Retinal venous pulsation in glaucoma and glaucoma suspects

PURPOSE: To determine whether changes in central retinal vein pulsation characteristics occur in glaucoma, and how these are related to indices of glaucoma severity. DESIGN: A large, consecutive, prospective, case-controlled study. PARTICIPANTS: Ninety-four consecutive glaucoma patients and 105 glaucoma suspects seen in a tertiary referral clinic were examined. Forty-one age-matched normal subjects also were examined. METHODS: The presence or absence of spontaneous venous pulsation was observed in these 3 groups. The ophthalmodynamometric force (ODF) required to induce venous pulsation at the optic disc was measured in those without spontaneous pulsation. Optic disc photographs were obtained and visual field testing was performed for all subjects. MAIN OUTCOME MEASURES: The prevalence of spontaneous venous pulsation between these 3 groups was compared. The relationship between ODF and visual field mean deviation, neuroretinal rim area, age, intraocular pressure (IOP), gender, and diagnosis of glaucoma was investigated using linear mixed models fitted by Gibb's sampling. RESULTS: Significantly fewer (chi-square, 27.7; P<0.001) glaucoma patients (54%) were observed to have spontaneous venous pulsation than suspects (75%) or normals (98%). A worse visual field mean deviation was shown to be the most significant predictor of a higher ODF (P<0.000), with younger age (P<0.000) also predictive of a higher ODF. A strong relationship between ODF and mean deviation was found in the glaucoma patients (r = 0.59; n = 52; P<0.001). CONCLUSIONS: Spontaneous venous pulsation is less common in glaucoma. The ODF required to induce venous pulsation is increased in glaucoma, and this ODF is greater in those with more severe field loss.     

Iridoschisis and glaucoma

Three patients with unilateral iridoschisis and glaucoma (1 with bilateral open-angle glaucoma, 1 with unilateral glaucoma) were observed for 3 to 15 years. In none of these patients did iridoschisis progress and a good control of the glaucoma was achieved. The mechanism of this rare condition is yet not clear.     

Bradykinin sensitivity in primary open-angle glaucoma and normal-tension glaucoma patients

PURPOSE: To report the reaction after intradermal injection of bradykinin in nonglaucoma, primary open-angle glaucoma, and normal-tension glaucoma subjects. DESIGN: Prospective comparative study. METHODS: The study participants were 14 healthy control subjects, 16 patients with primary open-angle glaucoma, and 15 patients with normal-tension glaucoma. In each participant, the wheal response to intradermal injection of 10 microg bradykinin in the volar forearm was measured by a masked observer. RESULTS: There was no significant difference in the wheal response to bradykinin between control subjects and primary open-angle glaucoma patients (P =.73) and between primary open-angle glaucoma patients and normal-tension glaucoma patients (P =.09). However, there was a significant difference in the wheal response to bradykinin between control subjects and normal-tension glaucoma patients (P =.04). CONCLUSIONS: These in vivo structure-activity studies may suggest abnormalities of the tissue kallikrein-kinin system in normal-tension glaucoma.     

Comparison of delayed-onset glaucoma and early-onset glaucoma after infantile cataract surgery

PURPOSE: To investigate the causes and characteristics of glaucoma in children following cataract surgery. METHODS: Twenty-four patients (37 eyes) with uncomplicated congenital cataracts who developed glaucoma after cataract surgery were studied retrospectively. Variables included cataract morphology, surgical techniques, post-operative complications, time to the onset of glaucoma, gonioscopic findings, presence of microcornea and the histopathologic characteristics of the filtration angle (in one case). RESULTS: There was a bimodal onset of glaucoma after cataract surgery. Early-onset glaucoma occurred at a mean age of 6 months in 15 eyes and delayed-onset glaucoma at a mean age of 12 years in 22 eyes. Early-onset glaucoma was significantly (p = 0.018) more likely to be due to angle closure than delayed-onset glaucoma. With delayed-onset glaucoma, the filtration angle was open in 86% of eyes and significantly (p = 0.006) more eyes in the delayed-onset group had microcornea. Medical treatment was sufficient to control intraocular pressure in the delayed-onset group while the early-onset group required surgical treatment (P < 0.001). CONCLUSIONS: The onset of glaucoma after cataract surgery during infancy follows a bimodal pattern that is correlated with the configuration of the filtration angle. The early-onset glaucoma group had high incidence of angle closure requiring surgical treatment, while in the delayed-onset group non-surgical treatment was sufficient to control intraocular pressure. Prophylactic iridectomy in eyes at risk for pupillary block is recommended. Eyes with delayed-onset glaucoma have open filtration angles yet also have findings of incomplete development of filtration structures. Microcornea is a risk factor for delayed-onset glaucoma.     

