Videographic and histologic comparison of Nd:YAG and diode laser contact transscleral cyclophotocoagulation

We performed contact transscleral cyclophotocoagulation in two human autopsy eyes with continuous-wave Nd:YAG and diode lasers. Duration of exposure was two seconds, and powers were 4 to 7.3 W with the Nd:YAG laser and 1.75 to 2.5 W with the diode laser. In both procedures, we used hand-held quartz fiberoptic contact probes for energy delivery. Tissue responses were viewed with high-magnification videographic recording technique to analyze the real-time laser effects. The treated tissues were then studied by light microscopy. We observed different tissue responses both videographically and histologically. Nd:YAG laser lesions were characterized by prominent tissue whitening and contraction of the ciliary epithelium, while the diode laser lesions had less whitening and the tissue contraction appeared to be deeper in the ciliary body. The histologic correlate was coagulation and disruption of the ciliary epithelium and little effect on the underlying ciliary muscle with the Nd:YAG laser, while the diode laser had less effect on the ciliary epithelium but caused a significant coagulative response in the ciliary muscle. Comparative trials are needed to establish the clinical significance of these videographic and histologic observations.     

Long-term outcome of initial ciliary ablation with contact diode laser transscleral cyclophotocoagulation for severe glaucoma. The Diode Laser Ciliary Ablation Study Group

PURPOSE: To learn the long-term outcome of ciliary ablation with diode laser contact transscleral cyclophotocoagulation (TSCPC) in eyes with recalcitrant, severe glaucoma. METHODS: Twenty-seven eyes of 27 patients with medically and surgically uncontrollable glaucoma and no previous ciliary ablation enrolled in this study. After baseline measurements and informed consent, the authors performed contact TSCPC. There were 14 pseudophakic, 7 aphakic, and 6 phakic eyes; 15 of these had primary open angle glaucoma and the remainder had various secondary or open- or closed-angle glaucomas. Median follow-up was 19 months (range, 6 weeks to 27 months). Initially after laser surgery, glaucoma medications were continued, except for a 2-week interruption of miotics; the ophthalmologist later adjusted medications in accordance with the patient's status. The authors define failure of TSCPC in two ways, based on IOP measurements during two consecutive study examinations 6 weeks or more after intervention or at the final examination: (1) less than 20% intraocular pressure (IOP) reduction from baseline, and (2) either less than 20% reduction of IOP from baseline or IOP greater than 22 mmHg. RESULTS: For 27 eyes, the baseline IOP (mean +/- standard deviation) was 36.4 +/- 12.4 mmHg (range, 20-70 mmHg). The mean IOP at last examination was 20.3 +/- 8.7 mmHg. With failure definition 1, the cumulative probability of success was 84% at 1 year and 62% at 2 years. With failure definition 2 the cumulative probability of success was 72% at 1 year and 52% at 2 years. At the last examination, 19 eyes (70%) had visual acuity improved within one line of visual acuity at eligibility. One of these eyes, with light perception vision at entry, declined to no light perception. Three eyes (11%) lost two lines of vision and five (19%) lost three or more lines. CONCLUSIONS: Contact diode laser TSCPC yields long-term improvement of IOP and preservation of visual acuity in a substantial proportion of eyes with severe, medically uncontrolled glaucoma.     

Transscleral cyclophotocoagulation with the diode laser for neovascular glaucoma

Despite a high prevalence of canine dirofilariasis, there is no case of pulmonary dirofilariasis reported from Thailand. We herein report a case of multisystem Langerhans cell histiocytosis who had an incidental pulmonary dirofilariasis found at the time of autopsy as a solitary nodule at the periphery of the right lower lobe. This is the first reported case in Thailand. Association between pulmonary dirofilariasis and Langerhans cell histiocytosis has not been described before in the literature.     

A clinical comparison of transscleral cyclophotocoagulation with neodymium: YAG and semiconductor diode lasers

PURPOSE: To compare the efficacy of transscleral cyclophotocoagulation using a neodymium: YAG (Nd:YAG) or semiconductor diode laser in controlling intraocular pressure in patients with refractory glaucoma. METHODS: In a prospective study, 95 eyes of 91 patients with refractory glaucoma randomly received Nd:YAG or diode cyclophotocoagulation. Patients were followed for a mean of 10.4 months (10.42 +/- 3.16, mean +/- SD). We compared available data preoperatively and at 1 week, 1 month, 6 months, and 12 months postoperatively. Data analyzed were corrected visual acuity, intraocular pressure, and the type of glaucoma. RESULTS: There was a statistically significant decrease in intraocular pressure after both Nd:YAG and diode cyclophotocoagulation at each time period. However, there were no significant differences in postoperative intraocular pressure or visual acuity change between Nd:YAG and diode procedures. CONCLUSIONS: Compared with the Nd:YAG laser for transscleral cyclophotocoagulation, the diode laser has technological advantages including portability, durability, and smaller size, while providing equivalent postoperative intraocular pressure and visual acuity change.     

