Histological characteristics of ocular structures after YAG-laser exposure of various sections of the crystalline lens in experimental studies]

This work was aimed at analysis of all the aspects, pathomorphologic included, of short-pulsed YAG laser exposure of the lens. Experiments were carried out with 79 rabbit eyes. After laser exposure the eyes were enucleated in 1-24 h and in 7-10 days. Thirty-one eyes were subjected to YAG laser ++capsule puncture. Fragmentation of intracapsular structures was carried out in 23 eyes. Combined operations were performed on 25 eyes. Every series comprised two groups, differing by the energy of laser exposure: 3-5 mJ. Histologic analysis has lead the authors to the following conclusions. The pattern and severity of pathomorphologic changes were directly related to the energy and time of laser exposure and site of the focal plane of irradiation. The major destructive shifts after YAG laser fragmentation of the cortical layer and capsulotomy are focussed at the site of exposure and involve the adjacent sections of the lens. Laser exposure of 3-5 mJ may be used to open the anterior capsule of the lens and to facilitate the cataract mass discharge in extracapsular cataract extraction. Use of combined method helps enhance induration and fragmentation of the cortical layers of the lens, rules out surgical discission of the anterior capsule of the lens, and facilitates removal of the nucleus and wash out of the lens mass.     

The results of removing a transparent lens in Marfan's syndrome

In 112 eyes of 65 patients a clear lens in the Marfan's syndrome was removed through the approach in the flat part of the ciliary body. Before operation, in all patients who had peripheral degeneration of the retina peripheral prophylactic argon laser coagulation of the retina was made. At the time of operation, in 12 eyes some pieces of lenticular substance penetrated into anterior segments of the vitreous body, which in all cases was removed by means of a lens vitreotome. One month after lensectomy, in 1 patient retinal detachment developed that totally reattached after surgical intervention. In 99 eyes (88.4%) visual acuity improved after surgery as compared with that before surgery. The analysis of the obtained results has shown that transciliary lensectomy is a reliable method of surgical treatment for subluxation of a clear lens in the Marfan's syndrome.     

Effects of laser fragmentation of the lens mass on ocular tissues in experimental animals]

Side effects of laser on the posterior corneal epithelium and the retina during intracapsular YAG laser fragmentation of transparent lens fibers in various modes of laser operation were experimentally studied. The pulse power varied from 3 to 7.7 mJ, number of pulses from 55 to 160, length of exposure 10(-8) sec, diameter of the spot in the focus 30 microns. Animal eyes were enucleated on days 3-6 after the procedure. Posterior corneal epithelium was examined in the Hitachi scanning electron microscope, the retina in a light microscope. The findings evidence that injury to the posterior corneal epithelium in intracapsular YAG laser fragmentation of the lens depends mostly on the number of pulses and not on the exposure energy. A safe number of coagulates should not surpass 100, this being quite sufficient for fragmentation of the lens fibers at exposure power of 5-6 mJ. Such operation mode is safe for the retina as well, this recommending it for clinical use.     

Primary implantation of posterior chamber lenses after traumatic cataract peneration

PURPOSE: To analyze the postoperative outcome and complication rate after phacoemulsification, lens aspiration or lensectomy with primary intraocular lens (IOL) implantation after traumatic cataract penetration. METHODS: We retrospectively reviewed the data of 15 patients who were admitted to our hospital from 1997 to 2001 because of traumatic cataract with corneal laceration with and without intraocular foreign body (IOFB). In all patients phacoemulsification, lens aspiration or lensectomy and primary IOL implantation were performed. Removal of IOFB was performed in 6 patients. RESULTS: The mean follow-up was 19.6 months, 8 eyes (53%) achieved a final visual acuity of 20/40 or better and 12 eyes achieved 20/100 or better final visual acuity. One patient (final visual acuity=1/40) had an additional macular pathology. Due to irregular astigmatism two patients achieved a final vision of less than 20/100. Major causes of limited visual acuity were central corneal scars and in one patient a photopic maculopathy. Four eyes (25%) developed secondary cataract and underwent YAG laser capsulotomy. In one patient PVR retinal detachment had to be treated by pars-plana vitrectomy with silicone oil tamponade. CONCLUSIONS: Primary implantation of posterior chamber lenses after penetrating ocular trauma is associated with a favourable visual outcome and a low rate of postoperative complications.     

