经瞳孔温热疗法照射对视网膜组织中VEGF和MMP-1 mRNA表达的影响

目的研究经瞳孔温热疗法（transpupillary thermotherapy,TTT）照射对视网膜组织中血管内皮生长因子（vascular endothelial growth factor，VEGF）和基质金属蛋白酶-1（matrix metalloproteinase-1，MMP—1）表达的影响。方法使用唧照射正常灰免视网膜．激光参数为：3min光斑直径，1min曝光时间，450mW功率。每眼照射15点。于照射后1d、3d、7d、2周和3周处死动物并取视网膜组织。抽提RNA后使用RT-PCR方法进行扩增。结果与正常视网膜相比，TTT照射后1d和3d时VEGF mRNA表达降低，7d时恢复正常；MMP-1 mRNA在TTT照射后升高，持续至2周，3周时明显下降。结论TTT照射可能通过降低视网膜组织VEGF的表达来起到抑制新生血管的作用．TTT照射引起MMP-1的表达升高可能通过增加胶原成分的降解来促进新生血管纤维膜的回退。     

阈下能量经瞳孔热疗对正常大鼠视网膜的影响

目的 研究正常棕色挪威大鼠(BN大鼠)视网膜在810 nm激光阈下能量经瞳孔热疗(TTT)后的改变。方法 雄性BN大鼠36只，使用810 nm激光，采用不同阈下能量对BN大鼠进行TTT。分别于TTT后第1、3、7、14 d进行彩色眼底照相和眼底荧光造影(FFA)。TTT后6、12h，1、3、7、14d各处死6只大鼠，进行组织病理学观察。6、12h和1 d的组织用TdT介导dUTP缺口末端标记法(TUNEL)检查细胞凋亡。结果 TTT后第1 d可见大部分光斑处视网膜灰白色水肿。第3 d视网膜水肿减轻，RPE脱色素。其后视网膜逐渐出现色素沉着。FFA中可见到不同程度的高荧光。组织病理学切片上可见所有在眼底照相上曾出现灰白水肿的病灶，视网膜结构均有显著破坏。TUNEL染色可见视网膜全层均有细胞凋亡。TTT能量最低组6 h时凋亡细胞最多；激光斑旁视网膜较激光斑中央视网膜凋亡细胞多。结论 TTT阈下能量可引起不可逆的视网膜损伤，即使无病理改变也能引起视网膜细胞的凋亡。     

经瞳孔温热疗法治疗脉络膜新生血管

目的 初步观察TTT激光治疗脉络膜新生血管的疗效。方法 23例24眼CNV行TTT（transpupillary thermotherapy，TTT）治疗，根据CNV（choroidal neovascularization，CNV）的大小选择不同的光斑大小和能量，照射时间为1分钟。结果 24眼CNV经TTT治疗后，大部分患者黄斑出血、渗出、水肿减轻或吸收，FFA显示大多数CNV渗漏减少或停止，原CNV瘢痕化，但视力无明显提高。结论 TTT盯治疗脉络膜新生血管有效，但还需要更多的病例来评价治疗效果。     

经瞳孔温热疗法(TTT)治疗高度近视黄斑部视网膜下新生血管

目的：观察TTT激光治疗高度近视黄斑部视网膜下新生血管的疗效结果。方法：15例17眼高度近视黄斑部视网膜下新生血管患者行TTT治疗。结果：15例17眼OCT显示治疗后黄斑水肿减轻，FFA显示治疗后渗漏减少或消失，视力无明显提高。结论：TTT激光治疗高度近视黄斑部视网膜下新生血管有效，安全。     

经瞳孔温热疗法治疗高度近视眼的脉络膜新生血管

目的：评价经瞳孔温热疗法(tmmpupillary ther-motherapy,TTT)治疗高度近视眼的黄斑区脉络膜新生血管膜(choroidal meovascularization,CNV)的疗效。方法：对17例21眼黄斑区具有QⅣ的高度近视患者进行TTT治疗，并定期随访，观察治疗前后视力、眼底、眼底荧光造影(fundus fluores-cein angiogmphy，FFA)及吲哚青绿眼底血管造影(indocyanine green angiogaphy，ICGA)的变化。结果：治疗后21眼中视力提高仅4眼，稳定8眼，下降9眼。治疗过程中有4眼发生脉络膜出血，1眼治疗后CNV仍反复生长。最终有16眼眼底出血渗出的情况得到改善。结论：经瞳孔温热疗法可以减少因脉络膜新生血管膜而引起的出血及渗出，加速疤痕化，对封闭黄斑区CNV有一定的疗效，但高度近视患者的CNV进行TTT治疗时能量较难控制，容易出血，对中心视力的恢复有一定的影响，应谨慎选择治疗方式。     

