上皮植入性虹膜囊肿的激光治疗

目的：观察Ｎｄ：ＹＡＧ激光治疗上皮植入性虹膜囊肿的疗效。方法：治疗前详细了解囊肿与周围组织的关系,首先激穿囊肿前壁,使腔内液体引流,然后降低能量,照射囊肿后壁及周围组织,以尽可能破坏上皮细胞,减少复发。激光治疗单脉冲能量为０．４ＭＪ,每次治疗总量为２０～３５ＭＪ。结果：所有治疗眼的视力均有不同程度提高。经术后６个月～１年的随访观察,未见明显复发。结论：激光治疗上皮植入性虹膜囊肿,既可破坏囊壁的上皮细胞,又可避免和减少囊肿邻近组织的损伤及反应,以尽可能多地保留和恢复有效视功能,以避免患者因再次手术所带来的痛苦,疗效满意     

微血管舒张功能障碍及体外反搏的改善作用

目的：通过测定微血管血流灌注来反映微血管的舒张功能,同时观察体外反搏治疗改善冠心病患者微血管舒张功能障碍的效果。方法：应用激光多普勒血流量计（ＬＤＦ） ,测量５８ 个被观察者的前臂皮肤在反应性充血前后微血管血流灌注增加比值,评价血流介导的微血管舒张功能。结果：冠心病组、高胆固醇血症组及吸烟组微血管舒张功能明显低于对照组,比值分别为１．８３±０．３７、２．６３±０．５１、３．１９ ±０．５６ 比３．５６±０．３６ ;Ｐ分别＜ ０．０１,＜０．０１,＜ ０．０５。冠心病组反搏治疗前后比,其微血管的舒张功能明显提高,比值为１．８３±０．３７ 比２．５４±０．４３; Ｐ＜０．０１。结论：ＬＤＦ可检测冠心病患者明显的微血管舒张功能障碍及高胆固醇血症者和吸烟者微血管功能的异常;体外反搏治疗可改善冠心病患者的微血管舒张功能。     

准分子激光PRK术后的临床分析

目的 对１１１眼屈光范围球镜在－３．００￣－１７．００Ｄ及柱镜在－０．５０Ｄ￣－４．５０Ｄ范围的患者进行了ＰＲＫ术后的分析。方法 采用美国ＶＩＳＸ２０／２０Ｂ准分子激光系统的最新软件包进行角膜切削,并行术前后的主客观验光及角膜透明度检查。结果与结论 准分子激光ＰＲＫ术是目前理想的屈光手术之一,特别对于中低度近视尤为适合,对高度近视则其预见性稳定性较差,并发症的发生并未成为影响术后效果的主要因素。     

Semiconductor diode laser transscleral cyclophotocoagulation versus filtering surgery with Mitomycin-C

Both filtering surgery with Mitomycin-C and diode laser cyclophotocoagulation have proved to be effective alternatives in cases of glaucoma with poor surgical prognosis. The right eyes of 40 pigmented rabbits were randomly divided into 2 groups: Mitomycin-C group underwent filtering surgery with application of 0.4 mg/ml of Mitomycin-C whereas the diode laser (DL) group received 15 applications of 1.8 J (1800 mW. 1000 ms) distributed in 270°. Mean IOP showed statistical differences in two periods between days 3–13 and 45–60 — Mann-Whitney U test — with a higher IOP lowering in the DL group. The comparison of IOP survival curves (Log-Rank test) was not significant p = 0.070809. Ocular hypertension, hyphema and inflammatory signs were higher in the DL group, both in short and long term, but in terms of statistical significance only ocular hypertension showed differences p = 0.00011717 - Fisher exact test. Microscopic examination revealed patent sclerostomies in 60% of the MMC group eyes with different grades of fibroblastic proliferation. In the DL group we observed necrosis of the sclieral stroma and of the pigmented and unpigmented ciliary epithelium, with signs of thermal coagulation of the ciliary stroma and of the stromal vasculature. We must point out that the treatment with laser has proved to be more effective although both treatments showed very acceptable IOP lowering until 2 months after the surgery.     

Induction of vascular haemostasis by Nd:YAG laser light in melanin-rich and melanin-free tissue

Haemostasis was effected in vessels of melanin-rich (MR: choroid) and melanin-free (MF: mesentery) rabbit tissue irradiated with a cw-Nd: YAG laser. The following parameters were employed: - pulse duration: 200 ms (MR) and 100ms (MF); focal spot diameter: 200 m (MR) and 80 m (MF); pulse energies: 100–250 mJ (MR) and 0.5-1J (MF); irradiances: 1.6–4.0kWcm^–2 (MR) and 1–2 × 10²kWcm² (MF). In melanin-rich tissue, laser energy is absorbed principally by melanin granules contained within the stromal melanocytes. The heat generated in these structures radiates into the surrounding tissue where it is dissipated. The damage thus incurred by the endothelium of blood vessels encompassed within this field triggers the haemostatic mechanism whereby blood flow is arrested. This effect is realized by the formation of an occluding plug of platelets, which is stabilized by the deposition of fibrin, particularly in capillaries, and to a lesser degree in larger vessels of the vascular lamina. In melanin-free tissue, haemoglobin serves as the primary site of energy absorption, which is thus shifted from the stroma to the vessel lumen. Irradiation of vessels in such tissue leads to thermocoagulation of plasma proteins and consequent stasis of blood flow.     

