角膜基质透镜在角膜溃疡或穿孔修复中的应用

目的：研究由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植材料治疗角膜溃疡的临床疗效。

方法：回顾性病例研究。收集本院2017-01/06角膜溃疡患者6例6眼,其中细菌性、真菌性、深层异物伴感染各1例1眼,角膜穿孔3例3眼。采用由全飞秒激光SMILE手术所得的角膜基质透镜作为角膜移植的材料进行修复手术,确保植片与角膜层间无空气间隙。术后随访1～6(平均3.71±1.56)mo,观察手术前后视力、角膜移植物存活情况及术后并发症发生情况等。

结果：所有患者均在控制感染下顺利完成手术,无术中并发症。术后所有角膜植片透明。末次随访时,患者最佳矫正视力(best corrected visual acuity,BCVA)较术前明显改善(0.48±0.12 vs 1.50±0.08),差异具有统计学意义(P<0.01)。

结论：来源于全飞秒激光屈光手术的角膜基质透镜用于角膜溃疡修复是安全有效的,但植片的远期疗效尚需进一步观察。     

飞秒激光辅助屈光性白内障手术效果的初步观察

目的：比较飞秒激光辅助屈光性白内障手术与常规屈光性白内障手术术后视力及角膜散光的差异。

方法：将老年性白内障合并角膜散光患者60例60眼,按随机自愿原则分为飞秒组及常规组。飞秒组将患者术前角膜散光陡峭轴、平坦轴轴向及屈光度数输入在线矢量计算器,得出相关切口位置、切口宽度后,利用飞秒激光做角膜松解切口、主切口及辅助切口,再按常规行白内障超声乳化+非球面多焦点人工晶状体(multifocal intraocular lenses,IOL)植入术。常规组利用角膜穿刺刀于角膜散光陡峭轴向上做角膜全层松解切口、辅助切口,然后行白内障超声乳化+非球面多焦点IOL植入术。分别于术后1d,1wk,1mo观察两组术眼的角膜散光情况及裸眼远视力(uncorrected distance visual acuity,UCDVA)、裸眼近视力(uncorrected near visual acuity,UCNVA),并进行统计分析。

结果：飞秒组和常规组术后裸眼视力均较术前提高,且飞秒组远、近视力均高于常规组; 而各时期角膜散光飞秒组均低于常规组。

结论：飞秒激光辅助下屈光性白内障手术较传统白内障手术术后角膜散光更小、视力更好,能给患者带来更好的视觉质量。     

FEMTO LDV飞秒激光制瓣LASIK术治疗近视疗效观察

目的：评价FEMTO LDV飞秒激光制瓣准分子激光原位角膜磨镶术(laser in situ keratomileusis,LASIK)治疗近视的临床效果。

方法：应用FEMTO LDV飞秒激光制瓣,设定角膜瓣厚度110μm。EC5000-CXIII准分子激光仪行LASIK手术治疗近视患者143例283眼。术前检查包括验光、最佳矫正视力(best corrected visual acuity,BCVA)、角膜厚度、ObscanⅡ等。术中测量其中35眼的角膜床厚度,推算其角膜瓣的厚度。观察术中及术后角膜瓣情况,手术并发症,术后裸眼视力(uncorrected visual acuity,UCVA),屈光度,角膜地形图,平均随访3mo。

结果：术中出现过小瓣(直径<5mm)3眼,角膜边缘切开不完全5眼,切口出血8眼,术后球结膜下出血6眼。35眼角膜瓣厚度108.75±8.52(98～117)μm,误差(实测值与预设值之差)6.49±8.62(3～12)μm,实际角膜瓣厚度与术前预先设计的角膜瓣厚度差异无统计学意义(P>0.05)。术后3mo平均等效球镜-0.29±0.47(-1.50～+1.00)DS,251眼(88.7%)裸眼视力达到或超过术前最佳矫正视力。