Intraocular pressure regulation after combined glaucoma and cataract operation

BACKGROUND: The success rate of combined glaucoma and small incision cataract surgery is not yet established. PATIENTS AND METHODS: Therefore, 56 eyes of 52 patients (mean age 79.0 years) having trabeculectomy combined with phacoemul-sification and implantation of a silicone posterior chamber lens were retrospectively investigated. RESULTS: The mean follow-up was 21.6 weeks. Due to the combined surgery the mean intraocular pressure decreased significantly (p < 0.001) from 21.8 to 14.8 mmHg. Seventy-five percent of the patients did not need any antiglaucomatous medication, while 25% still had to use a local medication, but less frequently. The overall visual acuity increased significantly (p < 0.001) from a preoperative value of 0.24 to 0.52 postoperatively. CONCLUSIONS: The results of combined glaucoma and cataract surgery seem as good as those reported for two separate glaucoma and cataract procedures.     

Pars plana vitrectomy with pars plana tube implantation in eyes with intractable glaucoma

Fas Ligand (FasL) can induce apoptosis of Fas-bearing cells. It is expressed on the cell surface of many tumor cells, immune-privileged tissues and activated lymphocytes. We report here that FasL can itself transduce signals, leading to cell-cycle arrest and cell death in CD4+ T cells. In vitro, FasL engagement inhibited CD4+ T-cell proliferation, cell-cycle progression, and IL-2 secretion. In vivo, FasL engagement prevented superantigen-mediated CD4+, but not CD8+, T-cell expansion. These findings demonstrate that FasL engagement regulates cell-cycle progression, and show that FasL engagement in vivo has a potent anti-inflammatory effect specific for CD4+ T cells.     

Treatment of retinoblastoma with the transscleral diode laser

PURPOSE: To report a case of retinoblastoma successfully treated by contact transscleral photocoagulation with a diode laser. METHODS: In an 18-month-old girl, a small (6.6 x 4.3 x 3.2-mm) discrete retinoblastoma anterior to the superotemporal arcade in the right eye was treated with transscleral photocoagulation using a diode laser (810 nm) and a fiberoptic probe. RESULTS: The tumor regressed after photocoagulation, leaving a pigmented chorioretinal scar. There was no regrowth of the tumor 12 months after photocoagulation. CONCLUSION: Contact transscleral photocoagulation with a diode laser may be a viable new treatment for small retinoblastoma.     

Phaco-emulsification of cataract in eyes with glaucoma

Previous observations on the dissemination of Coxiella burnetii between laboratory animals strongly support the hypothesis of venereal transmission. Serum and semen samples, from 57 bulls used for artificial insemination, were assayed for specific C. burnetii phase II antibodies and the presence of the organism respectively. Viable C. burnetii were detected in the semen of seropositive bulls. These findings indicate the possibility of sexual transmission of C. burnetii between cattle and further our knowledge of the epidemiology of the organism. The procedures used for investigations into the source of infection and route of tran-mission should be modified to take these findings into account.     

Effect of mitomycin C on aqueous humor flow, flare and intraocular pressure in eyes with glaucoma 2 years after trabeculectomy

BACKGROUND: The purpose of this study was to determine the intraocular pressure (IOP), aqueous humor flow, flare and ocular side effects in eyes with a history of hypotony after trabeculectomy with adjunctive mitomycin C (MMC). METHODS: Thirty-six eyes with primary or secondary open-angle glaucoma and IOP < or = 8 mmHg during the postoperative period were studied 745 +/- 315 days after surgery. MMC (0.2 or 0.5 mg/ml) was applied to the episclera with a cellular sponge. Flare was studied with the Kowa Laser Flare Meter 500. Aqueous humor flow was measured in the afternoon (Fluorotron Master II). IOP, visual fields and best corrected visual acuity were also examined. Twenty-two contralateral eyes without surgical intervention served as controls. RESULTS: The mean age of patients was 44.5 +/- 16.8 years. The mean IOP was significantly lower in the MMC group than in the control group: 9.6 +/- 6.4 mmHg vs 18.0 +/- 13.6 mmHg at 2 years (P < 0.001). Aqueous flow was significantly lower in subjects treated with MMC than in controls (P < 0.001). The flare values were significantly higher in the MMC-treated group, with a mean of 12.0 +/- 7.7 photon counts/ms, than in the control group, mean 7.9 +/- 4.6 photon counts/ms (P < 0.019). CONCLUSION: Our data suggest that MMC is a useful ocular hypotensive agent which seems to participate in a change in aqueous humor dynamics when applied topically as an aqueous solution.     

