恒河猴慢性青光眼模型的建立及相关生物学特性

目的建立两种激光光凝的恒河猴慢性高眼压性青光眼模型,评价模型眼的相关生物学特性。方法成年恒河猴15只,分别采用半导体倍频532激光和氩激光,在房角镜下对功能小梁网区行360°光凝。对其中7只恒河猴分别采用A超、视网膜断层成像仪和视网膜血流仪进行模型眼和另侧对照眼的眼球及视盘形态、血流参数的检测。结果两种光凝模式相比,眼压升高后第4周,倍频532激光组平均眼压为48.4±10.3mmHg,氩激光组平均眼压为44.2±7.0mmHg,倍频532激光组与氩激光组的三次光凝成功率的差异无显著性意义。除视盘面积外,恒河猴模型眼的视杯形态指数、杯盘面积比、盘沿面积、视网膜神经纤维层的平均厚度,与对照眼相比差异有极显著性意义。眼轴和前房深度与对照眼相比差异有显著性意义。筛板血流量、血流速度和红细胞移动速率与对照眼相比差异无显著性意义。结论两种激光光凝恒河猴小梁网均可用以建立慢性高眼压性青光眼模型,模型眼出现青光眼眼底特征性的形态学改变。     

上巩膜静脉结扎联合应用5-Fu建立大鼠慢性高眼压模型

目的建立一种稳定、持久的大鼠慢性高眼压模型,为青光眼视神经损伤及保护机制的研究提供基础资料。方法雄性SD大鼠(300±20 g)65只,分为改良实验组60只,经结扎上巩膜静脉联合术后球结膜下注射5-Fu;对照实验组5只,单独结扎上巩膜静脉。观察改良实验组模型建立后1周、4周、6周1、0周视网膜神经节细胞(retinal ganglion cells,RGCs)数量的变化情况。结果改良实验组可诱导较长时间(>10周)稳定高眼压,眼压升高1周4、周、6周、10周后,视网膜神经节细胞的存活率分别为:90.16%,83.50%,75.01%,62.37%;但对照实验组眼压升高仅维持2周左右。结论本模型具有操作简单,重复性好,成模率高,可稳定维持较长时间等优点,是较为理想的大鼠慢性高眼压模型。     

孤独症谱系障碍儿童听觉脑干反应特征分析

摘要 目的：探讨孤独症谱系障碍(autism spectrum disorder,ASD)儿童听觉脑干反应(auditory brainstem response,ABR)各波潜伏期和波间期特征与ASD行为表型间的关联。方法：对2019年7月-2020年12月来我科就诊的26例明确诊断的2~6岁ASD儿童的患儿进行声导抗,听性脑干反应,畸变产物耳声发射及多频稳态听觉诱发电位测试,以38例正常儿童为对照组,进行同样的测试,并对其测试结果进行统计分析。分析ASD儿童左右耳各波潜伏期,波间期特征及与ASD临床表型的关联。结果：ASD儿童左右耳Ⅰ,Ⅲ,Ⅴ波潜伏期分别为(1.42±0.09)ms,(3.67±0.09)ms,(5.65±0.13)ms;(1.45±0.11)ms,(3.69±0.08)ms,(5.62±0.15)ms。ASD组的右耳I,III波的潜伏期均值大于正常组 (P 值均＜0.05);ASD儿童两组间左耳III-V,右耳III-V,右耳I-V的波间期分别是(1.97±0.07)ms,(1.93±0.10)ms,(4.15±0.14)ms;ASD组的左耳III-V,右耳III-V,右耳I-V波间期均小于正常组(P 值均＜0.05);ASD组中小于等于3岁组与大于3岁组间ABR波间期差异不具有统计学意义。关联性分析发现,ASD儿童语言能力与右耳III波潜伏期,右耳最小阈值V波潜伏期负相关;社会行为能力与右耳I-III波间期负相关;社会生活能力与左耳最小阈值V波潜伏期负相关;而ABC评分与ASD儿童右耳III波潜伏期,左耳I-III波间期,右耳I-III波间期正相关。结论：ASD儿童存在异常的听觉脑干反应特征,且异常程度与 ASD 儿童语言,社会行为能力,社会生活能力的严重程度存在明显关联。     

