The Value of Anterior Segment Optical Coherence Tomography in Different Types of Corneal Infections: An Update

Anterior segment optical coherence tomography (AS-OCT) is a modality that uses low-coherence interferometry to visualize and assess anterior segment ocular features, offering several advantages of being a sterile and noncontact modality that generates high-resolution cross-sectional images of the tissues. The qualitative and quantitative information provided by AS-OCT may be extremely useful for the clinician in the assessment of a wide spectrum of corneal infections, guiding in the management and follow-up of these patients. In clinical practice, infections are routinely evaluated with slit-lamp biomicroscopy, an examination and imaging modality that is limited by the physical characteristics of light. As a consequence, the depth of pathology and the eventually associated corneal edema cannot be accurately measured with the slit-lamp. Therefore, it represents a limit for the clinician, as in vivo information about corneal diseases and the response to treatment is limited. Resolution of corneal infection is characterized by an early reduction in corneal edema, followed by a later reduction in infiltration: both parameters can be routinely measured with standardized serial images by AS-OCT.

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Modern Trends in Imaging V: Optical Coherence Tomography for Rapid Tissue Screening and Directed Histological Sectioning

Analytical Cellular Pathology ◽

10.1155/2012/757236 ◽

2012 ◽

Vol 35 (3) ◽

pp. 129-143 ◽

Cited By ~ 11

Author(s):

Woonggyu Jung ◽

Stephen A. Boppart

Keyword(s):

Optical Coherence Tomography ◽

Real Time ◽

Image Guidance ◽

Diagnostic Yield ◽

Imaging Modality ◽

Imaging Techniques ◽

Optical Coherence ◽

Sampling Errors ◽

Cross Sectional

In pathology, histological examination of the “gold standard” to diagnose various diseases. It has contributed significantly toward identifying the abnormalities in tissues and cells, but has inherent drawbacks when used for fast and accurate diagnosis. These limitations include the lack ofin vivoobservation in real time and sampling errors due to limited number and area coverage of tissue sections. Its diagnostic yield also varies depending on the ability of the physician and the effectiveness of any image guidance technique that may be used for tissue screening during excisional biopsy. In order to overcome these current limitations of histology-based diagnostics, there are significant needs for either complementary or alternative imaging techniques which perform non-destructive, high resolution, and rapid tissue screening. Optical coherence tomography (OCT) is an emerging imaging modality which allows real-time cross-sectional imaging with high resolutions that approach those of histology. OCT could be a very promising technique which has the potential to be used as an adjunct to histological tissue observation when it is not practical to take specimens for histological processing, when large areas of tissue need investigating, or when rapid microscopic imaging is needed. This review will describe the use of OCT as an image guidance tool for fast tissue screening and directed histological tissue sectioning in pathology.

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Role of Optical Coherence Tomography on Corneal Surface Laser Ablation

Journal of Ophthalmology ◽

10.1155/2012/676740 ◽

2012 ◽

Vol 2012 ◽

pp. 1-6 ◽

Cited By ~ 11

Author(s):

Bruna V. Ventura ◽

Haroldo V. Moraes ◽

Newton Kara-Junior ◽

Marcony R. Santhiago

Keyword(s):

Optical Coherence Tomography ◽

Laser Ablation ◽

Imaging Modality ◽

Corneal Thickness ◽

Optical Coherence ◽

Corneal Surface ◽

Cross Sectional ◽

Surface Laser ◽

The Time Domain

This paper focuses on reviewing the roles of optical coherence tomography (OCT) on corneal surface laser ablation procedures. OCT is an optical imaging modality that uses low-coherence interferometry to provide noninvasive cross-sectional imaging of tissue microstructurein vivo.There are two types of OCTs, each with transverse and axial spatial resolutions of a few micrometers: the time-domain and the fourier-domain OCTs. Both have been increasingly used by refractive surgeons and have specific advantages. Which of the current imaging instruments is a better choice depends on the specific application. In laserin situkeratomileusis (LASIK) and in excimer laser phototherapeutic keratectomy (PTK), OCT can be used to assess corneal characteristics and guide treatment decisions. OCT accurately measures central corneal thickness, evaluates the regularity of LASIK flaps, and quantifies flap and residual stromal bed thickness. When evaluating the ablation depth accuracy by subtracting preoperative from postoperative measurements, OCT pachymetry correlates well with laser ablation settings. In addition, OCT can be used to provide precise information on the morphology and depth of corneal pathologic abnormalities, such as corneal degenerations, dystrophies, and opacities, correlating with histopathologic findings.

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Longitudinal Monitoring of Flow-Diverting Stent Tissue Coverage After Implant in a Bifurcation Model Using Neurovascular High-Frequency Optical Coherence Tomography

Neurosurgery ◽

10.1093/neuros/nyaa208 ◽

2020 ◽

Author(s):

Jildaz Caroff ◽

Robert M King ◽

Giovanni J Ughi ◽

Miklos Marosfoi ◽

Erin T Langan ◽

...

