兔眼内窥镜下和经巩膜睫状体光凝术的组织病理学对比研究

目的探讨兔眼内窥镜下睫状体光凝术后组织病理学改变，并与经巩膜睫状体光凝术进行对比。方法正常灰兔5只，1只为正常对照，余每只兔随机选择1只眼行眼内窥镜下睫状体光凝术，另1只眼行经巩膜睫状体光凝术。术后第1、2、4、6周分别处死1只兔，取兔眼进行组织病理检查，对比睫状体病理改变及光凝部位的炎症反应。结果眼内窥镜下睫状体光凝术有效地破坏睫状突上皮细胞，光凝组织炎症反应轻，但均出现晶状体局限性混浊。经巩膜睫状体光凝术有效地破坏睫状突上皮细胞，但无色素上皮细胞有部分残留。结论与经巩膜睫状体光凝术相比，眼内窥镜下睫状体光凝术对无色素上皮细胞作用更彻底，对光凝部位的损伤轻微。     

内窥镜激光睫状体光凝术后的组织病理学改变

目的:观察内窥镜下睫状体光凝术后组织的形态和病理变化,提出激光能量和手术路径的选择原则。方法:采用角巩缘切口和睫状体平部切口对用于角膜移植的10只供体眼(猝死后24 h内使用)行内窥镜下睫状体光凝术。比较两种操作的优缺点,不同激光能量水平下睫状突的反应,并对光凝区行组织病理检查。结果:内窥镜下睫状突清晰可见,激光能量小于0.3W时,组织没有反应,大于0.6W则组织爆裂,能量0.4-0.6W时,睫状突变白挛缩。两种手术入口均可顺利到达睫状体区并进行手术。术后睫状体的组织病理改变主要表现为有色素的睫状上皮细胞和睫状体基质的蛋白质变性,细胞结构破坏,组织排列紊乱、挛缩,而非色素上皮细胞则保持结构完好。结论:内窥镜下能直观、准确地完成睫状体激光光凝手术,术后睫状体基质和睫状突色素上皮的破坏是内窥镜激光睫状体光凝术降低眼压的主要原理。     

内镜下睫状体光凝术的实验研究

目的探讨眼科内镜下二极管激光睫状体光凝术对眼压的影响及眼的组织学改变。方法将45只青紫蓝兔分成4组进行内镜下光凝,第1、2、3组术后观察眼压,在保持每个睫状突光凝程度一致的条件下,光凝不同的范围,依次为45°、90°和135°,术后观察眼压的变化。第4组做组织学检查。结果光凝术后,各组眼压均下降。经观察,第1组眼压又逐渐增高;第2组保持平稳;第3组出现过低的眼压。组织学检查,光凝后即刻睫状突上皮肿胀,基质血管扩张、充血。7d时,睫状突上皮大部分脱失,残存的上皮内以及上皮之间有较多囊肿。21d时,无色素上皮缺失或变薄,睫状突间质疏松程度减轻。光凝后3月,睫状体组织明显致密,有形成分减少。结论内镜下二极管激光睫状体光凝可以有效地破坏兔眼睫状突结构,光凝90°范围可以保持降压效果的稳定。     

兔眼内窥镜与经巩膜睫状体光凝术的组织病理学特点比较

目的比较内窥镜睫状体光凝术（ECP）与经巩膜睫状体光凝术（TSCP）的睫状体组织病理学改变特点,了解ECP的降眼压机制。方法取健康成年青紫蓝兔30只,选择1只眼行ECP,对侧眼行TSCP,另取2只兔为正常对照组。手术后的第1、3、5、7、14、28、42、56灭行裂隙灯及眼压测量。术后第7、14、28、42、56天分别随机抽取6只实验兔处死行组织病理学检查,光镜下观察2组光凝术后睫状体组织结构的改变以及邻近组织的损伤和炎症反应情况。结果与TSCP组相比,ECP组术后眼部炎症反应轻微但品状体混浊。ECP组术后各时间点降低眼压的幅度大于TSCP组（P〈0．01）。ECP组术后早期睫状突水肿、睫状体无色素上皮细胞破坏明显,42d后光镜下可见睫状体上皮细胞排列不规则及睫状突萎缩;TSCP组睫状突水肿、出血、结构破坏,而睫状体上皮细胞层破坏不充分,42d后可见睫状体萎缩、色素上皮和无色素上皮细胞不规则增生、巩膜变薄及睫状体基质瘢痕化。结论与TSCP相比,ECP对睫状突无色素上皮细胞的破坏更彻底,时邻近部位组织损伤轻微,但可引起品状体混浊。     

