中央孔型ICL V4c植入术矫正中高度近视的稳定性及高阶像差分析

目的：探讨中央孔型ICL V4c植入术矫正中高度近视的稳定性及对高阶像差的影响。

方法：观察采用ICL V4c人工晶状体植入术(研究组17例34眼)和全飞秒小切口基质透镜取出术(SMILE)(对照组18例34眼)治疗的高度近视患者术前、术后1d,1wk,1、3mo UCVA、BCVA、球镜(SE)、柱镜(CE)、IOP、角膜内皮细胞计数、总高阶像差(RMS)、球差、垂直彗差、水平彗差、彗差的差异。

结果：术后1、3mo研究组SE、CE高于对照组(P<0.05),术后1wk,1、3mo RMS、彗差低于对照组(P<0.05),术后3mo球差、水平彗差低于对照组(P<0.05)。

结论：ICL V4c植入术矫正中高度近视眼具有良好稳定性,对术眼高阶像差影响小。     

FS-LASIK和SMILE术后角膜前表面非球面性变化的比较

目的：分析并比较飞秒激光制瓣联合准分子激光原位角膜磨镶术(FS-LASIK)与飞秒激光小切口角膜基质透镜取出术(SMILE)对角膜前表面非球面性的影响。

方法：选取2016-11/2017-09在我院行FS-LASIK手术(FS-LASIK组)和SMILE手术(SMILE组)的近视患者各60例60眼,术前和术后3mo使用Pentacam眼前节分析系统测量角膜前表面6、7、8、9mm直径范围Q值和角膜前表面像差。

结果：术前,两组患者角膜前表面各直径范围Q值均无差异; 术后3mo,均明显高于术前,且FS-LASIK组患者角膜前表面6mm直径范围Q值明显高于SMILE组(0.89±0.43 vs 0.47±0.32,P<0.05)。术前,两组患者角膜总高阶像差和角膜球差均无差异; 术后3mo,两组患者角膜总高阶像差也无差异,但FS-LASIK组患者角膜球差高于SMILE组(0.43±0.23μm vs 0.31±0.11μm,P<0.05)。

结论：FS-LASIK和SMILE术均改变了角膜前表面非球面性,术后角膜前表面Q值均向正值方向变化,且SMILE术对角膜前表面Q值和角膜像差的改变均小于FS-LASIK术。     

波前像差引导FS-LASIK治疗近视合并中高度散光患者术后高阶像差变化

目的：评估波前像差引导飞秒激光辅助LASIK(femtosecond laser assisted LASIK, FS-LASIK)治疗近视合并中高度散光患者术后高阶像差变化。

方法：纳入我院于2016-07/2017-02收治的近视合并中度至高度散光患者50例88眼。术前51眼散光≥-1.50D且<-3.00D(中度散光),37眼散光≥-3.00D(高度散光),所有患者均接受波前像差引导FS-LASIK手术。术前和术后3mo评估未矫正视力(uncorrected distance visual acuity, UDVA)、矫正视力(corrected distance visual acuity, CDVA)、角膜曲率、角膜中心厚度(central corneal thickness, CCT)和部分高阶像差(higher order aberrations, HOAs)。

结果：术后3mo所有术眼的UDVA均达到20/20以上,均较术前提高且差异有统计学意义(P<0.05),而 CDVA和术前相比差异无统计学意义(P=0.36)。术后85眼(97%)散光在-1.00D以下,70眼(80%)散光在-0.50D以下,差异有统计学意义(P<0.05)。较术前相比,术后平均角膜曲率降低约为3.81±1.97D,CCT减少约78.66±37.22μm,差异有统计学意义(P<0.05)。术后3mo彗差与三叶草较术前无明显变化(P=0.078、0.065); 而球面像差、二次散光及高阶像差均方根(HOA-root mean square, HOA-RMS)术后较术前均有所增加,分别从术前的0.19±0.06、0.05±0.02 和0.42±0.12增加至术后的0.32±0.17、0.26±0.08 和0.78±0.28,差异有统计学意义(P<0.05)。

