近视眼高阶像差在低阶像差矫正后的变化

目的 探讨矫正近视眼低阶像差对高阶像差的影响,重点分析其对球差、彗差和三叶草的影响.方法 应用基于Hartmann-Shack传感器的波前像差仪分别测量34例(63眼)近视患者的,用球镜及柱镜矫正屈光不正前、后的高阶像差,依据屈光状态分为单纯近视组10例(18眼),近视低度散光组13例(26眼)(散光≤-0.50 D)和近视中度散光组11例(19眼)(-0.50 D<散光<-1.00 D).采用SPSS 13.0统计软件对波前像差的均方根和各Zernike项系数进行统计学处理.结果 屈光不正矫正后,单纯近视组C04由矫正前的(0.05±0.12)μm变为(0.01±0.14)μm,差异有统计学意义(t=2.770,P=0.022),其他各项差异均无统计学意义(P>0.05);近视低度散光组各Zernike项系数差异均无统计学意义(P>0.05);近视中度散光组C+4无显著性变化.由矫正前的(0.12±0.14)μm变为(0.11±0.17)μm(t=0.072,P=0.944),而C13由矫正前的(-0.01±0.17)μm变为(0.03±0.17)μm(t=-2.495,P=0.034),C33由矫正前的(-0.07±0.13)μm变为(-0.09±0.13)μm(t=2.676,P=0.025).三个屈光度组的高阶像差均方根(RMS)在低阶像差矫正前、后差异均无统计学意义(P>0.05),仅St和S3呈现增加趋势,S4和S5在单纯近视组增加,在近视散光组基本无变化.结论 单纯近视者矫正离焦后引起C04的明显变化:近视中度散光者完全矫正屈光不正后呈现C13和C33的显著变化.矫正不同的离焦和散光影响不同的高阶像差.     

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.     

Q值引导LASIK术后对比敏感度的变化

目的:对比Q值引导的LASIK与常规LASIK治疗近视术后术眼对比敏感度的变化差异。方法:选择27例近视度数在-2.50～-9.25D,散光度<-2.00D,无屈光参差的患者做LASIK,每名患者随机选择1眼行Q值引导LASIK(F-CAT组),另眼行常规LASIK(对照组)。Q引导值取术眼角膜Q20的平均值加上-0.5。术后随访1mo,比较F-CAT组和对照组的对比敏感度(contrast sensitivity,CS)的差异。结果:分别比较两组术后UCVA和残余的度数均无统计学差异。F-CAT组Q20的增加量比对照组增加量减少(P<0.05),并且术后球差增加量<对照眼(P<0.05)。两组术后各空间频率CS均无降低(P>0.05)。术后1mo,F-CAT组Q值引导眼在3c/d时对比敏感度高于对照组(P<0.05)。结论:用Q值引导的LASIK矫正近视,在提高术后CS方面比常规LASIK有优势。     

Corneal interactive programmed topographic ablation customized photorefractive keratectomy for correction of postkeratoplasty astigmatism.

OBJECTIVE: This study evaluated the efficacy, predictability, stability, and safety of a software program (Corneal Interactive Programmed Topographic Ablation [CIPTA], LIGI, Taranto, Italy), which, by transferring programmed ablation from the corneal topograph to a flying-spot excimer laser, provides customized laser ablation for correction of postkeratoplasty astigmatism. DESIGN: Noncomparative consecutive interventional case series. PARTICIPANTS: Ten eyes of 10 patients with a mean age of 41.4 years (range, 26-64) had CIPTA-guided photoastigmatic refractive keratectomy (PARK) at the Clinica Oculistica of Bari (Italy). Two patients were treated for hyperopic astigmatism and eight for myopic astigmatism. All the patients had irregular astigmatism after penetrating keratoplasty. OPERATION: Topography was acquired by a corneal topograph (Orbscan II, Orbtek, Inc., Salt Lake City, UT). This, together with refractive data, was processed to obtain a customized altimetric ablation profile that was transferred to a flying-spot laser (Laserscan 2000, Lasersight, Orlando, FL). MAIN OUTCOME MEASURES: Data on uncorrected (UCVA) and best-corrected (BCVA) visual acuity, predictability, stability of refraction, and any complications were analyzed. RESULTS: Mean follow-up was 8.4 months (range, 6-12; SD 2.4). At the last postoperative examination, seven eyes (70%) had a UCVA superior to 20/40. Three eyes (30%) had a UCVA of 20/20. Five eyes (50%) were within 0.50 diopters (D) of attempted correction in the spherical equivalent, and eight eyes (80%) within 1 D. Index of success of astigmatic correction was 0.19. All the eyes (100%) gained Snellen lines of BCVA. We did not observe any decentration and/or haze after PARK treatment performed in this study. CONCLUSIONS: The combination of topographic data with computer-controlled flying-spot excimer laser ablation is a suitable solution for correcting irregular astigmatism after penetrating keratoplasty.     