Extracapsular cataract extraction in diabetic eyes

Cataract surgery may exacerbate preexisting diabetic retinopathy. Especially diabetics with active retinal neovascularisation are at high risk of rubeosis iridis after intracapsular cataract extraction. Thirty-five eyes previously treated with panretinal photocoagulation underwent extracapsular cataract extraction with posterior chamber lens implantation. Twenty-eight eyes with retinal neovascularisation required further Argon laser PRP after surgery. Fourteen eyes required YAG-laser capsulotomy. From the group of eyes without YAG-laser capsulotomy none developed neovascular glaucoma. From the YAG laser capsulotomy group six eyes developed rubeosis iridis and neovascular glaucoma. Our results indicate that eyes in which PRP has been performed, have an excellent prognosis after ECCE with posterior chamber lens implantation only if YAG Laser posterior capsulotomy is not performed.     

Nd:YAG laser photodisruption of the lens nucleus before phacoemulsification

We studied the use of Q-switched Nd:YAG laser pulses to soften sclerotic lens nuclei before phacoemulsification. We obtained 105 lens nuclei from extracapsular cataract extractions, graded them for degree of sclerosis, and randomized them into laser treatment (53 lenses) or control groups (52 lenses). The treated lenses received laser pulses until confluent pits and clefts were visible. All lenses were phacoemulsified and the times recorded. Nd:YAG laser pretreatment decreased phacoemulsification time in all grades. In moderately sclerotic nuclei, average phacoemulsification time was reduced from 40.1 to 23.9 seconds (40.4%). The nuclei of ten lenses obtained from intracapsular cataract extractions were treated intracapsularly, and the posterior capsule was inadvertently ruptured in five.     

Cataract surgery after injection of silicone]

Thirty eyes were studied retrospectively, after cataract surgery following intraocular silicone oil injection. Cataract surgery took place before silicone oil removal in 9 eyes, at the same time as silicone oil removal in 2 eyes, and after silicone oil removal in 19 eyes. Extracapsular extraction was performed in 27 eyes, and intracapsular extraction was performed in 3 eyes. A posterior chamber intraocular lens was placed in 14 cases, and an anterior chamber intraocular lens in one case. Capsular fibrosis was observed in 19 cases, and it was treated with YAG laser in 10 eyes during follow-up. Twenty five eyes had a postoperative follow up of 3 to 37 months. Total retinal detachment occurred in 2 eyes.     

Effect of cataract surgery on intraocular pressure reduction obtained with laser trabeculoplasty

Thirty-nine eyes of 34 patients with open-angle glaucoma who had been treated successfully with argon laser trabeculoplasty underwent either extracapsular cataract extraction with posterior chamber intraocular lens implantation or intracapsular cataract extraction without lens implantation. Cataract surgery did not have a significant effect on the magnitude of intraocular pressure reduction obtained with laser trabeculoplasty. This study supports the view that eyes with coexisting cataract and glaucoma may benefit from laser trabeculoplasty before cataract surgery.     

New modified method of phacoemulsification in lenticular subluxation

A new method for cataract removal by phacoemulsification in impaired lenticular joints consists in fixation during surgery of the anterior lenticular chamber along the edge of the capsulorrhexis by 4 retractor hooks and subsequent implantation of a soft intraocular lens. The operation was performed in 6 patients with cataracts of different types complicated by subluxation of the lens. The operation did not involve such complications as vitreous prolapse or displacement of the incompletely dislocated lens. All operations were finished with complete evacuation of lenticular mass and implantation of soft silicone intraocular lenses. The proposed method widens the category of patients in whom modern phacoemulsification can be used.     