内窥镜睫状突光凝用于晶状体脱位继发青光眼

目的 探讨眼内窥镜下睫状突光凝对于挫伤性晶状体脱位继发青光眼联合手术的疗效。方法 对14例(14眼)晶状体脱位继发青光眼采取晶状体粉碎、超声乳化、晶状体切除或整体摘出，并联合玻璃体切除、内窥镜下睫状突光凝及人工晶状体经巩膜缝合固定术。术后观察视力、眼压及眼内组织反应等情况。结果 术前平均眼压52mmHg(1mmHg=0．133kPa)。术后1周平均眼压16mmHg。随诊平均5．9月，平均眼压19mmHg。术前视力≤0．1者11眼，术后视力≥0．3者11眼。未发现严重的手术并发症。结论 眼内窥镜下睫状突光凝，手术直观，定量准确，对周围组织损伤小，对于晶状体脱位继发青光眼有相当理想的手术疗效。     

经瞳孔睫状突光凝术治疗难治性青光眼

本文对于难治性青光眼用氩激光经瞳孔睫状突光凝固25例26只眼。26只眼中13只眼的眼压控制在2.74kPa(21mmHg)以下,眼压控制率为50%。其手术效果取决于光凝睫状突的范围。睫状突光凝术作为睫状体破坏手术方法之一,与睫状体冷凝相比,具有疼痛少、安全、并发症少的特点。     

内窥镜下睫状体光凝术治疗难治性青光眼

目的 探讨内窥镜下睫状体光凝术治疗难治性青光眼的方法和疗效。方法 对16例(16只眼)难治性青光眼先行三维闭合式玻璃体切除及晶状体切除，根据术前眼压情况，在内窥镜直视下行部分睫状体光凝。结果 以6mmHg≤眼压≤21mmHg为手术成功标准，在16只眼中，14只眼成功实施内窥镜下睫状体光凝术；另2只眼因玻璃体切除中发生再出血而无法窥见睫状突改为睫状体冷冻术。结论 内窥镜下行玻璃体晶状体切除合并睫状体光凝术治疗难治性青光眼，是一种相对安全、有效的方法。     

玻璃体切割联合睫状突光凝术治疗新生血管性青光眼

目的：对需行玻璃体手术且并发新生血管性青光眼的患者进行眼内睫状突光凝术,观察术后眼压控制效果及手术安全性。 方法：回顾12例14眼新生血管性青光眼患者,分别继发于糖尿病性视网膜病变、视网膜脱离术后及眼外伤。本术式主要是在玻璃体切除术后立即采用眼内光凝导管直接对睫状突进行光凝,直到睫状突出现白色萎缩或爆破音为止,曝光时间0.1~0.2ms,能量300~500mW。术后随访6mo,分别于术后1wk;1,6mo观察14只新生血管性青光眼的眼压和并发症情况。 结果：本研究发现11眼眼压出现明显下降至正常范围之内。光凝术后1wk平均眼压为16.7±14.4mmHg,1mo为15.7±8.8mmHg,6mo为12.9±4.5mmHg,与治疗前（39.6±10.0mmHg）相比差异具有统计学意义（P〈0.01）。随访期间3眼再次出现眼压升高,因其不具备再次玻璃体手术适应证而给予了经巩膜或内窥镜下睫状体突光凝术。随访期间患眼未出现眼内炎及眼球萎缩等并发症。 结论：眼内睫状突光凝与玻璃体手术同时进行,可同时处理原发疾病和青光眼。该术式可在直视下准确光凝睫状突,对治疗需要玻璃体切除术的新生血管性青光眼是一种较安全有效的方法。     

