非球面切削准分子激光角膜屈光手术的早期临床观察膊

目的 前瞻性研究非球面切削引导准分子激光角膜屈光手术的临床疗效.方法 将球镜-6.00D以下,柱镜0.00～2.00D的近视患者随机分成2组,Q调整组32例64眼行非球面切削引导准分子激光角膜屈光手术,对照组32例64眼行传统准分子激光原位角膜磨镶术(LASIK).观察术后裸眼视力,残余屈光度,高阶像差中的慧差、球差、总高阶像差均方根增加值和满意度等指标.结果 术后裸眼视力和残余屈光度两组比较差异无统计学意义,但Q调整组高阶像差的增加较对照组小,差异有统计学意义(P＜0.05).术后Q调整组患者的满意度情况比较,两组差异有统计学意义(P＜0.05).结论 非球面切削引导准分子激光角膜屈光手术可以减少术后角膜波面像差的增加,尤其是减少球差增加,明显改善视觉质量.     

非球面切削准分子激光角膜屈光手术的早期临床观察

目的前瞻性研究非球面切削引导准分子激光角膜屈光手术的临床疗效。方法将球镜-6.00D以下,柱镜0.00～2.00D的近视患者随机分成2组,Q调整组32例64眼行非球面切削引导准分子激光角膜屈光手术,对照组32例64眼行传统准分子激光原位角膜磨镶术（LASIK）。观察术后裸眼视力,残余屈光度,高阶像差中的慧差、球差、总高阶像差均方根增加值和满意度等指标。结果术后裸眼视力和残余屈光度两组比较差异无统计学意义,但Q调整组高阶像差的增加较对照组小,差异有统计学意义（P〈0.05）。术后Q调整组患者的满意度情况比较,两组差异有统计学意义（P〈0.05）。结论非球面切削引导准分子激光角膜屈光手术可以减少术后角膜波面像差的增加,尤其是减少球差增加,明显改善视觉质量。     

角膜波面像差引导准分子激光原位角膜磨镶术(ORK-W)治疗近视临床研究

目的前瞻性研究角膜波面像差引导准分子激光原位角膜磨镶术(ORK-W)治疗近视临床效果。方法将球镜-8.00D以下,柱镜0.00D-3.00D的近视患者随机分成2组,实验组36例72眼行角膜波面像差引导准分子激光个体化切削(ORK-W),对照组30例(60只眼)行常规LASIK。观察术后1m裸眼视力、残余屈光度,角膜波面像差中的慧差、球差及总像差均方根RMS增加值,对比敏感度的改变,满意度等指标。结果术后裸眼视力、残余屈光度和满意度两组比较差异无统计学意义(P>0.05);但实验组角膜波面像差(慧差、球差、均方根RMS)的增加均较对照组明显小,两组差异有统计学意义(P<0.05),对比敏感度的改善较对照组也明显的好,两组差异有显著统计学意义(P<0.01)。结论角膜波面像差引导准分子激光个体化切削(ORK-W)可以减少术后角膜波面像差的增加,尤其减少慧差增加效果更明显,明显改善视觉质量。     

SMILE手术光学区大小对像差的影响#br#

目的 探讨微小切口角膜基质透镜取出术（SMILE）不同大小光学区对术后3个月内视力及高阶像差的影响。设计 前瞻性比较病例系列。研究对象31例行SMILE手术的患者。所有患者均选择右眼做为研究对象。方法 全部患者由同一位医生采用相同设备行SMILE手术，手术序号单号的患者术中光学区大小为6.0 mm进行切削，双号患者术中光学区大小为6.5 mm进行切削。观察3个月，检查术后裸眼视力、等效球镜度数和像差变化。主要指标 术后视力、屈光度、高阶像差，包括均方根值（RMSh）、慧差（Coma）、三叶草（Trefoil）、球差（Sphere）。结果 术后3个月，6.0 mm组 和6.5 mm组平均视力分别为1.20±0.23和1.24±0.20（P=0.534）；平均等效球镜分别为（-0.45±0.32）D和（-0.29±0.42）D（P=0.235）；RMSh分别为（0.683±0.324）μm和（0.621±0.252）μm（P=0.646）；Coma分别为（0.124±0.080）μm和（0.100±0.052）μm（P=0.057）；Trefoil分别为（0.060±0.033）μm和（0.061±0.041）μm（P=0.147）；Sphere分别为（0.007±0.040）μm和（-0.002±0.032）μm（P=0.223）。6.5 mm组术后Coma与术前Coma（0.073±0.050 μm）相比略增加（P=0.065），而6.0 mm组术后Coma与术前（0.075±0.050 μm）相比显著增加（P=0.004）。结论 6.0 mm和6.5 mm光学区SMILE术均安全有效， 虽然较小光学区（6.0 mm）可能导致慧差增加，但不会引起其他高阶像差的增加。     

