The effect of hyperbaric oxygen on intraocular pressure.

The effects of hyperoxia on intraocular pressure (IOP) have been studied in experiments on human beings and animals. The changes occurring in IOP in patients during routine HBO2 therapy are unknown. In this study we investigated IOP changes arising during the HBO2 therapy at 2.5 ATA. Fifty-six patients receiving HBO2 therapy for various reasons were included in the study. Bilateral IOPs of patients measured with the Tono-pen XL (Medtronic, Solan, USA) tonometer before, during and after HBO2 therapy. Average IOPs were 14.85 +/- 3.17 mmHg (range, 10-24), 13.00 +/- 2.97 mmHg (range, 9-21) and 14.74 +/- 3.12 mmHg (range, 10-22), respectively. IOP was reduced significantly during HBO2 therapy and returned its pre- HBO2 levels after therapy. Our data indicated a statistically significant decrease in IOPs during therapy at 2.5 ATA. This decrease was of minor physiological significance in these patients whose baseline IOP values were within the normal range.     

兔氩离子激光虹膜切除术后的眼压变化

本实验目的在于观察激光虹膜切除术后眼压的动态变化，并为临床用药提供参考。用家兔行激光虹膜切除术，观察术后眼压的动态变化，发现术后出现明显的一过性眼压升高，峰值在半小时内出现，随之自然下降，至３小时恢复正常。这种眼压升高主要是由于血—房水屏障的破坏，房水渗出物突然增加所致，为一过性功能紊乱的可逆变化。术前滴用消炎痛或地塞米松可以减轻。     

高眼压模型大鼠血清中hsp27抗体的检测及其意义

 目的 观察高眼压模型大鼠血清中热休克蛋白27(heat shock protein 27,hsp27)抗体的情况,并分析眼压与hsp27抗体之间的关系.方法 将51只Wistar大鼠随机分为高眼压组(34只),Sham对照组(17只).采用双极水下电凝器电凝大鼠右眼巩膜表面3组静脉及角膜缘周围血管,升高大鼠眼内压,建立高眼压动物模型,分别于手术后1、2、4、6、8周处死大鼠,处死前测大鼠双眼眼压,并收集血清1ml供酶联免疫吸附实验(enzyme-linked immunosorbeat assay,ELISA)测定大鼠血清中hsp27抗体水平.结果 高眼压组右眼术后眼压明显升高.术前眼压(15.00±2.498)mmHg;术后3d眼压:(27.44±2.776)mmHg;术后2周眼压:33.96±2.603)mmHg;术后8周眼压:(35.50±2.390)mmHg.术后高眼压组右眼眼压与术前、左眼及Sham对照组右眼比较,差异有统计学意义(P＜0.05);高眼压组不同时间点血清中hsp27抗体水平相比差异有统计学意义(P＜0.05).结论 随着眼压的升高以及高眼压持续时间的延长,大鼠血清中的hsp27抗体水平逐渐升高.     

The effect of beta blockade on the reaction of pressure and mesenteric flow to biogenic amines in normal and X-irradiated rats

A beta-blocker, propranolol, was infused to control and irradiated rats the 1st and 3rd day after 2-kR X-ray irradiation. Blood pressure and mesenteric blood flow were recorded during infusion of biogenic amines (noradrenaline, dopamine, serotonin, acetylcholine and histamine). After beta-blockade, there was intensified increase in pressure and decrease in flow with increased overshoot after infusion of noradrenaline, no effect on the increase in pressure and flow after dopamine, but an enhanced increase in pressure and decrease in flow after serotonin. No effect on the decrease in pressure and flow was seen after acetylcholine, and a greater decrease in pressure and flow, after histamine. Irradiation altered the vascular reactivity, mainly for noradrenaline, serotonin and histamine.     