两种青光眼模型的比较

目的:研究前房灌注高眼压和视神经横断损伤两种模型病理变化的不同.方法:高眼压模型制备采用前房灌注生理盐水法,形成100 cmH<,2>O高眼压,诱导大鼠视网膜缺血60 min,建立急性青光眼模型;视神经损伤模型制备采用SD大鼠球后视神经切断法.两只方法都是在模型建立7天后断头处死大鼠并取标本,HE染色,光镜下观察视网膜各层厚度及视网膜节细胞形态和数量的变化.结果:两种模型都导致了视网膜节细胞的明显减少;前房加压导致视网膜内层厚度降低,视神经阻断法导致视网膜全层厚度降低.结论:前房灌注法使眼压升高更符合青光眼的病理变化过程,是比较好的模型.     

糖尿病大鼠的视网膜和脉络膜中VEGFR-2的表达

目的:研究早期糖尿病大鼠视网膜和脉络膜血管中VEGFR-2的表达。方法:24只雄性Wistar大鼠,随机分为两组:正常对照组和糖尿病组。实验组给予一次性静脉注射60 mg/kg STZ建立糖尿病模型。STZ注射后24 h,血糖水平超过250 mg/dL被认为是糖尿病模型。WB技术检测VEGFR-2在视网膜和脉络膜的表达水平,免疫组化法用来定位VEGFR-2。结果:STZ注射14天后,糖尿病组的平均体重较对照组显著降低(糖尿病组:177±10 g,对照组:243±19 g,P0.05),糖尿病组的平均血糖水平较对照组显著增高(糖尿病组的血糖为498±36 mg/m L,对照组的血糖为90±10 mg/m L,P0.05)。VEGFR-2在糖尿病鼠的视网膜和脉络膜中表达较对照组增加,其差异有统计学意义(P0.05)。免疫组化分析显示:VEGFR-2在糖尿病组的视网膜和脉络膜血管中表达显著增加,而在正常对照组中少量表达(P0.05)。结论:VEGFR-2在试验诱导的糖尿病模型的视网膜和脉络膜血管中的表达增加,VEGFR-2可能成为糖尿病视网膜病变新的诊断靶点。     

不同术式治疗新生血管性青光眼的疗效比较

目的:比较不同手术方法治疗新生血管性青光眼(neovascular glaucoma,NVG)的疗效。方法:对接受不同术式治疗的57例57只眼NVG的临床资料进行回顾性分析,其中行单纯睫状体冷凝术20例(A组),改良小梁切除术15例(B组),引流阀植入术联合全视网膜光凝术22例(C组)。比较各组患者手术前后主观眼痛症状、眼压及视力变化情况,并随访3~6个月。结果:A组患者出院时的平均眼压为(28.13±4.83)mmHg,B组为(19.24±5.48)mmHg,C组为(21.22±4.76)mmHg。随访期间,术后A组9例眼压正常,手术成功率45%;B组11例眼压正常,手术成功率73.3%;C组13例眼压正常,手术成功率57.1%。B组手术成功率最高,A组最低。结论:三种手术方法均可不同程度降低新生血管性青光眼的眼压。单纯睫状体冷凝术后眼压控制效果欠佳,有视力眼不宜采用此种手术方式;改良小梁切除术是治疗新生血管性青光眼安全、有效、经济的手术方式;引流阀植入术联合全视网膜光凝术费用较高。     

两种鼠耳蝠回声定位叫声的比较

对鼠耳蝠属两种蝙蝠飞行状态下的声发射进行了比较研究.结果表明两种鼠耳蝠声发射信号的声谱图都呈调频(FM)型,但在波形及频率范围上有明显差异.大鼠耳蝠(四川亚种)的声脉冲宽度很小(1.6±0.3ms),能率环较低(4.0%),其主频率(DF=44.6±4.3kHz)也较低;而水鼠耳蝠的声脉冲宽度较大(4.2±1.6ms),能率环(9.6%)及主频率(DF=83.0±4.0kHz)也较高.文中结合两种蝙蝠的形态及食性分析了回声定位对捕食生境及捕食策略的适应性.     