Visual outcomes in hyperopic myopic and emmetropic patients with customized aspheric ablation (Q factor) and micro-monovision

International Ophthalmology - To evaluate the visual outcomes, visual performance, and stereoacuity in presbyopic patients following treatment by a change in the corneal asphericity and...     

Corneal higher-order aberrations induced by overnight orthokeratology

PURPOSE: To evaluate corneal higher-order aberrations induced by overnight orthokeratology for myopia. DESIGN: Prospective, noncomparative, consecutive, interventional case series. METHODS: A prospective study was conducted in 64 eyes of 39 patients with overnight orthokeratology for myopia, who were followed up for at least 3 months and attained uncorrected visual acuity of 20/20 or better. Corneal height data were obtained with computerized videokeratography (TMS-2N, Tomey), and wavefront aberration was derived using Zernike polynomials. Higher-order aberrations of the cornea were calculated for 3- and 6-mm pupils. RESULTS: Orthokeratology significantly reduced manifest refraction from -2.60 +/- 1.13 (mean +/- SD) diopters to -0.17 +/- 0.31 diopters (P < .0001, paired t test). Root-mean-square (RMS) of third-order (coma-like) aberrations significantly increased by orthokeratology for both 3-mm (P < .0001, paired t test) and 6-mm (P < .0001) pupils. Fourth-order RMS (spherical-like) aberrations increased significantly by the treatment for both 3-mm (P < .0001) and 6-mm (P < .0001) pupils. Vertical coma significantly changed from positive to negative for both 3-mm (P = .0323) and 6-mm (P < .0001) pupils. Horizontal coma significantly increased to the positive direction for both 3-mm (P < .0001) and 6-mm (P < .0001) pupils. Increases in the third- and fourth-order RMS showed significant positive correlations with the amount of myopic correction for 3-mm (Pearson correlation coefficient, r = .452, P = .0001 for third-order RMS, r = .381, P = .0017 for fourth-order RMS) and 6-mm (r = .499, P < .0001, r = .455, P = .0001) pupils. CONCLUSIONS: Corneal higher-order aberrations significantly increased, even in clinically successful orthokeratology cases. The increases in the higher-order aberrations correlated with the magnitude of myopic correction.     

Bilateral comparison of conventional versus topographic-guided customized ablation for myopic LASIK with the NIDEK EC-5000

PURPOSE: To compare visual acuity and higher order aberrations before and after myopic LASIK using conventional versus customized ablation. METHODS: This prospective, randomized study included 54 myopic eyes in 27 patients who underwent bilateral LASIK using the NIDEK EC-5000 excimer laser system (NIDEK Technologies, Gamagori, Japan). Customized aspheric treatment zone (CATz) treatment was used in one eye (CATz group) and conventional ablation (conventional group) was used in the fellow eye. Uncorrected visual acuity (UCVA) and higher order aberrations (root-mean-square [RMS] in 4-mm and 6-mm zones) of both groups were observed with the NIDEK OPD-Scan aberrometer before and 3 months after LASIK. Preoperative mean refractive error was similar for both eyes of each patient (P>.05). RESULTS: No statistically significant differences were noted in preoperative higher order aberrations (RMS in 4-mm and 6-mm zones) between groups (P>.05). No statistically significant difference was noted between pre- and postoperative higher order aberrations in the CATz group (P>.05). However, a highly statistically significant increase in higher order aberrations was observed after conventional ablation (P<.001). There was a statistically significant higher increase of higher order aberrations after LASIK in the conventional group than the CATz group (P<.05). Postoperative UCVA with both conventional and customized ablation was not significantly different (P>.05). CONCLUSIONS: LASIK with conventional ablation and CATz ablation resulted in the same UCVA. The increase in higher order aberrations after CATz ablation was less than after conventional ablation.     