Intraocular pressure and acclimatization to 4300 M altitude

BACKGROUND: Studies were conducted to determine the effect of altitude exposure on intraocular pressure (IOP) and any relationship with the severity of acute mountain sickness (AMS). HYPOTHESES: a) IOP is decreased during exposure to 4300 m altitude; b) there is a positive correlation between IOP and AMS; and c) there is a correlation between changes in urinary catecholamines and IOP. METHODS: IOP (noncontact tonometry) was measured in 11 resting males during acute simulated altitude (446 mmHg, < 2 h, hypobaric chamber), during altitude acclimatization (15 d at 4300 m), and in 6 of the 11 volunteers during re-exposure in the chamber after 8 d at sea level (Study A). In a second study (Study B) of 12 females, IOP (contact tonometry) and 24-h urinary catecholamines were measured during a 50-h chamber exposure (446 mmHg). AMS severity was assessed using the Environmental Symptoms Questionnaire (ESQ-C). RESULTS: IOP decreased 25% after 2 d at altitude and returned toward sea level values by 15 d (Study A). IOP was reduced 13% after 5 h of exposure followed by return toward sea level values (Study B). Significant correlation was found between the sea level IOP and ESQ-C (Study A); significant correlation was found between the reduction in IOP and the ESQ-C and urinary epinephrine concentrations (Study B). CONCLUSIONS: Altitude exposure resulted in a reduction in IOP that occurred within hours and recovered during acclimatization. This reduction may be related to increases in epinephrine concentration. Measurement of IOP before and during altitude exposure may provide an objective method of assessing an individual's response to hypoxic stress.     

Intraocular pressure measured at ground level and 10,000 feet

BACKGROUND: Intraocular pressure (IOP) may be subject to change during altitude exposure. This may be an important consideration for long-haul flights. In this study, intraocular pressure change was investigated following exposure to an altitude of 10,000 ft during flight in an unpressurized aircraft. METHODS: We measured the IOP of the right eye of 20 healthy volunteers (18 men, 2 women; mean age 34.6 +/- 9.5 yr) at a ground level of 1,760 ft (536 m) above the sea level (ASL) using a Tono-Pen XL tonometer. We then repeated the measurements during a flight in the unpressurized cabin of a CASA (CN235-100 M) aircraft after gaining an altitude of 10,000 ft (3,048 m) ASL. Changes in the IOP were evaluated. RESULTS: Mean IOP was 16.2 +/- 2.46 mmHg at ground level and 15.0 +/- 2.61 mmHg at 10,000 ft (3,048 m) ASL. IOP was reduced in 13 eyes, increased in 6 eyes, and remained unchanged in 1 eye. The mean change in IOP was 1.2 +/- 2.69 mmHg. However, this was not statistically significant (p = 0.06). CONCLUSION: Acute change in altitude resulted in a statistically non-significant reduction in IOP in healthy subjects.     

超声乳化人工晶体置入联合房角分离术治疗慢性闭角型青光眼

 目的 探讨超声乳化白内障吸除人工晶体置入联合房角分离治疗慢性闭角型青光眼的疗效及其影响因素。方法 回顾性分析2008-09至2013-10收治的慢性闭角型青光眼患者80例共92眼经超声乳化白内障吸除人工晶体置入联合房角黏弹剂分离术治疗的效果。所有患者根据术前局部用药眼压控制与房角关闭及粘连情况分4组: G1组(术前用药后眼压≤25.0 mmHg,房角关闭≤270°)42眼、G2组(术前用药后眼压≤25.0 mmHg,房角关闭＞270°)12眼、G3组(术前用药后眼压＞25.0 mmHg,房角关闭≤270°)10眼和G4组(术前用药后眼压＞25.0 mmHg,房角关闭＞270°)28眼。比较分析术前、术后各组视力、眼压以及中央前房深度(anterior chamber depth,ACD)、前房容积(anterior chamber angle,ACV)和前房角宽度(anterior chamber angle,ACA)等眼前节结构变化。术后随访12～60个月,平均33个月。结果 术后各组患者视力显著改善、眼压也显著下降(P<0.01),术后视力改善情况:G1组、G2组 优于 G3组、G4组(P<0.01),G3组 也优于 G4组(P<0.01);眼压情况则除G4组[(22.98±4.54)mmHg]仍高于正常外,G1组、G2组和G3组均下降至正常水平,且G1组、G2组眼压下降较G3组(P<0.05)、G4组(P<0.01)明显,G3组也好于G4组(P<0.05),但G1组与G2组在视力和眼压差异均未显示出有统计学意义(P>0.05)。各组患者均有不同程度的视神经萎缩,并且与病程相关,术后仍有20眼(G3组2眼,G4组18眼)未达到有效眼压控制,需加用药物及手术干预。眼前节结构:术后各组ACD、ACA、ACV均较术前有明显改善(P<0.01);术后各组间,ACD变化最为显著,其中G1组、G2组显著深于G3组、G4组(P<0.01),G3组也较G4组深(P<0.05),G1组、G2组则明显差别(P<0.05);ACA则仅G1组宽于G4组(P<0.01),其他各组差异无统计学意义(P>0.05);各组间ACV均差异无统计学意义(P>0.05)。结论 超声乳化白内障吸除人工晶体置入联合房角分离术是一种治疗慢性闭角型青光眼的安全有效的方法,可有效提高视力,远期眼压控制效果确切,但疗效与术前眼压控制情况、房角关闭和粘连范围以及病程等密切相关。     

