The effect of colchicine on aqueous humor dynamics

The plant alkaloid, colchicine, which binds specifically to tubulin, was studied for its effect on aqueous humor dynamics in the rabbit. Topical application of either 50 or 100 μg of colchicine resulted in a significant lowering of intraocular pressure after 24 hr. Colchicine significantly increases the rate of aqueous humor outflow while having no effect on aqueous inflow. Intraocular pressure returns to baseline despite continued administration of colchicine, which results in severe ocular toxicity. This study suggests that the aqueous outflow system contains microtubules or membrane-associated tubulin, the integrity of which is necessary for the maintenance of intraocular pressure.     

Contralateral intraocular pressure lowering effect of prostaglandin analogues

Background:

Though the use of prostaglandin analogues (PGA) for reduction of intraocular pressure (IOP) has shown a marked increase, studies evaluating the contralateral effects of PGA are limited.

Aims:

To evaluate if PGA treatment in one eye has an effect on the IOP of the untreated fellow eye.

Design:

Retrospective study.

Materials and Methods:

Thirty patients of open-angle glaucoma with no previous antiglaucoma treatment underwent 24-hour diurnal IOP phasing. They subsequently were started on a uniocular trial with PGA, and had office diurnal IOP measurements 6 weeks later. Twenty-four hour diurnal consisted of 8 IOP readings over 24 hours and office diurnal consisted of 4 IOP readings between 8 AM and 6 PM at 3 hourly intervals.

Statistical Analysis:

IOPs of the fellow eye during the office diurnal were compared with IOPs at similar time points during the 24-hour diurnal using paired t-tests.

Results:

Mean (± standard deviation) IOP in the treated eye reduced (P < 0.001) from 17.17 ± 3.2 mm Hg at baseline to 13.7 ± 2.4 mm Hg at 6 weeks, while that in the untreated eye reduced from 16.4 ± 3.1 mm Hg to 14.8 ± 2.7 mm Hg (P = 0.01). The decrease in IOP in the untreated fellow eye was statistically significant at 8 AM (2.7 mm Hg, P = 0.003) and 11 AM (2.3 mm Hg, P = 0.01) but not so at 2 PM (1.2 mm Hg, P = 0.10) and 5 PM (0.9 mm Hg, P = 0.19). The amount of IOP reduction in the untreated eye was significantly associated with the magnitude of IOP reduction in the treated eye (β = 0.69, P = 0.008).

Conclusion:

Uniocular PGA treatment tends to reduce the IOP of the untreated fellow eye.     

降眼压治疗对前部缺血性视神经病变PVEP的影响

目的 研究降眼压治疗对前部缺血性视神病变图形视诱发电位（PVEP）的影响。设计 回顾性比较性病例系列。研究对象 2008-2011年甘肃省第二人民医院住院的前部缺血性视神病变68例（68眼）,非眼压干预30例（30眼）、眼压干预38例（38眼）。方法 眼压干预组患者在发病时用药物降低眼压≥8 mm Hg或降低眼压≥30%。对两组患者患眼治疗前后的PVEP指标变化进行比较。主要指标 PVEP P100潜伏期、P100振幅。结果 眼压干预组P100潜伏期（93.82±1.97 ms）比非眼压干预组（对照组）（112.38±1.45 ms）短（t=46.36, P＜0.001）;眼压干预组P100振幅（3.64±0.23 μv）比非眼压干预组（3.14±0.26 μv）高（t=8.76, P＜0.001）。结论 降眼压治疗对前部缺血性视神病变PVEP有明显的利好作用。（眼科, 2012, 21: 316-318）     

曲伏前列素与噻吗洛尔降眼压效果的对比研究

目的观察曲伏前列素(苏为坦)降眼压(intraocular pressure,IOP)效果及安全性。方法以噻吗洛尔为对照采用随机、单盲、平行对照试验,选取原发性开角型青光眼、高IOP症和抗青光眼术后高IOP患者。试验组30例(30眼)滴用曲伏前列素滴眼液,每天1次;对照组20例(20眼)滴用噻吗洛尔滴眼液,每天2次,共观察4周。观察的指标包括IOP、视力、血压、脉搏、眼部症状和体征以及不良反应。结果曲伏前列素与噻吗洛尔相比昼夜降IOP效果稳定、持续降IOP效果恒定。曲伏前列素组有16例出现了结膜充血,有2例出现睫毛增粗增长,1例眼睑皮肤颜色增加,无其他明显不良反应。结论曲伏前列素滴眼液对控制IOP是有效、稳定和安全的,有望成为理想的一线抗青光眼药物。     

