two or more lines of spectacle-corrected visual acuity. In Group 3, 76.8% (43/56 eyes) were within +/-0.50 D; 78.6% (44/56 eyes) had 20/20 or better uncorrected visual acuity; 5.4% (3/56 eyes) lost two or more lines of spectacle-corrected visual acuity. In Group 4, 42% (16/38 eyes) were within +/-0.50 D; 60.5% (23/38 eyes) had 20/20 or better uncorrected visual acuity; 15.8% (6/38 eyes) lost two or more Snellen lines. CONCLUSION: PRK with the flying spot Meditec MEL 70 G-scan was most safe and effective for low hyperopia.     

Outcomes of LASIK for myopia with FDA-approved lasers

PURPOSE: To report expected outcomes of laser in situ keratomileusis (LASIK) for myopia and myopic astigmatism from existing US Food and Drug Administration (FDA) data. METHODS: Data from Summaries of Safety and Effectiveness for each of the 12 lasers approved by the FDA for LASIK for myopia or myopic astigmatism between 1998 and 2004 were recorded from the FDA Web site. The Cochran-Armitage test for trend was used to determine whether improvements in outcomes occurred with laser technology changes. RESULTS: For all patients, there was a statistically significant trend toward improvement with improved laser technology in the proportion of patients with uncorrected visual acuity (UCVA) of 20/20 or better, UCVA of 20/40 or better, results within +/-0.50 D of intended correction, results within +/-1.00 D of the intended correction, and night vision symptoms (all P < 0.0002). Because there were preoperative differences across laser types, subgroup analyses were also completed. The results for subgroup analyses (high myopia, low to moderate myopia, spherical myopia, and myopic astigmatism) for visual acuity and refractive error outcomes were similar to results for analyses for all groups combined. Conversely, there was no difference across laser types in the proportion of patients who experienced dry eye symptoms or for the proportion of patients with low to moderate myopia who experienced night vision symptoms that were worse or significantly worse than before LASIK. CONCLUSIONS: LASIK provides excellent visual acuity and refractive error outcomes. Night vision and dryness symptoms still occur in a significant proportion of patients. Future studies should seek to determine whether additional changes in technology, patient selection criteria, or postoperative treatment could reduce or eliminate these symptoms.     

Mesopic vision after LASIK for myopia

Fragestellung: Bisher liegen keine Erfahrungen über das D?mmerungssehverm?gen nach LASIK vor. Wir untersuchten daher das D?mmerungssehen vor und nach LASIK zur Korrektur der Myopie.     

Mesopic vision after LASIK for myopia

Fragestellung: Bisher liegen keine Erfahrungen über das D?mmerungssehverm?gen nach LASIK vor. Wir untersuchten daher das D?mmerungssehen vor und nach LASIK zur Korrektur der Myopie. Patienten und Methode: 34 Patienten (67 Augen), die mit dem Automatic Corneal Shaper und dem Keracor 117CT Excimer Laser operiert wurden und pr?operativ einen korrigierten Visus von 0,8 erreichten. Wir untersuchten pr?operativ und 1 Jahr postoperativ die Refraktion, den Visus und das D?mmerungssehverm?gen ohne und mit Blendung (Nyktometer, Fa. Rodenstock) in Abh?ngigkeit von der Ausgangsrefraktion in drei Gruppen und verglichen den Anteil der Patienten, die einen Kontrast von 1 : 5 oder geringer erkannten. Ergebnisse: Myopie −1 bis −5 dpt (Gruppe 1; n = 26): Pr?operativ (postoperativ) erkannten ohne Blendung 89 % (96 %) (nur hier signifikanter Unterschied; p = 0,03) und mit Blendung 65 % (73 %) die Kontraststufe 1 : 5. Myopie −5,1 bis −10 dpt (Gruppe 2; n = 24): Pr?operativ (postoperativ) erkannten ohne Blendung 83 % (75 %) und mit Blendung 50 % (21 %) die Kontraststufe 1 : 5. Myopie −10,1 bis −15 dpt (Gruppe 3; n = 11): Pr?operativ (postoperativ) erkannten ohne Blendung 73 % (55 %) und mit Blendung 46 % (27 %) die Kontraststufe 1 : 5. Schlu?folgerung: Nach LASIK scheint es für Korrekturen von mehr als −5 Dioptrien zu einer Verschlechterung des D?mmerungssehverm?gens unter Blendung zu kommen. Bei Korrekturen ab −10 dpt verschlechtert sich auch das D?mmerungssehen ohne Blendung. Allerdings waren die Unterschiede nicht statistisch signifikant. Zudem ist das D?mmerungssehen bereits pr?operativ bei h?herer Myopie erheblich reduziert.      