Pseudophakic glaucoma

Summary Pseudophakia by itself does not cause ocular hypertension. Pseudophakic glaucoma should be defined as glaucoma that would not be present in an eye if it were not pseudophakic. Ocular hypertension was noted in 15 (9%) of 166 pseudophakic eyes. Only 5 eyes (3%) had ocular hypertension requiring treatment. Three of these eyes (1.8%) had permanent ocular hypertension resulting in chronic pseudophakic glaucoma. This study shows that pseudophakic glaucoma is no more frequent than aphakic glaucoma. Secondary glaucoma in pseudophakic eyes is not always related to the presence of the lens.Pupillary block glaucoma and UGH syndrome are directly related to the lens. Secondary glaucoma by ghost cells and by pigment-dispersion are also in some cases directly related to the lens.     

Long-term results after transscleral diode laser cyclophotocoagulation in refractory posttraumatic glaucoma and glaucoma in aphakia

Purpose To evaluate the long-term effect and safety of transscleral diode laser cyclophotocoagulation (TDLC) in eyes with advanced glaucoma in aphakia and posttraumatic glaucoma. Patients and methods Twenty-one eyes of 21 patients with glaucoma in aphakia and 25 eyes of 25 patients with posttraumatic glaucoma were treated with TDLC between 1996 and 2004. If the intraocular pressure (IOP) remained above 21 mmHg despite medication for more than 4 weeks after TDLC, the procedure was repeated. The IOP, number of medications, visual acuity, complications and need of further surgical intervention were all recorded during the follow-up period. Results Follow-up ranged from 12 to 93 months (mean 42.0 ± 29.2) in glaucoma in aphakia and from 12 to 73 months (mean 33.3 ± 17.4) in posttraumatic glaucoma. TDLC was successful in 48% of aphakic eyes with glaucoma and 40% of eyes with posttraumatic glaucoma. More than one TDLC was performed in 85% of cases of glaucoma in aphakia and 76% of cases of posttraumatic glaucoma). In both groups, TDLC was more effective in older patients than younger patients. Further glaucoma surgeries other than TDLC were performed in 43% of glaucoma in aphakic cases, and 44% of posttraumatic glaucoma cases, within the follow-up period. Loss of any light perception was recorded in two aphakic eyes with glaucoma (9.5%) and three eyes with posttraumatic glaucoma (12%). No hypotonia and no phthisis occurred. Conclusions TDLC is moderately effective in advanced posttraumatic glaucoma and glaucoma in aphakia, more effective in older than younger patients, not influenced by prior other glaucoma surgery, and despite a high re-treatment rate very safe in both groups of glaucoma. For younger patients with severe secondary glaucoma in particular, new treatment strategies are needed. The authors have no proprietary interest in any of the products used in the study. Presented at the 6th International Glaucoma Symposium, Athens, Greece, March 28–31, 2007.     

Combined phacoemulsification and goniotrephination on eyes with primary open-angle glaucoma and classical pseudoexfoliation glaucoma

Background: Combined glaucoma and cataract operation has been demonstrated to be effective in controlling IOP and increasing visual acuity. Because of the differences between patients with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXEG), for cataract and glaucoma surgery alone we evaluated the effects and complications for simultanous surgical management.     

Compliance and knowledge about glaucoma in patients at tertiary glaucoma units

To document the rate of self-reported compliance and glaucoma-related knowledge in Swiss patients and to identify risk factors for their poor compliance. This was an observational study, including a total of 200 consecutive patients already under glaucoma medication in two Swiss tertiary glaucoma clinics (Geneva and Bern). Personal characteristics, presence of systemic disease, compliance with glaucoma medication, attitude to the ophthalmologist, and glaucoma-related attitudes were ascertained by means of a predetermined questionnaire with 40 questions. Patients were subsequently assessed for the ability to correctly instil placebo eye drops. Non-compliance with glaucoma medication was defined as omitting more than two doses a week as reported by the patient. Logistic regression was used to evaluate how patient characteristics and knowledge about the disease were related to compliance. Overall, 81% (n = 162) of patients reported to be compliant. Forgetfulness was the most frequently cited reason for non-compliance with dosing regimen (63%). Although 90.5% (n = 181) of patients believed glaucoma medication to be efficient, only 28% (n = 56) could correctly define glaucoma. Factors positively associated with compliance were ‘knowledge of glaucoma’ [adjusted odds ratio (OR) 4.77 (95% CI 1.36–16.70)] and ‘getting help for administration of drops’ [OR 2.95 (1.25–6.94)]. These findings indicate that despite the comparatively high compliance rate among glaucoma patients, knowledge of glaucoma remains poor in long-term glaucoma sufferers. Improving knowledge about the disease is important since it is positively associated with compliance in our study.     