The determination of additive effect and intraocular pressure lowering effects of 0.05% bromocriptine and 0.25% timolol

It has been confirmed that topically applied bromocriptine has a satisfactory intraocular pressure (IOP) lowering effect without serious ocular or systemic side effects. We compared the IOP lowering effects of 0.05% bromocriptine and 0.25% timolol and determined whether they have an additive effect in lowering IOP in normal volunteers.In a double-blind, randomised, prospective, single-dose study, we measured IOP in 24 ocular normotensive subjects before (baseline) and 2, 4 and 6 hours after topical instillation of the following drugs: timolol and bromocriptine alone (n : 14), timolol + bromocriptine, timolol + placebo, bromocriptine + placebo (n : 10).Both bromocriptine and timolol have a significant IOP lowering effect (p < 0.01) compared with the baseline value during the study period. There were no significant differences in IOP lowering effect between timolol and bromocriptine at 2 and 4 hours (p > 0.05), but timolol was more efficacious than bromocriptine at 6 hours (p < 0.05). An additive effect in lowering IOP was not found.Although timolol and bromocriptine have no additive effect in lowering IOP, topically applied bromocriptine may be used in the treatment of glaucoma.     

玻璃体腔内注射曲安奈德的眼压变化

目的观察玻璃体腔内注射曲安奈德对眼压的影响。方法因治疗视网膜病变对28例（30眼）进行玻璃体腔内注射0.4mg/0.1mL曲安奈德,随访16周,并进行术前、术后不同时间眼压测量。结果30眼中25眼（83.33%）眼压上升5mmHg以上,术前眼压（13.74±4.32）mmHg,与术后最高眼压（25.53±5.24）mmHg之差异具有统计学意义（P〈0.01）。眼压上升者应用抗青光眼滴眼液眼压都恢复正常。结论玻璃体腔内注射0.4mg/0.1mL曲安奈德可致眼压升高。滴用抗青光眼药物能有效降眼压。     

国产与进口拉坦前列素滴眼液降眼压作用的短期效果比较

目的 比较国产与进口拉坦前列素滴眼液的短期降眼压效果。设计 随机、开放、平行对照的临床研究。 研究对象  原发性开角型青光眼患者和高眼压症患者42例。方法 对上述患者按所用药物的不同依随机表法分为A、B两组。A组28例（28眼）,滴用国产拉坦前列素滴眼液（特力洁）,B组14例（14眼）,滴用进口拉坦前列素滴眼液（适利达）,均为每日1次,每次1滴,共28天。受试者于入组当日及用药后第28天8:00、11:00、14:00、16:00测眼压,第7、14、21天则于8:00测眼压。眼压测量采用Goldmann压平眼压计,测量3次取平均值。裂隙灯显微镜观察角膜、虹膜、晶状体情况。主要指标  眼压值。结果 A组用药前眼压为（23.99±1.51）mm Hg, 用药后1～4周眼压分别为（18.04±1.27）mm Hg、（17.75±1.43）mm Hg、（17.63±1.50）mm Hg、（17.49±1.47）mm Hg,用药后眼压明显下降,与用药前相比差异有统计学意义（F=105.72,P=0.000）。B组用药前眼压为（24.37±1.55）mm Hg,用药后1～4周眼压分别为（17.91±1.35）mm Hg、（17.71±1.39）mm Hg、（17.55±1.34）mm Hg、（17.44±1.17）mm Hg,与用药前相比,用药后眼压明显下降,差异有统计学意义（F=67.85 P=0.000）。A、B两组用药前眼压比较无显著性差异（P=0.43）,用药后1～4周两组眼压比较无显著性差异（P值分别为0.76、0.93、0.86、0.89）。入组当日8:00、11:00、14:00、16:00  A、B两组眼压之间的比较无显著性差异（P值分别为0.46、0.44、0.50、0.31）,用药后28天8:00、11:00、14:00、16:00  A、B两组眼压之间的比较无显著性差异（P值分别为0.89、0.85、0.94、0.98）。用药28天时两组患者角膜、虹膜、晶状体均无异常改变。结论  本文的小样本、短期研究显示,国产拉坦前列素与进口拉坦前列素均能有效降低原发性开角型青光眼及高眼压症患者的眼压,两者之间的降眼压效果无显著差异。（眼科, 2012, 21: 111-114）     