重型脑损伤后Terson综合征

目的：研究重型脑损伤（SBI）后Terson综合征（TS）发生的相关因素和临床特点。方法：监测161例脑损伤病人的颅内压（ICP）、眼内压（IOP）、脑灌注压（CPP）、视觉诱发电位（VEP）和视力,分析它们与SBI后TS的关系。结果：SBI后TS的发生率显著高于对照组;TS的发生与急性ICP和IOP增高密相关,发生TS病人的ICP和IOP显著高于对照组;急性IOP增高与急性ICP增高呈正相关,ICP曲线上出现A波者大多发生TS。结论：SBI后IOP和ICP明显增高的病人易发生TS;有效控制ICP和IOP,防止ICP曲线上A波出现,有助于减少TS的发生和改善病人预后。     

半导体激光经巩膜睫状体光凝术治疗难治性青光眼的疗效观察

目的：探讨半导体激光经巩膜睫状体光凝术（transscleral cyclo-photocoagulation,TSCPC）治疗难治性青光眼的临床疗效。方法：回顾性分析2009-06～2009-12收治的46例46眼难治性青光眼患者,采用TSCPC治疗,观察并记录视力、眼压、眼部自觉症状及并发症。随访时间约3月,分别记录术后1 d,1周,1月,3月眼部情况。结果：术后随访3月以上,术前平均眼压55.86±11.46 mmHg,术后最后随访平均眼压为17.13±7.06 mmHg。经统计学检验,术前与术后眼压相比,差别具有统计学意义（P〈0.05）;术后视力：33例视力无变化,8例视力提高,5例视力下降;术后患者眼痛消失或缓解;并发症较少,程度较轻,主要有球结膜水肿、葡萄膜炎、角膜水肿、前房出血等。结论：TSCPC能够有效控制难治性青光眼患者的眼压,减轻患者痛苦,挽留患者眼球,成为晚期难治性青光眼治疗的首选方法。     

Neuroretinal function during mild systemic hypoxia

PURPOSE: Few studies have investigated the effect of systemic hypoxia on the vascular and neural function of the human retina. Such studies can help us understand physiological responses to environmental hypoxia, as well as the pathophysiological mechanisms underlying certain ocular diseases. The objective of this study was to investigate the impact of mild systemic hypoxia on neuroretinal function through photopic flash electroretinogram (fERG) and oscillatory potential (OP) recordings. METHODS: The photopic fERGs and OPs were recorded in 18 healthy adults under conditions of mild systemic hypoxia. The retinal responses were recorded before, during, and after a 5-min period of breathing 12% oxygen (O2) in 88% nitrogen. The heart rate (HR), respiratory rate (RR), end-tidal carbon dioxide pressure (Petco2), and O2 saturation (SaO2) were measured throughout testing. The systemic blood pressure (BP) and intraocular pressure (IOP) were measured to derive the ocular perfusion pressure (OPP). RESULTS: Systemic hypoxia reduced SaO2 and PetCO2, increased HR but did not alter the RR or OPP. The a-wave amplitude and latency were not altered throughout testing. The b-wave amplitude decreased with hypoxia, whereas its latency was not affected. The amplitude of OP1, OP2, and OP4 remained stable throughout testing, whereas the amplitude of OP3 tended to decrease with hypoxia and was increased at the end of testing. The latency of OP1, OP3, and OP4 did not vary. The latency of OP2 was reduced at the end of testing. CONCLUSIONS: Our results show that mild systemic hypoxia alters the fERG b-wave and OPs but not the a-wave. This suggests that the outer retina in humans is more resistant to a mild systemic hypoxic stress than the inner retinal layers.     

微创玻切联合手术治疗青光眼术后并发恶性青光眼

目的探讨23G微创玻切联合手术治疗青光眼术后恶性青光眼的临床疗效。方法对中国医科大学附属盛京医院眼科2014年1-12月收治的15例(15眼)患闭角型青光眼行小梁切除术后并发恶性青光眼的患者,采用前瞻性临床研究,施行23G玻切头前段玻璃体切割+白内障摘除+人工晶状体植入+后囊切开术。术后观察、比较的指标包括:视力,眼压,前房深度,角膜状况及手术并发症。所有研究对象平均随访6个月。结果 15例患者(15眼)术后视力较术前得到不同程度的改善。其中,14例患者眼压控制良好,眼压由术前的(39.48±2.43)mm Hg下降至术后的(14.20±3.62)mm Hg(P<0.01);1例患者加用抗青光眼药物治疗。15例患者前房均形成,术后前房深度增至(2.06±0.04)mm,较术前明显加深(F=9.68,P<0.01);术后6个月角膜均透明,无角膜内皮失代偿、眼压失控、眼球感染、球内出血等严重并发症。结论 23G微创玻璃体切割联合手术治疗小梁切除术后并发恶性青光眼有效,并且避免了传统玻璃体切割手术的并发症。     

