Erratum: Evaluation of asymmetry in right and left eyes of normal individuals using extracted features from optical coherence tomography and fundus images

AbstractIn this study, we investigated the correlation between pattern electroretinogram (PERG) and optical coherence tomography angiography (OCTA) parameters for diagnosis in patients with normal-tension glaucoma (NTG). Forty-nine normal individuals (49 eyes) and 60 patients with NTG (60 eyes) were enrolled. OCTA and PERG parameters, such as macular vessel density (VD) and the amplitude of N35–P50 and P50–N95, were measured. Correlation analyses were performed between the parameters, and the area under the curve (AUC) was used to identify their diagnostic ability for NTG. Macular VD and the amplitude of N35–P50 and P50–N95 showed significant differences between the normal individuals and patients with NTG. Correlation between P50 and N95 amplitude and macular VD was significant in the normal and early glaucoma groups. Macular VD showed a higher AUC value (0.730) than that of P50–N95 amplitude (0.645) in the early glaucoma group. In the moderate to severe glaucoma group, the AUC value of the amplitude of P50–N95 (0.907) was higher than that of macular VD (0.876). The results indicate that PERG and OCTA parameters may identify glaucoma in its early stage, based on the severity of glaucomatous damage in patients with NTG.

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Assessment of the Deformation of the Outer Nuclear Layer in the Epiretinal Membrane Using Spectral-Domain Optical Coherence Tomography

10.21203/rs.2.281/v2 ◽

2019 ◽

Author(s):

Seiji Takagi ◽

Shigeki Kudo ◽

Hideo Yokota ◽

Masahiro Akiba ◽

Michiko Mandai ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Epiretinal Membrane ◽

Outer Nuclear Layer ◽

Retinal Pigment ◽

Area Ratio ◽

Reference Plane ◽

Optical Coherence ◽

Axis Ratio ◽

Normal Individuals ◽

Normal Controls

Abstract Background We aimed to investigate the deformation of the outer nuclear layer using optical coherence tomography in patients with epiretinal membrane (ERM) and its relationship with metamorphopsia. Methods Thirty-nine eyes from 39 patients with ERM were included in the study. Patients with the subtypes of pseudo macula hole and lamellar hole were excluded. Twenty-one fellow eyes without macular disease were included as normal controls. Forty-nine B-scan images were obtained in the range of 20 degrees around the macula using SD-OCT. The outer nuclear layer (ONL) was evaluated as a three-dimensional image (3D-ONL) reconstructed using the distance between the ONL and retinal pigment epithelium (RPE) line. The deformation of the ONL was figured at the reference plane and evaluation plane (ONL-B). The characteristic parameters of the ONL-B were defined as circularity, area ratio, and axis ratio. The correlations between these parameters and visual acuity and MCHART score ratio (MH/MV) were then evaluated. Results ONL height was significantly higher in ERM patients than in normal controls (54.1 ± 5.3 μm and 84.1 ± 12.9 μm, respectively; P<0.001). In ERM patients, the MV score was 0.53 ± 0.50, the MH score was 0.71 ± 0.61, and the distance from the RPE line to the ONL-B was 153.5 ±13.5µm. The axis of the ONL-B in normal controls and ERM patients was -6.25±21.8 and -1.28±29.1, respectively, which indicates that the ONL is horizontally long in both normal individuals and ERM patients. The circularity and area ratio were significantly smaller in ERM patients than in normal controls. In all ERM patients, MH/MV had a significant correlation with axis (r=-0.29, p=0.034), circularity (r=-0.28, p=0.044), area ratio (r=-0.47, p=0.001). Moreover, we found that the correlation was more significant if the subjects had an axis of the ONL within ± 10 degrees (n=16); the correlations of MH/MV with axis (r=-0.29, p=0.034), circularity (r=-0.53, p=0.021), and area ratio were more significant (r=-0.78, P<0.0001). Conclusion The ONL is horizontally long in normal individuals and ERM patients. The direction of metamorphopsia is correlated with the direction of ONL deformation.