结论：FEMTO LDV飞秒激光制瓣LASIK术治疗近视并发症少、疗效确切、安全。     

稳定型圆锥角膜患者植入新型Phakic角膜接触镜的视觉效果分析

目的：评估可植入式Phakic角膜接触镜治疗稳定型圆锥角膜患者的疗效、安全性、稳定性和可预测性。

方法：共14例患者采用植入式Phakic角膜接触镜(IPCL)矫正屈光不正,测量了未矫正视力、最佳矫正视力、离焦曲线、对比敏感度、屈光度及可能的副作用。评估结果超过6mo。

结果：平均等效球镜度(SE)和散光在术后6mo末次检查时由术前-6.94±2.79 DS和-4.24±1.42 DC分别变为术后-0.23±0.43 DS和-1.05±0.49 DC。术前平均Snellen视力为0.18±0.10。6mo内未矫正视力和最佳矫正视力平均值分别为0.13±0.10和0.05±0.15。平均安全指数为1.11。所有眼视力均无降低,其中22眼视力提高超过1行。20眼(71.4%)屈光度在0.50 D以内,27眼(96.42%)在±1.00 D以内。术后1wk至6mo,屈光度变化为-0.23±0.43(范围： -1.00至+0.75)。6mo内角膜内皮细胞(ECL)丢失率小于5%。术后6mo眼压(IOP)为11.32±2.28 mmHg。

结论：Toric植入式Phakic角膜接触镜在矫正与稳定圆锥角膜相关的近视和近视散光方面具有有效性、安全性和可预测性。     

角膜地形图引导的FS-LASIK与TICL植入术矫正近视合并中高度散光的疗效

目的：探讨角膜地形图引导的飞秒激光制瓣的准分子激光原位角膜磨镶术(FS-LASIK)与有晶状体眼后房型环曲面人工晶状体(TICL)植入术矫正近视合并中高度散光的临床疗效。

方法：选取2019-06/2021-06在河源爱尔眼科医院屈光中心就诊的近视合并中高度散光患者60例115眼,按手术方式分组,接受角膜地形图引导的FS-LASIK患者32例62眼纳入A组; 接受TICL植入术的患者28例53眼纳入B组。记录术前、术后3mo的裸眼视力(UCVA)、最佳矫正视力(BCVA)、球镜度、残余散光度,评估手术安全性和有效性,并利用Alpins矢量分析方法评估散光的矫正效果。

结果：术后3mo,两组患者安全性指数(1.163±0.167 vs 1.136±0.194)和有效性指数(1.145±0.159 vs 1.123±0.196)均无差异(P>0.05),但散光矢量分析显示两组患者成功指数\〖0.125(0.091,0.200)vs 0.200(0.167,0.250)\〗、矫正指数\〖1.000(0.902,1.066)vs 0.834(0.783,0.869)\〗、变平指数\〖1.000(0.922,1.079)vs 0.835(0.795,0.870)\〗均有差异(P<0.01)。

结论：角膜地形图引导的FS-LASIK与TICL植入术均能安全、有效地矫正近视散光,角膜地形图引导的FS-LASIK手术矫正散光的效果优于TICL植入术。     

飞秒激光辅助白内障联合TECNIS Symfony人工晶状体植入术后视觉质量的评价

目的：通过观察飞秒激光辅助的白内障手术联合TECNIS Symfony连续视程人工晶状体植入术后远中近全程视力、对比敏感度,主观满意度,综合评价TECNIS Symfony人工晶状体植入术后患者的视觉质量。

方法：收集我院目前已实施40例55眼飞秒激光辅助白内障联合TECNIS Symfony 连续视程人工晶状体植入术资料,检测术后3mo裸眼远视力(5 m)、中视力(67 cm)及近视力(40 cm),绘制离焦曲线,根据多焦晶体满意度调查表并计算脱镜率。