波前像差手术与传统手术的切削深度比较

目的:探讨波前像差手术时角膜切削深度与传统手术切削深度的比较。方法:应用波前像差仪对648例近视度数-2.00～-10.00DS,散光0.00～-2.50DC的患者进行检查并设计手术,得出最大切削深度值。并与相应的常规LASIK角膜切削深度进行比较。结果:无散光患者,波前像差引导的LASIK手术的切削深度与常规手术之间基本没有差异。散光对切削深度有一定影响,屈光度越小,散光对切削深度的影响越大,屈光度越大,散光对切削深度的影响反而越小。光学区越大,则切削深度就越深,此时散光的变化对切削深度的影响也越明显。结论:波前像差手术对角膜切削深度的影响主要与光学区大小和散光大小有关。     

非球面切削LASEK和LASIK治疗不同厚度角膜的高度近视

目的 探讨角膜波前像差联合Q值优化的非球面切削准分子激光上皮下角膜切削术(LASEK)与角膜波前像差联合Q值优化的非球面切削准分子激光原位角膜磨镶术(LASIK),分别治疗角膜薄(<500μm)和角膜厚(>500μm)的高度近视的临床疗效比较.方法 选取角膜厚度薄的高度近视患者行LASEK治疗25例(42只眼),角膜厚的高度近视患者38例(65只眼),比较术前视力、年龄、角膜厚度、切削厚度、剩余角膜厚度、等效球镜度、球差、慧差、总阶像差,术后2周,4周,3月,6月的视力,比较术后6月两组视力、等效球镜度、球差、慧差、总阶像差、HAZE等级.结果 两种手术方式术后6月内的视力,术后6月的等效球镜度、球差、慧差、总阶像差均无统计学意义,治疗高度近视具有相同均具有很高的安全性、有效性及可预测性且两组具有相同的临床疗效.结论 非球面切削的LASEK治疗角膜薄的高度近视与非球面切削的LASIK治疗角膜厚的高度近视具有相同的临床疗效.     

LASIK后角膜高阶像差改变分析

目的 探讨近视LASIK术后角膜高阶像差的变化情况.方法 回顾性分析近视LASIK手术患者75例145只眼,比较患者术前术后角膜非球面系数(Q值)、总体高阶像差均方根值(RMSh)、3～7阶像差均方根值(RMS3-RMS7)、球差、慧差、三叶草像差等数值,用多元线性回归分析筛选引起术后角膜高阶像差改变的因素.结果 术前角膜高阶像差与年龄无相关关系;术后各观察值的大小主要受术前相应各数值的大小、预矫屈光度数、切削区大小等因素的影响,术前值越大、预矫屈光度越大以及切削区越小,术后角膜高阶像差值越大;术后Q值、RMSh以及球差的增加量主要受预矫屈光度数和切削区大小的影响;慧差以及三叶草像差的增加与切削区大小无关.使用较小切削区(5.25mm)时的单位屈光度矫正引起的高阶像差增加值以及角膜前表而非球面系数改变值高于使用较大切削区时,差异有统计学意义.结论 LASIK术后角膜高阶像差增大,预矫屈光度数高和切削区小是引起术后角膜高阶像差增加较大的主要原因.     

