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

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.

2020 ◽  
Vol 10 (2) ◽  
pp. 326-335
Author(s):  
Liming Liang ◽  
Xiaoqi Sheng ◽  
Bowen Liu ◽  
Zhimin Lan

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.


2020 ◽  
Vol 12 ◽  
pp. 251584142092274 ◽  
Author(s):  
Shorya Vardhan Azad ◽  
Vinod Kumar ◽  
Rohan Chawla ◽  
Bibhuti Kashyap ◽  
Shreyas Temkar ◽  
...  

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.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yasmine Derradji ◽  
Agata Mosinska ◽  
Stefanos Apostolopoulos ◽  
Carlos Ciller ◽  
Sandro De Zanet ◽  
...  

AbstractAge-related macular degeneration (AMD) is a progressive retinal disease, causing vision loss. A more detailed characterization of its atrophic form became possible thanks to the introduction of Optical Coherence Tomography (OCT). However, manual atrophy quantification in 3D retinal scans is a tedious task and prevents taking full advantage of the accurate retina depiction. In this study we developed a fully automated algorithm segmenting Retinal Pigment Epithelial and Outer Retinal Atrophy (RORA) in dry AMD on macular OCT. 62 SD-OCT scans from eyes with atrophic AMD (57 patients) were collected and split into train and test sets. The training set was used to develop a Convolutional Neural Network (CNN). The performance of the algorithm was established by cross validation and comparison to the test set with ground-truth annotated by two graders. Additionally, the effect of using retinal layer segmentation during training was investigated. The algorithm achieved mean Dice scores of 0.881 and 0.844, sensitivity of 0.850 and 0.915 and precision of 0.928 and 0.799 in comparison with Expert 1 and Expert 2, respectively. Using retinal layer segmentation improved the model performance. The proposed model identified RORA with performance matching human experts. It has a potential to rapidly identify atrophy with high consistency.


2011 ◽  
Vol 2011 ◽  
pp. 1-3 ◽  
Author(s):  
F. Nilüfer Yalçındağ ◽  
Huban Atilla ◽  
Figen Batıoğlu

Aim. To report the optical coherence tomography (OCT) findings in three members of the same family with nanophthalmos associated with elevated papillomacular retinal fold.Methods. Complete ophthalmic examination as well as ultrasonography and OCT was performed in all patients.Results. Axial lengths ranged from 16.75 mm to 17.48 mm and refractive errors ranged from +17.50 D to +20.50 D. Main fundus findings were the hyperopic crowded, cupless optic disc, and retinal fold through papillomacular region. Macular OCT scans revealed retinal fold with normal retinal pigment epithelium and choriocapillaris.Interpretation. It is presumed that the retinal folds in nanophthalmos result from a redundancy of the retinal layer caused by retarded growth of the scleral, choroidal, and retinal pigment epithelial layers. The anatomic information provided by the current study is consistent with this thesis.


2017 ◽  
Vol 27 (2) ◽  
pp. 201-204 ◽  
Author(s):  
Maurizio Battaglia Parodi ◽  
Pierluigi Iacono ◽  
Francesco Romano ◽  
Gianluigi Bolognesi ◽  
Francesco Fasce ◽  
...  

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.


2020 ◽  
Vol 13 (8) ◽  
Author(s):  
Worawee Janpongsri ◽  
Joey Huang ◽  
Ringo Ng ◽  
Daniel J. Wahl ◽  
Marinko V. Sarunic ◽  
...  

2018 ◽  
pp. 86-92
Author(s):  
Valentina Bilbao ◽  
Luis Manuel Sádaba ◽  
Gianfranco Ciufo ◽  
Alfredo García-Layana

The Acute Posterior Multifocal Placoid Pigment Epitheliopathy (APMPPE) is a rare acquired idiopathic inflammatory disease that affects the choriocapillaris and external retinal layers. It usually presents as a bilateral, asymmetric, acute, visual loss in young healthy adults. The etiology of APMPPE is unknown and the pathogenesis is controversial, but it is thought that an obstructive vasculitis is the underlying disorder, causing non-perfusion of the retina layers. Funduscopic evaluation is characterized by multiple yellow-white lesions at the level of the retinal pigment epithelium (RPE) and choriocapillaris. Recently, noninvasive techniques of optical coherence tomography angiography (OCT-A) have provided a detailed three-dimensional analysis of blood flow in the retina’s layers and the inner choroid. To our knowledge there have been only a few reports describing OCT-A findings in APMPPE, so we describe a case that might contribute to the growing evidence of a primary choroidal involvement with secondary damage to the overlying RPE and the outer retinal layers, rather than a primary RPE inflammatory etiology, as was originally thought.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 217
Author(s):  
Maria Jesus Rodrigo ◽  
Amaya Pérez del Palomar ◽  
Alberto Montolío ◽  
Silvia Mendez-Martinez ◽  
Manuel Subias ◽  
...  

Intravitreal injection is the gold standard therapeutic option for posterior segment pathologies, and long-lasting release is necessary to avoid reinjections. There is no effective intravitreal treatment for glaucoma or other optic neuropathies in daily practice, nor is there a non-invasive method to monitor drug levels in the vitreous. Here we show that a glaucoma treatment combining a hypotensive and neuroprotective intravitreal formulation (IF) of brimonidine–Laponite (BRI/LAP) can be monitored non-invasively using vitreoretinal interface imaging captured with optical coherence tomography (OCT) over 24 weeks of follow-up. Qualitative and quantitative characterisation was achieved by analysing the changes in vitreous (VIT) signal intensity, expressed as a ratio of retinal pigment epithelium (RPE) intensity. Vitreous hyperreflective aggregates mixed in the vitreous and tended to settle on the retinal surface. Relative intensity and aggregate size progressively decreased over 24 weeks in treated rat eyes as the BRI/LAP IF degraded. VIT/RPE relative intensity and total aggregate area correlated with brimonidine levels measured in the eye. The OCT-derived VIT/RPE relative intensity may be a useful and objective marker for non-invasive monitoring of BRI/LAP IF.


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