Influence of pupil and optical zone diameter on higher-order aberrations after wavefront-guided myopic LASIK

PURPOSE: To investigate the influence of pupil and optical zone (OZ) diameter on higher-order aberrations (HOAs) after myopic wavefront-guided laser in situ keratomileusis (LASIK). METHODS: Twenty-seven myopic eyes of 19 patients were included. The mean preoperative spherical equivalent was -6.86 diopters (D) +/- 1.24 (SD) (range -4.25 to -9.5 D); the mean planned OZ diameter was 6.26 +/- 0.45 mm (range 5.7 to 7.1 mm). All patients had uneventful wavefront-guided LASIK (Zyoptix version 3.1, Bausch & Lomb) and an uncomplicated follow-up of 12 months. Wavefront measurements were performed with a Hartmann-Shack sensor in maximum mydriasis preoperatively and 12 months after LASIK. Wavefront errors were computed for pupil diameters (PDs) of 3.0, 3.5, 4.0, 5.0, 6.0, and 7.0 mm for the individual OZ diameter and for the individual mydriatic PD (7.93 +/- 0.46 mm). The impact of the relationship between pupil diameter and OZ diameter (fractional clearance [FC]) on HOA was described and quantified using curvilinear regression with a 4th-order polynomial fit. RESULTS: There was a reproducible relationship between FC and the amount of induced HOA. The change in HOA root mean square and primary spherical aberration (Z(4)0) was significantly correlated with FC. If the OZ was 16.5% larger than the pupil (FC = 1.17), only half the amount of HOA was expected to be induced than if the OZ equaled the pupil. In contrast, an OZ that was 9% smaller than the pupil (FC = 0.91) resulted in an HOA induction 50% higher than at FC = 1. CONCLUSION: The OZ zone to pupil ratio (fractional clearance) had a significant impact on HOA induction after wavefront-guided LASIK.     

Ocular higher-order aberrations and contrast sensitivity after conventional laser in situ keratomileusis

PURPOSE: To investigate prospectively the relation between induced changes in higher-order aberrations of the eye and changes in contrast sensitivity by conventional laser in situ keratomileusis (LASIK) for myopia. METHODS: In 200 eyes of 110 consecutive patients (mean age, 32.7 +/- 8.4 years) undergoing LASIK, ocular aberrations and contrast sensitivity function were determined before and 1 month after surgery. The amount of myopic correction was 5.2 +/- 2.8 D (range, 1.0-13.0). Ocular higher-order aberrations were measured for a 4-mm pupil using the Hartmann-Shack wavefront analyzer (KR-9000PW; Topcon, Tokyo, Japan). The root mean square (RMS) of the third- and fourth-order Zernike coefficients was used to represent coma- and spherical-like aberrations, respectively. Total higher-order aberrations were calculated as the RMS of the third- and fourth-order coefficients. Contrast sensitivity and low-contrast visual acuity were measured. From the contrast sensitivity data, the area under the log contrast sensitivity function (AULCSF) was calculated. RESULTS: LASIK significantly improved logMAR best corrected visual acuity (Wilcoxon signed-rank test, P <0.001), but significantly reduced AULCSF (P <0.001) and low-contrast visual acuity (P=0.007). Total higher-order (P <0.001), coma-like (P <0.001), and spherical-like (P <0.001) aberrations were significantly increased after LASIK. The greater the amount of achieved myopia correction was, the more the changes in contrast sensitivity function and ocular higher-order aberrations were. The induced changes in AULCSF by LASIK showed significant correlations with changes in total higher-order (Pearson r=-0.221, P=0.003), coma-like (r=-0.205, P=0.006), and spherical-like (r=-0.171, P=0.022) aberrations. The changes in logMAR low-contrast visual acuity by surgery significantly correlated with changes in total higher-order (r=0.222, P=0.003), coma-like (r=0.201, P=0.007), and spherical-like (r=0.207, P=0.005) aberrations. CONCLUSIONS: Conventional LASIK significantly increases ocular higher-order aberrations, which compromise the postoperative contrast sensitivity function.     

