Iris and its relevance to angle closure disease: a review

2020 ◽  
Vol 105 (1) ◽  
pp. 3-8
Author(s):  
Zhi Da Soh ◽  
Sahil Thakur ◽  
Shivani Majithia ◽  
Monisha Esther Nongpiur ◽  
Ching-Yu Cheng
Keyword(s):  
Potential Role ◽  
Biomechanical Properties ◽  
Angle Closure ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
Ocular Imaging ◽  
Clinical Consequences ◽  
Closed Angle ◽  
Fluid Conductivity

Glaucoma is a leading cause of irreversible visual impairment, and primary angle closure glaucoma (PACG) affects Asians disproportionately. Whereas advances in ocular imaging have identified several anatomical risk factors, our ability to predict PACG still requires considerable improvement. The iris plays a crucial role in the pathophysiology of angle closure disease, either through a mechanical or vascular mechanism. Irises of closed-angle eyes inhibit vastly different structural constituents as compared with those of open-angle eyes, thereby effecting variations in biomechanical properties and iris fluid conductivity. The clinical consequences include a smaller change in iris volume on pupil dilation in closed-angle eyes, thereby bringing the iris and trabecular meshwork closer in apposition. In this review, we summarise the potential role of the iris in the pathogenesis of angle closure disease.

scholarly journals Managing Primary Angle Closure Glaucoma – The Role of Lens Extraction in this Era

2016 ◽  
Vol 10 (1) ◽  
pp. 86-93 ◽  
Author(s):  
Nafees Baig ◽  
Ka-Wai Kam ◽  
Clement C.Y. Tham
Keyword(s):  
Gold Standard ◽  
Open Angle Glaucoma ◽  
Angle Closure Glaucoma ◽  
Angle Closure ◽  
Predisposing Factor ◽  
Lens Extraction ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
Anterior Position

Trabeculectomy has been the gold standard in reducing intraocular pressure (IOP) in glaucoma patients, no matter it is angle closure or open angle glaucoma. However in primary angle closure glaucoma, no matter the lens is cataractous or not, it is likely to be pathological, this thicker than usual lens, with or without a more anterior position, is often regarded as a strong contributing factor to angle closure. Lens extraction, no matter it is cataractous or clear, can theoretically eliminate this anatomical predisposing factor of angle closure, and thus IOP can be reduced. Based on recent results of a number of clinical trials, lens extraction alone or in combination with other IOP-lowering surgeries, may therefore play a more important role in the treating primary angle closure glaucoma. In cases when greater IOP-lowering effect is needed or if drug dependency has to be minimized, combined procedures, such as phacotrabeculectomy, can be considered, but the surgical risk can be higher than lens extraction alone.

scholarly journals Evaluation of spontaneous retinal venous pulsation in primary open-angle and primary angle-closure glaucoma patients

2020 ◽  
Vol 2 (1) ◽  
pp. 27-41
Author(s):  
Sylves Patrick ◽  
Chan Hui Tze ◽  
Rasdi Abdul Rashid ◽  
Liza Sharmini Ahmad Tajudin
Keyword(s):  
Cross Sectional Study ◽  
Angle Closure ◽  
Control Group ◽  
Sectional Study ◽  
Cross Sectional ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
Venous Pulsation ◽  
Primary Glaucoma

Introduction: Spontaneous retinal venous pulsation (SRVP) is a rhythmic variation in the calibre of one or more retinal veins. The incidence of SRVP was reduced in glaucoma patients. It was also reduced in people with raised intracranial pressure compared to a healthy population. Purpose: The main objective was to report the frequency and rate of SRVP in primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) patients and to associate these with the severity of glaucoma in Malay patients. Design of study: A comparative cross-sectional study. Materials and methods: A comparative cross-sectional study involving primary glaucoma patients attending the eye clinic at Hospital Universiti Sains Malaysia (HUSM), Kelantan, Malaysia, was performed between December 2015 and June 2017. The main outcomes measured were the presence and rate of SRVP using a confocalscanning laser ophthalmoscope (Spectralis High-Resolution Optical Coherence Tomography Angiography, Heidelberg Engineering GmbH, Heidelberg, Germany). In the presence of SRVP, the rate of SRVP in one minute was counted manually based on the real-time fundus movie recorded using the confocal scanning laser ophthalmoscope. Results: Thirty-eight POAG, 14 PACG, and 51 control group subjects were included. There was a significantly lower incidence of SRVP in primary glaucoma patients than in the control group (p = 0.003). The presence of SRVP was significantly lower in POAG than PACG (p = 0.04). There was no significant difference in the rate ofSRVP between primary glaucoma patients and the control group (p = 0.873) or between the POAG group and PACG group (p = 0.511). There was no association of incidence (p = 0.574) and rate (p = 0.167) of SRVP according to the severity of glaucoma. Systolic blood pressure (95% CI: 0.95–1.00, p = 0.038) and retinal nervefibre layer thickness (95% CI: 1.01–1.09, p = 0.008) showed a significant association with the presence of SRVP. Conclusions: SRVP is a potential predictive factor for detection of primary glaucoma. The role of SRVP in the severity of glaucoma is still unclear. The role of SRVP in PACG patients warrants further studies in the future.

scholarly journals Comparison of the Stability of Two Intraocular Lenses in Primary Angle-Closure Glaucoma after Phacoemulsification