Surgical lowering of elevated intraocular pressure in monkeys prevents progression of glaucomatous disease

Recent reports from large clinical trials have clearly demonstrated that lowering intraocular pressure (IOP) in persons with ocular hypertension has a beneficial effect on reducing the progression of glaucomatous disease. Few studies of this effect have been conducted in controlled laboratory settings, however, none have been conducted using non-human primates, the model of experimental glaucoma considered most similar to the human disease. Using data collected retrospectively from a trabeculectomy study using 16 cynomolgous monkeys with experimental ocular hypertension, we evaluated both the threshold of elevated IOP required to cause clinically observable damage to the optic nerve head and also if lowering IOP below this threshold prevents further damage. An index of the level of elevated IOP experienced by experimental eyes (the Pressure Insult) was calculated as the slope of the difference in cumulative IOP between experimental and control eyes during four intervals of time over the course of the experiment, while damage to the optic nerve head was evaluated by measuring the Cup:Disc ratio for each eye from stereoscopic photographs taken at the end of each interval. An increase in the Cup:Disc ratio was significantly associated with both the maximum IOP obtained in the experimental eye during each interval (r=0.573, P<0.001) and the Pressure Insult (r=0.496, P<0.001). Pressure Insult values less than 11 mm Hg Days/Day were not associated with glaucomatous damage in monkey eyes, whereas values greater than 11 showed a significant correlation with increasing Cup:Disc ratios (P<0.001). Trabeculectomy to reduce the Pressure Insult below 11 was correlated with an attenuation of the rate of progression of the Cup:Disc ratio in eyes that had exhibited damage before surgery. These results contribute further to our understanding of this model of experimental glaucoma by demonstrating a threshold at which IOP needs to be elevated to stimulate damage, while also providing corroborating evidence that lowering IOP in ocular hypertensive monkeys can attenuate the progression of glaucomatous disease.     

选择性激光小梁成形术在青睫综合征中的降眼压作用

目的　评估选择性激光小梁成形术在青睫综合征中的降眼压作用。方法　采用回顾性临床病例研究,选择最大耐受药物治疗眼压仍未达到正常的青睫综合征患者１０例１０眼,于间歇期应用选择性激光小梁成形术治疗,观察再次发作时眼压、最佳矫正视力和手术并发症等情况。结果　选择性激光小梁成形术治疗后再次发作时眼压为（１４．５０±０．８９）ｍｍＨｇ（１ｋＰａ＝７．５ｍｍＨｇ）,与术前（４６．２０±７．１６）ｍｍＨｇ相比明显降低,差异有统计学意义（Ｐ＝０．０００１）;术后最佳矫正视力为０．９８±０．１５,与术前０．７９±０．０８相比差异有统计学意义（Ｐ＝０．０３）。术后２ｈ２眼出现一过性眼压升高,７眼出现轻度的前房炎性反应,未见全身不良反应。结论　选择性激光小梁成形术能明显降低青睫综合征患者再次发作时的眼压。     

The effect of corynanthine on intraocular pressure in clinical trials

A single drop, dose-response, double-masked study of the effect corynanthine, a selective alpha 1 adrenergic antagonist, on intraocular pressure (IOP) was carried out in 10 symmetrically ocular hypertensive patients. Corynanthine 1% had no significant pressure lowering effect. Topical application of a 2% solution significantly (P less than 0.05) reduced IOP for at least eight hours; at five hours, mean IOP (+/- SEM) was 20.6 +/- 2.0 mmHg and 26.0 +/- 4.9 mmHg, comparing treated and control eyes, respectively. The 5% solution caused a significant (P less than 0.05) bilateral reduction in IOP, comparing treated and control eyes to baseline IOP respectively. Two percent corynanthine applied topically two or three times daily for one, two, or three weeks to seven patients with symmetrical ocular hypertension did not reduce IOP. Alpha adrenergic antagonists may have a role in the treatment of glaucoma.     