外伤性白内障晶状体半脱位囊袋张力环的应用

目的探讨对外伤性白内障合并晶状体半脱位进行囊袋张力环和人工晶状体植入联合玻璃体切除术、经巩膜睫状体光凝及内窥镜下睫状突光凝术、小梁切除术等的可行性。方法对8例(8眼)外伤性白内障合并晶状体半脱位,行超声乳化吸出、囊袋张力环囊袋内植入、折叠式人工晶状体植入,联合玻璃体切除术、经巩膜睫状体二极管激光光凝及内窥镜下睫状突二极管激光光凝术、非穿通小梁切除术、虹膜根部离断复位术。结果术后对8例随访1~6月,囊袋张力环和人工晶状体位置正,患者视力有不同程度的提高,在0.1~0.8之间,眼压均在17 mmHg(1 mmHg=0.133 kPa)以下。结论囊袋张力环是一种安全有效的新型辅助工具,它有提高手术安全性、防止人工晶状体偏位及减少并发症的优点,同时它可以联合其它手术一次治疗外伤性白内障晶状体半脱位、玻璃体浑浊、继发性青光眼及虹膜根部断离者。     

不同点数半导体二极管激光经巩膜睫状体光凝对兔眼压影响的实验研究

目的研究不同点数半导体二极管激光睫状体光凝对兔眼压的影响及其病理变化。方法用波长为810nm半导体二极管激光对2组灰兔进行睫状体光凝,采用相同的能量不同的点数,并设一组对照,记录4周的眼压变化情况及不良反应,4周后取兔眼标本做睫状体的病理切片。结果光凝后2组灰兔的眼压均下降,随时间的增加,眼压有所回升,2组灰兔术前术后眼压变化值比较差异有统计学意义(P<0.01),光凝后睫状体的病理变化主要为睫状上皮的破坏和睫状体基质血管的充血及出血,并且激光的点数越多,对睫状体的破坏程度越严重。结论半导体二极管激光睫状体光凝的降眼压效果和激光击射的点数有关,不同点数的激光对睫状体有不同程度的破坏作用。     

Comparison of acute structural and histopathological changes of the porcine ciliary processes after endoscopic cyclophotocoagulation and transscleral cyclophotocoagulation

BACKGROUND: The objective of this study is to investigate the acute histological effects of transscleral cyclophotocoagulation and endoscopic cyclophotocoagulation on the ciliary body and other structures of porcine eyes compared with untreated controls. METHODS: Transscleral cyclophotocoagulation and endoscopic cyclophotocoagulation were performed on porcine eyes. Detailed histological evaluations were performed with light and scanning electron microscopy of treated eyes and compared with untreated controls. RESULTS: Histological changes were observed with both light and scanning electron microscopy for all treated tissues. Tissue treated with transscleral cyclophotocoagulation showed pronounced tissue disruption of the ciliary body muscle and stroma, ciliary processes, and both pigmented and non-pigmented ciliary epithelium. Endoscopic cyclophotocoagulation-treated tissue exhibited pronounced contraction of the cilliary processes with disruption of the ciliary body epithelium, with less architectural disorginization and sparing of the ciliary body muscle. The sclera was not affected by either laser treatment. CONCLUSION: The endoscopic cyclophotocoagulation treatment caused less damage to the ciliary body compared with the transscleral cyclophotocoagulation when evaluated by light and scanning electron microscopy. Compared with transscleral cyclophotocoagulation, endoscopic cyclophotocoagulation appears to be a more selective form of cyclophotocoagulation resulting in less tissue disruption while achieving the goal of destroying ciliary body epithelium.     

Proof that the ciliary epithelium can regenerate.

