Automatic screening of narrow anterior chamber angle and angle-closure glaucoma based on slit-lamp image analysis by using support vector machine

2013 ◽  
Author(s):  
C. Theeraworn ◽  
W. Kongprawechnon ◽  
T. Kondo ◽  
P. Bunnun ◽  
A. Nishihara ◽  
...  
Keyword(s):  
Support Vector Machine ◽  
Image Analysis ◽  
Anterior Chamber ◽  
Angle Closure Glaucoma ◽  
Angle Closure ◽  
Support Vector ◽  
Slit Lamp ◽  
Anterior Chamber Angle ◽  
Chamber Angle

scholarly journals Effect of Phacoemulsification on Anterior Chamber Angle in Eyes with Medically Uncontrolled Filtered Primary Angle-Closure Glaucoma

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Chengguo Zuo ◽  
Bing Long ◽  
Xinxing Guo ◽  
Liming Chen ◽  
Xing Liu
Keyword(s):  
Anterior Chamber ◽  
Angle Closure Glaucoma ◽  
Angle Closure ◽  
Anterior Chamber Angle ◽  
Iol Implantation ◽  
Anatomical Changes ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
The Mean ◽  
Chamber Angle

Purpose. To evaluate the effect of phacoemulsification and intraocular lens (IOLs) implantation in eyes with medically uncontrolled primary angle-closure glaucoma (PACG) previously treated with trabeculectomy and to quantify the anatomical changes in the anterior chamber angle by ultrasound biomicroscopy (UBM). Methods. Forty-four eyes of 37 consecutive patients with medically uncontrolled PACG coexisting cataracts with a surgical history of trabeculectomy were included in this study. Each patient underwent phacoemulsification and IOL implantation. Indentation gonioscopy and UBM were performed preoperatively and then again 3 months after surgery. The main outcome measures were best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of antiglaucoma medications and anatomical changes in the anterior chamber angle. Results. The mean logarithm of the minimum angle of resolution BCVA significantly improved from 0.52 ± 0.30 preoperatively to 0.26 ± 0.23 postoperatively (p<0.001). The mean IOP significantly decreased from 24.33 ± 9.65 mmHg preoperatively to 18.04 ± 7.86 mmHg postoperatively (p<0.05). 001). The median number of antiglaucoma medications decreased from 2 preoperatively to 1 postoperatively (p<0.001). There was no significant difference in the extent of peripheral anterior synechia after the surgery (p>0.05). Some parameters, including anterior central chamber depth, angle opening distance at 500 μm, trabecular-iris angle, and scleral ciliary process angle, were significantly higher after than before surgery (p<0.001). However, the crystalline lens rise was significantly smaller following the surgery (p<0.001). Conclusions. Phacoemulsification and IOL implantation reduced the IOP and improved vision in eyes with medically uncontrolled filtered PACG. The mechanism underlying the outcomes observed following surgery might be related to the anterior chamber deepening, widened drainage angle, and improved aqueous fluid flow to the trabecular meshwork.

Evaluation of anterior chamber angle under dark and light conditions in angle closure glaucoma: An anterior segment OCT study

2014 ◽  
Vol 37 (4) ◽  
pp. 300-304 ◽  
Author(s):  
Habibeh Masoodi ◽  
Ebrahim Jafarzadehpur ◽  
Alireza Esmaeili ◽  
Fereshteh Abolbashari ◽  
Seyed Mahdi Ahmadi Hosseini
Keyword(s):  
Anterior Chamber ◽  
Anterior Segment ◽  
Angle Closure Glaucoma ◽  
Angle Closure ◽  
Light Conditions ◽  
Anterior Chamber Angle ◽  
Anterior Segment Oct ◽  
Chamber Angle

Gonioscopy

Glaucoma ◽  
2012 ◽  
Author(s):  
Morales Jose
Keyword(s):  
Anterior Chamber ◽  
False Negative ◽  
Anterior Chamber Depth ◽  
Acute Angle ◽  
Angle Closure Glaucoma ◽  
Angle Closure ◽  
Anterior Chamber Angle ◽  
Negative Results ◽  
Laser Trabeculoplasty ◽  
Chamber Angle