抗青光眼药物长期使用对眼表的影响

目的：研究长期使用青光眼药物对患者眼表结构的影响,为正确选择青光眼治疗药物提供依据。方法：将采用青光眼药物治 疗≥ 3 个月的青光眼患者40 例（62 只眼）设为病例组,以同期健康志愿者30 例（30 只眼）设为对照组,比较两组基础泪液分泌长 度(ST)、泪膜破裂时间(BUT)、角膜荧光染色评分（FB）及结膜印记细胞评级（IC）。结果：病例组ST、BUT 分别为（6.12± 3.63）mm、 （5.21± 2.13）s,均短于对照组的（10.72± 4.62）mm、（11.45± 5.12）s（P<0.01);病例组FB 评分为（2.19± 0.42）分,高于对照组（0.62± 0.04）分（P<0.01）;病例组IC 评级为Ⅱ~Ⅲ级比例为54.84%,高于对照组的5.00%（P<0.01)。结论：青光眼患者长期使用青光眼药物 会导致泪液分泌减少,泪膜稳定性下降,并加快结膜细胞鳞状上皮化进程,对泪膜、角膜及结膜均有损伤,应引起重视。     

视网膜光凝术联合雷珠单抗治疗新生血管青光眼的疗效及对血液流变学和房水炎性因子的影响

摘要 目的：探讨新生血管青光眼采用视网膜光凝术联合雷珠单抗治疗的疗效及对房水炎性因子和血液流变学的影响。方法：选取我院2015年2月～2017年5月收治的172例（180眼）新生血管青光眼患者作为研究对象,按照随机数字表法分为两组,对照组患者85例（88眼）,采用视网膜光凝术进行治疗,观察组患者87例（92眼）,采用视网膜光凝术联合雷珠单抗进行治疗,对比两组治疗后虹膜新生血管消退情况及消退时间,治疗前后眼压变化情况和静脉循环时间、眼部光学相干断层扫描（OCT）、血液流变学、房水炎性因子检测结果与不良反应发生情况。结果：观察组虹膜新生血管消失率为95.65%,高于对照组的80.68%（P＜0.05）;与对照组对比,观察组虹膜新生血管消退时间更短（P＜0.05）;与对照组对比,观察组治疗后眼压更低,静脉循环时间更短（P＜0.05）;与对照组对比,观察组治疗后视野缺损值更小,视网膜神经纤维层（RNFL）厚度更厚（P＜0.05）;治疗后观察组血浆黏度(PV)、红细胞压积( HCT)、血小板黏附率(PAdT)水平均低于对照组（P＜0.05）;治疗后观察组房水炎性因子水平包括白介素-1β(IL-1β)、白介素-6(IL-6)、单核细胞趋化蛋白1(MCP-1)水平均低于对照组（P＜0.05）;对照组不良反应发生率为9.09%,与观察组的10.87%对比无统计学差异（P＞0.05）。结论：新生血管青光眼采用视网膜光凝术联合雷珠单抗治疗的疗效理想,可改善患者的血液流变学指标,降低房水炎性因子水平,且安全性高。     

视网膜激光光凝与复合式小梁切除术治疗新生血管性青光眼的临床疗效对比

目的:观察和比较视网膜激光光凝与复合式小梁切除术治疗新生血管性青光眼(NVG)的临床疗效和安全性。方法:选择2013年1月~2015年6月我院收治的新生血管性青光眼患者85例,随机分为两组,观察组采用视网膜激光光凝术治疗,对照组采用复合式小梁切除术治疗,比较两组的临床疗效和并发症的发生情况。结果:两组术后眼压均较治疗前明显降低(P0.05),且观察组明显低于对照组(P0.05);两组术后视力、虹膜新生血管退化情况相比差异无明显统计学意义(P0.05);观察组术中、术后前房出血发生率均明显低于对照组(P0.05)。结论:视网膜激光光凝与复合式小梁切除术对新生血管性青光眼均有较好的治疗效果,复合式小梁切除术对患者眼压控制效果更好,安全性更高。     