角膜塑形术后光学治疗区大小及偏心对光学及视觉质量的影响

目的：分析角膜塑形镜配戴后角膜高阶像差、对比敏感度的变化,以及光学治疗区大小及偏心对二者的影响。方法：前瞻性临床研究。选取2017年3-8月于温州医科大学附属第三医院验配角膜塑形镜的近视儿童31例（31眼）,测量戴镜前及戴镜1个月后的角膜地形图、对比敏感度、角膜高阶像差,分析光学治疗区大小及偏心情况对角膜高阶像差、对比敏感度变化的影响。对比敏感度以对比敏感度函数对数曲线下面积（AULCSF）衡量大小。采用配对t检验、Pearson相关分析、逐步多项线性回归分析等方法进行统计。结果：角膜塑形镜配戴1个月后,光学治疗区直径（3.48±0.49）mm,偏心距离（0.64±0.27）mm,偏心方向以颞下方为主（45%）。角膜总高阶像差、球差、垂直彗差、水平彗差均较配戴前明显增加（t=10.99、10.19、-2.21、-3.50,P<0.05）;光学治疗区垂直偏心距离（标准化B=0.620,P=0.001）和水平偏心距离（标准化B=0.422,P=0.049）分别是影响角膜垂直彗差增加量和水平彗差增加量的唯一因素。配戴1个月后亮环境及暗环境AULCSF有下降趋势,但与戴镜前相比无差异无统计学意义;亮环境AULCSF下降幅度与屈光度改变量有关（标准化B=0.452,P=0.021）,而暗环境AULCSF下降幅度则与屈光度改变量（标准化B=0.528,P=0.004）、偏心距离（标准化B=0.458,P=0.027）均相关。结论：角膜塑形镜偏心会导致角膜高阶像差增加,但对对比敏感度影响不大。     

波前像差联合Q值优化的非球面切削治疗中低度近视的临床研究

目的:探讨波前像差引导联合Q值优化的非球面切削的准分子激光原位角膜磨镶术(laser in situkeratomileusis,LASIK)治疗中低度近视眼的临床疗效。方法:随机选取欲行LASIK治疗的符合条件的中低度近视患者158例进行前瞻性研究,分别对40眼使用波前像差联合非球面切削程序(A组),38眼使用Q值优化的非球面切削程序(B组),39眼使用波前像差程序(C组),41眼使用标准切削进行LASIK手术(D组),比较术前和术后1,3,6mo的波前像差值、裸眼视力、最佳矫正视力和验光值。结果:158例研究对象中所有患者手术均成功,在术后6mo随访期间无1例患者发生严重的并发症,4组间比较手术的精确性、安全性、有效性无统计学差异(P>0.05);术后6moA组总高阶像差均方根值和球差均方根值较其它3组小。结论:与标准的LASIK、单独使用波前像差或Q值优化的非球面切削技术相比波前像差引导联合Q值优化的非球面切削的LASIK手术更能有效地减少术后高阶像差的增加、改善术后视觉质量。     

ORK-CAM引导准分子激光非球面切削个体化术优化设计方案的临床验证

目的 评价ORK-CAM引导的准分子激光非球面切削个体化手术优化设计方案的有效性和安全性.方法 选取2003年和2008年在广州市第一人民医院激光中心就诊的平均等效球镜度、角膜像差没有明显差异的近视患者300例分为两组,其中优化方案组150例(300只眼)接受ORK-CAM引导的非球面个性化切削手术,传统方案组150例(300只眼)接受传统LASIK手术.进行两组患者术前和术后6个月裸眼视力、残余等效球镜度、角膜像差和Q值的比较.结果 术后6个月,2组患者裸眼视力差异无统计学意义(P＞0.05).术后6个月,2组患者术后残余等效球镜度均减少,但两组间变化值比较差异无统计学意义(均P ＞0.05);两组患者角膜总体阶像差均方根值(RMS)、三阶像差均方根值(RMS3)、四阶像差均方根值(RMS4)、球差、慧差和Q值均增加,但优化方案组的增幅小于传统方案组,均P ＜0.05.结论 ORK-CAM引导的准分子激光非球面切削个体化手术优化设计方案能提高手术的有效性和安全性,能改善术后的视觉质量.     

