scholarly journals Analysis of the Retina, Choroid, and Optic Nerve Structures using Optical Coherence Tomography in Patients Recovered from Coronavirus Disease 2019

2021 ◽  
Author(s):  
Alev Ozcelik Kose ◽  
Nursal Melda Yenerel ◽  
Sevcan Balcı ◽  
Merve Beyza Yıldız ◽  
Serhat Imamoglu ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Healthcare Professionals ◽  
Retinal Hemorrhage ◽  
Optical Coherence ◽  
Chain Reaction ◽  
Fiber Layer ◽  
The Mean ◽  
Polymerase Chain ◽  
Swab Specimen

Abstract Purpose: To evaluate retina, choroid and optic nerve in patients recovered from coronavirus disease 2019 (COVID-19).Methods: Fifty healthcare professionals who had COVID-19 infection- confirmed with polymerase chain reaction from nasopharyngeal swabs- and were at least one-month swab specimen negativeness after the treatment (CG) compared with 40 sex-matched healthy controls (HG). The dilated fundoscopy examination and optical coherence tomography (OCT) scanning were performed. The fundoscopy examination, subfoveal and peripapillary choroidal vascularity index (CVI), retinal nerve fiber layer (RNFL) and Bruch membrane opening (BMO)-minimum rim width (MRW) were evaluated.Results: The mean subfoveal and peripapillary CVI were found significantly higher in the CG than the HG (p < 0.001, p < 0.001). In the CG, two (4 %) patients had cotton-wool spot (CWS), one (2 %) patients had retinal hemorrhage. Discussion: COVID-19 might be associated with increased subfoveal and peripapillary CVI and retinal changes after the healing period.

scholarly journals Longitudinal assessment of optic nerve head changes using optical coherence tomography in a primate microbead model of ocular hypertension

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anita S. Y. Chan ◽  
Tin Aung Tun ◽  
John C. Allen ◽  
Myoe Naing Lynn ◽  
Sai Bo Bo Tun ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Ocular Hypertension ◽  
Optic Nerve Head ◽  
Structural Damage ◽  
Structural Changes ◽  
Lamina Cribrosa ◽  
Optical Coherence ◽  
Longitudinal Assessment ◽  
The Mean

Abstract In humans, the longitudinal characterisation of early optic nerve head (ONH) damage in ocular hypertension (OHT) is difficult as patients with glaucoma usually have structural ONH damage at the time of diagnosis. Previous studies assessed glaucomatous ONH cupping by measuring the anterior lamina cribrosa depth (LCD) and minimal rim width (MRW) using optical coherence tomography (OCT). In this study, we induced OHT by repeated intracameral microbead injections in 16 cynomolgus primates (10 unilateral; 6 bilateral) and assessed the structural changes of the ONH longitudinally to observe early changes. Elevated intraocular pressure (IOP) in OHT eyes was maintained for 7 months and serial OCT measurements were performed during this period. The mean IOP was significantly elevated in OHT eyes when compared to baseline and compared to the control eyes. Thinner MRW and deeper LCD values from baseline were observed in OHT eyes with the greatest changes seen between month 1 and month 2 of OHT. Both the mean and maximum IOP values were significant predictors of MRW and LCD changes, although the maximum IOP was a slightly better predictor. We believe that this model could be useful to study IOP-induced early ONH structural damage which is important for understanding glaucoma pathogenesis.

Precision of Optic Nerve Head and Retinal Nerve Fiber Layer Parameter Measurements by Spectral-domain Optical Coherence Tomography

2018 ◽  
Vol 27 (5) ◽  
pp. 407-414 ◽  
Author(s):  
Laura M. Schrems-Hoesl ◽  
Wolfgang A. Schrems ◽  
Robert Laemmer ◽  
Friedrich E. Kruse ◽  
Christian Y. Mardin
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Nerve Fiber ◽  
Retinal Nerve Fiber Layer ◽  
Optic Nerve Head ◽  
Spectral Domain ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Nerve Fiber Layer ◽  
Layer Parameter

scholarly journals A Deep Learning Approach to Denoise Optical Coherence Tomography Images of the Optic Nerve Head