结论：波前像差引导FS-LASIK术后虽然产生部分高阶像,但依然是中高度散光患者进行角膜屈光手术的一个安全有效的选择。     

SMILE和ICL矫正中低度近视术后角膜前后表面和总角膜高阶像差的变化

目的：对比分析飞秒激光小切口角膜基质透镜取出术(small incision lenticule extraction,SMILE)和有晶状体眼人工晶状体植入术(implantable collamer lens,ICL)矫正中、低度近视术后角膜前表面、后表面和总角膜高阶像差的变化。

方法：回顾性研究,选取2017-11/2018-02在西安爱尔眼科医院屈光中心行SMILE手术及ICL手术矫正中、低度近视患者各35例70眼。术前及术后1、3、6mo应用基于Ray Tracing技术的Scheimpflug成相评估6mm直径的角膜前表面、后表面和总角膜高阶像差,采用重复测量方差分析对不同时间点角膜彗差、球差和总高阶像差均方根进行比较。

结果：术后1、3、6mo SMILE组和ICL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差异无统计学意义(P>0.05)。术后1mo,SMILE组角膜前表面高阶像差较术前显著增加,差异有统计学意义(P<0.05),而ICL组角膜前表面高阶像差无显著变化,差异无统计学意义(P>0.05); 术后两组患者角膜后表面高阶像差差异无统计学意义(P>0.05),两组间患者彗差、球差和总高阶像差比较差异无统计学意义(P>0.05)。

结论：相比SMILE手术,ICL术矫正中、低度近视在短期内引入的角膜前表面高阶像差更小。     

玻璃体腔注射雷珠单抗联合全视网膜光凝术后行小梁切除术治疗新生血管性青光眼

目的：评价玻璃体腔注射(IVR)雷珠单抗联合全视网膜光凝(PRP)术后行传统小梁切除手术治疗新生血管性青光眼的有效性及安全性。

方法：回顾性分析2015/08～2018/11在我院收治的27例27眼新生血管性青光眼(NVG)患者的病例资料。所有患眼均在接受IVR联合PRP治疗后,再行传统小梁切除手术。主要观察指标为眼压(IOP)控制情况、最佳矫正视力(BCVA)变化以及手术并发症。

结果：术后随访时间至少18(平均21.7±4.3)mo。末次随访时,平均IOP由治疗前的45.7±5.1mmHg下降至18.4±3.6mmHg,BCVA(LogMAR)由治疗前2.42±0.68提高至1.77±0.93。术后3mo至末次随访,周边虹膜前粘连(PAS)≤50%的患眼手术成功率高于PAS>50%的患眼。主要的并发症包括术后早期发生的前房积血(11.1%)、低眼压伴浅前房(14.8%),以及术后中、晚期发生的滤过泡包裹(37.0%)。未观察到严重的术中和术后并发症。

结论：IVR联合PRP术后进行传统小梁切除手术治疗NVG安全有效,特别适用于PAS≤50%的患眼。术前进行IVR和PRP治疗有助于提高小梁切除手术的成功率。     

拉坦前列素滴眼液对开角型青光眼患者眼压、角膜中央厚度和前房深度的影响

目的：探讨开角型青光眼患者局部应用拉坦前列素滴眼液6mo后(0.005%,一日一次),眼压(IOP)、角膜中央厚度(CCT)和前房深度(ACD)的变化。

方法：本研究包含初诊为原发性开角型青光眼(POAG)或剥脱性青光眼(PXG)患者24例37眼。采用Goldmann压平眼压计测量IOP,超声测厚仪测量CCT,超声生物测量仪测量ACD和ACD/轴长(AL)。比较治疗前,记录治疗后3mo和6mo的IOP,CCT,ACD和ACD/AL测量值。

结果：IOP于治疗前,治疗后3mo、6mo平均值分别为25.0±4.2、17.5±2.0、16.9±1.7,可见治疗后显著降低。CCT于治疗前,治疗后3mo、6mo平均值分别为546.6±31.5, 541.0±29.4、542.2±29.3,可见治疗后显著降低。ACD于治疗前,治疗后3mo、6mo平均值分别为3.00±0.43,2.95±0.42、2.97±0.41,可见治疗后3mo显著降低,6mo无显著改变。ACD/AL治疗后改变与ACD情况相似。CCT和ACD的测量值在POAG中有显著变化,而在PXG中则没有。

