A Level Set Method with Region-Scalable Fitting Energy for Retinal Layer Segmentation in Spectral-Domain Optical Coherence Tomography Images

2020 ◽  
Vol 10 (2) ◽  
pp. 326-335
Author(s):  
Liming Liang ◽  
Xiaoqi Sheng ◽  
Bowen Liu ◽  
Zhimin Lan
Keyword(s):  
Optical Coherence Tomography ◽  
Level Set ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Spectral Domain ◽  
Retinal Layer ◽  
Optical Coherence ◽  
Retinal Layers ◽  
Layer Segmentation ◽  
Sd Oct

Retinal layer segmentation of spectral-domain optical coherence tomography images plays an important role during diagnosis and analysis of ophthalmic diseases. In this paper, a novel variational level set framework with region-scalable fitting energy is proposed for automated retinal layer segmentation in SD-OCT. To the best of our knowledge, it is the first time that level set based method succeeds in ten retinal layers segmentation. The proposed framework consists of three steps. First, an anisotropic nonlinear diffusion filter is applied for speckle noise reduction and ROI contrast enhancement. Second, Canny edge detectors are used to extract initial layers: nerve fiber layer, connecting cilia and retinal pigment epithelium. Finally, the rest retinal layers are segmented by means of level set model combined with prior knowledge of retinal thickness and morphology, for which the energy function consists of region-scalable fitting energy data term, area constraint term, regularization term and length penalty term. The proposed method was tested on 50 retinal SD-OCT B-scans from 50 normal subjects. The overall unsigned border position error is 5.92 ± 4.72 μm. The result showed that data terms with border weight terms can keep layer segmentation results in strong border while retaining its fitting capability in weak border. The proposed method achieves better segmentation result than other active contour models.

scholarly journals Real-time Fully Automated Internal Layer Segmentation of Human Retina in Optical Coherence Tomography Images

2020 ◽  
Vol 9 (3) ◽  
pp. 1951-1957
Keyword(s):  
Optical Coherence Tomography ◽  
Real Time ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Intensity Variation ◽  
Frame Rate ◽  
Retinal Layer ◽  
Optical Coherence ◽  
Retinal Layers ◽  
Layer Segmentation

In the field of ophthalmology, optical coherence tomography (OCT) has proven to be a powerful imaging technique when it comes to diagnosing various eye-related diseases. This research article introduces a real-time automatic retinal layer segmentation algorithm based on intensity variation in the OCT images. The built algorithm is capable of detecting internal retinal layers like the internal limiting membrane (ILM), the retinal pigment epithelium (RPE) and the retinal nerve fiber layer (RNFL) with micrometer level precision, the algorithm uses openMP for parallelized computation for real-time visualization of the segmented retinal layers. The total execution time of the algorithm was evaluated using various image sizes and compared with the OCT frame rate to demonstrate the efficiency of real-time segmentation.

Optical Coherence Tomography in Best Vitelliform Macular Dystrophy

2017 ◽  
Vol 27 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Maurizio Battaglia Parodi ◽  
Pierluigi Iacono ◽  
Francesco Romano ◽  
Gianluigi Bolognesi ◽  
Francesco Fasce ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Visual Acuity ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Macular Dystrophy ◽  
Optical Coherence ◽  
Vitelliform Macular Dystrophy ◽  
Retinal Layers ◽  
Hyperreflective Foci ◽  
Sd Oct