经瞳孔温热疗法对大鼠视神经钳夹视网膜神经节细胞的保护作用

目的探讨经瞳孔温热疗法（TTT）阈下反应对BN大鼠视神经钳夹后视网膜神经节细胞（RGCs）的保护作用。方法采用阈下TTT对BN大鼠视网膜进行照射后3d,通过逆行标记RGCs的方法,对TTT＋视神经钳夹组（A组）、TTT＋假手术组（B组）、单纯视神经钳夹组（C组）和空白对照组（D组）在视神经钳夹后1、2、4周进行RGCs计数并比较;检测视网膜TTT阈下反应的热休克蛋白70（HSP70）表达;观察TTT阈下反应对视网膜的影响。结果视神经钳夹后4周,A组RGCs数显著高于C组（P=0.006）,而1周和2周时2组之间差异无统计学意义（P〉0.05）;各时间点B组和D组的RGCs数差异无统计学意义（P〉0.05）。视网膜经阈下TTT干预后,HSP70表达高于对照眼。阈下TTT照射能引起视网膜组织形态上的改变。结论阈下TTT可显著提高视神经钳夹4周后RGCs的存活数量;其保护机制可能与诱导视网膜内源性HSP70表达、启动内源性保护机制有关。     

脉络膜黑色素瘤TTT治疗后细胞凋亡的初步研究

对5例经瞳孔温热疗法(transpupillary thermotherapy,TTT)治疗失败的脉络膜黑色素瘤患者手术摘除眼进行分子生物学检测,研究TTT对人脉络膜黑色素瘤的组织病理学影响及对细胞凋亡的作用,以进一步了解TTT的治疗机制。1材料与方法1.1实验对象选取5例TTT治疗失败的脉络膜黑色素瘤患眼。所有患者均在同仁眼科中心门诊行TTT治疗。激光的光斑直径为3mm,能量800mW,时间1min×2次。患者治疗后1周肿瘤不能控制,无萎缩迹象。为了防止全身转移,在患者知情同意的情况下,门诊摘除患眼,送同仁医院眼科病理取材并制作蜡块,进行组织病理学、免疫组织化…     

经瞳孔温热疗法诱导大鼠热休克蛋白60在视盘中的表达

目的探讨经瞳孔温热疗法（TTT）阈下刺激诱导大鼠视盘中热休克蛋白（HSP）60的表达,探讨TTT对视盘组织超微结构的影响。方法采用810nm二极管激光对12周龄的BN大鼠56只右眼视盘进行阈值下TTT照射,选择激光参数为光斑直径0.5mm、持续时间60s、能量60mW;另设8只正常大鼠为对照。实验鼠分别于TTT照射后24h、72h和1周过量麻醉处死,实验眼的视盘组织切片制备后应用免疫组织化学染色法鉴别BN大鼠视盘TTT照射后HSP60的表达;Western blot法对TTT干预后HSP60在视盘组织中的表达进行半定量分析,并以吸光度（A）值表示。透射电镜下观察TTT照射后1周实验眼视盘组织的超微结构变化。结果免疫组织化学染色显示,HSP60在正常大鼠视盘局部呈弱阳性表达,TTT干预后24h、72h及1周HSP60的阳性染色明显增强,72h最强;Western blot蛋白质表达半定量分析显示,HSP60在正常大鼠视盘中的表达量为21458.13±156.32,在TTT干预后24h、72h及1周表达量分别为46907.24±10099.20、61848.02±2714.49、40738.01±5670.12,较正常大鼠视盘中的表达量明显上调,差异均有统计学意义（t=0.002、t=0.000、t=0.001,P〈0.01）,72h表达最强。阈下TTT干预后1周透射电镜下可见视盘神经纤维轴索部分髓鞘板层离散,个别轴索神经微丝、微管有溶解现象,有轻度轴膜下水肿,但神经纤维密度无明显减少。结论 TTT阈下刺激可诱导大鼠视盘中HSP60的表达,并对正常组织的超微结构产生轻度影响。     

恒河猴经瞳孔温热疗法与热休克蛋白相关研究

目的探讨恒河猴经瞳孔温热疗法（transpupillary thermotherapy，TTT）治疗后视网膜和脉络膜组织热休克蛋白70（heat shock protein 70，HSPT0）表达。方法利用恒河猴做动物模型。于1TIrr治疗后不同时间点（1h、1d、1周、2周、1月、4月）摘除双眼固定。应用免疫组化技术，分析TTT治疗对猴眼视网膜和脉络膜组织HSP70的影响。结果TTT治疗后，于1d起，在强反应光斑边缘视网膜和脉络膜有HSP70的表达，4个月时仍有弱表达。弱反应光斑1d时，在视网膜全层及脉络膜均有HSP70表达，4个月时消失。同时,TTT治疗可以引起视网膜不同程度组织病理学的损害。结论TTT可以引起视网膜、脉络膜组织病理学损害。局部温度的升高会诱导视网膜、脉络膜内源性HSP70的产生，并且这种表达在激光治疗后1～4个月的猴眼中仍可以存在。     