结果：所有患者术中术后无严重并发症发生。术后3mo,所有患者人工晶状体位置居中,无明显偏位或倾斜。术后3mo, 5 m、67 cm、40 cm平均裸眼LogMAR视力分别为：-0.04±0.08, -0.17±0.22, 0.37±0.17。总体脱镜率95%。不同空间频率的对比敏感度较普通单焦非球面人工晶状体无明显下降。无中等或严重光学干扰现象发生。远中近各功能区满意度评分分别为9.0,9.0,7.0分。

结论：飞秒激光辅助的白内障手术联合TECNIS Symfony连续视程人工晶状体植入术后可获得满意的远中裸眼视力和基本满足日常生活的近视力,术后光学干扰少,脱镜率高,患者满意度高。     

飞秒激光与机械板层刀制瓣LASIK对角膜瓣厚度稳定性的影响

目的：探究飞秒激光与机械板层刀制瓣准分子激光原位角膜磨镶(LASIK)术对角膜瓣厚度稳定性和干眼症的影响。

方法：回顾性分析于本院眼科行LASIK术的近视患者80例160眼,根据制瓣方式不同分为飞秒激光组和机械板层刀组。测量术后两组患者不同时间点(1h,1d,1wk,1、3mo)的角膜瓣厚度,并比较不同方向上距离角膜顶点1、2、3mm及角膜顶点角膜瓣厚度的差异。比较患者术后1、3mo,1、2a OSDI评分和干眼症的发生率。

结果：飞秒激光组角膜瓣顶点厚度为99.62±4.50μm,机械板层刀组角膜瓣顶点厚度为125.25±12.81μm。飞秒激光制瓣不同离心点位置的角膜瓣厚度较为均匀,而机械板层刀制瓣角膜厚度变化较大。术后1、3mo,1、2a机械板层刀组OSDI评分高于飞秒激光组(P<0.01)。随访2a时间,飞秒激光组干眼发病率低于机械板层刀组(χ²=4.692,P=0.030)。术后1、2a,飞秒激光组轻度干眼所占比例高于机械板层刀组(P=0.044、0.001)。

结论：相对于机械板层刀制瓣,飞秒激光制瓣LASIK术患者的角膜瓣厚度稳定性更好,更为均匀,误差更小,且患者术后干眼的发生率更低,以轻度干眼为主。     

透明角膜3.2mm切口Phaco联合IOL植入术治疗白内障的疗效

目的：探讨3.2mm透明角膜切口白内障超声乳化吸除术(Phaco)联合人工晶状体(IOL)植入术治疗白内障的疗效。

方法：回顾性分析2015-10/2016-10我院眼科接诊的白内障患者95例107眼,均行3.2mm透明角膜切口Phaco联合IOL植入术,观察术后视力、角膜曲率、角膜散光、前房深度等情况。

结果：术后3d,1wk,1mo本组患者裸眼视力(0.16±0.06、0.15±0.05、0.14±0.04)明显优于术前(0.48±0.15),前房深度(3.86±1.09、3.69±1.04、3.84±1.07mm)明显高于术前(2.71±0.88mm)(均P<0.05),但角膜曲率和角膜散光度与术前无明显差异,且术后各时间点手术源性散光度无差异(均P>0.05)。

结论：3.2mm透明角膜切口Phaco联合IOL植入术可有效改善视力,减小角膜散光,是治疗白内障安全有效的手术方式。     

飞秒激光辅助白内障手术联合三焦点人工晶状体植入术的疗效观察

目的：观察飞秒激光辅助白内障手术联合三焦点人工晶状体(IOL)植入术后的临床疗效。

方法：回顾性自身前后对照研究。选择2016-09/2017-11就诊于山西省眼科医院植入三焦点IOL的白内障患者42例59眼,随访至术后6mo,分别观察术前、术后1wk,1、3、 6mo单眼裸眼远、中、近距离视力(LogMAR)、离焦曲线、屈光稳定性、高阶像差、患者满意度和脱镜率。