结论：开角型青光眼患者应用拉坦前列素滴眼液治疗后,除IOP大幅降低外,角膜厚度及ACD亦出现短期内降低。     

超声乳化联合房角分离术与小梁切除术治疗急性闭角型青光眼合并白内障

目的：比较白内障超声乳化联合房角分离术与单纯小梁切除术治疗急性闭角型青光眼合并白内障的临床疗效。

方法：选取我院就诊的急性闭角型青光眼合并白内障患者46例60眼,其中行白内障超声乳化联合房角分离术30眼(A组),单纯行小梁切除术30眼(B组); 观察术后4、7d,1、3mo,患者BCVA(LogMAR视力)、眼压、中央前房深度及视野情况。

结果：术后3mo A组BCVA为0.20±0.18显著高于B组0.39±0.09(P<0.05)。 A组术前眼压(18.3±4.6mmHg)与术后3mo(17.2±1.9mmHg)无差异(P>0.05); 术前B组眼压(18.2±5.0mmHg)与术后3mo(12.4±2.1mmHg)有差异(P<0.05); 术后3mo,A组和B组眼压比较有差异(P<0.05)。术前A组前房深度(2.23±0.21mm)与术后3mo(3.46±0.10mm),B组术前前房深度(2.21±0.12mm)与术后3mo(3.36±0.09mm)均有差异(P<0.05)。A组术前视野缺损度(6.32±1.57db)与术后3mo(6.54±1.42db),B组术前视野缺损度(6.31±1.46db)与术后3mo(6.57±1.52db)均无差异(P>0.05)。

结论：白内障超声乳化联合房角分离术与单纯小梁切除术对急性闭角型青光眼眼压均能有效控制。     

FS-LASIK与FS-LASIK联合快速角膜胶原交联术矫正高度近视术后早期屈光度及角膜高阶像差比较

目的：比较飞秒激光辅助的准分子激光原位角膜磨镶术(FS-LASIK)与FS-LASIK联合快速角膜胶原交联术(FS-LASIK Xtra)矫正高度近视术后早期屈光度及角膜高阶像差变化特点,评估两种术式矫正高度近视的早期效果。

方法：回顾性病例对照研究。纳入2019-04/2020-04在我院进行FS-LASIK Xtra及FS-LASIK的高度近视患者42例84眼,每组各21例42眼,术后随访3mo,比较两组患者术后裸眼视力(UCVA)、等效球镜(SE)、散光度及角膜高阶像差。

结果：FS-LASIK Xtra组患者术后1d UCVA(LogMAR)低于FS-LASIK组(P<0.01),其余时间点两组间比较均无差异(P>0.05)。两组患者术后SE均较术前明显降低,术后3mo,FS-LASIK Xtra组有38眼(90%)、FS-LASIK组有41眼(98%)术眼SE在±1.00D以内。两组患者术后均有35眼(83%)的术眼残余散光在0.50D以内。两组术后3mo角膜总高阶像差、球差、彗差及三叶草差均较术前增大,FS-LASIK Xtra组总高阶像差及三叶草差大于FS-LASIK组(均P<0.05)。

结论：FS-LASIK与FS-LASIK Xtra矫正高度近视在术后早期均具有较好的有效性和可预测性,术后早期角膜总高阶像差均增加,且行FS-LASIK Xtra增加更显著。     

缺乏囊膜支持的无晶状体眼中两种人工晶状体植入方式的疗效比较

目的：在缺少囊膜支撑的无晶状体眼中,比较后房植入虹膜夹人工晶状体(IOL)与后房睫状沟巩膜缝合固定人工晶状体的疗效。

方法：本研究收集缺少囊膜支撑的无晶状体患者70例进行回顾性对比分析,患者根据手术方式的不同分为A、B两组,A组35眼行后房植入虹膜夹IOL,B组35眼行后房睫状沟巩膜缝合固定IOL。比较两组患者术前及术后3d,1、3、6mo,1a的裸眼视力(UCVA)、最佳矫正视力(BCVA)、眼压(IOP)、角膜内皮细胞密度(CECD),并且观察两组IOL的稳定性,记录术中及术后并发症。