Blood pressure modifies retinal susceptibility to intraocular pressure elevation

Primary open angle glaucoma affects more than 67 million people. Elevated intraocular pressure (IOP) is a risk factor for glaucoma and may reduce nutrient availability by decreasing ocular perfusion pressure (OPP). An interaction between arterial blood pressure and IOP determines OPP; but the exact contribution that these factors have for retinal function is not fully understood. Here we sought to determine how acute modifications of arterial pressure will affect the susceptibility of neuronal function and blood flow to IOP challenge. Anaesthetized (ketamine:xylazine) Long-Evan rats with low (∼60 mmHg, sodium nitroprusside infusion), moderate (∼100 mmHg, saline), or high levels (∼160 mmHg, angiotensin II) of mean arterial pressure (MAP, n = 5–10 per group) were subjected to IOP challenge (10–120 mmHg, 5 mmHg steps every 3 minutes). Electroretinograms were measured at each IOP step to assess bipolar cell (b-wave) and inner retinal function (scotopic threshold response or STR). Ocular blood flow was measured using laser-Doppler flowmetry in groups with similar MAP level and the same IOP challenge protocol. Both b-wave and STR amplitudes decreased with IOP elevation. Retinal function was less susceptible to IOP challenge when MAP was high, whereas the converse was true for low MAP. Consistent with the effects on retinal function, higher IOP was needed to attenuated ocular blood flow in animals with higher MAP. The susceptibility of retinal function to IOP challenge can be ameliorated by acute high BP, and exacerbated by low BP. This is partially mediated by modifications in ocular blood flow.     

两种手术方式治疗原发性闭角型青光眼疗效比较

目的:探讨治疗原发性闭角型青光眼二种手术方式的适应症和初步临床疗效观察。方法:拟订手术适应症,对临床收治的42例48眼原发性闭角型青光眼进行手术处理:单纯抗青光眼手术--小梁切除术(Trabeculectomy,Trab)、青白联合手术--超声乳化白内障吸除联合小梁切除+人工晶体植入术(Phacotrabeculectomy+IOL,PhacoTrab+IOL)。比较不同适应症下二种手术方式初步的临床疗效。包括术前术后眼压情况、前房深度、眼轴长度的变化。随访时间平均1个月。结果均经统计学处理。结果:原发性闭角型青光眼患者术后眼压有显著改变,有统计学差异,Trab组手术后平均(10.92±1.74)mmHg,Phaco Trab+IOL组手术后平均(10.86±1.73)mmHg。术后眼压明显降低(t检验,P值<0.001),Trab组和Phaco Trab+IOL组两组间术后眼压无显著差异(t检验,P值>0.05)。Trab组手术前后前房深度无统计学差异(t检验,P值>0.05),Phaco Trab+IOL组手术前后前房深度有统计学差异(t检验,P值均<0.001)。术前分别为(1.74±0.16)mm、(1.72±0.16)mm,术后分别为(1.74±0.17)mm、(2.06±0.14)mm。Trab组及Phaco Trab+IOL组手术前后眼轴长度无统计学差异(t检验,P值>0.05)。结论:青-白联合手术可以改善前房深度,明显降低眼压,不同手术方式适合不同的病人情况,但要注意适应症的选择。利用A超检查可快速、有效、准确地观察眼前节结构,有助于早期进行手术。     