Ahmed引流阀植入术治疗难治性青光眼

目的探讨Ahmed引流阀治疗难治性青光眼的效果及其并发症的防治。方法对21例难治性青光眼行Ahmed引流阀植入术，术后随访6～24月。结果眼压控制的有效率达到85．71％，术后并发症主要是早期的短暂性浅前房和高眼压，以及晚期的纤维化。结论Ahmed引流阀植入术对于难治性青光眼是一种有效的治疗方法。     

New aspects of corneal pachymetry in congenital glaucoma and pediatric aphakic glaucoma

BACKGROUND: Knowledge of individual corneal thickness in individual eyes is proving to be more and more crucial for correcting Goldmann applanation tonometry, as well as to assess its predictive value regarding the possible progression of glaucomatous damage. It has become an important factor in determining appropriate glaucoma therapy. Only few pachymetric data exist about eyes with congenital or secondary pediatric aphakic glaucoma. METHODS: 12 eyes with congenital glaucoma (6 patients, mean age 3.3 years, mean 3.9 previous operations) and 7 eyes with secondary pediatric aphakic glaucoma (4 patients, mean age 14.8 years, mean 3 previous operations) without clinical signs of corneal decompensation were investigated by ultrasound pachymetry. RESULTS: Eyes with glaucoma due to aphakia had a mean corneal thickness of 708 +/- 77.3 microm. Mean corneal thickness of the eyes with congenital glaucoma was 688.1 +/- 115.9 microm, which is far above the values known from the literature. Two eyes, which had a central corneal thickness of 646 microm and 640 microm, presented with a localised paracentral corneal thickness of only 402 microm and 405 microm, respectively, correlating with microscopic descemet scars. CONCLUSIONS: Congenital glaucoma and the pediatric aphakic glaucoma present with very heterogeneous clinical pictures. Especially for congenital glaucoma, this is confirmed by the high interindividual, but also intraindividual, variability of corneal pachymetry.     

Cannabinoids and glaucoma

Glaucoma is one of the leading causes of blindness in the world. In spite of the diverse therapeutic possibilities, new and better treatments for glaucoma are highly desirable. Cannabinoids effectively lower the intraocular pressure (IOP) and have neuroprotective actions. Thus, they could potentially be useful in the treatment of glaucoma. The purpose of this article is to provide the reader with an overview of the latest achievements in research into the potential use of cannabinoids for glaucoma.     

Secondary glaucoma

Purpose : To review the common causes of secondary glaucoma. Methods : Review of current literature. Results : Secondary open and closed angle glaucomas are an important cause of ocular morbidity and vision loss in our community. Secondary glaucoma occurs with acquired ocular diseases (pigment dispersion, pseudoexfoliation, intraocular infection, intraocular inflammation and retinal vascular disease), blunt anterior segment injury, intraocular surgery (especially corneal grafting and congenital cataract surgery) and topical corticosteroid use. The medical treatment of secondary glaucoma is different from that of primary open angle glaucoma and must be tailored for the individual patient. Surgical treatment of secondary glaucoma carries a higher risk of complications and a lower rate of success than does surgical treatment of primary open angle glaucoma. Conclusions : Secondary glaucoma occurs with a variety of intraocular conditions and after a variety of intraocular insults. Awareness of patients at high risk should enable early detection and referral for appropriate management.     