飞秒激光制瓣再次LASIK治疗LASIK术后近视的临床疗效观察

目的 探讨飞秒激光辅助制作角膜瓣再次LASIK治疗LASIK术后近视患者的临床疗效.方法 选择因LASIK术后近视患者40例(80眼),进行飞秒激光辅助制作角膜瓣再次行LASIK,术后予以药物治疗.观察并记录术后6个月患者的裸眼视力、屈光度、波前像差和对比敏感度(contrast sensitivity function,CSF)、眩光CSF,并与术前相比较.结果 术后6个月裸眼视力为1.07 ±0.11较术前0.10 ±0.05显著提高(P＜0.05).术后6个月屈光度为(-0.23 ±0.54)D较术前(-2.37±0.77)D显著改善(P＜0.05).术后6个月高阶像差为0.52±0.18与术前0.50±0.18相比差异无统计学意义(P＞0.05).术后6个月CSF在6.0c·d-1对数为1.80±0.11比术前1.62 ±0.12显著改善(P＜0.05);在18.0 c·d-1对数为1.25±0.08,比术前0.91±0.09显著改善(P＜0.05).术后6个月眩光CSF在18.0 c·d-1对数为1.02±0.09,较术前(0.55±0.08)显著改善(P＜0.05).结论 飞秒激光辅助制作角膜瓣再次LASIK可安全有效地治疗LASIK术后近视.     

角膜瓣蒂在上方的LASIK治疗近视

目的：观察角膜瓣蒂部位于上方角膜的LASIK治疗不同屈光度近视的效果。方法：利用准分子激光器联合微形角膜刀对131例（258眼）进行治疗。按屈光度不同（-8.0D以下,-8.0--15.0D,-15.0D以上）分为3组,该刀前进轨道呈环形,切削角膜瓣后蒂部位于上方,术后6月观察视功能、屈光度及并发症。结果：术后6个月裸眼视力3组达到0.5以上分别为97.8%、93.2%、55.6%,达到1.0以上分别为88.8%、80.7%、19.4%,术后4-6月屈光度趋于稳定。手术并发症包括角膜上皮脱落。层间异物残留等,结论：LASIK对不同屈光度近视治疗均有良好效果。角膜瓣蒂部位于上方比位于鼻侧的术后并发症可能比较少发生。     

Photorefractive keratectomy for myopia with the Meditec MEL 70G-Scan flying spot laser

PURPOSE: To evaluate the efficacy, predictability, stability, and safety of the Meditec MEL 70G-Scan flying spot excimer laser. METHODS: One hundred thirty myopic eyes were treated with the Aesculap Meditec Mel 70G-Scan ArF flying spot excimer laser with photorefractive keratectomy (PRK). Patient groups: low myopia (Group 1) from -1.50 to -6.00 D (90 eyes), medium myopia (Group 2) from -6.10 to -9.00 D (31 eyes), high myopia (Group 3) from -9.10 to -14.00 D (9 eyes). RESULTS: At 12 months in the low myopia group, uncorrected visual acuity (UCVA) of 20/40 or better was achieved in 95.5% (86 eyes), 20/20 or better in 77.7% (70 eyes); 2.2% (two eyes) lost two or more lines of best spectacle-corrected visual acuity (BSCVA); 73.3% (66 eyes) were within +/-0.50 D of the target correction and 98.8% (89 eyes) were within +/-1.00 D. In the medium myopia group, UCVA of 20/40 or better was achieved in 74.2% (23 eyes), 20/20 or better in 25.8% (eight eyes); 3.2% (one eye) lost two lines, 61% (19 eyes) were within +/-0.50 D of desired correction and 83.8% (26 eyes) were within +/-1.00 D. In the high myopia group, UCVA of 20/40 or better was achieved in 22.2% (two eyes); 20/25 or better in 11.1% (one eye); none of the eyes achieved 20/20 UCVA; 22.2% (two eyes) lost two lines of BSCVA; 44.4% (four eyes) were within +/-0.50 D and 66.6% (six eyes) were within +/-1.00 D of the target correction. Refractive stability was achieved between 3 and 6 months. Increased intraocular pressure was detected overall in 7.69%. CONCLUSIONS: The results of predictability, safety, and efficacy in low and medium myopia with the Meditec MEL 70G-Scan flying spot excimer laser were good, but poorer predictability, regression, and a significant loss of BSCVA were observed in the high myopia group.     

Flap lift for LASIK retreatment in eyes with myopia

PURPOSE: To analyze the results achieved with LASIK retreatment after lifting the original flap in a large series of patients. DESIGN: Retrospective, noncomparative, interventional consecutive case series. PARTICIPANTS: Two thousand four hundred twenty-two consecutive eyes undergoing LASIK surgery for myopia, including 334 eyes submitted to flap lift for LASIK retreatment. MAIN OUTCOME MEASURES: Uncorrected visual acuity, best-corrected visual acuity, refractive error, and complications. RESULTS: LASIK retreatment was performed in 334 eyes (14%), and the mean time between initial procedure and retreatment was 8.2+/-6.2 months. The mean spherical equivalent (SE) improved from -1.2+/-0.6 diopters (D) (range, -4.2 to +1.2 D) before retreatment to +0.2+/-0.4 D (range, -3.1 to +1.1 D) after the retreatment. The uncorrected visual acuity (UCVA) after retreatment was 20/20 or better in 58% and 20/40 or better in 92% of eyes. The mean SE was within +/-1.0 D in 96% of the patients and within +/-0.5 D in 80.5% after retreatment. Eighteen eyes (5%) lost 1 line of best-corrected visual acuity, and 4 eyes (1%) lost 2 lines. CONCLUSIONS: LASIK retreatment surgery performed by relifting the flap was a useful procedure for correcting residual refractive errors after the primary LASIK procedure. It provided good uncorrected visual acuity, predictable results, good refractive stability, and few complications.     

