漫谈眼压与青光眼的临床

眼压是青光眼最重要最易监控的临床指标,必须强调其测量的精确性。高眼压症、原发性开角型青光眼、正常眼压性青光眼和慢性闭角型青光眼都有其各自的特点以及独特的与眼压的关系。本文试从眼压的角度,结合近年来国外重要的多中心临床研究结果,讨论高眼压症和几种常见青光眼的临床诊治思路。     

高龄老年人眼剥脱综合征发病情况及其与青光眼的关系分析

目的:评估60岁以上老年人群中眼剥脱综合征(exfoliation syndrome,XFS)发病情况及其与青光眼的关系。方法:对1999-03-01/2004-12-31在我院南楼常规查体的14780人进行眼科常规查体,内容有:视力,角膜、虹膜,眼底状态,眼压,怀疑XFS者行散瞳和房角镜检查,怀疑青光眼者则进行视野及其他相关检查,将上述结果登记记录并予以分析。结果:在参与检查的14780人中,XFS患者共1276例(8.63%),青光眼患者共874例(5.91%),二者的患病率均随年龄增加逐渐升高。既有青光眼又有XFS的患者为233例(18.26%)。结论:眼XFS作为一种年龄相关性体征随年龄增加发生率增高,其青光眼发病率高于正常对照组,对该组患者需加强随访,及时治疗。     

Intraocular pressure in diabetic persons

Intraocular pressure measurements were taken in 2366 diabetic persons and 381 nondiabetic persons who lived in southern Wisconsin. Diabetic persons tended to have higher mean intraocular pressure than the nondiabetic persons. Higher blood pressure, earlier time of day of IOP measurement, absence of cataract and, in some comparisons, female gender, were significantly associated with higher intraocular pressure. In this study rates of a positive history of glaucoma were higher in diabetic persons than in nondiabetic persons and the population participating in the Health Interview Survey. These findings suggest that ophthalmologists must be aware of the increased risk of glaucoma when evaluating diabetic patients.     

Intraocular pressure the day of argon laser trabeculoplasty in primary open-angle glaucoma

Argon laser trabeculoplasty was performed in one eye of 57 phakic patients with primary open-angle glaucoma. The eyes received a mean of 78 +/- 7 treatments over 360 degrees to the anterior trabecular meshwork. The power was titrated to produce blanching without bubble formation. Increased intraocular pressure (range +1 to +22 mmHg) occurred in 30 of the 57 (53%) eyes 1 hour after treatment. Eight (14%) of these eyes had a clinically significant elevation defined by all of three criteria: (1) an intraocular pressure greater than 30 mmHg, (2) greater than a 30% increase over the mean prelaser intraocular pressure, and (3) greater than a 10 mmHg increase over the peak prelaser diurnal intraocular pressure curve. These eight patients received either oral glycerine or acetazolamide. A rebound increase in intraocular pressure requiring repeat medical treatment occurred in four of the eight eyes. Two additional eyes without a pressure elevation 1 hour after treatment showed a later elevation. This was first detected 4 hours postoperatively in one eye and 7 hours after treatment in another eye. The 1-hour postoperative measurement detected most patients with clinically significant increased intraocular pressure (8 of 10 eyes) but these required continued observation for rebound increases. Patients with advanced glaucomatous visual field loss should also be followed closely to detect late increases in intraocular pressure (2 of 10 eyes).     