Tube-shunt surgery versus neodymium:YAG cyclophotocoagulation in the management of neovascular glaucoma

OBJECTIVE: To determine the relative effectiveness of neodymium:YAG (Nd:YAG) cyclophotocoagulation (CPC) and tube-shunt surgery on intraocular pressure (IOP) control in eyes with neovascular glaucoma (NVG). DESIGN: Retrospective, case-by-case matched, comparative group study. PARTICIPANTS: Twenty-four patients with NVG treated with noncontact Nd:YAG-CPC were matched with 24 patients who underwent tube-shunt surgery. Matching criteria included the underlying disorder causing angle neovascularization, the lens status, and patient's age. INTERVENTIONS: Tube-shunt surgery or Nd:YAG-CPC. MAIN OUTCOME MEASURE: Postoperative IOP (IOP > or = 6 and < or = 25 mmHg), visual acuity, and presence of any postoperative complications. RESULTS: Satisfactory IOP control (IOP < or = 25 mmHg and > or = 6 mmHg) was achieved in 9 eyes (37.5%) treated with Nd:YAG-CPC compared with 16 eyes (66.7%) receiving a tube-shunt procedure (P = 0.04) over a mean follow-up of 16.9 +/- 14.6 and 15.2 +/- 11.8 months, respectively. In the matched pairs in both groups that had nonequivalent outcomes, the proportions with persistently high IOP or hypotony were both greater in the CPC group than in the tube-shunt group. The cumulative proportion of failure in the CPC group was 20.8% at 6 months, 35.4% at 1 year, and 71.2% at 3 years postoperatively. In the tube-shunt group, the cumulative proportions of failure at 6 months and 1 year were close to those in the CPC group (12.5% and 29.2%, respectively), but lower 3 years after surgery (43.3%). Eleven eyes (45.8%) in the CPC group lost light perception versus four eyes (16.7%) in the tube-shunt group. Complication rate was higher in the tube-shunt group. CONCLUSIONS: This study suggests that, in the management of NVG, tube-shunt surgery more frequently controls IOP in a satisfactory range, with less hypotony and less visual loss, than noncontact Nd:YAG-CPC.     

Distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma

We investigated histo-chemically the composition and distribution of proteoglycans in the trabecular tissue of eyes with neovascular glaucoma. Cupromeronic blue in combination with a series of enzyme digestions and nitrous acid treatment were used. The spaces between the trabecular beams were lined by a single layer of vascular endothelium and were filled with red blood cells. A basal lamina and microfibrils were detected just beneath the newly formed vascular endothelial cells. Chondroitin-sulfate- and dermatan-sulfate-type proteoglycans were present in association with collagen fibrils in the extracellular matrix. Heparan-sulfate-type proteoglycans were present in association with the basal lamina of both the vascular endothelial cells and the trabecular cells. It is unlikely that these abnormalities in the type or distribution of proteoglycans in the trabecular meshwork have a major role in the pathogenesis of glaucoma.     

Histologic effect of diode laser sclerostomy in human cadaver eyes

BACKGROUND AND OBJECTIVES: To study tissue effects and thresholds of efficacy in producing a full-thickness scleral fistula in human eyes obtained from cadavers. The effect of laser sclerostomies created with indocyanine green (ICG) was also evaluated. MATERIALS AND METHODS: Ab externo laser sclerostomies were produced in 12 fresh human eyes obtained from cadavers using a 200-micron diameter fiber optic connected to a diode laser system. Power settings were 500, 750, 1000, 1250, 1500, and 2000 mW with a constant duration of 100 and 200 ms. The same diode laser settings were repeated in the tissues injected with ICG. RESULTS: The laser sclerostomies were associated with heat coagulation damage adjacent to the burn margins, with disruption of stromal collagen. Tissue damage was greater at higher power and longer duration. Scleral injection of ICG prior to laser sclerostomy did not enhance laser penetration. CONCLUSION: The diode laser can create a sclerostomy in human sclera with an optimum level of 1500 mW and 100 ms. ICG did not significantly enhance the ease of penetration or reduce the association thermal damage to the sclera.     