结果：随访12～14mo。术后3d,A组的UCVA较术前明显改善(P<0.01),而BCVA较术前无差异(P=0.073); B组的UCVA较术前无差异(P=0.097),而BCVA较术前差(P=0.002); 两组患者术后1mo UCVA、BCVA均较术前显著改善(P<0.05),分别于术后6、3mo保持稳定。两组患者随访期间的IOP均维持于正常水平。A组、B组患者术后1a的CECD分别较术前平均降低0.7%、2.3%(均P<0.05)。两组患者随访期间各时间点IOP及CECD的均无差异(P>0.05)。两组患者术后1、3mo的全眼散光较角膜散光无明显差异(均P>0.05)。术后两组各有1眼IOL脱位,均经手术复位,其余患者术后随访期间IOL无显著倾斜和偏位; 其他术后并发症较轻微,组间并发症发生率无差异(P>0.05)。

结论：对于缺少囊膜支持的无晶状体眼患者,后房植入虹膜夹IOL与后房睫状沟巩膜缝合固定IOL均是安全有效的手术方式。后房植入虹膜夹IOL的操作相对简单,对眼球内组织损伤较小,手术时间较短,术后视力恢复较快,是有效的治疗方法之一。     

一种改良微创人工晶状体固定术的临床观察

目的：观察隐形锚钩式巩膜层间人工晶状体固定术的临床效果。

方法：前瞻性非对照性病例研究。选取2019-01/2020-12我院收治的无晶状体、人工晶状体脱位或晶状体脱位患者19例19眼,所有患者均接受锚钩式人工晶状体巩膜层间固定植入手术。观察手术前后最佳矫正视力(BCVA)、裸眼视力(UCVA)、角膜内皮细胞密度、术后人工晶状体位置有无倾斜和并发症。

结果：术前和术后1 mo ,UCVA(LogMAR)为1.06±0.63和0.40±0.26(P<0.01),BCVA(LogMAR)为0.27±0.51和0.06±0.15(P=0.09),角膜内皮细胞密度为2406±625和2004±759 cells/mm²(P=0.13)。术后1d房水闪辉2级或以上3眼,角膜后弹力层皱褶2眼,一过性眼压升高2眼。随访24 mo均未发生人工晶状体脱位。

结论：锚钩式人工晶状体巩膜层间固定技术,组织间线头顺行进入-逆向固定,类似锚钩原理,达到了良好的人工晶状体稳定性和视觉效果。     

Corneal wavefront-guided photorefractive keratectomy in patients with irregular corneas after corneal refractive surgery

PURPOSE: To evaluate the corrective potential of corneal wavefront-guided photorefractive keratectomy (PRK) in patients with high levels of corneal aberrations and symptoms after previous corneal refractive surgery. SETTING: Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain. METHODS: This study comprised 25 eyes (20 patients) that had 1 or more previous unsuccessful keratorefractive procedure. All eyes had PRK retreatment using the Esiris excimer laser and ORK-CAM software for customized ablation design. All eyes had a high preoperative level of corneal higher-order aberrations (HOAs) (coma-like or spherical-like root mean square [RMS] >0.5 microm). Changes in refractive outcomes, subjective symptoms, and corneal aberrometry were evaluated during a 6-month follow-up. RESULTS: Uncorrected visual acuity improved significantly from preoperatively (mean 0.48) to 6 months after retreatment (mean 0.75) (P<.01). The mean best spectacle-corrected visual acuity (BSCVA) also improved significantly, from 0.78 to 0.90, respectively (P<.01). Forty-four percent of patients gained 1 or more lines of BSCVA. The reduction in cylinder at 6 months was statistically significant (P= .01). Corneal aberrometry at 6 months showed a statistically significant reduction in total (P= .01), spherical-like (P<.01), coma-like (P= .02), and primary coma (P<.01) RMS. At 6 months, 72% of patients had low or no perception of halos and all reported no glare. CONCLUSION: Corneal wavefront-guided PRK enhancement with the ORK-CAM system minimized corneal HOAs in eyes with previous unsuccessful keratorefractive surgery.     