Purpose To analyze spectral-domain optical coherence tomography (SD-OCT)-specific findings in the different stages of vitelliform macular dystrophy (VMD). Methods Thirty-seven patients were prospectively recruited. All the patients underwent a complete ophthalmologic examination, including best-corrected visual acuity (BCVA), biomicroscopy, and SD-OCT. The examined findings were vitelliform material, neurosensory detachment, intraretinal hyperreflective foci, and the status of external limiting membrane, ellipsoid zone, and retinal pigment epithelium. The primary outcome was the stratification of SD-OCT findings in each VMD stage. Secondary outcomes included the description of different characteristics related to intraretinal hyperreflective foci. Results Outer retinal layers were preserved almost exclusively in stage 1 (range 70%-100%), whereas their disruption and absence were typical of stages 2 to 4 (83%-100%) and stage 5 (67%-83%), respectively. Vitelliform material was found always in stages 2 and 3, 89% of stage 4, and rarely in stage 5 (33%). Neurosensory detachment was to some extent representative of stages 3 and 4 (80% and 72%, respectively) when compared with the other stages (p<0.001). Hyperreflective foci (16% of all eyes) demonstrated a progressive increase across stages 2 to 4, with slightly reduced figure in stage 5. These foci were located in the outer nuclear and plexiform layers, showed different sizes, and were not associated with a visual acuity reduction (p = 0.64). Conclusions A progressive deterioration of the outer retinal layers was noticeable in more advanced stages of VMD. The reduction of vitelliform material from stage 3 to 4 was paralleled by an increased evidence of neurosensory detachment. Although showing different size and location, hyperreflective foci did not correlate with worse BCVA.

scholarly journals Acute Retinal Pigment Epitheliitis: Spectral Domain Optical Coherence Tomography, Fluorescein Angiography, and Autofluorescence Findings

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Tuğba Aydoğan ◽  
Esra Güney ◽  
Betül İlkay Sezgin Akçay ◽  
Tahir Kansu Bozkurt ◽  
Cihan Ünlü ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Fluorescein Angiography ◽  
Pigment Epithelium ◽  
Outer Nuclear Layer ◽  
Fundus Autofluorescence ◽  
Retinal Pigment ◽  
Spectral Domain ◽  
Fundus Examination ◽  
Optical Coherence ◽  
Sd Oct

A 17-year-old presented with central and paracentral scotomas in his right eye for one week. There was no remarkable medical or ocular history. Blood analyses were within normal range. At presentation both eyes’ best-corrected visual acuities were 20/20. Slit-lamp examination result was normal. Fundus examination revealed yellow-white hypopigmented areas in the macula. Fluorescein angiography (FA) showed hypofluorescence surrounded by ring of hyperfluorescence. Fundus autofluorescence (FAF) was slightly increased. Spectral domain optical coherence tomography (SD-OCT) showed disruption of IS/OS junction with expansion of abnormal hyperreflectivity from retinal pigment epithelium to the outer nuclear layer (ONL). One month later fundus examination showed disappearance of the lesions. FA revealed transmission hyperfluorescence. FAF showed increased autofluorescence and pigment clumping. Hyperreflective band in SD-OCT disappeared. Loss of photoreceptor segment layers was observed in some of the macular lesions. The diagnosis of acute retinal pigment epitheliitis can be challenging after disappearance of fundus findings. FA, FAF, and SD-OCT are important tests for diagnosis after resolution of the disease.

scholarly journals Topographic correlation between multifocal electroretinography, microperimetry, and spectral-domain optical coherence tomography of the macula in patients with birdshot chorioretinopathy

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Rubbia Afridi ◽  
Aniruddha Agarwal ◽  
Nam V. Nguyen ◽  
Muhammad Hassan ◽  
Mohammad Ali Sadiq ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Structural Changes ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Multifocal Electroretinogram ◽  
Spectral Domain ◽  
Implicit Time ◽  
Optical Coherence ◽  
Birdshot Chorioretinopathy ◽  
Sd Oct

