scholarly journals Moving beyond the Slit-Lamp Gonioscopy: Challenges and Future Opportunities

Diagnostics ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2279
Author(s):  
Carlo Alberto Cutolo ◽  
Chiara Bonzano ◽  
Riccardo Scotto ◽  
Michele Iester ◽  
Alessandro Bagnis ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Deep Learning ◽  
Angle Closure ◽  
Slit Lamp ◽  
Reference Standard ◽  
Anterior Chamber Angle ◽  
Steep Learning Curve ◽  
Advantages And Disadvantages ◽  
New Instruments ◽  
Chamber Angle

After almost a century from its introduction in clinical practice, slit-lamp gonioscopy is still considered the reference standard for evaluating the anterior chamber angle (ACA). Gonioscopy is essential for diagnosing angle closure disease, and ACA features are included in glaucoma’s diagnostics and treatments algorithms. However, shortcomings of slit-lamp gonioscopy include a steep learning curve, lack of agreement between examiners and poor documentation. Thanks to advances in miniaturization and computing, new instruments for digital gonioscopy have been developed and marketed. This narrative review focuses on the Gonioscope GS-1, which permits semi-automated circumferential documentation of the ACA in real-colour photographs. Advantages and disadvantages of GS-1 compared with slit-lamp gonioscopy and other ACA imaging technologies such as optical coherence tomography are discussed. Finally, potential opportunities offered by this device for telemedicine, virtual clinics, and automatic classification with deep learning are presented.

scholarly journals Anterior chamber angle imaging with swept-source optical coherence tomography: comparison between CASIAII and ANTERION

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Poemen Pui-man Chan ◽  
Gilda Lai ◽  
Vivian Chiu ◽  
Anita Chong ◽  
Marco Yu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Angle Closure ◽  
Optical Coherence ◽  
Anterior Chamber Angle ◽  
Swept Source ◽  
Scan Pattern ◽  
Chamber Angle

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).

scholarly journals Anterior Chamber Angle Evaluation with Fourier-Domain Optical Coherence Tomography

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Matthew Bald ◽  
Yan Li ◽  
David Huang
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
High Speed ◽  
Technology Development ◽  
Anterior Segment ◽  
Angle Closure ◽  
Fourier Domain ◽  
Optical Coherence ◽  
Anterior Chamber Angle ◽  
Chamber Angle

New advances in anterior segment optical coherence tomography (OCT) technology development allow visualizing the anterior chamber angle of the eye with high speed and high resolution. Fourier-domain (FD) OCT instruments working at 840 nm can reliably identify fine angle structures such as the Schwalbe's line. This paper demonstrates quantitative angle assessment with 840 nm FD-OCT and provides diagnostic cutoff values for occludable angle detection. This is useful for angle closure glaucoma diagnosis and management. Moreover, 840 nm FD-OCT is a useful tool for postsurgical evaluation in glaucoma patients.

scholarly journals Changing Trends of Imaging in Angle Closure Evaluation

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Syril Dorairaj ◽  
James C. Tsai ◽  
Tomas M. Grippo
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Ultrasound Biomicroscopy ◽  
Infrared Light ◽  
Angle Closure ◽  
Optical Coherence ◽  
Anterior Chamber Angle ◽  
Chamber Angle

Primary angle closure glaucoma (PACG) is a significant cause of visual disability worldwide. It predominantly affects the Eastern and South Asian population of the world. Early detection of anatomically narrow angles is important, and the subsequent prevention of visual loss from PACG depends on an accurate assessment of the anterior chamber angle (ACA). Gonioscopy has given way to modern day imaging technologies such as ultrasound biomicroscopy (UBM) and more recently, anterior segment optical coherence tomography (AS-OCT). Ultrasound biomicroscopy provides objective, high-resolution images of anterior segment anatomy, including the cornea, iris, anterior chamber, anterior chamber angle, and ciliary body. Optical coherence tomography (OCT) is a noncontact optical signal acquisition and processing device that provides magnified, high-resolution cross-sectional images of ocular tissues. Recent technological advances towards three-dimensional visualization broadened the scope of AS-OCT in ophthalmologic evaluation. Optical coherence tomography systems use low-coherence, near-infrared light to provide detailed images of anterior segment structures at resolutions exceeding that of UBM. This paper summarizes the clinical application of UBM and OCT for assessment of anterior segment in glaucoma.

