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

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. 

2021 ◽  
Vol 18 (3) ◽  
pp. 381-388
Author(s):  
N. I. Kurysheva ◽  
G. А. Sharova

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. The analysis of the use of modern technical devices — optical coherence tomography of the posterior segment, models with a frequency-modulated source (Swept Source) is presented. The emergence of new imaging technologies such as SS-OCT contributes to understanding the pathogenesis of primary angle closure diseases in terms of involvement of the choroid in the process. A thicker choroid in the macular area may be an anatomical risk factor for closed angle disease. The expansion of an abnormally thick choroid in combination with the structural features of the anterior segment in eyes with a short axial length, including against the background of psychoemotional stress, can lead to an attack of angle closure. Visualization of the structures of the posterior 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, allows to determine its progression and to predict its course. This plays a key role in the choice of treatment tactics for the anterior chamber angle closure. The review considers the effect of local antihypertensive eye drops on the choroid.Conclusion. Optical coherence tomography is a standard in modern diagnostics and evaluation of the effectiveness of treatment of diseases of primary angle closure, allowing a better understanding of the pathogenesis of the disease and its complex nature. Imaging improves the ability to accurately diagnose and choose the right treatment strategy.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Poemen Pui-man Chan ◽  
Gilda Lai ◽  
Vivian Chiu ◽  
Anita Chong ◽  
Marco Yu ◽  
...  

Abstract This study compared the test–retest variabilities and measurement agreement of anterior chamber angle (ACA) dimensions measured by two anterior segment swept-source optical coherence tomography (SS-OCT)—the ANTERION (Heidelberg Engineering, Heidelberg, Germany) and CASIAII (Tomey, Nagoya, Japan). Thirty-eight subjects, 18 patients with primary angle closure and 20 healthy participants with open angles, were included. The mean age was 54.7 ± 15.8 years (range: 26–75 years). One eye of each subject was randomly selected for anterior segment imaging by ANTERION and CASIAII, using the same scan pattern (6 evenly spaced radial scans across the anterior segment for three times) in the same visit. The between- and within-instrument agreement and repeatability coefficients of angle open distance (AOD500), trabecular-iris space area (TISA500), lens vault (LV), scleral spur-scleral spur distance (SSD), anterior chamber depth (ACD), and pupil diameter (PD) were measured. The anterior and posterior boundaries of the cornea, iris, and lens were automatically segmented by the SS-OCT instruments; the scleral spur was manually located by a single masked observer. There were significant differences between ANTERION and CASIAII measurements; the SSD, PD, and ACD were smaller whereas AOD500 and TISA500 were greater in ANTERION compared with CASIAII (P < 0.001). Anterior segment measurements obtained from the two SS-OCT instruments showed strong associations (R2 ranged between 0.866 and 0.998) although the between-instrument agreement was poor; the spans of 95% limits of between-instrument agreement were ≥ 1.5-folds than the within-instrument agreement for either instrument. Whereas both SS-OCT instruments showed low test–retest measurement variabilities, the repeatability coefficients of AOD500, TISA500, ACD, and PD were slightly smaller for CASIAII than ANTERION (P ≤ 0.012).


2019 ◽  
Vol 104 (6) ◽  
pp. 795-799 ◽  
Author(s):  
Natalia Porporato ◽  
Mani Baskaran ◽  
Tin A Tun ◽  
Rehena Sultana ◽  
Marcus Tan ◽  
...  

Background/aimsAlthough being a more objective tool for assessment and follow-up of angle closure, reliability studies have reported a moderate diagnostic performance for anterior segment optical coherence tomography (OCT) technologies when comparing with gonioscopy as the reference standard. We aim to determine factors associated with diagnostic disagreement in angle closure when assessed by anterior segment swept source OCT (SS-OCT, CASIA SS-1000; Tomey, Nagoya, Japan) and gonioscopy.MethodsCross-sectional study. A total of 2027 phakic subjects aged ≥50 years, with no relevant previous ophthalmic history, were consecutively recruited from a community polyclinic in Singapore. Gonioscopy and SS-OCT (128 radial scans) for the entire circumference of the angle were performed for each subject. A two-quadrant closed gonioscopic definition was used. On SS-OCT images, angle closure was defined as iridotrabecular contact (ITC) to the extent of ≥35%, ≥50% and ≥75% of the circumferential angle. Diagnostic disagreements between both methods, that is, false positives or overcalls and false negatives or undercalls were defined, respectively, as gonioscopic open/closed angles inversely assessed as closed/open by SS-OCT.ResultsTwo hundred and seventy-two (14.7%) resulted in overcall results (false positives) when ≥50% of the angle circumference was closed using SS-OCT. These eyes had significantly wider (anterior chamber width, 11.7 vs 11.6 mm, p<0.001) and deeper (anterior chamber depth (ACD), 2.4 vs 2.2 mm, p<0.001) anterior chambers than eyes assessed by both methods as closed (true positives). Deeper ACD (OR 9.31) and lower lens vault (LV) (OR 0.04) were significantly associated with a false positive diagnosis in the multivariate analysis. Most of these cases had short (52.6%) or irregular (39%) ITC in SS-OCT images.ConclusionsWe found that anterior chamber dimensions, determined by ACD and LV, were factors significantly associated with diagnostic disagreement between anterior segment SS-OCT and gonioscopy in angle closure assessment.


2021 ◽  
pp. 79-83
Author(s):  
G.А. Sharova ◽  
◽  
N.I. Kurysheva ◽  
◽  
◽  
...  

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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