Pars plana lensectomy by ultrasonic fragmentation: I. A versatile and simple technique for cataract removal

A comparison has been made between pars plana lensectomy and intracapsular cataract extraction. Pars plana lensectomy has been shown to have many advantages. It is applicable to any age, while intracapsular cataract extraction is restricted to patients over 30 years old. It can be used in any type of cataract, whereas intracapsular cataract extraction is restricted to senile cataracts. It requires less patient preparation, less instrumentation, and less surgical dexterity than does intracapsular cataract extraction. It allows intraocular examination at the time of surgery. It can be combined with other surgical procedures (intraocular lens implantation, vitrectomy, cryoretinopexy, scleral buckle, etc.). It leaves the eyes in better condition postoperatively with fewer postoperative complications, and it gives good or better visual results than intracapsular cataract extraction.It is now unnecessary to learn (and teach) multiple techniques to handle different ages and types of cataracts since pars plana lensectomy manages them all with fewer complications.     

晶状体脱位的手术方式选择探讨

目的 探讨晶状体脱位３种手术方式（晶状体捞出、切除、粉碎）的选择依据和方法。方法２７例（３０眼）晶状体脱位病例资料，按不同术式分组，对其临床表现、术式特点和并发症进行了观察分析。结果 ３种术式的手术效果良好，视力均有不同程度的提高。但切除法手术并发症相对较多。结论 晶状体脱位的部位、核的硬度以及眼前后段的状态等是术式选择的重要参考依据，多因素综合分析是确定术式的基本途径。     

Capsular block syndrome associated with femtosecond laser-assisted cataract surgery

We report intraoperative capsular block syndrome occuring during the first 50 femtosecond laser-assisted cataract surgeries performed in our facility. Two patients had uneventful combined laser fragmentation, capsulotomy, and corneal incision procedures. In both cases, following transfer to the operating room and manual removal of the laser-cut capsulotomy, posterior capsule rupture was noted during hydrodissection, resulting in posterior dislocation of the lens. Pars plana vitrectomy, removal of the crystalline lens, and sulcus implantation of an intraocular lens were performed in both patients with good visual outcomes. Femtosecond laser-assisted cataract surgery changes the intraoperative environment with the generation of intracapsular gas and laser-induced changes in the cortex. With awareness of the changed intraocular environment following laser lens fragmentation and capsulotomy and a modification of the surgical technique, no additional cases of intraoperative CBS have been seen in more than 600 laser-assisted cataract surgery procedures performed to date at our facility. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosure is found in the footnotes.     

Non-contact holmium:YAG laser thermal keratoplasty for hyperopia: two-year follow-up

PURPOSE: We evaluated the safety and efficacy of the non-contact holmium:YAG laser thermal keratoplasty (LTK) for the treatment of mild to moderate hyperopia without astigmatism. METHODS: A prospective, non-comparative case series included 50 eyes of 28 patients (aged > or =40 years) who had stable refraction and an astigmatic component < +0.50 diopters (D). We applied the non-contact pulsed holmium:YAG laser to treat the hyperopic spherical component using the Hyperion LTK System. All patients had minimum 12-month follow-up and 64% (18 patients) had 24-month follow-up. RESULTS: The mean age of patients was 48.4 +/- 8.23 years (range: 40 to 62 years). The preoperative hyperopic mean spherical equivalent refraction was +2.32 +/- 0.975 D (range: +1.00 to +4.75 D). Postoperatively, the subjective manifest refraction decreased from the preoperative mean value of +2.32 D to a mean -0.09 D at 1 month after surgery and regressed to +0.315 D at the last follow-up examination, resulting in a mean correction of +2.005 +/- 0.81 D at 24 months after surgery. Preoperatively, mean uncorrected visual acuity in LogMAR units was 0.798 +/- 0.353 and at 12 months after surgery, it was a mean 0.108 +/- 0.136. Keratometric power increased from 42.595 +/- 1.949 D before surgery to 44.605 +/- 1.626 D at 24 months after surgery. CONCLUSIONS: Holmium:YAG LTK was an acceptable alternative for the correction of mild to moderate hyperopia in this middle-aged population.     