Regeneration of the ciliary epithelium after cryo injury was investigated by light and electron microscopy. In addition, autoradiography done after [³H]thymidine incorporation, and, treatment with colchicine, a mitotic inhibitor, were employed to confirm the findings of regeneration.Histologically, cryo injury appeared to damage the pigment epithelium more severely than the nonpigmented epithelium. Two weeks after mild injury, both epithelia in the tips and lateral portions of the ciliary processes returned to a normal appearance under light microscope. When examined by electron microscopy four weeks were required for almost complete regeneration. Recovery of intraocular pressure slightly lagged behind the regeneration of the nonpigmented epithelium. In severely injured eyes we observed regeneration of the nonpigmented epithelium only. After colchicine treatment many mitotic figures were observed in regenerating nonpigmented epithelial cells. Autoradiographs indicated considerably more DNA synthesis in both epithelial cells of damaged processes than in the controls; however, nonpigmented cells showed more DNA synthesis than pigmented cells. The regenerative ability of the nonpigmented epithelial cell layer was greater than that of the pigmented epithelial cell layer.     

Comparison of acute structural and histopathological changes in human autopsy eyes after endoscopic cyclophotocoagulation and trans-scleral cyclophotocoagulation

AIM: To study the histological effects of trans-scleral cyclophotocoagulation (TCP) and endoscopic cyclophotocoagulation (ECP) on the ciliary body and other structures collected at autopsy and to compare with untreated controls. Materials and methods: TCP and ECP were performed on human eyes at autopsy. Detailed histological evaluations were perfomed using light microscopy and scanning electron microscopy on treated eyes and compared with untreated controls. RESULTS: Histological changes were observed with both light microscopy and scanning electron microscopy for all treated tissues. Tissue treated with TCP showed pronounced tissue disruption of the ciliary body muscle and stroma, ciliary processes, and both pigmented and non-pigmented ciliary epithelium. ECP-treated tissue exhibited pronounced contraction of the ciliary processes with disruption of the ciliary body epithelium, sparing of the ciliary body muscle and less architectural disorganisation. The sclera was not affected by either laser treatment. CONCLUSIONS: ECP treatment caused less damage to the ciliary body compared with TCP when evaluated by light microscopy and scanning electron microscopy. Compared with TCP, ECP seems to be a more selective form of cyclophotocoagulation, resulting in less tissue disruption while achieving the goal of destroying ciliary body epithelium.     

Variation of inflammatory reaction of ciliary body--harmony between clinic and basic science