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Combination of Enhanced Depth Imaging Optical Coherence Tomography and Fundus Images for Glaucoma Screening

Journal of Medical Systems ◽

10.1007/s10916-019-1303-8 ◽

2019 ◽

Vol 43 (6) ◽

Cited By ~ 1

Author(s):

Zailiang Chen ◽

Xianxian Zheng ◽

Hailan Shen ◽

Ziyang Zeng ◽

Qing Liu ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Enhanced Depth Imaging ◽

Fundus Images ◽

Optical Coherence ◽

Depth Imaging ◽

Glaucoma Screening ◽

Imaging Optical Coherence Tomography

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Correlation in foveal thickness measurements between spectral-domain and time-domain optical coherence tomography in normal individuals

Eye ◽

10.1038/eye.2009.76 ◽

2009 ◽

Vol 24 (2) ◽

pp. 251-258 ◽

Cited By ~ 16

Author(s):

P Carpineto ◽

M Nubile ◽

L Toto ◽

A Aharrh Gnama ◽

L Marcucci ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Time Domain ◽

Spectral Domain ◽

Optical Coherence ◽

Foveal Thickness ◽

Normal Individuals ◽

Thickness Measurements

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Automated combination of optical coherence tomography images and fundus images

Computer Optics ◽

10.18287/2412-6179-co-892 ◽

2021 ◽

Vol 5 (45) ◽

pp. 721-727

Author(s):

A.D. Fida ◽

A.V. Gaidel ◽

N.S. Demin ◽

N.Yu. Ilyasova ◽

E.A. Zamytskiy

Keyword(s):

Optical Coherence Tomography ◽

Best Approximation ◽

Random Search ◽

Three Dimensional ◽

Fundus Images ◽

Optical Coherence ◽

Affine Transformations ◽

The Best Approximation ◽

Image Pixels

We discuss approaches to combining multimodal multidimensional images, namely, three-dimensional optical coherence tomography (OCT) data and two-dimensional color images of the fundus. Registration of these two modalities can help to adjust the position of the obtained OCT images on the retina. Some existing approaches to matching fundus images are based on finding key points that are considered invariant to affine transformations and are common to the two images. However, errors in the identification of such points can lead to registration errors. There are also methods for iterative adjustment of conversion parameters, but they are based on some manual settings. In this paper, we propose a method based on a full or partial search of possible combinations of the OCT image transformation to find the best approximation of the true transformation. The best approximation is determined using a measure of comparison of preprocessed image pixels. Further, the obtained transformations are compared with the available true transformations to assess the quality of the algorithm. The structure of the work includes: pre-processing of OCT and fundus images with the extraction of blood vessels, random search or grid search over possible transformation parameters (shift, rotation and scaling), and evaluation of the quality of the algorithm.

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Comparison of retinal nerve fiber layer thickness between normal population and patients with diabetes mellitus using optical coherence tomography

Pakistan Journal of Medical Sciences ◽

10.12669/pjms.35.1.65 ◽

2019 ◽

Vol 35 (1) ◽

Cited By ~ 2

Author(s):

Mohammad Asim Mehboob ◽

Zulfiqar Ali Amin ◽

Qamar Ul Islam

Keyword(s):