中高度近视选择LASEK术前的预防性视网膜光凝的疗效观察

目的:评价中、高度近视选择LASEK术前的预防性视网膜光凝的疗效。方法:对中、高度近视患者279例551眼术前美多丽滴眼液充分散瞳后,用90D裂隙灯前置镜或三面镜详细检查眼底,明确有视网膜变性(格子样变性、蜗牛样变性、囊样变性等)或(伴)有干性裂孔共18例26眼,行倍频Nd:YAG532nm激光治疗并选择LASEK手术矫正近视。结果:对18例26眼行预防性倍频Nd:YAG532nm激光光凝术后周边视网膜变性及干性裂孔区封闭良好,色素斑形成明显。LASEK术后6～18mo随访,没有发生孔源性视网膜脱离。结论:对明确有视网膜变性或(伴)干性裂孔预防性行倍频Nd:YAG532nm激光光凝术及选择LASEK术矫正近视是预防准分子激光术后出现孔源性视网膜脱离的重要措施。     

Preliminary results of primary implantation of flexible intraocular lenses in infants under 1 year of age

The paper presents the results of surgical treatment in 12 (12 eyes) infants aged 3 to 11 months who had different forms of unilateral congenital cataract. The surgical techniques involved the following stages: formation of a sclerocorneal tunnel cut, 3.5 mm in width, anterior continuous circular capsulotomy (anterior capsular rhexis), aspiration-irrigation techniques for removal lens masses, implantation of a flexible intraocular lens (IOL) into the capsular sac, graded opening of the posterior capsule with anterior vitrectomy in some infants. The authors could achieve symmetrical capsular rhexis in 75% and intracapsular IOL fixation in all the cases. During 3-month-to-2-year follow-ups after surgery, IOL held its position in the capsular sac; IOL dislocation and lenticular body capture were not observed in any case.     

Unilateral lens extraction for high anisometropic myopia in children and adolescents.

INTRODUCTION: A subpopulation of children with anisometropic myopia, amblyopia, and neurobehavioral disorders is noncompliant with spectacle wear and ill-suited to correction using contact lenses. We report the results of refractive surgery in a series of these children treated using lensectomy alone (clear lens extraction) or lensectomy with simultaneous implantation of an intraocular lens (refractive lens exchange). METHODS: Clinical course and outcome data were collated retrospectively in a group of 7 children and adolescents (mean age, 9.1 years; range, 4-20 years) with neurobehavioral disorders and noncompliance with spectacle wear for anisometropic myopia. Myopia in the 7 eyes ranged -11.9 to -24.5 D (mean, -16.7 D). Goal refraction was 0 to + 4 D. Correction was achieved by lensectomy in 5 eyes and lensectomy with intraocular lens implantation in 2 eyes. Primary posterior capsulectomy/subtotal vitrectomy was performed during the primary procedure in 5 eyes (71%). Mean follow-up was 3.8 years (range, 0.5-5.4 years). RESULTS: Myopia correction averaged 17.3 D. A total of 86% (6 eyes) were corrected within +/- 3 D of the goal refraction and the remaining 14% to within +/- 4 D. Uncorrected visual acuity improved postoperatively in all 7 eyes, albeit modestly (average gain 0.14 Snellen fraction; gain from a mean 20/2550 to a mean 20/130). Myopic regression averaged approximately 0.43 D/year. Capsular opacification necessitated YAG-laser membranectomy in the 2 eyes that had preservation of the posterior capsule at the primary procedure. Retinal detachment has not occurred in any of the eyes during the follow-up period. CONCLUSIONS: Refractive myopic lensectomy reduced high anisometropia and improved functional vision in children who have high myopia beyond the range of excimer laser correction and who will not wear glasses. Further study is indicated to determine the long-term safety of this procedure in similar pediatric populations.     