Abstract Purpose To correlate the findings of retinal function with multifocal electroretinogram (mfERG), microperimetry (MP), and structural assessments with spectral-domain optical coherence tomography (SD-OCT) in topographically corresponding areas of the macula of patients with birdshot chorioretinopathy (BSCR). Methods Patients diagnosed with BSCR by clinical and imaging findings were included in the study. The mfERG was performed using 61 hexagon stimulus patterns grouped into 5 rings (Diagnosys Inc., USA). Individual responses [N1-P1 amplitudes in nanovolt (NV)/degree2 and P1 implicit time in milliseconds (msec)] for each hexagon in the central 3 rings (R1, 0°–2.3°; R2,2.3°–7.7°; and R3, 7.7°–12°) were obtained (19 hexagons). MP examination consisted of Polar 3–12° test with 28 points in 3 concentric rings with diameters of approximately 2.3°, 6.6°, and 11.1° from the foveal center. SD-OCT was performed using macular scans of 20° × 20°. The retinal sensitivity values on MP and thickness values of retinal layers were correlated with the responses on the mfERG for each topographically correlated hexagon. Results Sixteen eyes of eight patients were included in the study (mean age, 59.87 ± 10.01 years; range, 41–73 years). The amplitudes and the implicit times on mfERG and retinal sensitivities on MP were decreased for each of the 19 hexagons. Considering retinotopically matched points, there was correlation between the retinal sensitivities and mfERG implicit times and response amplitudes in all three rings. The thickness of the retinal pigment epithelium showed modest correlation with the mfERG parameters (ρ = 0.29; p = 0.04). The structural changes on SD-OCT, such as IS-OS disruption, were associated with changes in the mfERG trace arrays. Conclusions The structural and functional assessments in retinae of eyes with BSCR suggest that each imaging tool may be capturing unique aspects of retinal dysfunction. Multimodal imaging may allow detailed analyses of retinal damage at various corresponding loci. These findings are important when considering the use of these techniques in BSCR.

scholarly journals Automated Retinal Layer Segmentation Using Spectral Domain Optical Coherence Tomography: Evaluation of Inter-Session Repeatability and Agreement between Devices

PLoS ONE ◽  
2016 ◽  
Vol 11 (9) ◽  
pp. e0162001 ◽  
Author(s):  
Louise Terry ◽  
Nicola Cassels ◽  
Kelly Lu ◽  
Jennifer H. Acton ◽  
Tom H. Margrain ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Spectral Domain ◽  
Retinal Layer ◽  
Optical Coherence ◽  
Layer Segmentation

Changes of outer retinal thickness with increasing age in normal eyes

2020 ◽  
Vol 1 (2) ◽  
pp. 108-112
Author(s):  
Zi-Jing Li ◽  
◽  
Jian-Hui Xiao ◽  
Peng Zeng ◽  
Xiang Gao ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Outer Segment ◽  
Retinal Thickness ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Layer ◽  
External Limiting Membrane ◽  
The Cost ◽  
The Relationship ◽  
Sd Oct

AIM: To comprehensively investigate the relationship between outer retinal layer thickness and age in normal eyes. METHODS: One hundred normal eyes of 100 subjects who underwent spectral-domain optical coherence tomography (SD-OCT) were included in this retrospective study. The distances between the external limiting membrane (ELM) line and the photoreceptor inner segment/outer segment (IS/OS) line (ELM-IS/OS), the IS/OS line and the cone outer segment tips (COST) line (IS/OS-COST), the COST line and the retinal pigment epithelium (RPE) complex (COST-RPE) and the full retinal thickness (RT) were measured at the fovea and on four quarters. The relationship between thickness and age or sex was then analysed. CONCLUSION: In normal eyes, the RT thickness on the nasal quarter and the ELM-IS/OS thickness were significantly and negatively correlated with age. The IS/OS-COST and COST-RPE thicknesses were not significantly correlated with age or sex.

scholarly journals Early Detection of Incipient Retinal Pigment Epithelium Atrophy Overlying Drusen with Fundus Autofluorescence vs. Spectral Domain Optical Coherence Tomography

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Anabel Rodríguez ◽  
Marc Biarnés ◽  
Rosa M. Coco-Martin ◽  
Anna Sala-Puigdollers ◽  
Jordi Monés
Keyword(s):  
Optical Coherence Tomography ◽  
Retinal Pigment Epithelium ◽  
Median Time ◽  
Pigment Epithelium ◽  
Fundus Autofluorescence ◽  
Retinal Pigment ◽  
Geographic Atrophy ◽  
Optical Coherence ◽  
Rpe Atrophy ◽  
Sd Oct