Optical Coherence Tomography ◽

Normal Population ◽

Diabetic Patients ◽

Optical Coherence ◽

Type Ii ◽

Fiber Layer ◽

Nerve Fiber Layer Thickness ◽

Rnfl Thickness ◽

Normal Individuals ◽

Patients With Diabetes

Objective: To compare the difference in peripapillary Retinal Nerve Fibre Layer (RNFL) thickness between normal population and Type-II diabetic patients without diabetic retinopathy using Spectral Domain Optical Coherence Tomography (SD OCT). Methods: This cross sectional study was carried out at PNS Shifa Naval Hospital, from May 2017 to November 2017. Out of 200 eyes, 100 eyes were of normal individuals and 100 eyes were of Type-II diabetic patients without diabetic retinopathy. Both groups were age and gender matched. Average RNFL thickness, along with RNFL of each quadrant of individuals was noted using SD OCT, and compared between two groups. Results: Mean age of study population was 44.63 ± 4.30 years. Mean axial length was 23.46 ± 0.59 mm. Mean peripapillary RNFL thickness was 126.98 ± 10.07 µm in Group-A (normal individuals), and 120.77 ± 5.41 µm in Group-B (Type-II diabetics). Difference in mean RNFL thickness, as well as RNFL thicknesses of each quadrant was statistically significant between both groups (p-value < 0.001). Conclusion: Diabetic patients have thin RNFL as compared to normal individuals, and must be taken in account while making diagnosis of any disease based on thinning of RNFL. How to cite this:Mehboob MA, Amin ZA, Qamar Ul Islam. Comparison of retinal nerve fiber layer thickness between normal population and patients with diabetes mellitus using optical coherence tomography. Pak J Med Sci. 2019;35(1):---------. doi: https://doi.org/10.12669/pjms.35.1.65 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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Optical Coherence Tomography Angiography of The Macular Microcirculation in Acute Primary Angle Closure Treated With Phacoemulsification

10.21203/rs.3.rs-695251/v1 ◽

2021 ◽

Author(s):

Lin Fu ◽

Yau Kei Chan ◽

Jia Fang ◽

Junbo Liu ◽

Shumei Wen ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Vessel Density ◽

Angle Closure ◽

Field Pattern ◽

Control Group ◽

Optical Coherence ◽

Acute Primary Angle Closure ◽

Primary Angle Closure ◽

Normal Individuals

Abstract Purpose To measure the changes of macular microcirculation in cases with unilateral acute primary angle closure (APAC) who were managed by phacoemulsification. Methods Patients with unilateral APAC and managed by phacoemulsification were enrolled. The contralateral unaffected eyes were served as fellow group, and normal individuals were recruited as control group. Optical coherence tomography angiography (OCT-A) was performed to analyse the macular whole image vessel density (wiVD) and parafoveal vessel density (pfVD). The retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thicknesses were assessed using spectral-domain optical coherence tomography. Results A total of 36 APAC patients and 35 eyes from 35 normal individuals were recruited. In the APAC eyes, the mean wiVD (42.1% ± 3.7%) and pfVD (45.2% ± 3.8%) in the superficial layers (wiVD-SL and pfVD-SL) were both significantly reduced, compared to fellow eyes (45.7% ± 3.1%, 48.7% ±3.1%) and control eyes (44.4% ± 4.7%, 47.4% ± 5.1%) (P < 0.05). They were all statistically correlated with RNFL, GCC, visual field pattern standard deviation (PSD), and mean deviation (MD). Conclusion The macular OCT-A parameters including wiVD-SL and pfVD-SL were significantly reduced in the eyes with APAC compared the fellow unaffected eyes and normal control eyes. They were correlated well with RNFL, GCC, PSD and MD. The macular vessel density parameters may help monitor the progression of APAC.

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Assessment of the Deformation of the Outer Nuclear Layer in the Epiretinal Membrane Using Spectral-Domain Optical Coherence Tomography

10.21203/rs.2.281/v1 ◽

2019 ◽

Author(s):

Seiji Takagi ◽

Shigeki Kudo ◽

Hideo Yokota ◽

Masahiro Akiba ◽

Michiko Mandai ◽

...

Keyword(s):