Glutamine immunoreactivity in Müller cells of monkey eyes with experimental glaucoma

Irritable bowel syndrome (IBS), a chronic disorder that includes symptoms such as abdominal pain and altered bowel habits, affects up to 22% of people in Western populations. The causes of IBS are not well understood, but are believed to be multifactorial. Although stress is widely believed to be implicated, empirical evidence in support of this is lacking, perhaps because a typical between-participants analysis ignores individual differences and therefore may obscure any link. The present study used a within-person, lagged time-series approach to investigate the links between everyday stress and symptomatology in 31 IBS sufferers. Both everyday stress and symptomatology exhibited serial dependence for a statistically significant proportion of sufferers. Multiple regression analysis carried out on same-day and lagged relationships up to and including 4 days found that, for over half the participants, everyday stress and symptoms were related. The best regression model was one in which symptoms were a function of hassles and symptoms on the previous 2 days, and hassles on the same day, fitting the data for 67% of participants. This prospective study confirms other studies that have suggested stress is a significant factor in IBS, and concludes that stress management programs may be both useful and cost-effective in the treatment of IBS.     

Longer-term visual outcome of eyes with retinopathy of prematurity treated with cryotherapy or diode laser

AIMS: Visual outcome of 66 eyes in 37 patients who had undergone treatment with either cryotherapy or diode laser for threshold retinopathy of prematurity was assessed. METHODS: 17 patients, representing 30 eyes treated with cryotherapy, were examined at between 56 and 98 months corrected age (median 68 months). 20 patients representing 36 eyes treated with diode laser, were examined at between 30 and 66 months corrected age (median 51 months). Structural outcome was categorised as: optimal--flat posterior pole; suboptimal--macular ectopia, optic nerve hypoplasia, retinal fold involving the macula, and retinal detachment involving the macula. RESULTS: Optimal structural outcome was, in the absence of amblyopia, associated with optimal visual acuity (of 6/12 or better) in all cases, with most eyes achieving a visual acuity of 6/9 or 6/6. Suboptimal structural outcome was invariably associated with suboptimal visual acuity. Amblyopia was present in eight out of 20 cryotherapy treated eyes and in five out of 26 laser treated eyes with an optimal structural outcome. Refractive errors were significantly less in laser treated eyes as was the incidence of anisometropic amblyopia. CONCLUSION: Eyes treated with either cryotherapy or diode laser for threshold retinopathy of prematurity with optimal structural outcome are associated with development of optimal visual acuity--that is, 6/12 or better. Treatment with either cryotherapy or laser does not in itself reduce the visual potential of these eyes.     

辊形配置对辊间接触压力与板形调控影响分析

为系统分析不同辊形配置下辊间接触压力分布形式与板形调控特性,以某1 800 mm热轧生产线使用的2种典型辊形配置为研究对象,建立对应的辊系有限元模型,计算不同带钢规格与调控手段下辊间接触压力分布形式,分析得出常规凸度支撑辊对应的辊间接触压力分布形式与CVC工作辊辊形呈现出明显的对应性,且压力分布形式受轧制规格与调控手段的影响明显小于CVC支撑辊。利用接触压力峰值和不均匀度表述辊间接触压力分布特征,将不同规格与调控手段对辊间接触压力分布特征的影响进行量化处理,得到更为具体的不同参量在整个变化范围内对分布特征的整体影响趋势。同时还对2种辊形配置下不同辊间接触压力对轧机板形调控特性影响进行分析,得出CVC支撑辊对应辊形配置的弯辊力与窜辊位置在板形调控能力上均强于常规凸度支撑辊辊形配置,而不同辊形配置对辊缝形状的影响表现出较为明显的差异,引入辊间接触压力边中比得到调控特性与辊间接触压力之间的具体关系,并结合现场的实际生产数据对仿真分析结果进行验证,研究结果可为现场辊形配置与板形调控提供较好的理论基础和生产指导。     

辊形配置对辊间接触压力与板形调控影响分析

为系统分析不同辊形配置下辊间接触压力分布形式与板形调控特性,以某1 800 mm热轧生产线使用的2种典型辊形配置为研究对象,建立对应的辊系有限元模型,计算不同带钢规格与调控手段下辊间接触压力分布形式,分析得出常规凸度支撑辊对应的辊间接触压力分布形式与CVC工作辊辊形呈现出明显的对应性,且压力分布形式受轧制规格与调控手段的影响明显小于CVC支撑辊。利用接触压力峰值和不均匀度表述辊间接触压力分布特征,将不同规格与调控手段对辊间接触压力分布特征的影响进行量化处理,得到更为具体的不同参量在整个变化范围内对分布特征的整体影响趋势。同时还对2种辊形配置下不同辊间接触压力对轧机板形调控特性影响进行分析,得出CVC支撑辊对应辊形配置的弯辊力与窜辊位置在板形调控能力上均强于常规凸度支撑辊辊形配置,而不同辊形配置对辊缝形状的影响表现出较为明显的差异,引入辊间接触压力边中比得到调控特性与辊间接触压力之间的具体关系,并结合现场的实际生产数据对仿真分析结果进行验证,研究结果可为现场辊形配置与板形调控提供较好的理论基础和生产指导。