经瞳孔温热疗法治疗渗出型相关性黄斑变性的临床观察

目的 观察经瞳孔温热疗法(TTT)对渗出型老年性黄斑变性(AMD)的临床效果。方法 对19例荧光素眼底血管造影(FFA)和吲哚菁绿血管造影(ICGA)检查确诊为AMD的患者的22只患眼进行TTT治疗。采用810mm半导体激光，光斑0．5～3．0mm，能量200～400mW，照射时间60s。对三面镜眼底检查、FFA、ICGA图像所显示的脉络膜新生血管(CNV)进行照射，照射区未出现颜色变化或旱淡灰白色。对比分析患者治疗前后视力、眼底及OCT检查。结果 22患眼治疗后1～10个月，平均随访观察时间4．8个月，视力不变者13例，占59．1％；进步者7例，占31．8％；下降者2例，占9．1％。20眼OCT复查者中，黄斑水肿不变者11例，占55％；好转者7例，占35％；恶化者2例，占10％。再次行TTT治疗者5眼，占接受TTT治疗者的22．7％。治疗随访期间无明显治疗副作用。结论 TTT治疗能使大部分渗出性AMD患眼视力稳定或提高，使用安全，值得临床推广应用。     

Changes in Bruch's membrane in experimental hypercholesteremia in rats

PURPOSE: We investigated the effect of high cholesterol diet for the aging changes in Bruch's membrane of rats. METHODS: After feeding a 4% cholesterol diet for 15 weeks to three young rats 3 months old and four aged rats 23 months old, we observed the morphological changes of Bruch's membrane by electron microscopy, and made a comparison with rats fed an ordinary diet. RESULTS: In one young rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris formed multiple folds separated from the plasma membrane of the endothelium and showed lamellar thickening and crack in some areas. The elastic fiber layer in Bruch's membrane disappeared partly and some new microfibrils appeared. In one aged rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris showed more lamellar thickening with lumps in some parts. Compared with rats fed an ordinary diet, rats fed a high-cholesterol diet showed thickening of the basement membrane and the changes were more severe. CONCLUSIONS: Our data indicated that high-cholesterol diet might promote age-related changes of Bruch's membrane.     

Advances in imaging in oculoplastics

Color Doppler imaging, computed tomography (CT) and magnetic resonance (MR) imaging are the most precious imaging tools for the clinician in the field of oculoplastics. Orbital and facial vasculature, with its dynamic changes and flow velocities seen in orbital varices, carotid-cavernous fistulas, and dural cavernous arteriovenous malformations, is best detected by Color Doppler imaging. Computed tomography remains the dominant imaging modality in the evaluation of orbital trauma. Helical CT axial scanning with multiplanar reconstruction and three-dimensional CT imaging are most helpful in assessing iatrogenic, traumatogenic, and teratogenic orbital abnormalities. Despite its poor histologic specificity, MR imaging provides superior soft tissue contrast, and contrast-enhanced MR imaging has an established role regarding soft tissue tumor infiltration. The greatest value of MR studies in the evaluation of orbital and palpebral tumors is that it has the capacity to show the precise relation between lesions and adjacent structures before the clinician contemplates a surgical approach. Finally, contrast-enhanced MR imaging proved to be a valuable vascularization indicator based upon the extent of relative enhancement within porous orbital implant in anophthalmic socket.     

Follow-up studies in pattern VECP in demyelinating diseases in children

Spectral sensitivity functions and the transient decrease of sensitivity to short wavelengths after the offset of yellow light (transient tritanopia) were measured by increment threshold techniques in patients suffering from hereditary macular degenerations. Color vision defects were determined by arrangement tests and the anomaloscope. Central areolar choroidal dystrophy was found to produce a mild protan defect and to reduce foveal spectral sensitivity throughout the visible spectrum by a factor of 100; it also abolishes transient tritanopia. Electroretinogram (ERG) was normal, electrooculogram (EOG) subnormal. Stargardt's disease, despite numerous fluorescent macular spots, does not abolish transient tritanopia nor does it reduce spectral sensitivity, although scotopic matches were performed on the Nagel anomaloscope. Only in severe, advanced cases was transient tritanopia reduced and spectral sensitivity found to follow the absorption spectrum of rods. Routine ERGs and EOGs were normal. Vitelliform macular degeneration, despite the ophthalmoscopically pronounced dystrophic macula, produced only very small changes in spectral sensitivity and transient tritanopia, although a widened matching range on the Nagel anomaloscope and electrophysiological abnormalities were found. Apparently damage of the retinal circuit which connects long and short wavelength-sensitive cones, caused by hereditary conditions, is different from that caused by retinotoxic drugs.     