Optical Coherence Tomography ◽

Epiretinal Membrane ◽

Outer Nuclear Layer ◽

Retinal Pigment ◽

Area Ratio ◽

Reference Plane ◽

Optical Coherence ◽

Axis Ratio ◽

Normal Individuals ◽

Normal Controls

Abstract Background: We aimed to investigate the deformation of the outer nuclear layer using optical coherence tomography in patients with epiretinal membrane (ERM) and its relationship with metamorphopsia. Methods: Thirty-nine eyes from 39 patients with ERM were included in the study. Patients with the subtypes of pseudo macula hole and lamellar hole were excluded. Twenty-one fellow eyes without macular disease were included as normal controls. Forty-nine B-scan images were obtained in the range of 20 degrees around the macula using SD-OCT. The outer nuclear layer (ONL) was evaluated as a three-dimensional image (3D-ONL) reconstructed using the distance between the ONL and retinal pigment epithelium (RPE) line. The deformation of the ONL was figured at the reference plane and evaluation plane (ONL-B). The characteristic parameters of the ONL-B were defined as circularity, area ratio, and axis ratio. The correlations between these parameters and visual acuity and MCHART score ratio (MH/MV) were then evaluated. Results: ONL height was significantly higher in ERM patients than in normal controls (54.1 ± 5.3 μm and 84.1 ± 12.9 μm, respectively; P<0.001). In ERM patients, the MV score was 0.53 ± 0.50, the MH score was 0.71 ± 0.61, and the distance from the RPE line to the ONL-B was 153.5 ±13.5µm. The axis of the ONL-B in normal controls and ERM patients was -6.25±21.8 and -1.28±29.1, respectively, which indicates that the ONL is horizontally long in both normal individuals and ERM patients. The circularity and area ratio were significantly smaller in ERM patients than in normal controls. In all ERM patients, MH/MV had a significant correlation with axis (r=-0.29, p=0.034), circularity (r=-0.28, p=0.044), area ratio (r=-0.47, p=0.001). Moreover, we found that the correlation was more significant if the subjects had an axis of the ONL within ± 10 degrees (n=16); the correlations of MH/MV with axis (r=-0.29, p=0.034), circularity (r=-0.53, p=0.021), and area ratio were more significant (r=-0.78, P<0.0001). Conclusion: The ONL is horizontally long in normal individuals and ERM patients. The direction of metamorphopsia is correlated with the direction of ONL deformation. Keywords: Epi retinal membrane, outer nuclear layer, metamorphopsia, M chart.

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Ultrawide Field Imaging and OCT Angiography in Late-Onset Chloroquine Retinopathy

Journal of VitreoRetinal Diseases ◽

10.1177/2474126417737009 ◽

2017 ◽

Vol 2 (1) ◽

pp. 58-60

Author(s):

Beatriz Abadía ◽

Víctor Llorenç ◽

Marina Mesquida ◽

Maria Teresa Sainz de la Maza ◽

Alfredo Adán

Keyword(s):

Optical Coherence Tomography ◽

Optical Coherence Tomography Angiography ◽

Retinal Pigment ◽

Ophthalmological Examination ◽

Fundus Images ◽

Optical Coherence ◽

Temporal Area ◽

Palindromic Rheumatism ◽

Capillary Plexus ◽

Chloroquine Retinopathy

Purpose: To describe the clinical features of a 57-year-old female with palindromic rheumatism and a 15-year history of chloroquine use and bilateral vision loss. Methods: Ophthalmological examination, including ultrawide field (UWF) fundus images (Optomap-200TX) and cross-sectional retinal scans obtained with Zeiss spectral domain optical coherence tomography angiography (SD-OCTA, HD-5000, Angioplex), was performed. Results: Best-corrected visual acuity was 20/60 in both eyes. Ultrawide field fundus images revealed a ring-shaped area of pericentral and paracentral mottling of the retinal pigment epithelium (RPE), vascular attenuation, and loss of foveal reflex bilaterally. The SD-OCT showed obvious thinning in the outer retina, loss of the photoreceptor inner/outer segment junction corresponding to the location of the hypofluorescent lesion in the macular inferior temporal area, as well as a granular appearance of the RPE. Optical coherence tomography angiography showed the integrity of the superficial capillary plexus in both eyes, but the deep capillary plexus and the choriocapillaris layer detailed the loss of vasculature and the hyperreflective lesions located pericentrally. Multifocal central electroretinogram diminished in both the eyes. Conclusions: Optical coherence tomography angiography is able to show alterations produced by chloroquine toxicity. New technologies, such as UWF imaging and OCTA, could be suitable alternatives for screening and follow-up of chloroquine retinopathy.

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