Influence of tilt and decentration of scleral-sutured intraocular lens on ocular higher-order wavefront aberration

AIM: To investigate the influence of tilt and decentration of scleral-sutured intraocular lenses (IOLs) on ocular higher-order wavefront aberrations. METHODS: In 45 eyes of 36 patients who had undergone scleral suture fixation of posterior chamber IOL, tilt and decentration of IOLs were determined by Scheimpflug videophotography, and higher-order aberration for a 4-mm pupil was measured using the Hartmann-Shack aberrometer. In another 100 eyes of 100 patients after standard cataract surgery with posterior chamber IOL implantation, ocular higher-order aberration was measured. RESULTS: In eyes with scleral-sutured IOL, the mean (SD) tilt angle and decentration were 4.43 degrees (3.02 degrees ) and 0.279 (0.162) mm, respectively. Ocular coma-like aberration in the sutured IOL group was 0.324 (0.170) microm, which was significantly greater than that of the standard cataract surgery group (0.169 (0.061) microm, p<0.001, Student's t test). No significant difference was found in ocular spherical-like aberration between the sutured IOL group (0.142 (0.065) microm) and standard surgery group (0.126 (0.033) microm; p = 0.254). In the sutured IOL group, IOL tilt significantly correlated with ocular coma-like aberration (Pearson's correlation coefficient r = 0.628, p<0.001), but no significant correlation was found between IOL tilt and ocular spherical-like aberration (r = 0.222, p = 0.175). The IOL tilt did not correlate with corneal coma-like (r = 0.289, p = 0.171) and spherical-like (r = 0.150, p = 0.356) aberrations. The IOL decentration did not correlate with any higher-order aberrations. CONCLUSION: In eyes with scleral-sutured posterior chamber IOL, tilting of the lens induces considerable amount of ocular coma-like aberrations.     

Wavefront analysis of higher-order aberrations in patients with cataract

PURPOSE: To determine local refractive changes and higher-order aberrations in patients with nuclear or cortical cataract. SETTING: Osaka University Medical School, Osaka, Japan. METHODS: Wavefront analysis of both ocular and corneal aberrations was performed with the Hartmann-Shack aberrometer in 2 patients, a 22-year-old woman with bilateral developmental nuclear cataract and a 68-year-old woman with mild bilateral cortical cataract. RESULTS: Case 1 showed a delay in the wavefront that caused a myopic shift in the central pupillary area in both eyes, associated with the nuclear cataract. The spherical-like aberration (right eye, 36%; left eye, 21%) was greater than the coma-like aberration in both eyes. Case 2 showed an advancement of the wavefront that caused a hyperopic shift, especially in the lower temporal pupillary area, that was associated with the cortical cataract. The coma-like aberration (right eye, 63%; left eye, 52%) was greater than the spherical-like aberration in both eyes. The polarity of the third-order spherical aberration was negative in Case 1 and positive in Case 2. Corneal higher-order aberrations were small and had a different distribution than ocular higher-order aberrations in both patients. CONCLUSIONS: The Hartmann-Shack aberrometer was useful in detecting local refractive changes and higher-order aberrations in patients with mild cataract. The polarity and the absolute value of ocular higher-order aberrations may be useful parameters to characterize eyes with cataract.     

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.     

Effects of Reference Axes Used During Measurements of Ocular and Corneal Higher-Order Aberrations in Patients Following LASIK

Purpose

To determine the effects of the reference axes used during the measurements of ocular and corneal higher-order aberrations (HOAs) in patients before and after laser in situ keratomileusis (LASIK).

Methods

Wavefront sensing and corneal topography were determined for 29 eyes of 15 patients before and after LASIK. Ocular and corneal HOAs were calculated for 4-mm- and 6-mm-diameter pupils with the instrument aligned with the line of sight (LOS) or with the vertex normal (VN).

Results

For ocular HOAs after surgery, the spherical-like aberration was significantly larger when the VN axis rather than the LOS axis was used for pupils of both diameters. For corneal HOAs before surgery, in addition to the larger spherical-like aberration for VN, coma-like aberrations were significantly larger with LOS than with VN for both pupil diameters. For corneal HOAs after surgery, the spherical-like aberrations and total HOAs for 4-mm-diameter pupils with VN were significantly larger than those with LOS.