陕西省农村人群青光眼的流行病学调查

目的:调查陕西省农村≥50岁人群中青光眼的患病情况。方法:2003-07/12,采用按比例随机整群抽样的方法在陕南、陕北及关中3个地区农村调查8500人,其中≥50岁人群有2125人。所有受检人员均进行标准问卷调查,包括询问青光眼确诊史、家族史、发作史及手术史,并进行了相关的眼科检查,包括视力、外眼、前房深度及眼底检查。≥50岁人群应用压平式眼压计测量眼压,对可疑青光眼者进行进一步检查,包括复查眼压、前房角镜检查、激发试验、视野检查。结果:≥50岁人群中有1775人完成了青光眼的相关检查,受检率为83.53%。青光眼的患病率为2.14%,其中原发性闭角型青光眼、原发性开角型青光眼、继发性青光眼患病率分别为1.63%、0.39%、0.11%。55.26%青光眼患者存在不同程度的视力损伤,其中单眼低视力、双眼低视力、单眼盲及双眼盲所占比例依次为18.42%、5.26%、18.42%和13.16%。事前未被诊断为青光眼的患者占71.05%(27例),在另外28.95%(11例)有确诊史的青光眼患者中只有6例(54.55%)曾接受过治疗。正常眼的眼压平均值为13.9±2.2mmHg(1mmHg=0.133kPa),随着年龄的增加眼压有增加的趋势(P<0.05)。结论:陕西省农村人群青光眼的患病率为2.14%,但原发性闭角型青光眼和原发性开角型青光眼在原发性青光眼中的比例为4.18:1。无确诊史的青光眼患者占大多数。     

Why is Intraocular Pressure Elevated in Chronic Simple Glaucoma?: Anatomical Considerations

Ultrastructural analysis of 400 trabeculectomy specimens of glaucomatous eye revealed three types of extracellular deposits within the cribriform layer of the trabecular meshwork. One of these derives from the sheath of the subendothelial elastic-like fibres. Tissue culture and ultrahistochemical studies led to the assumption that these deposits contain glycoproteins, probably secreted by the cribriform layer cells.     

Intraocular pressure fluctuation and the risk of glaucomatous damage deterioration: a Meta-analysis

AIM: To systematically review whether the increased fluctuation of intraocular pressure (IOP) is a risk factor for open angle glaucoma (OAG) progression. METHODS: Scientific studies relevant to IOP fluctuation and glaucoma progression were retrieved from MEDLINE, EMBASE and CENTRAL databases, and were listed as references in this paper. The hazard ratio (HR) was calculated by using fixed or random-effects models according to the heterogeneity of included studies. RESULTS: Individual data for 2211 eyes of 2637 OAG patients in fourteen prospective studies were included in this Meta-analysis. All studies were longitudinal clinical studies with follow-up period ranging from 3 to 8.5y. The combined HR was 1.23 (95%CI 1.04-1.46, P=0.02) for the association between IOP fluctuation and glaucoma onset or progression with the evidence of heterogeneity (P<0.1). Subgroup analyses with different types of IOP fluctuation were also evaluated. Results indicated that the summary HR was 0.98 (95%CI 0.78-1.24) in short-term IOP fluctuation group, which showed no statistical significance with heterogeneity, whereas, the combined HR was 1.43 (95%CI 1.13-1.82, P=0.003) in long-term IOP fluctuation group without homogeneity. Sensitivity analysis further showed that the pooled HR was 1.10 (95%CI 1.03-1.18, P=0.004) for long-term IOP fluctuation and visual function progression with homogeneity among studies (P=0.3). CONCLUSION: Long-term IOP fluctuation can be a risk factor for glaucoma progression based on the presented evidence. Thus, controlling the swing of IOP is crucial for glaucoma or glaucoma suspecting patients.     

Population-based glaucoma prevalence studies in Asians

Glaucoma-related population-based studies from Japan, Mongolia, India, Singapore, Thailand, China, Bangladesh, Myanmar, Sri Lanka, and South Korea show a higher glaucoma prevalence in Asian patients, including a higher incidence of primary angle-closure glaucoma, than in white patients, although primary open-angle glaucoma (POAG) is still the most commonly reported. Among POAG, normal tension glaucoma predominates over high tension glaucoma, a distinctive finding. Risk factors for glaucoma in population-based studies in both Asian and white patients are similar, except that myopia is a greater risk factor in Asian patients. Diagnostic criteria differ among studies, some using the International Society of Geographic and Epidemiologic Ophthalmology (ISGEO) classification and others not. The devices used to observe the optic disk and test the visual field are also not uniform across studies. Moreover, the ages of patients, and whether rural or urban, were different. To allow reliable comparison of the results of epidemiologic studies, efforts to standardize the diagnostic criteria, devices, and the age range of the study population are required.     

