Non-invasive anterior segment and posterior segment optical coherence tomography and phenotypic characterization of aniridia

2011 ◽  
Vol 46 (4) ◽  
pp. 337-344 ◽  
Author(s):  
Kevin Gregory-Evans ◽  
Richard Cheong-Leen ◽  
Sheena M. George ◽  
Judy Xie ◽  
Mariya Moosajee ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Posterior Segment ◽  
Phenotypic Characterization ◽  
Optical Coherence ◽  
Non Invasive

Results of the project «Optimization of the process of obtaining the service OCT “ (project implementation period 20.06.2019–08.10.2019)

2021 ◽  
pp. 29-37
Author(s):  
Irina Aleksandrovna Rakitina ◽  
Alfiya Gumyarovna Iskhakova ◽  
Evgeny Andreevich Zamytsky ◽  
Marina Vladimirovna Makolina ◽  
Farida Sagitovna Goleeva ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Segment ◽  
Contact Method ◽  
Optical Coherence ◽  
Non Invasive ◽  
Risk Of Injury ◽  
Eye Tissues ◽  
Implementation Period ◽  
Project Optimization ◽  
Theoretical Foundations

Optical Coherence Tomography (OCT) is a modern, highly accurate, non-invasive study of various eye structures. OCT is a non-contact method that allows a specialist to visualize eye tissue with a very high resolution (1–15 microns), the accuracy of which is comparable to microscopic examination. The theoretical foundations of the OCT method were developed in 1995 by the American ophthalmologist K. Pulafito, and already in 1996–1997 Carl Zeiss Meditec introduced the first device for optical coherence tomography into clinical practice. Today, OCT devices are used to diagnose various diseases of the fundus and anterior segment of the eye. Due to the maximum accuracy, the method of light scanning greatly simplifies the diagnosis of pathologies of the organs of vision, regardless of the cause of their occurrence and the stage of the course. In terms of information content, the technique is not inferior to histology, but the advantage of OCT is the absence of the risk of injury to the eye tissues [1, 2].

scholarly journals Imaging depth extension of optical coherence tomography in rabbit eyes using optical clearing agents

2020 ◽  
Vol 245 (18) ◽  
pp. 1629-1636
Author(s):  
Ruiming Kong ◽  
Wenjuan Wu ◽  
Rui Qiu ◽  
Lei Gao ◽  
Fengxian Du ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Ex Vivo ◽  
Light Attenuation ◽  
Anterior Segment ◽  
Posterior Segment ◽  
Glycerol Solution ◽  
Optical Coherence ◽  
Optical Clearing ◽  
Imaging Depth

Optical coherence tomography has become an indispensable diagnostic tool in ophthalmology for imaging the retina and the anterior segment of the eye. However, the imaging depth of optical coherence tomography is limited by light attenuation in tissues due to optical scattering and absorption. In this study of rabbit eye both ex vivo and in vivo, optical coherence tomography imaging depth of the anterior and posterior segments of the eye was extended by using optical clearing agents to reduce multiple scattering. The sclera, the iris, and the ciliary body were clearly visualized by direct application of glycerol at an incision on the conjunctiva, and the posterior boundary of sclera and even the deeper tissues were detected by submerging the posterior segment of eye in glycerol solution ex vivo or by retro-bulbar injection of glycerol in vivo. The ex vivo rabbit eyes recovered to their original state in 60 s after saline-wash treatment, and normal optical coherence tomography images of the posterior segment of the sample eyes proved the self-recovery of in vivo performance. Signal intensities of optical coherence tomography images obtained before and after glycerol treatment were compared to analysis of the effect of optical clearing. To the best of our knowledge, this is the first study for imaging depth extension of optical coherence tomography in both the anterior and posterior segments of eye by using optical clearing agents.