Comparative study of ablation profiles of six different excimer lasers

PURPOSE: To compare the morphological features of photorefractive ablations produced by six different excimer lasers. METHODS: A spherocylindrical photoablation (-2.00 -2.00 x 90 degrees; 6-mm optical zone) was performed on regular fluence plates with six excimer lasers: Bausch & Lomb Technolas 217C, Schwind Esiris, Kera Technology Isobeam D200, Ladarvision 4000, Zeiss Meditec MEL 70 G-Scan, and Visx Star S3. Morphometric analysis of the fluence plates provided superficial measurements of the ablated areas. RESULTS: Two areas were identified visually: a central area with a complete ablation of the metallic surface layer and a surrounding area with a partial ablation. The dimensions of the ablated areas were highly variable in the lasers tested. The major differences appeared in the total ablated area (ranging from 38.55 mm2 [Schwind] to 81.94 mm2 [Bausch & Lomb] and in the peripheral to total area ratio (ranging from 36.95% [Schwind] to 59.51% [Ladarvision]). CONCLUSION: Large differences appeared in the superficial dimensions and contours of the ablations produced by different excimer lasers for the treatment tested in this study. It remains unknown how these different ablation patterns induce the same optical correction, but we assume that the depth of the ablation compensates for the differences in the surface extension of the ablated areas.     

Conservation of corneal tissue with wavefront-guided laser in situ keratomileusis

PURPOSE: To determine whether corneal tissue can be conserved with wavefront-guided ablation compared to conventional surgery with a larger ablation zone for attempted prevention of glare and halo. SETTING: Department of Ophthalmology, Ilsan Paik Hospital, Inje University, Korea. METHODS: This prospective study was composed of 2 parts: First, 40 eyes of 20 patients were studied to determine whether a larger optical ablation could be beneficial in prevention of glare after conventional laser in situ keratomileusis (LASIK) surgery. One eye in each patient was treated with a 6.00 mm optical zone, and the other with a 6.25 mm optical zone. Second, 20 eyes of 10 patients with a higher-order root mean square (RMS) value of 0.3 or greater were evaluated to learn whether a wavefront-guided ablation could be as effective as a larger conventional optical ablation. One eye in each patient was treated by conventional LASIK surgery with a 6.25 mm optical zone, and the other eye was treated by wavefront-guided LASIK surgery with a 6.00 mm optical zone. All patients were analyzed with a WASCA analyzer (Carl Zeiss Meditec) preoperatively, and 1 month and 3 months after surgery. RESULTS: Higher-order aberrations including coma, spherical aberration, and higher-order RMS were statistically significantly increased after conventional surgery with both a 6.00 mm and 6.25 mm optical zone. High-order aberrations including comaer- and spherical aberration after conventional surgery with 6.25 mm zone were statistically significantly increased. However, coma and higher-order RMS did not show a statistically significant increase between pre-LASIK and post-LASIK in wavefront-ablated eyes with a 6.00 mm optical zone. CONCLUSION: Wavefront ablation showed less increase of coma and higher-order RMS regardless of a smaller optical zone. This finding might provide a clinical clue for an advantage of wavefront-guided ablation from the standpoint of corneal tissue conservation.     