结果：所有患者在术后各随访时间点远、中、近距离均可获得优于0.1LogMAR的良好视力,术后各距离视力与术前相比显著提高(P<0.05)。术后6mo离焦曲线在0～-2.5D之间曲线过渡平缓,术眼达到优于0.8的视力水平。术后6mo,63%(37眼)的患眼SE位于±0.25D之间,88%(52眼)的患眼SE则位于±0.50D之间。术后各时期全眼的总高阶像差、彗差、球差、三叶草像差明显低于术前(P<0.05)。

结论：飞秒激光辅助白内障手术联合三焦点IOL植入术可以为患者提供舒适自然的全程视力,实现真正的脱镜,患者术后满意度高。     

Toric人工晶状体植入矫正特殊角膜散光的疗效观察

目的：回顾分析Toric(环曲面)人工晶状体植入治疗合并特殊角膜散光的白内障患者的临床治疗效果。

方法：对10例12眼合并特殊角膜散光的白内障患者行超声乳化白内障吸出及人工晶状体植入术治疗,进行回顾性分析。其中4眼为翼状胬肉切除术后,3眼为外伤后角膜散光,5眼为角膜云翳或斑翳患者。术后随访6mo,分析不同时间点裸眼视力、术后残余散光、并发症等,观察Toric人工晶状体植入后的疗效,旋转稳定性。

结果：术后随访观察6mo,术后裸眼视力平均0.62±0.31,最佳矫正视力0.70±0.35。裸眼视力≥0.8者2眼,占17%。裸眼视力≥0.5者9眼,占75%。术后残余散光0.51±0.36D。术后角膜源性散光未见明显改变,全眼总合散光得到明显改善,差异有统计学意义。术后全眼总合散光与术前预计残余散光值接近,无显著性差异。术后6mo旋转度为(3.80±1.46)°。末次随访时间点,植入Toric人工晶状体的12眼中,旋转度小于5°的11眼,占92%。仅1例术后旋转度为6°。

结论：对于某些特殊原因导致角膜散光的白内障患者,经过严格的手术前筛选,行白内障超声乳化吸出联合Toric人工晶状体植入,能够安全、有效的改善患者的散光,提高术后视觉质量,预测性好。     

Clinical effectiveness of intrastromal corneal ring segments among keratoconus patients

AIM: To evaluate the clinical effectiveness of intrastromal corneal ring segments (ICRS) among the patients suffering from keratoconus. METHODS: A retrospective and non-comparative interventional design had been utilized on the basis of postoperative follow-up among 56 keratoconus patients. Visual acuity was significantly assessed during complete ophthalmic examination of the patients. The femtosecond laser had been used to create the corneal tunnels in 15 eyes; whereas, the corneal tunnels were created in 72 eyes mechanically. RESULTS: The ranges and standard deviations had been used to obtain results. It had been revealed through ophthalmic assessment that the mean preoperative uncorrected visual acuity observed was 1.38±0.37 logarithm of Minimal Angle of Resolution. Moreover, a significant improvement was observed postoperatively in visual acuity by 0.58±0.32 during the 4th month. The improvement was also witnessed in the 16th month by 0.48±0.30. CONCLUSION: The implantation of ICRS is an efficient and effective surgical intervention for the treatment of keratoconus. Thus, identified intervention seems to be associated with appropriate visual outcomes and safety after the development of femtosecond as well as mechanical tunnels.     

Intrastromal corneal ring segment implantation with the femtosecond laser in a post-keratoplasty patient with recurrent keratoconus

A 50-year-old woman had implantation of intrastromal corneal ring segments for recurrent keratoconus 15 years after penetrating keratoplasty. Two segments (0.15 mm and 0.25 mm) were inserted without any intraoperative or postoperative complications, using the femtosecond laser to create the tunnels (superior and inferior). Ten months after the procedure, the uncorrected visual acuity was 20/100, compared with counting fingers preoperatively, and the best spectacle-corrected visual acuity improved from 20/63 to 20/32. Although the results are encouraging, the long-term effect of this approach for the management of post-keratoplasty patients with recurrent keratoconus is not known.     