Delayed intraocular pressure elevation after pupillary dilation in exfoliation syndrome

Purpose: To determine the effect of pupillary dilation on intraocular pressure (IOP) in normotensive patients with exfoliation syndrome (XFS). Methods: Patients with XFS were enrolled in this prospective trial. All eyes were untreated, had no previous laser or operative surgery and were normotensive with full visual fields and open angles. IOP was measured before dilation and hourly for four consecutive hours after dilation with tropicamide 1% and phenylephrine 2.5% eyedrops. Results: Twenty‐five eyes of 19 White patients (nine male, 10 female) with XFS were enrolled. Twelve eyes (48%) had a rise in IOP of ≥ 4 mmHg above the pre‐dilation baseline IOP and four (16%) had a rise of ≥ 9 mmHg (9–28 mmHg). Post‐dilation gonioscopy confirmed the presence of an open anterior chamber angle in all eyes. The maximum IOP was reached 3 hr post‐dilation in three eyes and after 2 hr in the remaining eyes. The four eyes with marked IOP rise exhibited an elevation of between 1 and 7 mmHg at 1 hr. Extensive pigment release was noticed in all eyes that had a rise in IOP. Conclusion: Patients with XFS are at risk of developing delayed post‐dilation IOP rises. Awareness of this phenomenon is particularly important in patients with advanced cupping and/or severe visual field loss who may not be able to tolerate a marked elevation of IOP. An early, mild rise in IOP at 1 hr may serve as a warning sign for a more severe, delayed response. Eyes with XFS should be monitored carefully after dilation, especially those with marked pigment release.     

Course of exfoliation and simplex glaucoma after primary trabeculectomy

AIM: To study the course of exfoliation and simplex glaucoma with respect to intraocular pressure (IOP) regulation and visual field survival after primary trabeculectomy. METHODS: Postoperative IOP regulation and complications were analysed prospectively in 95 patients. Mean follow up was 46 months. Visual field survival was studied by high pass resolution perimetry (HRP) in a subsample of 28 patients. RESULTS: Medical treatment was reinstated in 42% of exfoliation and in 36% of simplex glaucoma. In these patients, mean medicine free survival time, last untreated IOP, and mean IOP at the end of follow up were similar for both glaucoma types. Among patients with controlled postoperative IOP without added medication, mean IOP at the end of follow up was significantly lower in exfoliation glaucoma. Visual field deterioration and the pattern of complications were similar for both glaucoma types. CONCLUSION: The effect of trabeculectomy on IOP regulation was good in both types of glaucoma, and somewhat better in exfoliation glaucoma. The magnitude of IOP lowering could not separate patients with continued visual field deterioration from those in whom visual fields remained stable. Visual field preservation was similar for both glaucoma types.     

青光眼昼夜眼压波动

病理性高眼压和较大的昼夜眼压波动是青光眼视神经损害进展的重要危险因素.眼压具有波动性,正常人眼压波动的峰值多出现于凌晨,这种波动与体位、眼灌注压、眼轴等有关.正常眼压性青光眼患者眼压波动是视野进展的重要危险因素,且经24小时眼压监测发现大部分眼压是存在异常的,因此需根据其昼夜眼压曲线明确诊断和针对性治疗;原发性开角型青光眼患者昼夜眼压波动规律与正常人相似,眼压高峰多在夜间,但波动范围可能比正常人大,且双眼的波动呈明显的一致性;激光周边虹膜切开术后的慢性闭角型青光眼患者的昼夜眼压波动较大,其眼压波动与基线眼压和房角粘连程度呈正相关.与激光和药物相比,小梁切除术更有利于控制长期和昼夜的眼压波动.抗青光眼药物中前列腺素类药物是控制昼夜眼压波动效果最好的滴眼剂.     