Gonioscopy allows visualization of the anterior chamber angle using special lenses. The anterior chamber angle cannot be visualized by direct observation because of its position in the angle recess and the phenomenon of total internal reflection of the light caused by the cornea. Goniolenses with appropriate optical properties and mirrors or prisms allow adequate visualization of its structures through a “periscope effect” and provide a more favourable reflection angle. Clinical circumstances where gonioscopy is essential or helpful in the diagnosis and management of glaucoma are as follows: • To diagnose primary angle closure and to assess the results of medical, laser, or surgical treatment on angle configuration • The Van Herick method of estimating the peripheral anterior chamber depth with the slit lamp gives a useful but rough estimate and does not replace gonioscopy. It can give false-negative results in patients with plateau iris configuration and false-positive results in patients with moderate anterior chamber depth but an open angle. • To assess the risk of angle closure in patients with shallow anterior chambers before undergoing pupillary dilation • To diagnose and follow treatment of acute angle-closure glaucoma attacks To establish the diagnosis of secondary angle-closure glaucoma • To determine precise anatomic landmarks for accurate laser application during trabeculoplasty • For the evaluation and follow-up of congenital or acquired abnormalities of the anterior chamber angle • To detect and evaluate mass lesions that affect the anterior chamber angle • To evaluate the anatomic angle changes and patency of the ostium after trabeculectomy • To visualize the angle during “angle surgery” • Such as goniotomy, trabectome surgery,or trabecular micro-bypass stent •During laser trabeculoplasty and after laser iridoplasty Three goniolens prototypes have been most used in the past and represent the precursors of newer lenses Their main features are displayed on Table 2.1. Explain the procedure to the patient and its purpose. Reassure him or her that with the use of topical anesthetic the test will not be painful, and request cooperation in terms of avoiding lid squeezing and excessive eye movement during the exam.

REVIEW CLINICAL CHARACTERISTICS AND TREATMENT OUTCOME OF PRIMARY ANGLE CLOSURE GLAUCOMA BY USED ND: YAG LASER PERIPHERAL IRIDOTOMY

2012 ◽  
pp. 18-24
Author(s):  
Huu Quoc Nguyen Nguyen ◽  
Nam Trung Nguyen
Keyword(s):  
Anterior Chamber ◽  
Angle Closure Glaucoma ◽  
Angle Closure ◽  
Anterior Chamber Angle ◽  
Yag Laser ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
Low Levels ◽  
Angle Width ◽  
Chamber Angle

Objectives: To review the clinical characteristics of primary angle closure glaucoma and the outcome of Nd: YAG laser peripheral iridoctom. Materials and Methods: Prospective study of 46 eyes underwent iridotomy, evaluation of the intraocular pressure and the anterior chamber angle within 2 weeks, 1 month, 3 months & 6 months after treatment. Results: The majority of subjects were females 73.33%, over 60 years of age (80%), blurred vision and decrease visual acuity when the patient were hospitalized (43.48%), 19.65% eye pain, physical symptoms are mainly shallow anterior chamber or pupillary reflexes relaxing lazy. Embryonic glaucoma and chronic angle glaucoma distribution percentage 69.57%. Mean IOP after 2 weeks X = 18.17 ± 1.37 mmHg, 7.66 mmHg lower than before treatment. Anterior chamber angle width increased significantly after 2 weeks of treatment. And no significant changer after 1 month, 3 months & 6 months. There was a precise inverse relation between anterior chamber angle width before treatment with low levels of IOP after treatment, and there was a precise proportional relation between the low levels of IOP with the increase of chamber angle width after treatment. Conclusion: Nd: YAG laser iridotomy is effective in widening the anterior chamber angle and lowering intraocular pressure in primary angle closure glaucoma.

scholarly journals New capabilities of optical coherence tomography in the diagnostics of primary angle-closure glaucoma

2021 ◽  
Vol 20 (2) ◽  
pp. 14-22
Author(s):  
V. P. Erichev ◽  
R. P. Poleva ◽  
Kh. Hadiri
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Angle Closure Glaucoma ◽  
Angle Closure ◽  
Ophthalmological Examination ◽  
Optical Coherence ◽  
Anterior Chamber Angle ◽  
Primary Angle Closure ◽  
Primary Angle Closure Glaucoma ◽  
Chamber Angle

INTRODUCTION. Recently, posterior vitreous detachment (PVD) was suggested as a fundamental pathologic process in primary angle-closure glaucoma (PACG) in morphologically predisposed patients with anatomically narrow anterior chamber angle.PURPOSE. To study the role of PVD in the development and clinical manifestation of PACG in anatomically predisposed eyes and to assess the capabilities of posterior segment optical coherence tomography (PS-OCT) in PACG diagnostics.MATERIALS AND METHODS. Thirty eyes with newly diagnosed stage I-II PACG and thirty eyes predisposed to PACG (with narrow anterior chamber angle without glaucoma signs) were enrolled in the study. All patients underwent ophthalmological examination, Hyams test, ocular ultrasound (OU) and PS-OCT.RESULTS. PVD with retrohyaloid space (RHS) formation was revealed in all PACG eyes. Positive Hyams test was in 86.67% eyes with PACG, and 13.33% were negative. All the eyes with PVD as a result of Hyams test experienced RHS enhancement correlating with IOP rise. Despite the negative results of Hyams test in some PACG eyes with PVD — glaucomatous optic neuropathy signs were present. Possible causes are discussed.PVD with RHS formation was revealed in 53.33% predisposed to PACG eyes — all with positive result of Hyams test. The other 46.67% eyes predisposed to PACG had negative Hyams test, no PVD and no RHS.CONCLUSION. Obtained results confirm a new theory of PACG etiopathogenesis suggesting PVD with PGS to be the essential mechanism of POAG development in morphologically predisposed eyes. PS-OCT appears to be crucial in PACG early diagnostics.

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