SMILE与Trans-PRK手术矫正近视对角膜前表面像差的影响

目的：观察飞秒激光小切口角膜基质透镜取出术(SMILE)和经上皮准分子激光屈光性角膜切削术(Trans-PRK)矫正近视对角膜前表面三阶水平彗差、三阶垂直彗差、四阶球差和总高阶像差的影响。

方法：前瞻性非随机对照研究。收集2016-12/2017-02在乐山市眼科中心行SMILE手术及Trans-PRK手术矫正近视患者各20例40眼,分别于术前及术后1、3mo用Pentacam角膜地形图仪进行角膜像差检查。采用重复测量方差分析对角膜前表面三阶水平彗差、三阶垂直彗差、四阶球差和总高阶像差均方根进行统计分析。

结果：术后1、 3mo SMILE组和Trans-PRK组患者裸眼视力均达到或超过术前最佳矫正视力。术前两组患者各项角膜像差比较差异无统计学意义(P>0.05),术后两组患者角膜像差较术前均增高,差异有统计学意义(P<0.05),两组患者角膜像差在术后1、 3mo之间比较差异无统计学意义(P>0.05),术后各时间点两组患者水平彗差、垂直彗差之间比较差异无统计学意义(P>0.05),SMILE组患者术后四阶球差及总高阶像差均方根低于Trans-PRK组,差异有统计学意义(P<0.05)。

结论：SMILE与Trans-PRK手术矫正近视术后角膜像差均增高,两种手术方式对角膜三阶水平彗差和垂直彗差影响相似,SMILE手术对四阶球差及总高阶像差的影响较Trans-PRK手术更小。     

Q-value customized ablation (custom-Q) versus wavefront optimized ablation for primary myopia and myopic astigmatism

Comparison between treatment with wavefront optimized and custom-Q laser-assisted in situ keratomileusis (LASIK) ablations. Our study included 400 eyes of 200 patients divided into two equal groups. All patients were treated for myopia and myopic astigmatism with LASIK. The first group was treated with wavefront optimized ablation and the second group with custom-Q ablation. They were examined preoperatively and postoperatively to assess asphericity, image quality, and other classical outcome parameters. The wavefront optimized ablation group comprised 200 eyes with a mean spherical equivalent refraction (SE) of ?5.2188 diopters (D) (range: ?1.15 to ?10.50 D); the mean Q-value changed from 0.30 preoperatively to 0.06 postoperatively. The custom-Q ablation group also comprised 200 eyes with a mean SE of ?5.1575 D (range: ?1.35 to ?9.00 D); the mean Q-value changed from 0.32 preoperatively to 0.03 postoperatively. A statistically significant difference in postoperative change in Q-values (P = 0.02) and in postoperative visual acuity (P = 0.42) between the two groups was noted. There was no difference between the two groups regarding refractive correction. There was a marginally significant change in BSCVA (best spectacle-corrected visual acuity) between the two groups, and less impairment in the corneal asphericity in the custom-Q group.     