Purpose. This study aims to find out which tool, fundus autofluorescence (FAF) or spectral domain optical coherence tomography (SD-OCT), is more sensitive in detecting retinal pigment epithelium (RPE) demise overlying drusen and can, therefore, help predict geographic atrophy (GA) appearance in Age-Related Macular Degeneration (AMD). Methods. A single-site, retrospective, observational, longitudinal study was conducted. Patients with intermediate AMD (iAMD) (large (>125 μm) or intermediate (63–125 μm) drusen with hyper/hypopigmentation) with a minimum follow-up of 18 months were included. Drusen with overlying incipient RPE atrophy were identified on SD-OCT defined as choroidal hypertransmission or nascent geographic atrophy (nGA). These selected drusen were, then, traced backwards in time to determine if incipient RPE atrophy overlying drusen was observed on FAF (well-demarcated region of absence of autofluorescence) before, simultaneously, or after having detected the first signs of incipient RPE atrophy on SD-OCT. The number of drusen in which signs of incipient RPE atrophy was detected earlier using FAF or SD-OCT was compared. The time elapsed from the identification with the more sensitive method to the other was recorded and analyzed. Results. One hundred and thirty-three drusen in 22 eyes of 22 patients were included. Of these, 112 (84.2%) drusen showed choroidal hypertransmission and 21(15.8%) nGA. Early signs of atrophy overlying drusen were found simultaneously on SD-OCT and FAF in 52 cases (39.1%, 95% CI 30.8–47.9%), earliest on FAF in 51 (38.3%, 95% CI 30.0–47.2%) and first on SD-OCT in 30 (22.6%, 95% CI 15.8–30.6%; p<0.05). Statistically significant differences were found between both techniques (p=0.005), with FAF detecting it earlier than SD-OCT. When RPE atrophy was found first on FAF, the median time to diagnosis with SD-OCT was 6.6 months (95% CI 5.5 to 8.6), while if detection occurred earlier on SD-OCT, the median time until identification with FAF was 12.6 months (95% CI 6.0 to 23.4; p=0.0003). Conclusions. In iAMD cases in which early atrophy overlying drusen is not detected simultaneously in FAF and SD-OCT, FAF was significantly more sensitive. Nevertheless, a multimodal approach is recommended and required to evaluate these patients.

scholarly journals In vivo optical biopsy of choroidal osteoma: a swept source optical coherence tomography–based tumor characterization

2020 ◽  
Vol 12 ◽  
pp. 251584142092274 ◽  
Author(s):  
Shorya Vardhan Azad ◽  
Vinod Kumar ◽  
Rohan Chawla ◽  
Bibhuti Kashyap ◽  
Shreyas Temkar ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Signal Transmission ◽  
Retinal Pigment ◽  
Optical Coherence ◽  
Choroidal Neovascular Membrane ◽  
Swept Source ◽  
Retinal Layers ◽  
Choroidal Osteoma

Objective: To study tumor characteristics of choroidal osteoma by swept source optical coherence tomography. Methods: A retrospective case series done at tertiary referral center in northern India. All patients diagnosed with choroidal osteoma examined on swept source optical coherence tomography were included. Swept source optical coherence tomography images were analyzed for integrity of retinal layers—intraretinal layers, outer retinal layers (photoreceptor), retinal pigment epithelium, and contour abnormalities. Choroidal changes assessed were tumor attributes such as shape, depth of choroidal involvement, tumor mass reflectivity pattern, tumor vascularity, and evolutionary structural abnormalities such as deossification, focal depressions, or choroidal neovascular membrane. Results: A total of 15 eyes of 11 patients were analyzed. Seven of 11 patients were females. Mean age of presentation was approximately 26 years. Tumor was large in nine cases (>7.5 mm). Deossification was seen in 12 eyes. Inner and outer retinal integrity was maintained in 7 and 2 eyes, respectively. Most common internal tumor reflectivity pattern seen was a lamellar appearance (12/15). Increased signal transmission to choroid and focal area of deep excavation was present in 11 and 4 eyes, respectively. Osteoclastic activity was noted in 12 eyes. Choroidal neovascular membrane was seen in 6 eyes. Small lesions showed lamellar pattern of tumor reflectivity with preservation of retinal pigment epithelium and overlying retina. Larger tumors were deossified with 6 irregular tumor contour, disorganization of the outer retina, increased signal transmission to choroid, and areas of osteoclastic activity. Conclusion: Swept source optical coherence tomography was helpful in assessing tumor attributes and predicting the different timelines in tumor evolution.

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