An insight into Principle and Practice of Anterior Segment Optical Coherence Tomography

2020 ◽  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Corneal Transplantation ◽  
Anterior Segment ◽  
Angle Closure ◽  
Optical Coherence ◽  
Anterior Chamber Angle ◽  
Advanced Technique ◽  
Anterior Segment Oct ◽  
Chamber Angle

Proper visualization of the eye structures is the hallmark of diagnosis in eye diseases. With advent of newer techniques and instruments, the significance of anterior segment eye structures is further elaborated. This article explores the basic working principle of optical coherence tomography (OCT) and also provides a list of commonly available instruments and their advantages over one another. It then sheds light upon the use of anterior segment OCT in the observation of cornea, conjunctiva, lacrimal gland and other anatomic structures of eye within the living subject. Anterior segment OCT is also helpful in the demonstration of dynamics involving aqueous flow system. The application of this advanced technique in diagnosis of dry eye disease, keratoconus, anterior segment eye tumors and other diseases is also explained. The examination of normal cornea along with all its layers is possible with anterior segment OCT and it can also point out any abnormality in corneal epithelium, edema or any other change that may occur after intra ocular lens placement or corneal transplantation. Anterior chamber angle measurement is an essential step in the diagnosis of angle closure glaucoma and quite accurate results are provided by this technique. The data was searched from PubMed and Google Scholar, from the articles published during 2014 and 2020, using the keywords “optical coherence tomography”, “glaucoma” and “anterior segment of eye”. A few of the limitations of OCT are also discussed along with the future perspectives of this powerful instrument. Keywords: Anterior Eye Segment; Optical Coherence Tomography; Glaucoma; Anterior Chamber Angle.

scholarly journals Evaluation of the Anterior Chamber Angle in Angle-Closure Suspect Patients by Anterior Segment Optical Coherence Tomography (AS-OCT) and Pentacam

2021 ◽  
Author(s):  
Mohamed Salah El-Din Mahmoud ◽  
Nosiba Essam ◽  
Layla Mohamed Hammouda ◽  
Ahmed Shawkat Mohamed
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Angle Closure ◽  
P Value ◽  
Optical Coherence ◽  
Anterior Chamber Angle ◽  
Cross Sectional ◽  
Chamber Angle

Abstract Purpose: The study aims is to detect primary angle-closure glaucoma (PACG) suspects using both anterior segment optical coherence tomography (AS-OCT) and Scheimpflug imaging. Methods: A prospective cross-sectional observational study on forty PACG suspect patients with a range of ages from 20 to 70 years. Angle imaging by AS-OCT (Optovue Inc., Fairmont, CA) with study parameters in the superior, inferior, nasal, and temporal quadrants were anterior chamber angle (ACA), angle opening distance at 750 µm (AOD750), and trabecular-iris space area at 750 μm (TISA). Also, angle imaging using Pentacam (Oculus Optikgeräte GmbH, Wetzlar, Germany) with study parameters were the anterior chamber angle (ACA), anterior chamber depth (ACD) and, anterior chamber volume (ACV). The angle evaluation was done before and after the mydriatic test.Results: As regarding AS-OCT, after the mydriatic test, we noticed a decrease in all parameters measured, some decreased significantly while others did not. A significant decrease was noticed in ACA (TIA750) in all quadrants (P value<0.001in nasal, 0.001in superior &temporal, 0.003 in inferior) and in TISA750 in the nasal quadrant only (P-value 0.004). AOD750 and TISA750 in the remaining quadrants also decreased but not significantly as ACA. As regarding Pentacam, all parameters decreased after the mydriatic test. ACA (P-value <0.001) and ACD (P-value 0.004) showed significant statistical decrease but ACV showed statistically non-significant decrease (P-value 0.558).Conclusions: AS-OCT and Pentacam are reliable investigations for the detection of PACG suspects which needs more close follow-up for a possible increase in IOP.

Sign in / Sign up

Export Citation Format

Share Document