Intrastromal corneal ring segments: visual outcomes from a large case series

Background: To evaluate the clinical safety and efficacy of implanted Ferrara intrastromal corneal ring segments in a large sample of patients with ectatic corneal disease. Design: Retrospective, consecutive case series. Samples: A total of 1073 eyes of 810 patients consecutively operated from January 2006 to July 2008 were evaluated. Methods: Two groups were created according to the type of ring implanted: Group 1 – patients implanted with the 160° of arc ring – and Group 2 – patients implanted with the 210° of arc ring. Main Outcome Measures: Uncorrected visual acuity, best‐corrected visual acuity, keratometry, asphericity and pachymetry at the thinnest point of the cornea. All patients were evaluated using a corneal tomography (Pentacam, Oculus, Inc., Lynnwood, WA, USA). Results: For Group 1 patients, uncorrected visual acuity increased to 20/80, best‐corrected visual acuity increased to 20/40, asphericity decreased to ?0.35, spherical equivalent decreased to ?2.26 D and keratometry decreased to 45.72 D (P < 0.001 for each compared with preoperative values). For Group 2 patients, uncorrected visual acuity increased to 20/130, best‐corrected visual acuity increased to 20/60, asphericity decreased to ?0.56, spherical equivalent decreased to ?4.14 D and keratometry decreased to 48.10 D (P < 0.001 for each compared with preoperative values). The 210° intrastromal corneal ring segments reduced keratometry and asphericity more than the 160° intrastromal corneal ring segments did. The complication rate was 3.82%. Conclusions: Ferrara intrastromal corneal ring segments implantation is safe and effective and has a low complication rate. It can effectively reduce the corneal steepening and improve uncorrected visual acuity and best‐corrected visual acuity in patients with keratoconus.     

Ferrara intrastromal corneal rings for the correction of keratoconus

PURPOSE: To evaluate the safety and efficacy of Ferrara intrastromal corneal rings in the treatment of eyes with keratoconus without central corneal scarring. SETTING: Vlemma Eye Institute, Athens, Greece. METHODS: Twenty-six patients with bilateral keratoconus, clear central corneas, and contact lens intolerance participated in the study. Videokeratographic corneal topography and ultrasonic pachymetry were performed in all eyes to identify the cone area and to select the thickness of the segments to be implanted, respectively. Ferrara intrastromal corneal rings were implanted around the center of the cone in 1 eye of each patient. RESULTS: The minimum follow-up after ring implantation was 6 months. In 2 cases, the rings had to be removed early in the postoperative period because of superficial implantation in 1 patient and asymmetrical placement in the other. The rest of the operated eyes demonstrated a reduction in astigmatism and spherical correction and improved uncorrected visual acuity. No eye lost best corrected visual acuity. CONCLUSIONS: Ferrara intrastromal corneal rings reduced corneal steepening and normalized the central cornea in eyes with keratoconus. Ferrara ring implantation was a safe procedure that may be considered in patients who are unable to have other surgical techniques, particularly contact-lens-intolerant keratoconus patients whose only option is corneal transplantation.     