Conclusions

The HOAs were significantly different depending on the axes used and should be described on the basis of a common axis. These results suggest that the anterior surface of the normal or post-LASIK cornea is more rotationally symmetrical along the VN than along the LOS.?Jpn J Ophthalmol 2006;50:318–322 © Japanese Ophthalmological Society 2006     

Corneal aberrations after astigmatic keratotomy combined with laser in situ keratomileusis

PURPOSE: To evaluate the optical aberrations in the cornea before and after astigmatic keratotomy (AK) combined with laser in situ keratomileusis (LASIK) in a group of patients with high myopic astigmatism. SETTING: Refractive Surgery Unit, NISA Hospital Virgen del Consuelo, Valencia, Spain. METHODS: Twelve patients (24 eyes) with high myopic astigmatism (from 3.50 to 6.00 diopters) participated in the study. Astigmatic keratotomy was performed as the first step to reduce astigmatism; after 2 months, the residual refractive error was corrected with LASIK. Videokeratography measurements were conducted before and after each procedure. Topography maps were used to calculate the wavefront corneal aberrations for a 6.0 mm pupil diameter. RESULTS: Total, coma-like, and spherical-like aberrations increased significantly from preoperatively to post LASIK (x6.34, x2.52, and x10.50, respectively; P<.01). Astigmatic keratotomy significantly increased coma-like (x4.04; P<.01) and spherical-like (x5.66; P<.01) aberrations. After LASIK, the coma-like aberration was significantly reduced (x0.62; P =.008) and the spherical-like aberration was significantly increased (x1.86; P<.01). CONCLUSION: Astigmatic keratotomy increased higher-order corneal aberrations, both coma-like and spherical-like, whereas LASIK performed after AK increased the spherical-like aberration and reduced the coma-like aberration.     

Corneal higher order wavefront aberrations after hyperopic laser in situ keratomileusis

PURPOSE: To evaluate the changes in corneal higher order wavefront aberrations after hyperopic laser in situ keratomileusis (LASIK). METHODS: In a prospective case series, 15 eyes of 12 patients who had hyperopic LASIK were evaluated. Corneal topography was obtained before and after hyperopic LASIK with a Nidek EC 5000 laser using 5.5/8.0 ablation zones. Using anterior corneal height data, the changes in corneal higher order wavefront aberrations were calculated. RESULTS: The surgery significantly increased both corneal coma-like aberration (preoperative/6 months postoperative, 0.054/0.147 [172% increase] for 3-mm pupil and 0.381/1.076 [182% increase] for 6-mm pupil) and corneal spherical-like aberration (preoperative/6 months postoperative, 0.039/0.067 [72% increase] for 3-mm pupil and 0.297/0.959 [223% increase] for 6-mm pupil). The surgery significantly decreased Zernike coefficient 12 and the polarity of corneal spherical aberration changed from preoperative positive value to negative postoperatively. For a 3-mm pupil, the achieved changes in spherical equivalent refraction significantly correlated with the induced changes in the corneal coma-like aberration (R = 0.629, P = .010), but not with those in corneal spherical-like aberration (R = 0.408, P=.133) or Zernike coefficient 12 (R = -0.301, P = .282). For a 6-mm pupil, the achieved changes in spherical equivalent refraction significantly correlated with the induced changes in the corneal spherical-like aberration (R = 0.862, P < .0001) and Zemike coefficient 12 (R = -0.872, P < .001) but not with those in corneal coma-like aberration (R = 0.449, P = .094). CONCLUSIONS: Hyperopic LASIK significantly increases corneal coma-like and spherical-like aberrations and changes corneal spherical aberration from a positive to negative value.     