不同术式治疗新生血管性青光眼的疗效比较

目的：比较不同手术方法治疗新生血管性青光眼（neovascular glaucoma,NVG）的疗效。方法：对接受不同术式治疗的57例57只眼NVG的临床资料进行回顾性分析,其中行单纯睫状体冷凝术20例（A组）,改良小梁切除术15例（B组）,引流阀植入术联合全视网膜光凝术22例（c组）。比较各组患者手术前后主观眼痛症状、眼压及视力变化情况,并随访3～6个月。结果：A组患者出院时的平均眼压为（28．13＋4．83）mmHg,B组为（19．24±5．48）mmHg,C组为（21．22±4．76）mmHg。随访期间,术后A组9例眼压正常,手术成功率45％;B组11例眼压正常,手术成功率73．3％;C组13例眼压正常,手术成功率57．1％。B组手术成功率最高,A组最低。结论：三种手术方法均可不同程度降低新生血管性青光眼的眼压。单纯睫状体冷凝术后眼压控制效果欠佳,有视力眼不宜采用此种手术方式;改良小梁切除术是治疗新生血管性青光眼安全、有效、经济的手术方式;引流阀植入术联合全视网膜光凝术费用较高。     

Systemic hypertension, headache, and ocular hemodynamics: a new hypothesis

The association between systemic hypertension and headache remains controversial and its pathophysiologic basis is uncertain. A rather characteristic early-morning pulsating headache is commonly seen in hypertensive patients, and a recent meta-analysis supports the link between these 2 entities. Epidemiologic evidence has paradoxically suggested a negative association between hypertension and headache. Unpredictable clinical association between severe hypertension and headache indicates that another cranial perfusion-related variable exerts a critical role. Neuroanatomically, head and neck pain primarily involves the ophthalmic division of the trigeminal nerve (V1). A link between systemic hypertension, pulsatile choroidal blood flow (CBF), and intraocular pressure (IOP) has been established. I propose that a trait ocular sympathetic hypofunction permits rapid episodic ocular choroidal overperfusion that stretches the ocular globe in the cohort of hypertensive patients with headache. Rapid distension of the pain-sensitive corneoscleral envelope can stimulate corneoscleral and iridial pain-sensitive V1 nerve endings and generate headache. Ocular tamponade function physiologically limits choroidal overperfusion. A higher basal IOP in some patients with moderate-to-severe hypertension may dampen pulsatile CBF and account for the negative epidemiologic link between sustained systemic hypertension and headache. Besides activation of the baroreceptor reflex, the association of hypalgesia with hypertension probably involves activation of the vasopressin-endorphin adaptive system consequent to mechanical stimulation of V1. The analogy between hypertensive headache and angle-closure glaucoma is rather limited because typical ocular and visual signs and symptoms of angle-closure glaucoma are not seen in hypertension-related headache. Hypertensive crises, including those associated with pheochromocytoma, are not accompanied by attacks of angle-closure glaucoma. Glaucoma is not associated with ocular choroidal congestion, but with reduced pulsatile CBF. The predisposition to develop angle-closure glaucoma is theoretically not associated with ocular autonomic hypofunction and should be conceptually dissociated from this hypothesis. The hypothesis can be evaluated by establishing significant circadian elevations of blood pressure, including nondipping nighttime pattern as well as circadian and periheadache measurements of IOP in patients with attacks of hypertension-related headache.     

