全程飞秒激光屈光手术的研究进展

应用飞秒激光实施全部屈光性切削步骤的全程飞秒激光屈光手术已逐步应用于临床,可用于矫治包括近视、远视、散光和老视在内的所有屈光手术,其矫治效果已得到初步验证.随着飞秒激光技术的不断发展和飞秒激光系统设备的进一步普及,全程飞秒激光屈光手术将具有广阔的应用前景.     

全程飞秒激光屈光手术的研究进展

应用飞秒激光实施全部屈光性切削步骤的全程飞秒激光屈光手术已逐步应用于临床,可用于矫治包括近视、远视、散光和老视在内的所有屈光手术,其矫治效果已得到初步验证.随着飞秒激光技术的不断发展和飞秒激光系统设备的进一步普及,全程飞秒激光屈光手术将具有广阔的应用前景.     

飞秒激光在基质内屈光手术中的应用

飞秒（10^-15S）激光经证实可以有效的降低切割组织所需的能量并可减少对周围组织的损伤。该激光系统的灵活性使得它不仅可以完成传统的角膜基质内手术,而且可以进行新的角膜屈光手术。本研究就其机制、手术方法和过程、并发症等方面做一综述。     

飞秒激光在眼屈光手术中的应用

飞秒激光的光致分解作用允许在角膜组织内任意位置进行精确切削。可用于角膜基质内切割、制作角膜基质环植入的切口、准分子激光原位角膜磨镶术中制作角膜瓣、完成飞秒激光角膜磨镶术,是一种全新的屈光不正矫正方法。     

飞秒激光角膜屈光手术后视觉质量

目前飞秒激光在角膜屈光手术的应用主要有两类,飞秒激光制作角膜瓣联合基质面行准分子激光切削(FS-LASIK)以及全飞秒激光手术;后者可分为飞秒激光基质透镜切除术(FLEx)和飞秒激光小切口基质透镜切除术(SMILE).本文回顾了与传统LASIK相比,FS-LASIK手术后裸眼视力、矫正视力、安全指数、有效指数的差别,FS-LASIK术后对比敏感度、高阶像差等客观视觉质量以及主观视觉质量问卷的影响;与FS-LASIK相比,FLEx对术后裸眼视力、波前像差等客观视觉质量以及主观满意的影响;并对三种手术方式的术后的安全性、有效性、可预测性以及在角膜知觉方面的优缺点进行综述.     

全飞秒激光在角膜屈光手术中应用的利与弊

飞秒激光基质透镜切除术(femtosecond lenticule extraction,FLEx)以及微小切口透镜切除术(small incision lenticule extraction,SMILE)是一类新的全飞秒激光角膜屈光矫正方式.该类术式具有较好的安全性、有效性、可操作性和可预测性.然而目前全飞秒激光的应用相对有限,手术技术要求较高,角膜表面质量还不够完美.因此,理性地看待全飞秒激光在屈光手术中的应用,认识其先进性及自身劣势,合理选择患者,扬长避短,对指导临床工作非常重要.     

飞秒激光用于角膜屈光手术应注意的问题

虽然大量的临床数据显示飞秒激光辅助下角膜屈光手术治疗屈光不正安全、可靠,但尚需在视觉质量上与常规方法相比较来证实。在飞秒激光角膜屈光手术中合理选择手术适应证,注意操作要点,个性化选择手术方案,防范并发症的发生是提高患者视觉质量的重要前提。（眼科, 2014, 23： 289-291）     

An in vivo model of femtosecond laser intrastromal refractive surgery

BACKGROUND AND OBJECTIVE: To develop an animal model for evaluation of femtosecond laser intrastromal refractive surgery. METHODS: Intrastromal photodisruption was performed in New Zealand Albino rabbits using a femtosecond laser system. This surgical pattern consisted of a 100 microm-tick pyramid of laser pulses starting 180 microm below the corneal surface. Animals underwent serial slit lamp examinations and corneal thickness measurements at 1,3,7,14, and 28 days, then monthly up to 1 year. RESULTS: Approximately 70 microm of central corneal thinning were seen at 1 week, remaining stable up to 7 months. CONCLUSIONS: Intrastromal photodisruption with femtosecond lasers produced consistent changes in corneal thickness without loss of corneal transparency. These changes were more stable than those produced with excimer laser procedures in a similar animal model.     

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。     

飞秒激光在角膜屈光手术应用中的并发症

飞秒激光是一种以脉冲发射的低能量红外线激光,具有切削精确、安全性高、重复性好等特点,可用于角膜屈光手术中制作角膜瓣、角膜基质内切割、制作角膜切口等。尽管飞秒激光的应用使得角膜屈光手术更加安全,但仍然存在一些不容忽视的并发症,本文就飞秒激光在角膜屈光手术中的并发症作一综述。     

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.     

飞秒激光角膜屈光手术的临床研究进展

目前飞秒激光已广泛应用于激光角膜屈光手术中.激光角膜屈光手术根据飞秒激光的应用可分为两大类:飞秒激光辅助的准分子激光角膜原位磨镶术(FS-LASIK)以及全飞秒激光角膜屈光术,即屈光性透镜取出术(ReLEx).ReLEx又可分为飞秒激光透镜取出术(ReLEx-flex,FLEx)和飞秒激光小切口透镜取出术(ReLEx-smile,SMILE).本文回顾了FS-LASIK手术中瓣的侧切角、厚度、直径、形状等参数的设置,SMILE术中切口大小、位置,以及飞秒激光能量、点间距等参数的最新设置;并对三种手术的预测性、安全性、有效性,对角膜知觉的影响及其优点和不足进行综述.     

正确看待全飞秒激光角膜屈光手术的临床优势与局限

全飞秒激光角膜屈光手术,尤其是飞秒激光微小切口角膜基质透镜切除术（SMILE）,由于其切口小、“无瓣”、角膜生物力学稳定等优势,临床上越来越受到关注,但是全飞秒激光角膜屈光手术与其他任何一种角膜屈光手术一样,既有其临床优势,又有其局限性,应正确看待全飞秒激光角膜屈光手术的临床优势与局限.     

Tissular and mechanical effects observed with an experimental femtosecond laser microkeratome for corneal refractive surgery

PURPOSE: Despite progress in mechanical microkeratomes used in refractive surgery, mechanical complications during cutting of the cornea still occur. Cutting by laser could reduce these complications and to date, the femtosecond laser is the only potential candidate for this purpose. Our study reports preliminary results with a femtosecond microkeratome for cutting porcine corneas ex vivo. METHODS: We first examined the fundamental principles of the interaction between the femtosecond laser and the corneal stroma, including the volume of tissue lesions, the laser breakdown threshold of the stroma and the laser ablation selectivity. We then analyzed the quality of cutting corneal flaps with the laser, focusing on collateral tissue effects and the roughness of the interfaces observed both histologically and with scanning electron microscopy. RESULTS: The photoablative and photodisruptive effects were very similar with the femtosecond laser. This characteristic is specific to ultrashort impulsion photodisruptor lasers and allows for a very precise surgical procedure. The laser-induced breakdown threshold of porcine corneal stroma was found to be 0.55 J/cm2. Collateral tissue lesions were on the submicrometer level. The roughness of the stromal bed was optimal for postage stamp cutting, providing very many contiguous points of impact which were as spherical as possible. CONCLUSION: Corneal photodisruption with a femtosecond laser is reproducible and extremely accurate. The optomechanical parameters involved with this technique require great technological skill and should be placed in experienced hands.