Geerling G, Roider J, Schmidt-Erfurt U, Nahen K, Laqua H, Vogel A
Department of Ophthalmology, Medical University of Lübeck, Germany.
Br J Ophthalmol. 1998 May;82(5):504-9. doi: 10.1136/bjo.82.5.504.
AIMS/BACKGROUND: Compared with nanosecond (ns) pulses of conventional Nd-YAG lasers, picosecond (ps) laser pulses allow intraocular surgery at considerably lower pulse energy. The authors report initial clinical experiences using a Nd:YLF ps laser for the treatment of various indications for photodisruption.
A Nd:YLF laser system (ISL 2001, wavelength 1053 nm) was used to apply pulse series of 100-400 microJ single pulse energy at a repetition rate of 0.12-1.0 kHz. Computer controlled patterns were used to perform iridectomies (n = 53), capsulotomies (n = 9), synechiolysis (n = 3), and pupilloplasties (n = 2). Other procedures were vitreoretinal strand incision (n = 2) and peripheral retinotomy (n = 1). For comparison, 10 capsulotomies and 20 iridotomies were performed with a Nd:YAG ns laser. The ps laser cut of an anterior capsule was assessed by scanning electron microscopy (SEM).
Open, well defined iridectomies (mean total energy 4028 mJ, mean diameter 724 microns), were achieved at first attempt in 92% of the cases. In 64% an iris bleeding and in 21% an IOP increase of > 10 mm Hg occurred. All capsulotomies were performed successfully (mean energy 690 mJ/mm cutting length) but with a high incidence of intraocular lens damage. The attempted vitreoretinal applications remained unsuccessful as a result of optical aberrations of the eye and contact lens. Although ps laser capsulotomies and iridectomies required much higher total energy than ns procedures, the resulting tissue effects of the ps pulses were more clearly defined. SEM examination of a ps incision of the anterior lens capsule demonstrated, nevertheless, that the cut was more irregular than the edge of a continuous curvilinear capsulorhexis.
Series of ps pulses applied in computer controlled patterns can be used effectively for laser surgery in the anterior segment and are considerably less disruptive than ns pulses. The ps laser is well suited for laser iridectomies while the ns laser is preferable for posterior capsulotomies. As vitreoretinal applications remained unsuccessful, the range of indications for intraocular photodisruption could not be extended by the ps laser.
目的/背景：与传统Nd:YAG激光的纳秒（ns）脉冲相比，皮秒（ps）激光脉冲能以低得多的脉冲能量进行眼内手术。作者报告了使用Nd:YLF皮秒激光治疗各种光致破裂适应症的初步临床经验。
使用Nd:YLF激光系统（ISL 2001，波长1053 nm），以0.12 - 1.0 kHz的重复频率施加单脉冲能量为100 - 400微焦的脉冲序列。采用计算机控制模式进行虹膜切除术（n = 53）、囊切开术（n = 9）、粘连松解术（n = 3）和瞳孔成形术（n = 2）。其他手术包括玻璃体视网膜条索切开术（n = 2）和周边视网膜切开术（n = 1）。作为对照，使用Nd:YAG纳秒激光进行了10次囊切开术和20次虹膜切开术。通过扫描电子显微镜（SEM）评估前囊膜的皮秒激光切割情况。
92%的病例首次尝试就成功完成了开放、边界清晰的虹膜切除术（平均总能量4028 mJ，平均直径724微米）。64%的病例出现虹膜出血，21%的病例眼压升高>10 mmHg。所有囊切开术均成功完成（平均能量690 mJ/mm切割长度），但人工晶状体损伤发生率较高。由于眼睛和接触镜的光学像差，玻璃体视网膜手术尝试未成功。尽管皮秒激光囊切开术和虹膜切除术所需的总能量比纳秒手术高得多，但皮秒脉冲产生的组织效应更清晰。然而，对前晶状体囊膜的皮秒切口进行SEM检查发现，该切口比连续曲线形撕囊边缘更不规则。
以计算机控制模式施加的皮秒脉冲序列可有效用于眼前节的激光手术，且比纳秒脉冲的破坏性小得多。皮秒激光非常适合激光虹膜切除术，而纳秒激光更适合后囊切开术。由于玻璃体视网膜手术未成功，皮秒激光未能扩大眼内光致破裂的适应症范围。