Scleral suspension pars-plana lensectomy for ectopia lentis followed by suture fixation of intraocular lens

PURPOSE: To describe a simple technique of scleral suspension-pars plana lensectomy (SS-PPL) in acquired and congenital ectopia lentis and scleral fixation of intraocular lens (IOL). MATERIALS AND METHODS: Twenty eyes of 16 patients (12 unilateral and 4 bilateral cases of "essential familial lens subluxation") aged 10-40 years (mean 25 years) underwent SS-PPL with implantation of scleral fixated IOL. Indications for surgery were best-corrected visual acuity < 6/18, bisection of pupil by the lens, and lens-induced glaucoma. Prerequisites for SS-PPL were, visibility of part of the lens in the pupillary area and soft lens. RESULTS: Postoperative visual acuity ranged from 6/6 - 6/36. Lens tilt in 3 cases(15%) and small decentration in 2 cases(10%) were seen; however these did not seriously compromise the visual result. Scant vitreous bleeding on the first postoperative day was seen in 3 cases (15%). CONCLUSION: The advantages of the scleral suspension of subluxated lens prior to lensectomy include stabilization; it allows proper viewing of the lens, avoids injury to the iris and ciliary body during lensectomy and reduces the possibility of dislocation of the lens.     

Recurrent endophthalmitis after neodymium: YAG laser capsulotomy

A 69-year-old woman underwent phacoemulsification and aspiration with intraocular lens implantation and sutureless wound closure in the right eye. Two days after cataract surgery, Staphylococcus aureus endophthalmitis occurred and was treated successfully. After neodymium: YAG laser capsulotomy 9 1/2 months later, endophthalmitis recurred, and retinal detachment ensued. Vitreous and aqueous cultures were negative for bacteria. Vitrectomy and removal of the intraocular lens were performed. The inflammation diminished, and visual acuity returned to 0.2.     

超声乳化白内障吸出为主的睫状环阻滞性青光眼手术治疗模式探讨

目的探讨超声乳化白内障吸出为主的睫状环阻滞性青光眼治疗模式的可行性。设计回顾性病例系列。研究对象北京同仁医院青光眼滤过术后药物治疗无效合并有白内障的睫状环阻滞性青光眼患者12例12眼。方法对所有患眼优先行透明角膜切口超声乳化白内障吸出联合折叠式人工晶状体（IOL）植入术,必要时联合术中抽玻璃体水囊及房角分离术;无效者再行Nd：YAG激光晶状体后囊膜及玻璃体前界膜切开或前部玻璃体切割术。除常规检查外,手术前及手术后2周行超声生物显微镜检查。术后平均随访（15．8±5．2）个月。主要指标眼压、中央前房深度及视力变化。结果12眼中术前平均中央前房深度（0．38±0．17）mm,平均眼压（31．50±3．50）mmHg。5／12眼经单纯超声乳化白内障吸出折叠式IOL植入术联合房角分离术;5／12眼又联合Nd：YAG激光晶状体后囊膜及玻璃体前界膜切开术;2／12眼又联合前部玻璃体切割术。术后2周平均中央前房深度（2.31±0．37）mm;末次随访时平均眼压（14．60±4．80）mmHg;视力提高或不变。结论本文小样本的资料显示,药物治疗无效的睫状环阻滞性青光眼病例先行白内障超声乳化吸出术,无效者依次行Nd：YAG激光晶状体囊膜、玻璃体前界膜切开及前部玻璃体切割术的治疗模式是可行的。（眼科,2012,21：43-46）