Risk factors for incident open‐angle glaucoma: a population‐based 20‐year follow‐up study

Purpose:  To study the effect of potential risk factors on the development of open‐angle glaucoma (OAG) in a population in which pseudoexfoliation (PEX) is a common finding. Methods: In 1984–1986, a population‐based survey of 760 people aged 65–74 years was conducted in the municipality of Tierp, Sweden. From 1988 to 2006, a follow‐up study of the 530 people with normal visual fields has been in progress. To increase the cohort, 273 ophthalmic outpatients were enroled. Reliable visual fields were available for 679 people, representing 6 126 person‐years at risk. A time‐weighted mean intraocular pressure (IOP) for all visits was calculated. Results: Sixty‐four subjects developed definite OAG, 29 of whom were exposed to PEX. Risk factors associated with OAG were higher age, a positive family history, increased IOP and PEX. The age‐standardized rate ratio (SRR) was 14.8 times (95% confidence interval [CI] 7.92–27.8) greater in subjects with mean IOP ≥20 mmHg than in those with mean IOP <20 mmHg. When subjects with IOP <20 mmHg at baseline were affected by PEX, the SRR increased 5.01‐fold (95% CI 1.97–12.8), compared with the unaffected group. However, when mean IOP at follow‐up was taken into account, there was no relationship between OAG and PEX as a distinct risk factor. Among participants in the population survey, 69% of all cases were attributable to a mean IOP ≥20 mmHg. Conclusion: Increased IOP and PEX were serious risk factors for incident OAG. The effect of PEX was mediated by increased IOP.     

同步监测青光眼患者24h眼压与血压的意义

青光眼是世界范围内致盲和引起视力损害的主要眼病,也是不可逆性致盲性眼病之一.眼压是青光眼发生发展的重要危险因素,但除眼压外,血压在青光眼进展引起的影响也不可忽视.眼灌注压是血压和眼压的差值,可调节视神经的血液供应.眼压、血压、灌注压在青光眼发生发展中有一定相关性.本文通过对眼压和血压在青光眼中的影响以及24 h眼压和血...     

Tight orbit syndrome: a previously unrecognized cause of open‐angle glaucoma

Purpose: To describe a new syndrome of tight orbit and intractable glaucoma with a poor visual prognosis. Methods: A retrospective observational case series of six patients seen at two centres between 2001 and 2007 assessing intraocular pressure (IOP), best‐corrected visual acuity and visual field. Results: Three men and three women, ranging in age at diagnosis from 14 to 53 years, demonstrated similar orbital features and progressive visual field loss despite intensive management with medication and laser and operative surgery. Highest IOPs ranged from 30 to 50 mmHg. Trabeculectomy and/or glaucoma drainage devices were attempted in five patients but all failed. One patient underwent orbital decompression with achievement of IOP control. Final IOP at last follow‐up was variable; only two patients achieved IOP in the normal range, with the rest ranging from 25 to 40 mmHg. All patients had advanced visual field loss. Conclusion: Tight orbit syndrome presents a serious clinical challenge. Despite maximum medical therapy and surgical intervention IOP is difficult to control, resulting in progressive visual field loss.     

Intraocular pressure reduction with topical medications and progression of normal‐tension glaucoma: a 12‐year mean follow‐up study

Purpose: To investigate whether the amount of intraocular pressure (IOP) reduction with topical medications is associated with the progression of normal‐tension glaucoma (NTG) and to identify risk factors for NTG progression. Methods: The medical records of 121 eyes of 121 NTG patients, who were treated with topical medications for more than 7 years, were reviewed. NTG progression was defined by either structural (optic disc or retinal nerve fibre layer) or functional (visual field) deterioration. Patients were divided into tertile groups according to the percentage IOP reduction from baseline, and the cumulative probability of NTG progression between upper and lower tertile group was compared using Kaplan–Meier survival analysis. Multivariate analysis with Cox’s proportional hazard model was performed to identify the hazard ratio (HR) of clinical factors for NTG progression. Results: The average follow‐up period was 12.2 years, and 56 of 121 eyes (46.3%) showed the NTG progression. Kaplan–Meier analysis revealed that upper tertile group (percentage IOP reduction >22.1%) showed a greater cumulative probability of non‐progression than lower tertile group (percentage IOP reduction < 13.3%; p = 0.012). Multivariate Cox’s proportional hazard model indicated that percentage reduction of IOP (HR = 0.964; p = 0.007) and the occurrence of disc haemorrhage (HR = 2.410; p = 0.008) were significantly associated with NTG progression. Conclusions: The amount of IOP reduction using topical medications was related to NTG progression, and lower percentage reduction in IOP was a consistent risk factor for progression.     