小梁切除术中应用丝裂霉素C对角膜内皮细胞的影响

目的：观察小梁切除术中应用丝裂霉素C（MMC）对角膜内皮细胞的影响。方法：收集2010年9月2011年5月在我院行小梁切除术的青光眼患者60例（78眼）,随机分为术中应用丝裂霉素c的36例（46眼）患者为A组,术中不用丝裂霉素c的24例（32眼）为B组。分别观察术前、术后1个月和术后3个月两组眼压（10P）、角膜内皮细胞的密度（co）、平均细胞面积（AVG）及细胞面积变异系数（cv）,分析其数量的改变及两组间的差异。结果：A组术前眼压为（35．4±13．7）mmHg,B组术前眼压为（32．5±13．5）mmHg差异无统计学意义（P〉0．05）,A组术后1个月及术后3个月眼压分别为（15．7±3．7）mmHg、（17．0±3．2）mmHg,均低于B组的（19．4±3．7）mmHg、（20．2±2．1）mmHg,差异有统计学意义（P〈0．05）。A组术前、术后1个月及术后3个月角膜内皮细胞密度分别为（2475±484）个／mm2、（2199±373）个／mm2、（2164±332）个／mm2;平均细胞面积分别为（431．4±67．6）μm2、（480．6±66．8）μm2、（463．8±46．2）μm2;细胞面积变异系数分别为（31．1±7．4）％、（34．4±6．3）％、（31．2±7．5）％;术后1个月及术后3个月各参数与术前比较,差异均有统计学意义（P〈0．05）。B组术前、术后1个月及术后3个月角膜内皮细胞密度分别为（2342±94）个／mm2、（2185＋215）个／mm2、（2074218）个／mm2;平均细胞面积分别为（453．9土94．8）μm2、（516.3±100．8）μm2、（499．81＋106．4）μm2;细胞面积变异系数分别为（30．2土3．0）％、（32．7±2．9）％、（31．4±4．3）％;除术后3个月角膜内皮细胞与术前比较有意义（P〈0．05）外,余参数术后1个月及术后3个月与术前比较差异均无统计学意义（P〉0．05）。术后1个月A组的角膜内皮细胞丢失率为10．4％高于B组的6．1％,差异有统计学意义（P〈0．05）;术后3个月A组的角膜内皮细胞丢失率为11．1％高于B组的10．0％,差异无统计学意义（P〉0．05）。结论：小梁切除术中用丝裂霉素C的降压效果比不用丝裂霉素C的效果好,但短期内前者角膜内皮细胞的丢失率高于后者。     

小梁切除术中应用丝裂霉素C 对角膜内皮细胞的影响

目的:观察小梁切除术中应用丝裂霉素C(MMC)对角膜内皮细胞的影响。方法:收集2010年9月2011年5月在我院行小梁切除术的青光眼患者60例(78眼),随机分为术中应用丝裂霉素C的36例(46眼)患者为A组,术中不用丝裂霉素C的24例(32眼)为B组,分别观察术前、术后1个月和术后3个月两组眼压(IOP)、角膜内皮细胞的密度(CD)、平均细胞面积(AVG)及细胞面积变异系数(CV),分析其数量的改变及两组间的差异。结果:A组术前眼压为(35.4±13.7)mmHg,B组术前眼压为(32.5±13.5)mmHg差异无统计学意义(P>0.05),A组术后1个月及术后3个月眼压分别为(15.7±3.7)mmHg、(17.0±3.2)mmHg,均低于B组的(19.4±3.7)mmHg、(20.2±2.1)mmHg,差异有统计学意义(P<0.05)。A组术前、术后1个月及术后3个月角膜内皮细胞密度分别为(2475±484)个/mm2、(2199±373)个/mm2、(2164±332)个/mm2;平均细胞面积分别为(431.4±67.6)μm2、(480.6±66.8)μm2、(463.8±46.2)μm2;细胞面积变异系数分别为(31.1±7.4)%、(34.4±6.3)%、(31.2±7.5)%;术后1个月及术后3个月各参数与术前比较,差异均有统计学意义(P<0.05)。B组术前、术后1个月及术后3个月角膜内皮细胞密度分别为(2342±94)个/mm2、(2185±215)个/mm2、(2074±218)个/mm2;平均细胞面积分别为(453.9±94.8)μm2、(516.3±100.8)μm2、(499.81±106.4)μm2;细胞面积变异系数分别为(30.2±3.0)%、(32.7±2.9)%、(31.4±4.3)%;除术后3个月角膜内皮细胞与术前比较有意义(P<0.05)外,余参数术后1个月及术后3个月与术前比较差异均无统计学意义(P>0.05)。术后1个月A组的角膜内皮细胞丢失率为10.4%高于B组的6.1%,差异有统计学意义(P<0.05);术后3个月A组的角膜内皮细胞丢失率为11.1%高于B组的10.0%,差异无统计学意义(P>0.05)。结论:小梁切除术中用丝裂霉素C的降压效果比不用丝裂霉素C的效果好,但短期内前者角膜内皮细胞的丢失率高于后者。     