Refractive error in children in a rural population in India

PURPOSE: To assess the prevalence of refractive error and related visual impairment in school-aged children in the rural population of the Mahabubnagar district in the southern Indian state of Andhra Pradesh. METHODS: Random selection of village-based clusters was used to identify a sample of children 7 to 15 years of age. From April 2000 through February 2001, children in the 25 selected clusters were enumerated in a door-to-door survey and examined at a rural eye center in the district. The examination included visual acuity measurements, ocular motility evaluation, retinoscopy and autorefraction under cycloplegia, and examination of the anterior segment, media, and fundus. Myopia was defined as spherical equivalent refractive error of at least -0.50 D and hyperopia as +2.00 D or more. Children with reduced vision and a sample of those with normal vision underwent independent replicate examinations for quality assurance in seven clusters. RESULTS: A total of 4414 children from 4876 households was enumerated, and 4074 (92.3%) were examined. The prevalence of uncorrected, baseline (presenting), and best corrected visual acuity of 20/40 or worse in the better eye was 2.7%, 2.6%, and 0.78%, respectively. Refractive error was the cause in 61% of eyes with vision impairment, amblyopia in 12%, other causes in 15%, and unexplained causes in the remaining 13%. A gradual shift toward less-positive values of refractive error occurred with increasing age in both boys and girls. Myopia in one or both eyes was present in 4.1% of the children. Myopia risk was associated with female gender and having a father with a higher level of schooling. Higher risk of myopia in children of older age was of borderline statistical significance (P = 0.069). Hyperopia in at least one eye was present in 0.8% of children, with no significant predictors. CONCLUSIONS: Refractive error was the main cause of visual impairment in children aged between 7 and 15 years in rural India. There was a benefit of spectacles in 70% of those who had visual acuity of 20/40 or worse in the better eye at baseline examination. Because visual impairment can have a significant impact on a child's life in terms of education and development, it is important that effective strategies be developed to eliminate this easily treated cause of visual impairment.     

Vitrectomy in traumatic cataracts and in the complications of surgery in congenital cataract in children

Vitrectomies were carried out in 35 children with traumatic cataracts and complications of surgery for cataracts, caused by injury to the posterior lenticular capsule and incorporation of its fragments to the vitreous. Complete removal of lenticular rudiments rapidly eliminated phacogenic iridocyclitis and improved visual acuity. Improvement of visual functions was attained in 66.6% cases; in 33.4% cases visual acuity did not change. Hemorrhages to the vitreous cavity occurred in 4 cases with pronounced iridocyclitis; therefore, a corneal approach is preferable for cases with pronounced iridocyclitis.     

Refractive error in children in an urban population in New Delhi

PURPOSE: To assess the prevalence of refractive error and related visual impairment in school-aged children in an urban population in New Delhi, India. METHODS: Random selection of geographically defined clusters was used to identify a sample of children 5 to 15 years of age. From December 2000 through March 2001, children in 22 selected clusters were enumerated through a door-to-door survey and examined at a local facility. The examination included visual acuity measurements, ocular motility evaluation, retinoscopy and autorefraction under cycloplegia, and examination of the anterior segment, media, and fundus. Myopia was defined as spherical equivalent refractive error of at least -0.50 D and hyperopia as +2.00 D or more. Children with reduced vision and a sample of those with normal vision underwent independent replicate examinations for quality assurance in four of the clusters. RESULTS: A total of 7008 children from 3426 households were enumerated, and 6447 (92.0%) examined. The prevalence of uncorrected, baseline (presenting), and best corrected visual acuity of 20/40 or worse in the better eye was 6.4%, 4.9%, and 0.81%, respectively. Refractive error was the cause in 81.7% of eyes with vision impairment, amblyopia in 4.4%, retinal disorders in 4.7%, other causes in 3.3%, and unexplained causes in the remaining 5.9%. There was an age-related shift in refractive error from hyperopia in young children (15.6% in 5-year-olds) toward myopia in older children (10.8% in 15-year-olds). Overall, hyperopia was present in 7.7% of children and myopia in 7.4%. Hyperopia was associated with female gender. Myopia was more common in children of fathers with higher levels of education. CONCLUSIONS: Reduced vision because of uncorrected refractive error is a major public health problem in urban school-aged children in India. Cost-effective strategies are needed to eliminate this easily treated cause of vision impairment.