Intraocular pressure assessment after laser in situ keratomileusis: a review

This paper aims to review the current methods available for the measurement of intraocular pressure after myopic laser in situ keratomileusis for the correction of myopia. Searches were performed for studies that assessed or compared various methods of intraocular pressure assessment. There were 20 eligible studies that explored the use of pneumotonometry, pressure phosphene tonometry, rebound tonometry, dynamic contour tonometry, statistical modeling, mathematical formulae, ocular response analyzer and even measuring intraocular pressure on the nasal cornea. Our review shows that an ideal method would be one that is independent of corneal factors. Dynamic contour tonometry and pressure phosphene tonometry held promise in research settings. More studies need to be done to validate the new methods of intraocular pressure assessment, especially in glaucoma patients. It is important to empower laser in situ keratomileusis patients with knowledge of these difficulties and potential implications for the future.     

Intraocular pressure before and after cataract surgery in participants of the Melbourne Visual Impairment Project

The purpose of this study was to investigate the effect of cataract surgery on intraocular pressure (IOP) in a cluster‐stratified random sample of the population of Victoria, Australia. A total of 3271 participants aged 40 years or older were examined at baseline for the Visual Impairment Project. The baseline study (1992–1994) was followed by a 5‐year incidence study. The IOP data were compared between participants who had cataract surgery between the two stages of the study and participants with and without cataract at follow up. The IOP was also compared before and after cataract extraction in glaucoma participants. An eligible 89 non‐glaucoma and 24 glaucoma participants had cataract surgery between the two time points. The analyses showed that IOP increases with age in non‐operated eyes in both glaucoma and non‐glaucoma groups. However, IOP decreased significantly after cataract surgery in eyes with glaucoma but did not change significantly in non‐glaucoma participants.     

The interaction between intracranial pressure,intraocular pressure and lamina cribrosal compression in glaucoma

This review examines some of the biomechanical consequences associated with the opposing intraocular and intracranial forces. These forces compress the lamina cribrosa and are a potential source of glaucomatous pathology. A difference between them creates a displacement force on the lamina cribrosa. Increasing intraocular pressure and/or decreasing intracranial pressure will increase the trans‐lamina cribrosa pressure difference and the risk of its posterior displacement, canal expansion and the formation of pathological cupping. Both intraocular pressure and intracranial pressure can be elevated during a Valsalva manoeuvre with associated increases in both anterior and posterior lamina cribrosa loading as well as its compression. Any resulting thinning of or damage to the lamina cribrosa and/or retinal ganglion cell axons and/or astrocyte and glial cells attached to the matrix of the lamina cribrosa and/or reduction in blood flow to the lamina cribrosa may contribute to glaucomatous neuropathy. Thinning of the lamina cribrosa reduces its stiffness and increases the risk of its posterior displacement. Optic nerve head posterior displacement warrants medical or surgical lowering of intraocular pressure; however, compared to intraocular pressure, the trans‐lamina cribrosa pressure difference may be more important in pressure‐related pathology of the optic nerve head region. Similarly important could be increased compression loading of the lamina cribrosa. Reducing participation in activities which elevate intraocular and intracranial pressure will decrease lamina cribrosa compression exposure and may contribute to glaucoma management and may have prognostic significance for glaucoma suspects.     

Intraocular pressure: New perspectives

Reevaluation of normal intraocular pressure (IOP) was attempted to investigate possible background factors that contribute to variations in IOP. It is well known that IOP increases with age among Western populations, while in the Japanese IOP has been confirmed to decrease with aging. Such paradoxical results can not be reasonably explained without considering systemic conditions rather than local factors peculiar to different races. Accumulated evidence indicates that IOP is positively correlated with blood pressure, obesity and other cardiac risk variables. Incorporation of these factors by stratifying the sample may provide the baseline IOP in those who are different in systemic conditions.