不同准分子激光治疗仪对角膜组织切削深度预测性的评价

目的 评价蔡司 MEL80和威视VISX Star S4两种准分子激光治疗仪切削深度的预测性.设计前瞻性对比研究.研究对象84例（168眼）近视及散光患者.方法 采用眼前节OCT分别测量两种激光仪治疗前后患者的角膜厚度,计算实际切削量,与相应仪器显示的预计切削量比较,并对其差异值作回归分析.主要指标角膜厚度、切削深度.结果 蔡司MEL80实际切削量与预计切削量比较,差异无统计学意义.威视VISX Star S4实际切削量大于预计切削量,在中度近视组和高度近视组差异有统计学意义.△切削量为实际切削量与预计切削量的差值,威视△切削量与近视、散光相关分析,r=0.643,P=0.000,具有高度相关性.其回归方程为：△切削量（VISX Star S4）=2.324 ＊｜近视｜＋5.270＊｜散光｜-6.772.结论 不同的准分子激光治疗仪其预测切削深度与实际深度存在差异,临床医师需掌握其特点,以提高LASIK手术的安全性. 关     

准分子激光角膜原位磨镶术治疗高度近视合并中高度散光

目的:观察准分子激光原位角膜磨镶术(LASIK)治疗高度近视合并中高度散光的临床疗效。方法:采用准分子激光原位角膜磨镶术治疗43例(79眼)高度近视合并中高度散光患者,屈光度为-6.0～-15.5D,散光为-2.0～-5.0D。结果:术后随访6mo,裸眼视力≥术前矫正视力者占91%,屈光度在±0.75D以内者占86%,残留散光平均为-0.45D。结论:LASIK治疗高度近视伴中高度散光,效果明显,安全可靠。     

分区切削模式在LASIK治疗超高度近视的应用

目的评价对角膜相对较薄的超高度近视,应用分区切削模式进行LASIK治疗的临床效果。方法对95例(185眼)超高度近视,因选择6.0 mm直径的切削区,剩余角膜厚度小于250μm,而进行LASIK分区切削治疗,分区切削分为2～3区,切削光区4.7～6.0 mm。随访时间6～20月,观察手术前后的屈光状态、裸眼视力、矫正视力、角膜地形图及并发症的发生情况。结果术后1月视力达到最好并趋于稳定,所有患者的裸眼视力均较术前提高,术后3月183眼(98.92%)裸眼视力超过或等于术前最佳矫正视力。屈光回退47眼(25.41%),术后眩光51眼(27.57%),分析手术后角膜地形图,切削过度区光滑,无偏心切削。与标准手术相比可节省角膜厚度20%～25%,视力、屈光度变化与分区多少及近视度数有关。少数患者出现的眩光、夜视力下降等并发症,1个月后减轻或消失,角膜地形图均为正常负性形态。结论LASIK分区切削模式是对角膜相对较薄的超高度近视进行激光治疗有效安全的方法。可节省角膜组织,具有安全可靠,稳定性、可预测性强的临床效果。     

Rhegmatogenous retinal detachment after LASIK for myopia

PURPOSE: To report the characteristics and incidence of rhegmatogenous retinal detachment in myopic eyes after LASIK. METHODS: The medical records of 49 patients with rhegmatogenous retinal detachment after LASIK were reviewed. The incidence of rhegmatogenous retinal detachment after LASIK was determined and potential risk factors were evaluated. RESULTS: LASIK was performed on 59,424 eyes with spherical equivalent refraction (SE) ranging from -0.75 to -26.50 diopters (D) (mean: -6.10 +/- 3.5 D). Forty-nine eyes developed rhegmatogenous retinal detachment between 1.5 and 76 months (mean: 27.3 +/- 21.7 months) after LASIK. The mean preoperative refractive error in these eyes was -8.6 +/- 3.9 D. Mean age of these patients was 38.2 +/- 11.2 years. Thirty-five (71.4%) patients were male. The cumulative incidence of rhegmatogenous retinal detachment was 0.082% (95% confidence interval [CI]: 0.061-0.109), and the yearly incidence was 0.032% (95% CI: 0.023-0.042) after LASIK. The most frequent location of the retinal breaks was the superior temporal quadrant (22.7%). Male sex, older age, and higher preoperative myopia were significantly related to the incidence of rhegmatogenous retinal detachment after LASIK (P<.001). CONCLUSIONS: Based on the results of this study, following the treatment of high-risk peripheral retinal lesions, LASIK did not appear to be an additional risk factor for the development of rhegmatogenous retinal detachment after LASIK in our patients; however, patients should be informed of the possibility of this complication as a consequence of myopia. Patients who are male, older in age, and have high myopia preoperatively may be at increased risk.