Ferrara intrastromal corneal ring segments for severe keratoconus

PURPOSE: Intrastromal Ferrara ring segments were inserted in eyes with severe keratoconus to evaluate safety and efficacy of this procedure. METHODS: Intrastromal Ferrara ring segments were placed in 36 eyes of 35 patients with severe keratoconus, who were evaluated after 12 months of follow-up. All patients had highly disabling visual acuity, contact lens intolerance, and a previous indication for penetrating keratoplasty. Statistical analysis included preoperative and postoperative uncorrected visual acuity, best spectacle-corrected visual acuity, manifest refraction, anterior chamber depth, keratometry, and pachymetry. RESULTS: No patient had a loss of visual acuity. Uncorrected visual acuity improved in 28 eyes (77.78%) and best spectacle-corrected visual acuity improved in 29 eyes (80.56%). Spherical equivalent refraction decreased from -7.29 +/- 3.12 D to -4.80 +/- 3.04 D at 12 months after Ferrara intrastromal ring segment implantation. Corneal topography and ultrasound biomicroscopy showed corneal flattening, demonstrated by thinning of the central cornea and a reduction in anterior chamber depth. Segment decentration occurred in one eye (2.7%), asymmetric positioning of the segments in two eyes (5%), inadequate depth in two eyes (5%), migration of the segments in two eyes (5%), segment extrusion in five eyes (13.8%), conjunctivitis in one eye (2.7%), bacterial keratitis in one eye (2.7%), and hydrops in one eye (2.7%). CONCLUSIONS: With these early results, Ferrara intrastromal ring segments appear to be an alternative for the treatment of severe keratoconus.     

Evaluation of anterior and posterior surfaces of the cornea using a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments

AIM: To evaluate corneal parameters measured with a dual Scheimpflug analyzer in keratoconus patients implanted with intrastromal corneal ring segments (ICRS). METHODS: Fifty eyes of 40 keratoconus patients had Ferrara ICRS implantation from November 2010 to April 2014. Uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), refraction, keratometry, asphericity, elevation, pachymetry, root mean square (RMS), spherical aberration and coma were studied. All patients were evaluated using a dual Scheimpflug system. RESULTS: The mean follow-up time after the procedure was 12.7mo. The mean UCVA improved from 0.82 to 0.31 (P<0.001); the mean BCVA improved from 0.42 to 0.05 (P<0.0001), the mean spherical refraction changed from -3.06±3.80 D to -0.80±2.5 D (P<0.0001) and the mean refraction astigmatism reduced from -4.51±2.08 D to -2.26±1.18 D (P<0.0001). The changes from preoperative to postoperative, in parameters of the anterior and posterior surface of the cornea, were statistically significant except the elevation posterior at the apex of the cornea and posterior asphericity. CONCLUSION: The implantation of Ferrara ICRS induces changes in both anterior and posterior surfaces of the cornea.     

Intrakorneale Ringsegmente beim Keratokonus

Introduction

The spectrum of stage-related therapy of keratoconus has been broadened through surgical implantation of intracorneal ring segments (INTACS) as a possible method of reducing irregular astigmatism, leading to a reduction of corneal grafts especially in young, working-aged patients with keratoconus. The purpose of the present study was to evaluate the preoperative and postoperative results of femtosecond laser-assisted implantation of INTACS in ectatic corneal diseases.

Patients and methods

From August 2011 to January 2013, 20 eyes from 16 patients with a clear cornea in the visual axis suffering from hard contact lens intolerance underwent surgery in the Homburg/Saar Keratoconus Center (HKC) by the same surgeon (MEH). Among these were 16 keratoconus eyes, 1 eye with pellucid marginal degeneration und 3 eyes with post-LASIK iatrogenic keratectasia. The insertion of the INTACS ring segments was achieved by a femtosecond laser-assisted procedure that created a precise 360° tunnel at a depth of 80?% of the corneal thickness (395.8?±?38.5 μm) in the 6–7 mm zone.

Results

At 6 months follow-up mean uncorrected distance visual acuity improved from 0.07?±?0.07 preoperatively to 0.6?±?0.26 postoperatively. Mean best-corrected distance visual acuity changed from 0.4?±?0.15 preoperatively to 0.9?±?0.29 postoperatively. Mean sphere decreased from ??7.6?±?6.1 dpt to ??1.4?±?2.8 dpt. Astigmatism decreased from ??6.0?±?2.8 dpt preoperatively to ??4.3?±?2.0 dpt postoperatively. There was also a reduction in the mean flat K from 47.8?±?4.7 dpt preoperatively to 44.2?±?5.0 dpt postoperatively and in mean steep K from 51.9?±?5.0 dpt to 48.4?±?6.6 dpt. The central eccentricity index in the Pentacam was reduced to around 50?%. Neither intraoperative nor postoperative complications (including non-responders) were observed.