Increased higher-order optical aberrations after laser refractive surgery: a problem of subclinical decentration

PURPOSE: To study the clinical and theoretical effects of subclinical decentrations on the optical performance of the eye after photorefractive laser surgery. SETTING: Department of Ophthalmology, University of Dresden, Dresden, Germany. METHODS: Ocular aberrations were determined before and 1 month after uneventful photorefractive keratectomy (PRK) with the Multiscan laser (Schwind) in 10 eyes of 8 patients. The corrections ranged from -2.5 to -6.0 diopters, and ablation zones of 6.0 mm and larger were used. The measured wavefront errors were compared to numerical simulations using the individually determined decentrations and currently used ablation profiles. RESULTS: The PRK-induced aberrations were significantly greater than the preoperative aberrations. The numerically calculated increase in the higher-order optical aberrations correlated with the clinical results, demonstrating a major increase in coma- and spherical-like aberrations. Subclinical decentration (less than 1.0 mm) was found to be a major factor in increased coma-like and spherical-like aberrations after corneal laser surgery. CONCLUSION: To minimize higher-order optical errors, special efforts to center the ablation zone are necessary; for example, by eye-tracking systems that consider the visual axis.     

Influence of intraocular lens tilt and decentration on wavefront aberrations

PURPOSE: To investigate the influence of intraocular lens (IOL) tilt and decentration on higher-order aberrations (HOAs) using wavefront analysis. SETTING: Department of Ophthalmology, Nara Medical University, Nara, Japan. METHODS: Forty eyes of 40 patients with a 5.5 mm optic, foldable acrylic IOL were examined 4 to 48 months postoperatively. Ocular wavefront aberrations of the central 4.0 mm aperture diameter were measured using a Hartmann-Shack aberrometer. Higher-order aberrations from the 3rd to 4th order were calculated using Zernike polynomials. The relationship between IOL tilt and decentration, measured with a Scheimpflug camera, and ocular HOAs were investigated. RESULTS: The correlation between IOL tilt and coma-like aberrations was significant (r=0.431, Spearman rank correlation coefficient; P=.007). However, the correlation between IOL tilt and the spherical-like and total aberrations was not significant (P>.05), nor was the correlation between IOL decentration and coma-like, spherical-like, and total aberrations (P>.05). CONCLUSIONS: Intraocular lens tilt influenced ocular coma-like aberrations. The quality of the retinal image may improve by reducing IOL tilt.     

Influence of wavefront aberration and corneal subepithelial haze on low-contrast visual acuity after photorefractive keratectomy

PURPOSE: To assess low-contrast visual acuity (LCVA) after photorefractive keratectomy in relation to ocular higher-order wavefront aberration and corneal subepithelial haze. DESIGN: Prospective, cross-sectional analysis. METHODS: Photorefractive keratectomy was performed in 51 eyes of 27 subjects with myopic refractive error of -2.0 to -10.5 diopters. Ocular higher-order wavefront aberrations for a 4-mm pupil were measured using Topcon Hartmann-Shack wavefront aberrometer, and the extent of corneal subepithelial haze was quantified with Nidek TSPC-3 hazemeter before and 1 month after photorefractive keratectomy. Low-contrast visual acuity was recorded with Vector Vision CSV-1000LanC10% chart. Total higher-order, third-order (coma-like), and fourth-order (spherical-like) aberrations of the eye were determined. The influence of wavefront aberration and corneal subepithelial haze on LCVA was analyzed. RESULTS: Total higher-order, third-order, and fourth-order aberrations significantly increased by surgery (P < .001, Wilcoxon signed rank test). Photorefractive keratectomy induced a significant increase in corneal haze (P < .01), but no case presented severe corneal haze (grade 3 or greater by Fantes grading). By surgery, LCVA was reduced significantly (P < .001). The logarithm of the minimal angle of resolution LCVA showed a significant correlation with total higher-order aberration (Spearman rank correlation coefficient, r(s) = 0.642, P < .0001). Both third-order (r(s) = 0.618, P < .0001) and fourth-order aberrations (r(s) = 0.552, P < .0001) also significantly correlated with logarithm of the minimal angle of resolution LCVA. There was no correlation between the degree of corneal haze and logarithm of the minimal angle of resolution LCVA (r(s) = 0.094, P = .523). CONCLUSIONS: In eyes with mild to moderate corneal haze after photorefractive keratectomy, deterioration of LCVA is mainly attributable to increases in wavefront aberration, and not to corneal haze.