Nomogram considerations with the Technolas 217A for treatment of myopia

PURPOSE: To determine whether surgeon-specific nomogram adjustments are useful when using the Technolas 217A excimer laser for treating myopia and myopic astigmatism. METHODS: We conducted a prospective evaluation of 216 consecutive eyes with 6 months follow-up after treatment of myopia or myopic astigmatism with the Technolas 217A laser. Attempted vs. achieved change in refraction was analyzed with a statistical analysis software program. Factors such as age, corneal thickness (pachymetry), preoperative spherical equivalent refraction, preoperative cylinder, and optical zone were studied to evaluate their role in predicting refractive outcome at 6 months after LASIK. RESULTS: The mean value of attempted spherical equivalent refraction was -5.32 +/- 2.72 D. The mean achieved refractive correction at 6 months was -5.55 +/- 2.78 D, with a mean spherical equivalent of 0.13 +/- 0.54 D. The percent achieved effect at 1 month was 105%, and at 6 months, 103%. Preoperative spherical equivalent refraction and optical zone size were strong predictors of 6-month LASIK outcome. There was a 9% difference in the percent achieved effect between a 4 and 7-mm optical zone. There was no correlation between age, preoperative cylinder, or surgeon and 6-month outcome. CONCLUSIONS: Surgeons using the planoscan software on the Technolas 217A may experience a small initial overcorrection. There may be a benefit to reducing the treatment given with larger optical zones and smaller corrections.     

Clinical outcome of wavefront-guided laser in situ keratomileusis in eyes with moderate to high myopia with thin corneas

PURPOSE: To evaluate the clinical outcome of wavefront-guided laser in situ keratomileusis (LASIK) for the treatment of moderate to high myopia associated with a thin cornea. SETTING: Enaim Laser Medical Center, Tel Aviv, Israel. METHODS: This retrospective study included 98 eyes of 49 patients with moderate to high myopia (-5.20 to -10.35 diopters [D]) and thin corneas (456 to 498 mum) treated with wavefront-guided LASIK (Zyoptix, Bausch & Lomb) and followed for 36 months. Preoperative wavefront analysis was performed with a Hartmann-Shack aberrometer, and treatment was performed with the Technolas 217 z excimer laser system (Bausch & Lomb). Final refraction data, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), optic zone size, ablation depth, optical aberrations, and night glare complaints were evaluated. RESULTS: Mean patient age was 28 years +/- 7 (SD), and mean preoperative spherical equivalent refraction was -7.06 D (range -5.20 to -10.35 D). Final UCVA ranged between 6/6 and 6/30. The safety index of the technique was 1.03, and the efficacy index was 0.67. Undercorrection of more than 0.50 D was observed in 41.3% of the high-myopic eyes (-7.00 to -10.35 D, n = 58) compared with 10% in the moderately myopic eyes (-5.00 to -6.75 D, n = 40). A significant reduction in spherical aberration (Z(4)0) was found 12 months postoperatively in all eyes. Night glare was documented in 4 eyes (4%) in the high myopia group. There were no cases of corneal ectasia. CONCLUSION: Zyoptix was safe in eyes with moderate to high myopia with relatively thin corneas (<498 microm). For myopia between -7.00 D and -10.35 D, a small optical zone (4.3 to 5.6 mm) may be applied as night glare was relatively rare, but significant undercorrection should be expected.     

Aberrations induced in wavefront-guided laser refractive surgery due to shifts between natural and dilated pupil center locations

PURPOSE: To determine the aberrations induced in wavefront-guided laser refractive surgery due to shifts in pupil center location from when aberrations are measured preoperatively (over a dilated pupil) to when they are corrected surgically (over a natural pupil). SETTING: Center for Visual Science and Department of Ophthalmology, University of Rochester, Rochester, New York, USA. METHODS: Shifts in pupil center were measured between dilated phenylephrine hydrochloride (Neo-Synephrine [2.5%]) and nonpharmacological mesopic conditions in 65 myopic eyes treated with wavefront-guided laser in situ keratomileusis (Technolas 217z, Bausch & Lomb). Each patient's preoperative and 6-month postoperative wave aberrations were measured over the dilated pupil. Aberrations theoretically induced by decentration of a wavefront-guided ablation were calculated and compared with those measured 6 months postoperatively (6.0 mm pupil). RESULTS: The mean magnitude of pupil center shift was 0.29 mm +/- 0.141 (SD) and usually occurred in the inferonasal direction as the pupil dilated. Depending on the magnitude of shift, the fraction of the higher-order postoperative root-mean-square wavefront error that could be due theoretically to pupil center decentrations was highly variable (mean 0.26 +/- 0.20 mm). There was little correlation between the calculated and 6-month postoperative wavefronts, most likely because pupil center decentrations are only 1 of several potential sources of postoperative aberrations. CONCLUSIONS: Measuring aberrations over a Neo-Synephrine-dilated pupil and treating them over an undilated pupil typically resulted in a shift of the wavefront-guided ablation in the superotemporal direction and an induction of higher-order aberrations. Methods referencing the aberration measurement and treatment with respect to a fixed feature on the eye will reduce the potential for inducing aberrations due to shifts in pupil center.     