Histopathological findings of ciliary epithelium and muscle were discussed in the inflammatory conditions that are induced in endophthalmitis, blood-aqueous barrier destruction, cyclocryotherapy and cyclophotocoagulation. The clinical results were also discussed regarding the reduction of aqueous production and uveoscleroplasty which are introduced by the experimental cyclophotocoagulation at the pars plicata/pars plana. Tissue destruction by inflammatory reaction occurred in not only the ciliary body but also in the retina if the endophthalmitis had progressed to the point of severity. The post-inflammatory reactive hypertrophy of nonpigmented and pigmented ciliary epithelium was mild at pars plicata and the anterior portion of the pars plana. On the other hand, it was severe at the posterior portion of the pars plana and the ora serrata, and it was clear that the cyclitic membrane developed into proliferative vitreoretinopathy. Adult pig cultured nonpigmented ciliary epithelium showed proliferated tissue resembling the cyclitic membrane. These results show that nonpigmented ciliary epithelium has a strong proliferative activity as much the same as fibroblasts. The destruction of the blood-aqueous barrier was produced by corneal perforation, paracentesis, prostaglandin E1 (PGE1) subconjunctival injection, and hyperosmotic agent intraophthalmic artery injection. The localization of the tissue destruction was made clear at the beginning portion of the ciliary process and the posterior part of the pars plana. The repetitive instillation of latanoprost and cyclosporin A eye drops showed the same localization of the tissue damage. These results suggest that the beginning portion of the ciliary process is vulnerable to inflammatory agents. Cyclosporin A might produce a toxic reaction on nonpigmented ciliary epithelium, and latanoprost destroys the blood-aqueous barrier. Cyclocryotherapy produces severe necrosis of the pigmented ciliary epithelium and melanocytes, and atrophy of pigmented ciliary epithelium and ciliary muscle, and the proliferation of nonpigmented ciliary epithelium follows. Because cyclocryotherapy is a blind therapy, hypotony and phthisis bulbi will occur if the pars plicata is damaged severely, and the intraocular pressure (IOP) decrease will not be achieved if pars plana is damaged locally. Finally, we demonstrated that it is difficult to predict the therapeutic outcome of cyclocryotherapy. Cyclophotocoagulation of the pars plicata and the pars plana produced severe necrosis of pigmented ciliary epithelium and melanocytes, and atrophy of pigmented ciliary epithelium and ciliary muscle, and the proliferation of nonpigmented ciliary epithelium followed. Cyclitic membrane was developed from the proliferation of nonpigmented ciliary epithelium depending on the severity of photocoagulation. From these experiments the complete destruction of the pars plicata might result in for hypotony and phthisis bulbi. The reduction of aqueous production for angle-closure glaucoma was achieved by moderate cyclophotocoagulation of the pars plicata. On the other hand, moderate cyclophotocoagulation of the pars plicata for open-angle glaucoma produced the obstruction of uveoscleral aqueous outflow which compensated for the reduction of aqueous production. From these results we suggested that moderate cyclophotocoagulation of the pars plana for open-angle glaucoma might be necessary to effect the increase of uveoscleral aqueous outflow. Moderate and severe cyclophotocoagulation of the transit area between the pars plicata and the pars plana might bring about reduction of aqueous production and the increase of uveoscleral aqueous outflow.     

Diode laser contact transscleral cyclophotocoagulation: getting the most from the G-probe.

BACKGROUND AND OBJECTIVE: To determine the multi-use behavior of the G-probe that is traditionally marketed as a single-use cyclophotocoagulation instrument. MATERIALS AND METHODS: A diode laser equipped with a G-probe was used to perform cyclophotocoagulation of the ciliary body in 4 human cadaver eyes and 15 porcine eyes (1,750 mW x 2 seconds). A determination of G-probe effectiveness was made following measurements of G-probe energy output, scanning electron microscopy examination of probe tips, and histologic examination of treated tissue. RESULTS: The mean energy output of 12 of the 15 G-probes remained constant at 3.10 J (range, 3.04 to 3.14 J) for 20 treatment cycles of 20 applications each. Scanning electron microscopy demonstrated minimal surface change. Three G-probes suffered a significant drop-off in energy output during the experiment, and scanning electron microscopy showed significant surface change. Histologic examination of human eyes treated with laser revealed disruption of the ciliary body stroma and separation of pigmented and nonpigmented layers of the ciliary epithelium. More pronounced tissue necrosis and disruption was observed in eyes treated with newer G-probes. Milder coagulative damage with cellular vacuolization was observed in G-probes used for higher numbers of treatment cycles. CONCLUSION: Every G-probe tested delivered more than 100 consecutive applications of laser energy before any loss of efficiency was noted. This suggests that in the absence of obvious structural damage, a G-probe may be safely used for treatment of at least 5 eyes.     

Alteration of the vascular supply in the rabbit ciliary body by transscleral diode laser cyclophotocoagulation