非接触眼压计测量高眼压兔模型的准确性

目的:探讨非接触眼压计(NCT)测量高眼压兔模型的准确性。方法:兔全身麻醉后前房、玻璃体腔穿刺,通过平衡盐水柱高低调控眼内压,前房插管显示实际眼压于15.00±0.50,20.00±0.50,25.00±0.50,30.00±0.05,35.00±0.50,40.00±0.50,45.00±0.50mmHg,同时测量相对应的NCT眼压。分析实际眼压与NCT眼压的差异及相关性,以实际眼压作为应变量进行回归分析。结果:兔NCT眼压均低于实际眼压值,有显著性差异(P<0.01)。兔NCT眼压与实际眼压两者具有显著相关性(相关系数r=0.985,P<0.01)。筛选回归方程Y=10.875+1.170X(方差分析F=2691.389,P<0.01),式中Y为实际眼压,X为NCT眼压。结论:NCT能够用于测量高眼压兔模型,实际眼压与NCT眼压之间有直线关系,可借助回归方程通过NCT眼压推断实际眼压,为兔青光眼模型眼压测量提供了实验支持。     

高眼压症患者的随访观察

目的:探讨高眼压症的危险因素、随访指标。方法:对29例高眼压症患者进行3～4(平均3.5)a的随访,随访内容包括眼压、视野、视盘及视神经纤维层等方面的检查。结果:随访过程中25例患者眼压无明显变化,2例眼压呈下降趋势,眼压增高2例。结论:高眼压症与多种致病因素有关,应密切随访观察,出现可疑青光眼改变,积极行抗青光眼的治疗。     

The effect of hypotensive drugs on the intraocular pressure after waterloading in rabbits

The waterloading test in rabbits, using 100 ml of waterloads per kg body weight, without general anaesthesia and with applanation tonometry to measure intraocular pressure (IOP), deserves a place in glaucoma research. Using this model we found adrenaline not to have an effect on the IOP with or without waterloading. Isoprenaline and to a lesser degree physostigmine reduced the pressure in the normal eye markedly, but these drugs did not have any effect on the pressure after waterloading. 9-THC (Tetrahydrocannabinol) and pilocarpine increased the IOP in the normal rabbit eye. After waterloading 9-THC decreased the pressure, but its value was still significantly higher than the control pressure. Pilocarpine did not reduce the pressure after water-loading. Acetazolamide and timolol did not reduce the pressure in the normal eye, but after waterloading a significant reduction was observed.     

Change in appearance of the optic disc associated with lowering of intraocular pressure

This report provides additional documentation that the appearance of the optic disc may improve after intraocular pressure is lowered in patients with glaucoma. Photographic records of one of the authors (GLS) were reviewed retrospectively. Seven previously unreported cases showing apparent improvement of the optic disc were found, and the patients' charts were reviewed. In two cases the improvement was transient, and in five it was lasting. Patients with evidence of disc improvement had an age range of 5 to 55 years. In one case, the scleral ring decreased in size following the lowering of intraocular pressure. In the other cases, the disc appeared to "fill in" without change in the size of the scleral ring. When improvement is short-lived, it presumably represents edema. When of longer duration, it may be a response to anterior repositioning of a posteriorly displaced lamina cribrosa, a decrease in diameter of the scleral ring, hypertrophy and/or proliferation of glial cells, or return towards normal of axonal metabolism. Because apparent improvement in the appearance of the optic disc can be subtle, it is usually not sought and is probably often unrecognized. Its true incidence is still unknown but appears to be underestimated.     

LASIK手术时眼压波动对视神经轴突影响的实验研究

目的:定量观察LASIK手术时不同大小的负压吸引对兔视神经轴突的影响,以评估LASIK手术的安全性。方法:33只新西兰兔随机分为常规负压组、高负压组和超高负压组,分别采用不同大小的负压吸引,吸引阶段眼压分别升高至60mmHg、90mmHg和120mmHg,6w后取视神经标本,应用计算机图像分析进行视神经轴突计数。结果:超高负压组手术眼和对照眼视神经轴突数差异有统计学意义,P<0.01;另外两组手术眼与对照眼视神经轴突数差异无统计学意义,P>0.05。结论:在LASIK手术时,不宜采用过高的负压吸引,过高的负压吸引存在着潜在的危险性,瞬间的大幅度非生理性眼压波动可导致视神经轴突的不可逆损害。     