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Sripad Krishna Devalla ◽  
Giridhar Subramanian ◽  
Tan Hung Pham ◽  
Xiaofei Wang ◽  
Shamira Perera ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Deep Learning ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Similarity Index ◽  
Optical Coherence ◽  
Patient Discomfort ◽  
Single Frame ◽  
The Mean ◽  
Noise Ratio

Abstract Optical coherence tomography (OCT) has become an established clinical routine for the in vivo imaging of the optic nerve head (ONH) tissues, that is crucial in the diagnosis and management of various ocular and neuro-ocular pathologies. However, the presence of speckle noise affects the quality of OCT images and its interpretation. Although recent frame-averaging techniques have shown to enhance OCT image quality, they require longer scanning durations, resulting in patient discomfort. Using a custom deep learning network trained with 2,328 ‘clean B-scans’ (multi-frame B-scans; signal averaged), and their corresponding ‘noisy B-scans’ (clean B-scans + Gaussian noise), we were able to successfully denoise 1,552 unseen single-frame (without signal averaging) B-scans. The denoised B-scans were qualitatively similar to their corresponding multi-frame B-scans, with enhanced visibility of the ONH tissues. The mean signal to noise ratio (SNR) increased from 4.02 ± 0.68 dB (single-frame) to 8.14 ± 1.03 dB (denoised). For all the ONH tissues, the mean contrast to noise ratio (CNR) increased from 3.50 ± 0.56 (single-frame) to 7.63 ± 1.81 (denoised). The mean structural similarity index (MSSIM) increased from 0.13 ± 0.02 (single frame) to 0.65 ± 0.03 (denoised) when compared with the corresponding multi-frame B-scans. Our deep learning algorithm can denoise a single-frame OCT B-scan of the ONH in under 20 ms, thus offering a framework to obtain superior quality OCT B-scans with reduced scanning times and minimal patient discomfort.

scholarly journals Optical Coherence Tomography in Patients with Chiari I Malformation

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Michele Figus ◽  
Chiara Posarelli ◽  
Francesco Nasini ◽  
Paolo Perrini ◽  
Mario Miccoli ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Optic Nerve Head ◽  
Chiari I Malformation ◽  
Nerve Fibers ◽  
Healthy Controls ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Rnfl Thickness ◽  
Chiari I

Background/Aims. To evaluate optic nerve head with spectral domain optical coherence tomography (OCT) in patients with Chiari I malformation (CMI) compared to healthy controls.Methods. Cross-sectional study. OCT of the optic nerve head of 22 patients with CMI and 22 healthy controls was quantitatively analyzed. The healthy controls were matched for age and sex with the study population. Mean retinal nerve fiber layer (RNFL) thickness was calculated for both eyes; the mean thickness value was also registered for each quadrant and for each subfield of the four quadrants.Results. CMI patients showed a reduction of the RNFL thickness in both eyes. This reduction was more statistically significant (P<0.05) for the inferior quadrant in the right eye and in each quadrant than nasal one in the left eye.Conclusion. A distress of the retinal nerve fibers could explain the observed reduction of the RNFL thickness in patients with CMI; in our series the reduction of the RNFL thickness seems lower when CMI is associated with syringomyelia.

scholarly journals Optical coherence tomography angiography in glaucoma: a mini-review

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1686 ◽  
Author(s):  
Kelvin H. Wan ◽  
Christopher K. Leung
Keyword(s):  
Optical Coherence Tomography ◽  
Optic Nerve ◽  
Layer Thickness ◽  
Optical Coherence Tomography Angiography ◽  
Plexiform Layer ◽  
Inner Plexiform Layer ◽  
Optical Coherence ◽  
Fiber Layer ◽  
Vascular Abnormalities ◽  
Additional Information

The advent of optical coherence tomography angiography (OCT-A) provides a new opportunity to visualize the retinal vasculature in a non-invasive and dye-free manner which may help identify vascular abnormalities in glaucoma. While a reduction in retinal and optic nerve head vessel densities and blood flow indexes measured by OCT-A has been demonstrated in patients with glaucoma in many studies, it is unclear whether OCT-A provides additional information for the detection and monitoring of glaucoma compared with OCT measurements such as retinal nerve fiber layer thickness, neuroretinal rim width, and ganglion cell inner plexiform layer thickness. Longitudinal studies are needed to elucidate whether vascular abnormalities detected by OCT-A are a cause or a consequence of optic nerve damage in glaucoma.

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