东莨菪碱在家猪基础麻醉中对心率的控制

目的评价东莨菪碱在不使用呼吸机家猪基础麻醉中对心率、血压的影响。方法与结果48头家猪分为东莨菪碱组和山莨菪碱（654-Ⅱ）组,基础麻醉后两组心率、收缩压、舒张压分别为532．08±105．67ms与394．17±59．78ms,157．00±18．26mmHg与178、63±20．73mmHg,118．63±16．51mmHg与128．21±17．00mmHg,两组比较有统计学差异。结论东莨菪碱作为家猪的基础麻醉用药,对心率血压的影响较654-Ⅱ小。     

System for Rapid,Precise Modulation of Intraocular Pressure,toward Minimally-Invasive In Vivo Measurement of Intracranial Pressure

Pathologic changes in intracranial pressure (ICP) are commonly observed in a variety of medical conditions, including traumatic brain injury, stroke, brain tumors, and glaucoma. However, current ICP measurement techniques are invasive, requiring a lumbar puncture or surgical insertion of a cannula into the cerebrospinal fluid (CSF)-filled ventricles of the brain. A potential alternative approach to ICP measurement leverages the unique anatomy of the central retinal vein, which is exposed to both intraocular pressure (IOP) and ICP as it travels inside the eye and through the optic nerve; manipulating IOP while observing changes in the natural pulsations of the central retinal vein could potentially provide an accurate, indirect measure of ICP. As a step toward implementing this technique, we describe the design, fabrication, and characterization of a system that is capable of manipulating IOP in vivo with <0.1 mmHg resolution and settling times less than 2 seconds. In vitro tests were carried out to characterize system performance. Then, as a proof of concept, we used the system to manipulate IOP in tree shrews (Tupaia belangeri) while video of the retinal vessels was recorded and the caliber of a selected vein was quantified. Modulating IOP using our system elicited a rapid change in the appearance of the retinal vein of interest: IOP was lowered from 10 to 3 mmHg, and retinal vein caliber sharply increased as IOP decreased from 7 to 5 mmHg. Another important feature of this technology is its capability to measure ocular compliance and outflow facility in vivo, as demonstrated in tree shrews. Collectively, these proof-of-concept demonstrations support the utility of this system to manipulate IOP for a variety of useful applications in ocular biomechanics, and provide a framework for further study of the mechanisms of retinal venous pulsation.     

A study of replacement of timolol-pilocarpine with latanoprost in pseudoexfoliation glaucoma

The aim of the study was to evaluate the efficacy of replacing current dual local therapy (timolol and pilocarpine) with latanoprost 0.005% in 71 pseudoexfoliation glaucoma patients with controlled intraocular pressure (IOP). 39 patients switched to latanoprost 0.005%) and 32 patients continued timolol-pilocarpine therapy. Mean diurnal (IOP) was measured at baseline, after 0.5, 1, 3 and 6 months of treatment. After 6 months 38 patients with latanoprost and 30 patients with timolol-pilocarpine had completed the study. At baseline the mean diurnal IOP was 20.4 +/- 2.0 mmHg for patients in latanoprost treatment group and 21.4 +/- 2.1 mmHg for patients in timolol-pilocarpine group. At the end of the study, after 6 months of treatment, the mean diurnal IOP values were 16.6 +/- 2.4 and 17.9 +/- 2.0 mmHg respectively. IOP was statistically significantly reduced from baseline (p < 0.001). The mean diurnal IOP change from baseline was -3.3 +/- 0.5 mmHg (mean +/- SEM, ANCOVA) for the patients treated with latanoprost and -3.2 +/- 0.4 mmHg for the patients treated with timolol + pilocarpine. This difference in IOP reduction between groups was not statistically significant (z = 0.69; p = 0.49). This study showed that combination therapy (timolol plus pilocarpine) in pseudoexfoliation glaucoma can effectively be replaced by latanoprost monotherapy.