Conclusions

The femtosecond laser-assisted INTACS implantation provides a valid alternative to early keratoplasty for keratoconus patients with a clear central cornea and contact lens intolerance. It is a minimally invasive and reliable method for stage-related surgical management of keratoconus.     

Intacs insertion with the femtosecond laser for the management of keratoconus: one-year results

PURPOSE: To assess the outcomes of intrastromal ring segment (Intacs, Addition Technology) implantation for keratoconus using the femtosecond laser. SETTING: Kudret Eye Hospital, Ankara, Turkey. METHODS: In a retrospective noncomparative case series, 118 eyes of 69 patients with keratoconus who had Intacs segments implanted with the femtosecond laser were evaluated. Preoperative and postoperative evaluations included slitlamp examination, uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), and mean keratometry values measured with the Pentacam Scheimpflug camera (Oculus Opticgerate GmbH). All parameters were assessed preoperatively and 1 year after Intacs implantation. RESULTS: Intacs were successfully implanted in all eyes. At the end of the first postoperative year, 81.3% of eyes had improved UCVA and 73.7% had improved BCVA. The mean keratometry decreased from 51.56 diopters (D) to 47.66 D, and the mean refractive spherical equivalent decreased from -7.57 D to -3.72 D. CONCLUSIONS: Intacs implantation with the femtosecond laser was safe and effective for the treatment of keratoconus. All parameters had improved by the 1-year follow-up.     

First clinical results with the femtosecond neodynium-glass laser in refractive surgery

PURPOSE: We evaluated four femtosecond laser intrastromal cutting procedures: creation of a corneal flap for laser in situ keratomileusis (LASIK), tunnel and entry cut for intracorneal ring, corneal flap and removable lens for keratomileusis, and intrastromal ablation for myopia and hyperopia. METHODS: A clinical trial using a femtosecond surgical laser (IntraLase Corporation) was performed in partially sighted eyes. Femto-LASIK treatment was performed on 46 eyes up to -14.00 D; 16 patients received intracorneal ring segments (Femto-ICRS); 5 patients each with one highly myopic eye had femtosecond laser keratomileusis (FLK), and 13 patients each with one myopic or hyperopic eye had intrastromal ablation (ISPRK). In Femto-LASIK, excimer laser ablation was done under the flap. In Femto-ICRS, ring segments were introduced into the laser-created channels. In femtosecond laser keratomileusis, a lens-shaped block of stroma was removed manually from under the flap. RESULTS: No difference was found between the results obtained with Femto-LASIK and a standard microkeratome. No refractive effects occurred when the created flap was not elevated. In cases of Femto-ICRS and conventional ICRS produced the same refractive results. With Femto-ICRS, no intraoperative complications occurred and visual acuity improved immediately after surgery. In femtosecond laser keratomileusis, high myopia was corrected without using excimer laser ablation; centralization of the treatment area was excellent. In intrastromal ablation, 1 to 2 hours after surgery the corneas were highly transparent; refractive results were stable. CONCLUSIONS: Femtosecond lasers can produce precise intrastromal cutting, offering significant safety and other advantages (no razor blades, corneal trauma, partial resections, or sterilization issues) over current techniques.     

Cross-linking and intrastromal corneal ring segment

Corneal cross-linking is a procedure used for stabilizing the cornea in patients with progressive keratoconus by increasing corneal rigidity, and it is also used in corneal inflammatory melting process. The intrastromal corneal ring segments act by flattening the center of the cornea. Originally designed for the correction of mild myopia, the segments are now being used for reduction of keratoconus in order to improve the uncorrected visual acuity, the best spectacle corrected visual acuity, to allow good tolerance to the use of contact lenses and delay the need for corneal grafting procedures. The present text presents a review of corneal cross-linking and insertion of intrastromal corneal ring segments, emphasizing their indications, results and complications related until now.