Q-factor customized ablation profile for the correction of myopic astigmatism

PURPOSE: To compare the results of the Q-factor customized aspheric ablation profile with the wavefront-guided customized ablation pattern for the correction of myopic astigmatism. SETTING: Institute for Refractive and Ophthalmic Surgery, Zurich, Switzerland. METHODS: Thirty-five patients were enrolled in a controlled study in which the nondominant eye was treated with the Q-factor customized profile (custom-Q study group) and the dominant eye was treated with wavefront-guided customized ablation (control group). Preoperative and 1-month postoperative high-contrast visual acuity, low-contrast visual acuity, and glare visual acuity, as well as aberrometry and asphericity of the cornea, were compared between the 2 groups. All eyes received laser in situ keratomileusis surgery, and the laser treatment was accomplished with the Wavelight Eye-Q 400 Hz excimer laser. RESULTS: For corrections up to -9 diopters (D) of myopia, there were no statistically significant differences between the 2 groups regarding any visual or optical parameter except coma-like aberrations (3rd Zernike order), where the wavefront-guided group was significantly better 1 month after surgery (P = .002). For corrections up to -5 D (spherical equivalent), the Q-factor optimized treated eyes had a significantly smaller shift toward oblate cornea: DeltaQ15 = 0.25 in Q-factor customized versus DeltaQ15 = 0.38 in wavefront-guided treatment (P = .04). CONCLUSIONS: Regarding safety and refractive efficacy, custom-Q ablation profiles were clinically equivalent to wavefront-guided profiles in corrections of myopia up to -9 D and astigmatism up to 2.5 D. Corneal asphericity was less impaired by the custom-Q treatment up to -5 D of myopia.     

Analysis of customized corneal ablations: theoretical limitations of increasing negative asphericity

PURPOSE: To determine the ablation depths of customized myopic excimer laser photoablations performed to change corneal asphericity after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). METHODS: A mathematical model of aspheric myopic corneal laser surgery was generated. The initial corneal surface was modeled as a conic section of apical radius R(1) and asphericity Q(1). The final corneal surface was modeled as a conic section of apical R(2) and asphericity Q(2), where R(2) was calculated from the paraxial optical formula for a given treatment magnitude (D), and Q(2) was the intended final asphericity. The aspheric profile of ablation was defined as the difference between the initial and final corneal profiles for a given optical zone diameter (S), and the maximal depth of ablation was calculated from these equations. Using the Taylor series expansion, an equation was derived that allowed the approximation of the central depth of ablation (t(0)) for various magnitudes of treatment, optical zone diameters, and asphericity. In addition to the Munnerlyn term (M), incorporating Munnerlyn's approximation (-D small middle dot S(2)/3), the equation included an asphericity term (A) and a change of asphericity term (Delta). This formula (t(0) = M + A + Delta) was used to predict the maximal depth of ablation and the limits of customized asphericity treatments in several theoretical situations. RESULTS: When the initial and final asphericities were identical (no intended change in asphericity; Q(1) = Q(2); Delta = 0), the maximal depth of ablation (t(0) = M + A) increased linearly with the asphericity Q(1). To achieve a more prolate final asphericity (Q(2) < Q(1); dQ < 0; Delta > 0), the maximal depth of ablation (M + A + Delta) was increased. For treatments in which Q(2) was intended to be more oblate than Q(1) (Q(2) > Q(1); dQ > 0; Delta < 0), the maximal depth of ablation was reduced. These effects sharply increased with increasing diameters of the optical zone(s). Similarly, in the case of PRK, the differential increase in epithelial thickness in the center of the cornea compared with the periphery resulted in increased oblateness. CONCLUSIONS: Aspheric profiles of ablation result in varying central depths of ablation. Oblateness of the initial corneal surface, intentional increase in negative asphericity, and enlargement of the optical zone diameter result in deeper central ablations. This may be of clinical importance in planning aspheric profiles of ablation in LASIK procedures to correct spherical aberration without compromising the mechanical integrity of the cornea.     