角膜厚度与青光眼危险性的关系

眼压是青光眼主要的致病因素与诊断指标之一，眼压测量值受中央角膜厚度的影响。中央角膜厚度个体差异较大，导致眼压测量值变异较大。中央角膜厚度与原发性开角型青光眼、正常眼压性青光眼及高眼压症患者的眼压之间存在一定的量化关系。角膜越厚，眼压测量值越高。对于正常角膜厚度青光眼患者，眼压受中央角膜厚度的影响不大。高眼压症患者、正常眼压性青光眼患者应常规作角膜厚度测量以排除角膜厚度的影响。中央角膜厚度，眼压与青光眼之间的关系有待于进一步研究。     

Myocilin glaucoma

Genetic factors have long been implicated in the pathophysiology of primary open-angle glaucoma (POAG). Recently, myocilin, a gene of unknown function, was associated with both juvenile open-angle glaucoma (JOAG) and POAG. Forty-three different myocilin mutations have been reported in open-angle glaucoma patients, and several large studies have suggested that as a group these mutations are associated with 3–4% of POAG in patient populations worldwide. Support for the pathogenicity of the individual myocilin mutations has been obtained from in vitro assays, statistical methods, and conservation of gene sequence arguments. Several of these myocilin mutations were observed in multiple patients allowing the identification of mutation-specific glaucoma phenotypes (maximum intraocular pressure and age at diagnosis). Associations between myocilin and other forms of open-angle glaucoma have been explored. At present there is no evidence to link myocilin mutations and steroid-induced ocular hypertension or normal-tension glaucoma. Clinical vignettes of POAG patients from four generations of a family harboring the TYR437HIS myocilin mutation are presented, highlighting the benefits of elucidating the genetics of glaucoma.     

Nerve fiber layer assessment with scanning laser polarimetry in glaucoma patients and glaucoma suspects.

PURPOSE: To investigate whether scanning laser polarimeter can differentiate glaucoma and suspected glaucoma patients from normals. METHODS: Polarimetric measurements were obtained using the nerve fiber analyzer (NFA)-I from 80 eyes of patients with glaucoma with mostly moderate glaucomatous optic nerve damage (37 eyes with primary open angle glaucoma, 21 with normal tension glaucoma, 17 with pseudoexfoliative glaucoma, 3 with angle closure glaucoma, and 2 with juvenile glaucoma), 53 eyes of patients suspected of glaucoma based on disc appearance, and from age-matched healthy volunteers as control groups. Ratios (superior/nasal, inferior/nasal, superior/inferior) were used for assessing nerve fiber layer (NFL) thickness. Student's t-test and linear regression analysis were used for statistical analysis. RESULTS: Both the glaucoma patients and glaucoma suspects had significantly lower NFL ratios (mean S/N 2.34 +/- 0.47, I/N 2.46 +/- 0.52, S/I 0.94 +/- 0.18) than the control groups (respectively 2.88 +/- 0.48, 2.88 +/- 0.48, 1.00 +/- 0.13) (p<0.05). There was an ample overlap between the patient groups and the normals. The superior and inferior NFL ratios in glaucoma patients gradually decreased as the mean defect in visual field increased (linear regression analysis, p<0.05). CONCLUSIONS: The NFL of glaucomatous eyes and eyes suspected of glaucoma based on disc appearance was significantly less thick than normals. NFA-I detects pathological abnormalities in some patients with glaucomatous optic nerve damage and normal visual fields as measured by conventional achromatic computerized perimetry. NFA-I, however, is unable to distinguish these patients from normals, at least using these parameters, because of the considerable overlap.     

Molecular genetics in glaucoma

Glaucoma is a family of diseases whose pathology is defined by the progressive loss of retinal ganglion cells. Clinically, glaucoma presents as a distinctive optic neuropathy with associated visual field loss. Primary open-angle glaucoma (POAG), chronic angle-closure glaucoma (ACG), and exfoliation glaucoma (XFG) are the most prevalent forms of glaucoma globally and are the most common causes of glaucoma-related blindness worldwide. A host of genetic and environmental factors contribute to glaucoma phenotypes. This review examines the current status of genetic investigations of POAG, ACG, XFG, including the less common forms of glaucoma primary congenital glaucoma (PCG), the developmental glaucomas, and pigment dispersion glaucoma.     