Changes in higher-order aberrations after implantation of a foldable iris-claw lens in myopic phakic eyes

PURPOSE: To evaluate the change in higher-order aberrations (HOAs) after implantation of a foldable iris-claw phakic intraocular lens (pIOL) in myopic eyes. SETTING: Department of Ophthalmology, Johannes Gutenberg-University, Mainz, Germany. METHODS: This prospective nonrandomized comparative self-controlled trial included 41 eyes that had implantation of a foldable iris-claw pIOL between July 2003 and November 2004. All patient data for HOAs (Zernike coefficient) were measured and calculated using the same pupil size preoperatively and postoperatively, and the root-mean-square (RMS) wavefront error was calculated. Examinations were performed preoperatively as well as 1 week and 3, 6, and 12 months after pIOL implantation. RESULTS: The mean preoperative sphere was -8.12 diopters (D) +/- 2.01 (SD) (range -12.25 to -3.75 D) and the mean preoperative cylinder, -0.90 +/- 0.62 D (range -2.50 to 0.00 D). The Z3(1) and Z(3)(-1) coefficients decreased after implantation of the foldable iris-claw pIOL, but the decrease was not statistically significant (P = .078 and P = .45, respectively). There was a statistically significant reduction in Z4(0) in the first postoperative week (P = .038), but the decrease was not significant thereafter. There was a statistically significant reduction in total RMS wavefront error from preoperatively to all values postoperatively (P = .008). CONCLUSION: Over a 12-month follow-up, 3rd-order and 4th-order HOAs did not increase after foldable iris-claw pIOL implantation in myopic eyes.     

LASIK非球面与标准切削治疗近视及近视散光的早期观察

目的:分析比较LASIK非球面切削与标准切削治疗近视及近视散光后的视功能、角膜非球面形态(Q值)情况,并评价治疗效果.方法:分别对16名患者(32眼)使用非球面切削程序以及18名患者(36眼)使用标准切削进行LASIK手术,记录所有手术眼术前、后视力,屈光度、Q值以及术后眩光发生情况.结果:术后3mo所有手术眼视力矫正均满意,非球面切削组与标准切削组之间屈光度无差别(P＞0.01);但非球面切削组与标准切削组比较其术后角膜更倾向于长椭球形,Q值(0.19±0.26)明显低于标准切削组Q值(0.88±0.52)(P＜0.01),术后眩光发生率较标准切削组更低(P＜0.05).结论:使用非球面切削与标准切削行LASIK治疗近视及近视散光均是安全有效的,但采用非球面切削由于能够更好地维持角膜形态,与标准切削比较其术后视觉质量更好,效果更为理想.     

Corneal higher-order aberrations in eyes with chronic ocular graft-versus-host disease

PurposeChronic ocular graft-versus-host disease (GVHD) is a long-term complication after hematopoietic stem cell transplantation (HSCT) and leads to irreversible visual morbidity due to severe ocular surface impairments including visual disfunction. However, knowledge about the optical function in chronic ocular GVHD is limited because it is difficult to assess quantitative optical function objectively. The development of anterior segment optical coherence tomography has allowed objective quantification of optical function by evaluating corneal higher-order aberrations (HOAs). Therefore, we applied this quantification in chronic ocular GVHD patients and verified the correlation between corneal HOAs and visual acuity.MethodsWe retrospectively reviewed chronic ocular GVHD patients and the recipients after HSCT. Then, analyzed the relationship between visual function and the severity of chronic ocular GVHD.ResultsThe eyes of patients with chronic ocular GVHD had higher corneal HOAs than those of non-GVHD patients (HOAs; 0.481 ± 0.306 vs 0.254 ± 0.084, and 0.917 ± 0.609 vs 0.529 ± 0.130. P < 0.001, and 0.002. 4-mm and 6-mm diameters respectively. Corneal HOAs were correlated with the severity of chronic ocular GVHD (r = 0.436. P < 0.001). Moreover, corneal HOAs were correlated with visual acuity, especially in eyes with severe chronic ocular GVHD cases (HOAs; 4-mm r = 0.636. P = 0.036. Total 6-mm r = 0.871. P =<0.001).ConclusionsWe succeed to assess the objective value in the optical function of the chronic ocular GVHD. Quantification of corneal HOAs could be an objective evaluation to assess optical function in eyes with chronic ocular GVHD.     

Wave front aberrations induced from biomechanical effects after customized myopic laser refractive surgery in finite element model

International Ophthalmology - A customized myopic refractive surgery was simulated by establishing a finite element model of the human eye, after which we studied the wave front aberrations induced...