Uptake and localisation of O-(β-hydroxyethyl)-rutosides in the venous wall,measured by laser scanning microscopy

Summary The uptake and localisation of O-(-hy-droxyethyl)-rutosides (HR) in the venous wall was studied in 8 patients undergoing crossectomy for a varicose long saphenous vein. The fluorescence of cross-sections of the vein wall was measured by laser scanning microscopy, based on the autofluorescence of HR. Four patients (treated group) received 2 × 1.5 g HR IV before surgery, and four (untreated patients) served as controls.Uptake of HR into the veins from treated patients was seen, with a mean fluorescence intensity of 80.9 units compared to 49.4 units in the untreated veins. The increase in fluorescence was clearly demarcated on the endothelial side of the vein wall.It is concluded that HR passes into the vascular wall, where it is localised in the endothelial and sub-endothelial areas.     

Comparative study of low power neodymium-YAG laser interstitial hyperthermia versus ethanol injection for controlled hepatic tissue destruction

A solitary hepatic metastasis is amenable to surgery. However, if surgery is contraindicated or if multiple lesions are present in both liver lobes, other treatment modalities have to be considered. We compared the effect of interstitial laser hyperthermia with damage caused by alcoholization. Six anaesthetized beagle dogs were studied. Three animals were treated with laser hyperthermia. A bare laser fibre (400m diameter) was introduced through a 17-gauge needle, length 170 mm, positioned into the liver under real time ultrasonographic guidance. Lesions were produced by continuous 500-s exposure of 1W YAG laser (Medilas MBB 40N) power. Three dogs were subjected to an injection of 4 ml of 98% pure ethanol into the liver through the same needle system. Two days after the procedure the animals were killed and the livers examined. The surface of the livers treated with the YAG laser were entirely normal; superficial lesions were, however, clearly visible. Laserinduced lesions were well reproducible, clearly demarcated, roughly spherical with a mean diameter of 1.01±0.23 cm (n=16). In contrast, the dogs treated with alcohol had free intraperitoneal serohaemorrhagic fluid and the surface of the liver was diffusely abnormal. The lesions had a more or less cylindrical shape, 1.22±0.43 cm on 0.40±0.10 cm (n=12) although exact measurement was often difficult. The border of the lesions was irregular and there was a clear necrotic zone along the puncture track. On microscopic examination the laser-induced lesions consisted of a central evaporation area, a zone of carbonized material and an outer zone of coagulation necrosis. The alcohol-induced lesions were characterized by both fixation necrosis and coagulative necrosis but surprisingly, there was also necrosis present at a distance of the lesions extending along the centrilobular and even portal veins. These data show that laser-induced interstitial necrosis in the liver is better controlled and more reproducible than necrosis induced by injection of pure ethanol. Moreover, pure ethanol may cause damage to the liver surface and even at a distance of the injection site.     

Optical response of the cultured bovine lens; testing opaque or partially transparent semi-solid/solid common consumer hygiene products

This study determines the relative ocular lens irritancy of 16 common partially transparent or non-transparent consumer hygiene products. The irritancy was found by measuring the changes in the sharpness of focus [referred to as the back vertex distance (BVD) variability] of the cultured bovine lens using a scanning laser In Vitro Assay System. This method consists of a laser beam that scans across the lens, and a computer, which then analyses the average focal length (mm), the BVD variability (mm), and the intensity of the beam transmitted. Lenses were exposed to the 16 hygiene products and the lens’ focusing ability was monitored over 192 h. The products are semi-solids or solids (e.g. gels, lotions, shampoos). They are categorized into six groups: shampoos, body washes, lotions, toothpastes, deodorant, and anti-perspirant. Damage (measured by > 1 mm BVD variability) occurred slower for the shampoos, especially in the case of baby shampoo. The results indicate that shampoos exhibit the lowest level of ocular lens toxicity (irritability) while the deodorant is the most damaging.     

Use of the KTP-532 Laser in Acoustic Neuroma Surgery

The potassium titanyl phosphate (KTP-532) laser has been applied to otologic surgery with a proven record of both safety and efficacy. The aim of this study was to demonstrate the use, safety, and advantages of laser dissection in the surgical treatment of acoustic neuromas. The authors' experience with 111 patients in whom laser surgery was used in acoustic neuroma is presented, with emphasis on surgical technique employed and facial nerve functional outcome. The method of laser dissection did not result in deleterious neurologic sequelae or laser-specific complications. In addition, laser dissection afforded certain advantages to traditional techniques, especially in larger tumors. The facial nerve functional outcome as assessed by the House-Brackmann grading system revealed that 90.2% of small tumors, 72.2% of medium tumors, and 75.0% of large tumors achieved satisfactory (grades I and II) functional results. These results compare favorably with the literature describing nonlaser dissection techniques. The observations and results reported in this article demonstrate the safety of the KTP-532 laser in the posterior cranial fossa, and specific advantages that this technology may offer to the surgical armamentarium of the neuro-otologist are outlined.     

YAG激光与药物结合治疗文唇后接触性唇炎130例临床观察

目的探讨YAG激光与药物联合治疗文唇后接触性唇炎的疗效。方法随机选取130例文唇后接触性唇炎患者，应用美国Coherent公司生产的多功能多波长皮肤美容激光器（Nd：YAG激光）进行治疗，联合应用抗组胺药物等内服以及皮质类固醇激素外用。结果130例患者，完全治愈112例（占86．2％），显效16例（占12．3％），有效2例（占1．5％），无效为0，总有效率100％。结论YAG激光与药物结合治疗文唇后接触性唇炎获得满意疗效，具有创伤小，疗效高，副作用少，不留疤痕等特点。