810 nm激光经巩膜睫状体光凝治疗难治性青光眼的效果

 目的 观察810 nm激光经巩膜睫状体光凝术(trans-scleral cyclophotocoagulation, TSCP)治疗难治性青光眼的效果。方法 回顾性分析2014-04至2016-06保定市第一中心医院收治的78例(78眼)接受810 nm激光TSCP治疗的难治性青光眼患者的临床资料,记录患者术后视力、眼压的变化,观察患者术后眼部疼痛程度,统计治疗相关并发症发生情况。结果 (1)治疗成功73例,成功率为93.59%。(2)术后1 d,患者视力降低13例,术后1周降低11例,术后1、3、6个月患者视力趋向稳定,术后6个月患者视力不变所占比例高达74.36%。视力提升12例,占15.38%;视力降低8例,占10.26%。(3)术后1 d、1周、1个月、3个月、6个月患者眼压均明显降低,与术前比较差异有统计学意义(P<0.05),术后1、3、6个月患者眼压趋向稳定,均低于术后1 d(P<0.05)。(4)术后不同时间所有患者VAS评分均降低,术后1~6个月趋向稳定,明显低于术后1 d及术后1周(P<0.05)。(5)患者术中并发症以眼部疼痛为主,术后早期以前房轻度炎性反应为主,术后晚期并发症发生率较低,以白内障、眼球萎缩、色素膜炎为主。结论 810 nm激光TSCP可降低难治性青光眼患者眼压,减轻眼部疼痛程度,且术后并发症发生率低,安全性高。     

选择性激光小梁成形术联合药物治疗激素性青光眼

目的观察选择性激光小梁成形术（Selective laser trabeculoplasty,SLT）治疗激素性青光眼的疗效和安全性。方法激素性青光眼患者15例26只眼,行360°全周小梁网SLT治疗。激光治疗光斑直径400μm,脉冲时间3 ns,能量0.6-1.0 mJ。术后随访1-12个月,观察眼压、视力及并发症等。结果 6只眼术前平均眼压（29.5±4.3）mmHg,随访末次眼压（19.0±2.6）mmHg,术后各个时间点的眼压较术前显著下降,差异具有显著意义（P〈0.05）。结论 SLT治疗激素性青光眼是一种安全有效的方法。     

Ocular refraction with body orientation

Body inversion is used experimentally to raise the intraocular pressure (IOP). Psychophysical and electrophysiological methods of assessing visual function in artificially raised IOP are generally influenced by the clarity of the retinal image. It is therefore essential to be aware of any changes in ocular refraction induced by changes in body orientation. The present study reports on the refractive changes occurring with body orientation in conditions where accommodation is freely responding, and also immobilized pharmacologically. Ocular refraction varies by less than 0.50D across all body orientations as measured by a laser optometer which provides refractive measurements independent of the perception of blur. These results indicate that pattern-dependent tests of visual function are not likely to be influenced by refractive changes on body inversion.     

选择性激光小梁成形术治疗早期开角型青光眼的临床疗效观察

目的评价选择性激光小梁成形术（selective laser trabeculoplasty angioplasty,SLT）治疗早期原发性开角型青光眼（primary openangle glaucoma,POAG）的有效性和安全性。方法选择局部单纯用药眼压控制效果不理想的早期POAG42例81只眼。观察SLT治疗后12个月的眼压变化。结果术前、术后2,24 h,1周及1、3、6和12个月平均眼压分别为（29.93±4.57）、（24.01±5.13）、（19.86±5.19）、（17.57±3.43）、（14.21±3.09）、（13.64±2.95）、（13.96±3.18）和（14.10±3.17）mmHg。结论 SLT可以安全有效地降低POAG的眼压,具有损伤小和可重复的优点,可用于治疗早期开角型青光眼。     

飞行员在明暗环境下眼波前像差的分析

目的 研究视力正常飞行员在明暗环境下波前像差变化及在暗环境下对飞行员视觉评估的意义.方法 现役飞行员22例(44眼),平均年龄31.7±6.4岁,视力均在4.9以上,采用WFA-1000型主觉像差仪分别在明暗环境下检测受试者的波前像差,得到各阶像差成分的均方根值(RMS).并测量眼压(10P)、角膜曲率、中央角膜厚度(CCT)等常规参数.结果 飞行员的IOP、角膜曲率、CCT均在正常范围.波前像差在暗环境下仅5阶像差的差异有统计学意义(t=-2.190,P<0.05),5阶以下及总像差无统计学意义.结论 暗环境条件下飞行员的视觉质量在高阶波前像差方面有所下降,但总体无影响.波前像差对飞行员视觉功能的评估具有一定意义.     