Aspheric wavefront-guided versus wavefront-guided LASIK for myopic astigmatism with the Technolas 217z100 excimer laser

Purpose

To compare clinical outcomes of wavefront-guided LASIK with and without aspheric compensation in myopic eyes.

Methods

In this observational, single-center study, 134 eyes were treated using an aspheric module in combination with wavefront-guided profiles (PTA-algorithm) and compared to 146 eyes treated with the predecessor wavefront-guided software (APT) that has no aspheric compensation. All treatment plans included the Rochester nomogram that accounts for the preoperative manifest refraction and interaction of higher order aberrations. Active eye-tracking (including cyclorotational movements) was utilized during photoablation.

Results

Results at the 3-month follow-up: 67 % of PTA-treated eyes and 39 % of APT-treated eyes achieved an uncorrected distance visual acuity (UDVA) of 20/20 or better. Change in mean higher order aberration root-mean-square (HOA RMS) after PTA treatments was not statistically significant (p?=?0.18). The increase in HOA RMS after APT treatments was statistically significant (p?=?0.003). Change in mean postop spherical aberration (SA) after PTA treatments was not statistically significant (p?=?0.27). The change in SA after APT treatments was statistically significant (p?=?0.001). In both cohorts, mean uncorrected low-contrast visual acuity was statistically not different to preoperative corrected values.

Conclusions

Adding an aspheric compensation to wavefront-guided myopic LASIK statistically improved clinical results in terms of visual acuity and refractive outcomes. Low-contrast visual acuity was not negatively affected in either group. While in APT-treated eyes mean HOA RMS and mean SA were significantly increased postoperatively, PTA-treated eyes showed neither induced HOA RMS nor induced SA.     

Comparison of corneal aberration changes after laser in situ keratomileusis performed with mechanical microkeratome and IntraLase femtosecond laser: 1-year follow-up

PURPOSE: To compare corneal aberration changes 1 year after myopic laser in situ keratomileusis (LASIK) performed with a mechanical microkeratome and IntraLase femtosecond laser. METHODS: Twenty four eyes of 15 patients underwent LASIK with the Hansatome microkeratome, and 23 eyes of 13 patients underwent LASIK with the IntraLase femtosecond laser. A standard ablation was performed with the Bausch & Lomb Technolas 217 excimer laser. Topography data were used to calculate corneal aberrations with a 3.0 mm and 5.00 mm pupil, before and 12 months after surgery. The increasing factor (IF), defined as the ratio between the postoperative and preoperative mean value of the optical aberration, was calculated. The method of Mulhern et al was used to evaluate the centration of ablation. The comalike aberration was correlated with the decentration of ablation. The Student t test was used for the statistical anaylsis. RESULTS: The postoperative mean decentration of ablation was <0.5 mm. The comalike aberration appeared to be positively correlated with the decentration of ablation in both groups with a 5.0-mm pupil (P < 0.05). With a 3.00-mm pupil, the comalike aberration changed in the Hansatome group, whereas with a 5.00-mm pupil, all aberrations statistically significantly changed in both groups (P < 0.05). The IF similarly increased in 2 groups for spherical-like aberration, whereas IF greatly increased for total and comalike aberrations in the Hansatome group. CONCLUSIONS: Wavefront corneal aberrations change significantly 1 year after myopic LASIK performed with the Hansatome microkeratome as well as with IntraLase femtosecond lasers. Both of the procedures induce higher-order aberrations in the anterior corneal surface, but the amount of comalike aberration increases more with the Hansatome mechanical microkeratome.