Characterization of deeply embedded corneal foreign bodies with anterior segment optical coherence tomography

2019 ◽  
Vol 257 (6) ◽  
pp. 1247-1252 ◽  
Author(s):  
Sharon Armarnik ◽  
Michael Mimouni ◽  
Dafna Goldenberg ◽  
Fani Segev ◽  
Amit Meshi ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Foreign Bodies ◽  
Anterior Segment ◽  
Optical Coherence

scholarly journals Optical coherence tomography angiography in diabetic retinopathy: a review of current applications

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Kai Yuan Tey ◽  
Kelvin Teo ◽  
Anna C. S. Tan ◽  
Kavya Devarajan ◽  
Bingyao Tan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Diabetic Retinopathy ◽  
Optical Coherence Tomography Angiography ◽  
Vision Loss ◽  
Imaging Modality ◽  
Anterior Segment ◽  
Foveal Avascular Zone ◽  
Imaging Method ◽  
Optical Coherence ◽  
Non Invasive

Abstract Background Diabetic retinopathy (DR) is a leading cause of vision loss in adults. Currently, the standard imaging technique to monitor and prognosticate DR and diabetic maculopathy is dye-based angiography. With the introduction of optical coherence tomography angiography (OCTA), it may serve as a potential rapid, non-invasive imaging modality as an adjunct. Main text Recent studies on the role of OCTA in DR include the use of vascular parameters e.g., vessel density, intercapillary spacing, vessel diameter index, length of vessels based on skeletonised OCTA, the total length of vessels, vascular architecture and area of the foveal avascular zone. These quantitative measures may be able to detect changes with the severity and progress of DR for clinical research. OCTA may also serve as a non-invasive imaging method to detect diabetic macula ischemia, which may help predict visual prognosis. However, there are many limitations of OCTA in DR, such as difficulty in segmentation between superficial and deep capillary plexus; and its use in diabetic macula edema where the presence of cystic spaces may affect image results. Future applications of OCTA in the anterior segment include detection of anterior segment ischemia and iris neovascularisation associated with proliferative DR and risk of neovascular glaucoma. Conclusion OCTA may potentially serve as a useful non-invasive imaging tool in the diagnosis and monitoring of diabetic retinopathy and maculopathy in the future. Future studies may demonstrate how quantitative OCTA measures may have a role in detecting early retinal changes in patients with diabetes.

scholarly journals A pilot study investigating anterior segment optical coherence tomography angiography as a non-invasive tool in evaluating corneal vascularisation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hon Shing Ong ◽  
Kai Yuan Tey ◽  
Mengyuan Ke ◽  
Bingyao Tan ◽  
Jacqueline Chua ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optical Coherence Tomography Angiography ◽  
Objective Assessment ◽  
Anterior Segment ◽  
Optical Coherence ◽  
Non Invasive ◽  
Imaging Tool ◽  
Model Study ◽  
Animal Model Study ◽  
Endothelial Growth Factor

AbstractThe current assessment of corneal vascularisation (CV) relies on slit-lamp examination, which may be subjective. Dye-based angiographies, like indocyanine green angiography (ICGA), allows for good visualisation of anterior segment blood vessels. However, ICGA is invasive and can be associated with systemic adverse effects. Anterior segment optical coherence tomography angiography (AS-OCTA) is a non-invasive tool that has been shown to successfully delineate CV. However, there are no previous studies that have reported if AS-OCTA can determine CV stage and activity. We used an established CV model in rabbits to examine serial AS-OCTA scans of CV development and regression following treatment with anti-vascular endothelial growth factor. We compared AS-OCTA derived vascular measurements to that of ICGA determined vessel leakage and CV staging. Our results showed that AS-OCTA vessel densities and vessel branch area significantly correlated with the severity of CV based on ICGA (all p ≤ 0.05). We also found that AS-OCTA vessel densities correlated with ICGA vessel leakage time, following an inverse linear relationship (r2 = − 0.726, p < 0.01). Changes in aqueous levels of CXCL-12 and PIGF cytokines significantly correlated with AS-OCTA vessel densities (r2 = 0.736 and r2 = 0.731 respectively, all p < 0.05). In summary, we found that AS-OCTA derived vessel parameters may be useful for assessing CV severity, while vessel density correlates with CV activity and leakage. Thus, our pilot animal model study suggests that AS-OCTA may be a useful non-invasive imaging tool to provide objective assessment of CV to examine progression or response in treatment, which requires confirmation in clinical studies.

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