2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Chang Zhang ◽  
Meng Zhang ◽  
Bing Zhang ◽  
Shanhong Wang ◽  
Yuhong Wang
Keyword(s):  
Randomized Study ◽  
Angle Closure Glaucoma ◽  
Intraocular Lenses ◽  
Angle Closure ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
Age Related ◽  
The Difference ◽  
The Stability ◽  
Closed Angle

Objective. To observe the stability of intraocular lenses (IOLs) in primary angle-closure glaucoma by ultralong scan depth spectral-domain optical coherence tomography (UL-OCT) after phacoemulsification. Methods. A prospective, randomized study. 73 patients (82 eyes) with primary closed-angle glaucoma and age-related cataract were included in the study. 42 eyes were implanted with ZCB00, while 40 eyes were implanted with Softec HD after phacoemulsification. The tilt, decentration, and space between IOL and posterior capsule (IOL-PC space) were analyzed using UL-OCT at 1 week, 1 month, and 3 months after surgery. The intergroup difference was compared with the paired t-test. Result. The difference of decentration and tilt was not statistically significant (both P > 0.05 ) both in the horizontal and vertical positions at 1 week, 1 month, and 3 months postoperatively. The horizontal IOL-PC space is 0.111 ± 0.091 mm2, 0.044 ± 0.066 mm2, and 0.055 ± 0.055 mm2 in the Softec HD group and 0.458 ± 0.488 mm2, 0.497 ± 0.363 mm2, and 0.492 ± 0.441 mm2 in the ZCB00 group. The vertical IOL-PC space is 0.102 ± 0.061 mm2, 0.037 ± 0.052 mm2, and 0.053 ± 0.079 mm2 in the Softec HD group and 0.692 ± 0.815 mm2, 0.510 ± 0.415 mm2, and 0.691 ± 0.635 mm2 in the ZCB00 group. The difference was statistically significant ( P < 0.05 ) both in the horizontal and vertical positions except for the first week on the horizon. The Softec HD group is smaller than the ZCB00 group. Conclusion. There is no difference in the stability of the IOL although the IOL-PC space is different. The thickness of IOL may affect the IOL-PC space.

scholarly journals The Role of Optical Coherence Tomography in the Diagnosis of Angle Closed Diseases of the Anterior Chamber. Part 1: Visualization of the Anterior Segment of the Eye

2021 ◽  
Vol 18 (2) ◽  
pp. 208-215
Author(s):  
N. I. Kurysheva ◽  
G. A. Sharova
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Angle Closure ◽  
Optical Coherence ◽  
Swept Source ◽  
Primary Angle Closure ◽  
Choice Of Treatment ◽  
Closed Angle

The purpose of this work is to review the literature data on the role of optical coherence tomography in the diagnosis of diseases of the closed angle of the anterior chamber. An analysis of the modern technical devices use — optical coherence tomography of the anterior segment (AS-OST) and models with a frequency-modulated source (Swept Source) is presented. The advent of new imaging technologies such as SS-OCT is advancing the understanding of the pathogenesis of primary angle closure diseases. Visualization of the structures of the anterior segment of the eye is an important part of the strategy aimed at solving the problem of identifying risk factors, diagnosing, monitoring and evaluating the effectiveness of treatment of diseases of primary angle closure. Qualitative and quantitative data analysis based on optical coherence tomography significantly increases the diagnostic accuracy, which undoubtedly plays a key role in the choice of treatment tactics for the closed angle of the anterior chamber. The interpretation of research results should take into account the strengths and weaknesses of traditional methods and newly developed technologies.Conclusion. Optical coherence tomography of the eye’s anterior segment is a standard in modern diagnostics and evaluation of the effectiveness of treatment of diseases of primary angle closure, taking into account pathogenetic mechanisms. 

Complex visualization of the anterior segment of the eye in the diagnosis, monitoring and treatment of angle closed disease

2021 ◽  
pp. 79-83
Author(s):  
G.А. Sharova ◽  
◽  
N.I. Kurysheva ◽  
◽  
◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Ultrasound Biomicroscopy ◽  
Angle Closure ◽  
Optical Coherence ◽  
Advantages And Disadvantages ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
The Right

The aim of this work is to review the literature on the role of anterior segment imaging in the diagnosis, monitoring, and treatment of primary angle closed disease. An analysis of the use of modern technical devices – optical coherence tomography of the anterior segment (ASOST), ultrasonic biomicroscopy, Scheimpflug camera – is presented, the advantages and disadvantages in comparison with gonioscopy are assessed. Visualization of the structures of the anterior segment of the eye is an important part of the strategy aimed at solving the problem of identifying risk factors, diagnosing, monitoring and evaluating the effectiveness of treatment of diseases of primary angle closure. Qualitative and quantitative analysis of data based on optical coherence tomography, ultrasound biomicroscopy, and Scheimflug camera data confirms high comparability with gonioscopy, but each of the methods complements each other. Conclusion. Visualization of the anterior segment of the eye is the standard in modern diagnostics and evaluation of the effectiveness of treatment of primary angle closure disease. Multimodal imaging improves the ability to accurately diagnose and choose the right treatment strategy. Key words: primary angle closure, primary angle-closure glaucoma, optical coherence tomography, ultrasound biomicroscopy, Scheimflug camera, gonioscopy.

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