Total intravenous anesthesia with propofol with midazolam coinduction--the anesthesia of choice in cataract surgery

Comparative clinical investigation was performed in 80 ASA I/II patients undergoing cataract surgery on one eye. Patients were randomly divided in to four groups, according to the method of anesthesia. Intraoperatively (T0-T6), decreasing of intraocular pressure (IOP) to the optimal values at the start of the operation (T3), and the hemodynamic stability of patients after the induction (T1) were evaluated. Postoperatively, the recovery rate, and the incidence of vomiting were measured. Optimal decreasing of IOP was noticed in the second group (75% of patients). Best hemodynamic stability was observed in the second group (80% patients). Fast recovery rate was noticed in the first and the second groups (13.9 +/- 1.1 and 14.4 +/- 0.8 min). Vomiting was noticed in 5% patients in the first group, 15% in the third group, and in 20% in the 4th group. The authors have concluded that TIVA fourth propofol and coinduction with midazolam is anesthesia of choice in the cataract surgery.     

染料激光虹膜切割对青光眼房水动力学的影响

本文应用房水荧光素浓度曲线测定法,观测原发性闭角型青光眼患者20例(35眼)在行染料激光虹膜周边切除术前后的房水动力学变化,同时观察眼压、前房轴深和前房角宽度的改变,并以20名正常人(40眼)作对照分析了其间的关系。结果发现:青光眼患者在染料激光虹膜周切术后,其房水引流阻力较术前明显降低,其眼压、前房轴深和前房角宽度也有不同程度的改善。文章对染料激光的优越性和青光眼术后房水循环的改善程度作了讨论。     

外伤性aPVR引起慢性低眼压的发病机制探讨

目的探讨外伤性前部增生性玻璃体视网膜病变(aPVR)病理状态下低眼压的发生、发展及转归,为防治外伤性aPVR引起的慢性低眼压提供理论依据。方法利用青紫兰兔制作外伤性aPVR引起慢性低眼压的动物模型(n=8),于术前及术后不同时间点分别观测眼压(IOP),并行光镜及电镜观察。结果术后1周、2周、4周、8周实验组平均眼压明显低于对照组(P＜O．01)。光镜检查发现实验组术后2周、4周、8周睫状体水肿,术后4周及8周睫状体无色素上皮萎缩、缺失。电镜检查发现实验组术后4周和8周睫状体无色素上皮线粒体明显减少,细胞内空泡。结论外伤性aPVR睫状膜的增生和收缩引起对睫状上皮的牵拉,造成睫状体无色素上皮萎缩和睫状体水肿,进而促进慢性低眼压的发生。     

Intraocular pressure at a simulated altitude of 9000 m with and without 100% oxygen

INTRODUCTION: Exposure to high altitude may affect intraocular pressure (lOP). This study aimed to determine how IOP was altered by two different inspired oxygen tensions at altitude. METHODS: There were 34 healthy male pilots, ages 26-39 yr (mean 31.9 yr), who were studied at the Air Health Examination and Physiological Training Centre in Eskisehir, Turkey. They were studied at ground level, which is 792 m (2414 ft), and during a training session in a hypobaric chamber at a simulated altitude of 9144 m (30,000 ft). IOP was measured with a Tone-pen XL tonometer before subjects entered the chamber, at altitude while breathing 100% oxygen by mask and after removing the mask, and again 30 min after leaving the chamber. RESULTS: Ground level values for IOP (mean +/- SD) were 12.31 +/* 2.98 mmHg. Levels increased significantly at altitude on oxygen (16.75 +/- 4.14 mmHg) and decreased slightly on breathing ambient air (14.37 +/- 3.44 mmHg). In 30 min after leaving the chamber, IOP was 12.81 +/- 1.74 mmHg, indistinguishable from pre-test values. DISCUSSION: Healthy subjects whose baseline IOP is in the normal range experience only a small, temporary elevation of IOP during passive exposure to high altitude with either normoxia or acute hypoxia.