Background: Besides the direct destruction of the non-pigmented ciliary epithelium by cyclodestructive procedures, further mechanisms are responsible for the decrease of intraocular pressure. This study evaluates the alteration of the ciliary body vascularization by contact transscleral diode laser cyclophotocoagulation in rabbit eyes. Methods: Pigmented chinchilla bastard rabbits were used. Preliminary experiments were conducted to determine the parameters for diode laser cyclophotocoagulation of the pars plana or pars plicata. Then, treatment of the pars plicata (three rabbits) or pars plana (three rabbits) was performed in the right eye of six rabbits. After 2, 6 and 12 weeks histologic and transmission electron microscopic studies were performed. Furthermore, three rabbits received pars plicata cyclophotocoagulation of the right and pars plana cyclophotocoagulation of the left eye. After 2, 6 and 12 weeks, vascular casts of the ciliary body were investigated by scanning electron microscopy. Results: Histologic and transmission electron microscopic studies showed a marked coagulation necrosis with subsequent ciliary body atrophy, destruction of the ciliary epithelium, pigment dispersion in the ciliary body stroma and peripheral anterior synechiae. Examination of vascular casts of the ciliary body revealed a marked rarefication of the capillary network within the treated areas of the ciliary body in all eyes and at every time of investigation. Anterior to the laser burns the capillary network was not markedly affected in the eyes with cyclophotocoagulation of the pars plana. After 3 months short vessel sprouts were seen, but regeneration was mostly incomplete. Conclusions: The vascular casting technique is an excellent method for the investigation of changes in ciliary body vascularization after cyclodestruction. This study is the first to demonstrate a marked rarefication of the ciliary body vascularization after diode laser cyclophotocoagulation using vascular casts. The results suggest that alteration of vascularization probably acts as a strong synergistic mechanism in the decrease of intraocular pressure after cyclophotocoagulation of the pars plicata. Received: 27 June 2000 Revised: 16 August 2000 Accepted: 17 August 2000     

Histochemical observation of distribution of chloride ion around ciliary epithelium

Chloride ions are shown to be actively transported by the ciliary epithelium. The distribution of these ions around the ciliary epithelium was studied by electron microscopy: chloride ions were deposited as silver chloride (AgCl) in the tissue. Albino rabbits, bullfrogs and chick embryos just before hatching were used. In all the animals examined, the concentration of chloride ions was lower in the nonpigmented and pigmented epithelial cells of the ciliary epithelium than in the extracellular space. The chloride ions appeared to accumulate between the nonpigmented epithelial cells.     

Desmosomal-mitochondrial complexes in human nonpigmented ciliary and retinal pigment epithelia

In the normal human nonpigmented ciliary epithelium structural associations between mitochondria and desmosomes are described electron-microscopically: either a single desmosome or a linear array of several desmosomes joined by filamentous bundles is associated with one or two mitochondria (19.6 +/- 5.4%; n = 29). The frequency of occurrence of these complexes was studied in five different regions of the ciliary body; analysis of covariance revealed a significantly increased number of associations in the ciliary processes. Further, the age dependence of their occurrence was examined in 29 different age classes (15 to 86 years); correlation analysis revealed no correlation between age and number of associations. Similar complexes occur, in addition, in the retinal pigment epithelium, but have not been observed in ciliary pigmented, lens, iris and corneal epithelia. Desmosomal-mitochondrial complexes are considered to be a characteristic feature of basic physiological significance of certain epithelia only. The cytochemical demonstration of calcium in the associated mitochondria provides support for the hypothesis that the mitochondria may serve as buffers for intracellular calcium by controlling the local calcium concentration, thus increasing the stability and functional integrity of desmosomal junctions in secretory or actively transporting epithelia with high endogenous calcium levels.     

Regeneration of damaged ciliary epithelium in aphakic and pseudophakic eyes

Mechanically damaged ciliary epithelium in aphakic and pseudophakic rabbit eyes was studied for up to 2 years after extracapsular lens extraction.Histopathological examination of the epithelium revealed more severe damage in pseudophakic eyes. The nonpigmented epithelium (NE) was missing from the middle to basal portion of each ciliary process. Regenerative ability of the NE was extremely poor. The damaged NE continued to disappear for at least 2 years, and only the pigmented epithelium (PE) covered the stroma. In some of the affected areas, the stroma of the ciliary body (CB) was substituted by fibrous materials.Abbreviations NE nonpigmented epithelium - PE pigmented epithelium - CB ciliary body - IOL intraocular lens