Keyword(s):

Optical Coherence Tomography ◽

High Frequency ◽

Imaging Modality ◽

Rabbit Model ◽

Flow Diverter ◽

Tissue Growth ◽

Data Sets ◽

Optical Coherence ◽

Cross Sectional

Abstract BACKGROUND Tissue growth over covered branches is a leading cause of delayed thrombotic complications after flow-diverter stenting (FDS). Due to insufficient resolution, no imaging modality is clinically available to monitor this phenomenon. OBJECTIVE To evaluate high-frequency optical coherence tomography (HF-OCT), a novel intravascular imaging modality designed for the cerebrovascular anatomy with a resolution approaching 10 microns, to monitor tissue growth over FDS in an arterial bifurcation model. METHODS FDS were deployed in a rabbit model (n = 6), covering the aortic bifurcation. The animals were divided in different groups, receiving dual antiplatelet therapy (DAPT) (n = 4), aspirin only (n = 1), and no treatment (n = 1). HF-OCT data were obtained in vivo at 3 different time points in each animal. For each cross-sectional image, metal and tissue coverage of the jailed ostium was quantified. Scanning electron microscopy images of harvested arteries were subsequently obtained. RESULTS Good quality HF-OCT data sets were successfully acquired at implant and follow-up. A median value of 41 (range 21-55) cross-sectional images were analyzed per ostium for each time point. Between 0 and 30 d after implant, HF-OCT analysis showed a significantly higher ostium coverage when DAPT was not given. After 30 d, similar growth rates were found in the DAPT and in the aspirin group. At 60 d, a coverage of 90% was reached in all groups. CONCLUSION HF-OCT enables an accurate visualization of tissue growth over time on FDS struts. The use of FDS in bifurcation locations may induce a drastic reduction of the jailed-branch ostium area.

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Characteristics of Linear Interstitial Keratitis by In Vivo Confocal Microscopy and Anterior Segment Optical Coherence Tomography

Cornea ◽

10.1097/ico.0000000000001552 ◽

2018 ◽

Vol 37 (6) ◽

pp. 785-788

Author(s):

Aleksandra Petrovic ◽

Kattayoon Hashemi ◽

Frank Blaser ◽

Wolfgang Wild ◽

George Kymionis

Keyword(s):

Optical Coherence Tomography ◽

Confocal Microscopy ◽

Anterior Segment ◽

Optical Coherence ◽

In Vivo Confocal Microscopy ◽

Interstitial Keratitis

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Uveo-scleral outflow pathways after ultrasonic cyclocoagulation in refractory glaucoma: an anterior segment optical coherence tomography and in vivo confocal study

British Journal of Ophthalmology ◽

10.1136/bjophthalmol-2015-308069 ◽

2016 ◽

Vol 100 (12) ◽

pp. 1668-1675 ◽

Cited By ~ 17

Author(s):

Rodolfo Mastropasqua ◽

Luca Agnifili ◽

Vincenzo Fasanella ◽

Lisa Toto ◽

Lorenza Brescia ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Anterior Segment ◽

Optical Coherence ◽

Refractory Glaucoma

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Evaluation of the Lower Punctum Parameters and Morphology Using Spectral Domain Anterior Segment Optical Coherence Tomography

Journal of Ophthalmology ◽

10.1155/2015/591845 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 5

Author(s):

Riham S. H. M. Allam ◽

Rania A. Ahmed

Keyword(s):

Optical Coherence Tomography ◽

Anterior Segment ◽

Normal Subjects ◽

Cross Sectional Study ◽

Spectral Domain ◽

Outer Diameter ◽

Optical Coherence ◽

Cross Sectional ◽

Air Bubble ◽

Inner Diameter

Purpose. To study features of the lower punctum in normal subjects using spectral domain anterior segment optical coherence tomography (SD AS-OCT).Methods. Observational cross-sectional study that included 147 punctae (76 subjects). Punctae were evaluated clinically for appearance, position, and size. AS-OCT was used to evaluate the punctal shape, contents, and junction with the vertical canaliculus. Inner and outer diameters as well as depth were measured.Results. 24 males and 52 females (mean age44±14.35 y) were included. Lower punctum was perceived by OCT to be an area with an outer diameter (mean412.16±163 μm), inner diameter (mean233.67±138.73 μm), and depth (mean251.7±126.58 μm). The OCT measured outer punctum diameter was significantly less than that measured clinically (P: 0.000). Seven major shapes were identified. The junction with the vertical canaliculus was detectable in 44%. Fluid was detected in 34%, one of which had an air bubble; however, 63% of punctae showed no contents and 4% had debris.Conclusions. AS-OCT can be a useful tool in understanding the anatomy of the punctum and distal lacrimal system as well as tear drainage physiology. Measuring the punctum size may play a role in plugs fitting.

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