微创青光眼手术在儿童青光眼治疗中的应用现状和展望

儿童青光眼是一类难治性青光眼,微创青光眼手术(MIGS)为儿童青光眼提供了安全有效的治疗选择。多数已发表的研究倾向于支持应用全周内路小梁切开术,其治疗儿童青光眼的安全性和有效性与非MIGS的全周外路小梁切开术相似。关于KDB刀、小梁消融术和Xen凝胶支架的研究较为有限,但在某些特定的病例中可能有其各自的优势。每一种MIGS手术在考虑其优势之处的同时须特别权衡每种手术方法的长期效果。此外,还需要更多的前瞻性和比较性研究、更大的样本量和更长的随访时间来验证MIGS手术治疗儿童青光眼的安全性和有效性。     

青光眼的眼压及眼脉动幅度比较分析

目的:观察比较慢性闭角型青光眼、原发性开角型青光眼、正常眼压性青光眼以及正常人的眼压,眼脉动幅度特征及其相关性。方法:收集临床确诊为慢性闭角型青光眼患者19例,原发性开角型青光眼18例,正常眼压性青光眼15例,正常人20例,用动态轮廓眼压计测量其眼压及眼脉动幅度,同时测量患者的血压及心率。运用SPSS14.0进行统计学分析。结果:慢性闭角型青光眼组的平均眼压为25.42±9.95mmHg,OPA为3.84±0.88mmHg;原发性开角型青光眼组的平均眼压为23.12±5.47mmHg,OPA为3.29±0.90mmHg;正常眼压性青光眼组的平均眼压为16.52±2.23mmHg,OPA为1.85±0.47mmHg;正常人组的平均眼压为16.31±2.67mmHg,OPA为2.47±0.80mmHg。前两组与后两组之间的眼压存在着显著性差异,四组之间的OPA均存在统计学差异。四组患者的眼压及眼脉动幅度之间存在着弱相关性,但无统计学意义。结论:慢性闭角型青光眼、原发性开角型青光眼及正常眼压性青光眼的OPA之间存在统计学差异,眼压与OPA之间存在弱相关性,但无统计学意义。     

Poor utility of intraocular pressure correction formulae in individual glaucoma and glaucoma suspect patients

Background: To compare Pascal dynamic contour tonometry (DCT) measurements with Goldmann applanation tonometry (GAT) readings after adjustment with correction formulae in a population of Caucasian glaucoma and glaucoma suspect patients. Design: Retrospective cross‐sectional case series in a specialist glaucoma practice. Participants: Consecutive glaucoma and glaucoma suspect Caucasian patients. Methods: Case notes review of the GAT and DCT intraocular pressure (IOP) measurements from patients who presented on a non‐acute basis over a 30‐month period. The GAT measurement was adjusted with six different correction formulae. Agreement between GAT IOP, adjusted GAT IOP and DCT IOP was evaluated with the Bland‐Altman analysis. Main Outcome Measures: Agreement between GAT IOP (both unadjusted and adjusted) and DCT IOP. Results: Data from 200 patients with a mean age of 58.4 (±12.7) years were analysed. The mean central corneal thickness was 554.8 (±36.9) µm and the mean corneal hysteresis was 9.8 (±1.9) mm Hg. Sixty five (32.5%) had confirmed glaucomatous optic neuropathy. GAT IOP demonstrated poor agreement with DCT IOP. GAT IOP was on average 2.1 mm Hg less than DCT IOP. None of the six correction formulae resulted in improved agreement with DCT IOP. General linear model analysis found no statistically significant measurement differences between the glaucoma and glaucoma suspect groups. Conclusions: GAT demonstrated poor agreement with DCT, and agreement did not improve after adjustment with correction formulae. Our results suggest that correction formulae for GAT IOP are unsuitable to clinically approximate ‘true’ IOP in Caucasian glaucoma and glaucoma suspect patients.     

青光眼引流装置植入术在治疗难治性青光眼中的作用

难治性青光眼是主要的致盲眼病之一,目前青光眼引流装置植入术已成为治疗难治性青光眼的主要方法,因其具有安全、有效、并发症较少等优点,青光眼引流装置在临床已得到广泛应用.通过近几年大量临床应用与青光眼微创手术的创新发展,青光眼引流装置植入术展现出良好的治疗前景.本文总结分析了青光眼外引流装置(Molteno、Schocket、Baerveldt、国产HAD房水引流物、Krupin、Ahmed、Joseph、Whites、Optimed房水引流物)及青光眼微创手术(Ex-PRESS青光眼引流器、Xen凝胶支架、CyPass微型支架、小梁消融术、Schlemm管支架、iStent引流器、SOLX Gold Shunt等)的结构特点和临床疗效,就青光眼引流装置植入术在治疗难治性青光眼中的作用进行综述.