Rescula对无色素兔的降眼压作用及安全性研究

目的 了解前列腺素PGF2αDocosanoide衍生物Rescula滴眼液对正常无色素兔的降眼压作用和安全性。方法 雄性无色素兔40只,随机分为2组,每组20只,实验组和对照组均选左眼分别滴用Rfescula和0.5%贝特舒,为期4周。2组中对侧眼同期滴用等量的无菌生理盐水。观察并比较用药前后眼压、结膜、虹膜、角膜和晶状体的情况。结果 滴用Rescula后1h眼压明显下降,2h眼压达最低点,并维持近3h。Rescula和贝特舒分别使眼压降低23%和7%。停用Rescula后6h眼压开始升高,但仍低于正常眼压,大部分兔眼在首次点用Rescula后10-30min即出现结膜和虹膜充血,并有明显畏光,2h后逐渐消退,随着用药时间延长。充血逐渐减轻,持续时间缩短。结论 Rescula对正常无色素兔所显示的显著降眼压作用和眼部滴用的安全性表明,它是一种有希望的降眼压药物。     

Intravenous hypertonic saline to reduce intraocular pressure

Purpose: To quantitate the effect of intravenous hypertonic saline (IVHTS) injection on elevated intraocular pressure (IOP). Methods: Nineteen patients (median age, 65 years; range, 41–84 years) with glaucoma and an IOP 30 mmHg or higher were recruited. A bolus of IVHTS (sodium chloride concentration 23.4%) was injected in an antecubital vein over 10–20 seconds. The IOP and systolic and diastolic blood pressure (BP) were measured frequently for 2 hr. The dosage was 0.5 mmol/kg sodium in 11 patients (Group 1) and 1.0 mmol/kg in eight patients (Group 2). Results: In both groups, a median absolute IOP reduction of 7 mmHg was achieved in 5 min. The maximum median reduction was 7 mmHg (range, 4–16) and 9 mmHg (range, 3–14) at 5 and 16 min after IVHTS in Group 1 and 2, respectively, at which point the median IOP had reduced from 38 and 35 mmHg to 31 and 27 mmHg (p < 0.001), respectively. In both groups, the IOP remained 7 mmHg reduced 2 hr after IVHTS. Systolic BP increased a median of 14.5 mmHg at 3 min and was comparable with baseline after 6 min. Conclusion: Intravenous hypertonic saline solution reduces IOP moderately within minutes for up to 2 hr.     

New perspectives on target intraocular pressure

The evidence in support of intraocular pressure (IOP) lowering to reduce risk of glaucoma onset or progression is strong, although the amount and quality of IOP reduction is less well defined. The concept of a target IOP includes a percentage reduction, calculated IOP, or a predetermined IOP figure or range. Yet none of these strategies have been validated. In addition, our understanding of the way IOP influences glaucoma risk is continuously evolving. Examples of this include the data on IOP fluctuation and lamina cribrosa and cerebrospinal fluid pressure differentials. That these variables are not included in target IOP calculation potentially undermines its accuracy and usefulness. We summarize the evidence for target IOP, new developments in our understanding of IOP and glaucoma pathogenesis, as well as emerging strategies for setting targets and assessing response to treatment.     

长期高眼压状态对人眼波前像差的影响

目的探讨长期高眼压状态对人眼波前像差的影响。设计非随机化前瞻性临床试验。研究对象开角型青光眼患者及因单眼病变需甘露醇治疗的对侧健眼。方法检测18只青光眼眼和12只正常眼20%甘露醇静脉滴注降眼压治疗前后的屈光度、波前像差、眼轴长度和前房深度。主要指标波前像差RMS值。结果降眼压治疗前长期高眼压眼的RMSg、RMSh、RMS1～RMS6、C7、C8和C12值均显著高于正常对照组。治疗后,长期高眼压组患眼的RMSg、RMSh和RMSI～RMS6值均显著下降;Zemike系数C7、C8、C12值均明显减小;C8的变化程度与眼压的下降幅度显著正相关。而正常对照组RMSh显著升高。结论长期高眼压状态会增加人眼的波前像差,经降眼压治疗后波前像差有所下降。