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Artificial Intelligence in Medicine Aug 2019Diabetic retinopathy (DR) results in vision loss if not treated early. A computer-aided diagnosis (CAD) system based on retinal fundus images is an efficient and... (Review)
Review
Diabetic retinopathy (DR) results in vision loss if not treated early. A computer-aided diagnosis (CAD) system based on retinal fundus images is an efficient and effective method for early DR diagnosis and assisting experts. A computer-aided diagnosis (CAD) system involves various stages like detection, segmentation and classification of lesions in fundus images. Many traditional machine-learning (ML) techniques based on hand-engineered features have been introduced. The recent emergence of deep learning (DL) and its decisive victory over traditional ML methods for various applications motivated the researchers to employ it for DR diagnosis, and many deep-learning-based methods have been introduced. In this paper, we review these methods, highlighting their pros and cons. In addition, we point out the challenges to be addressed in designing and learning about efficient, effective and robust deep-learning algorithms for various problems in DR diagnosis and draw attention to directions for future research.
Topics: Biomarkers; Deep Learning; Diabetic Retinopathy; Diagnosis, Computer-Assisted; Fundus Oculi; Humans; Image Interpretation, Computer-Assisted; Machine Learning; Retina
PubMed: 31606116
DOI: 10.1016/j.artmed.2019.07.009 -
Seminars in Ophthalmology Oct 2021Neurofibromatosis, Von Hippel Lindau disease, and tuberous sclerosis complex are classified under the term phakomatoses. They are characterized by ocular vascular... (Review)
Review
BACKGROUND
Neurofibromatosis, Von Hippel Lindau disease, and tuberous sclerosis complex are classified under the term phakomatoses. They are characterized by ocular vascular abnormalities such as vascular tortuosity, corkscrew retinal vessel configuration, moyamoya-like aspect, microaneurysms, hemangioblastomas, and focal sheathing of retinal arteries, possibly due to abnormal formation, migration, and differentiation of neural crest cells. These alterations can be the first sign or the hallmark of disease and can be related to vasoproliferative tumors.
PURPOSE
Novel imaging technologies in ophthalmology, such as near-infrared reflectances and spectral domain optical coherence tomography, have improved our knowledge in the diagnosis of these pathologies. Previously undetected macular vascular alterations have been reported in phakomatoses using optical coherence tomography angiography. This review will summarize the ophthalmic vascular abnormalities and novel imaging methods in the phakomatoses.
CONCLUSION
Active research is being led into the ophthalmic management of these conditions and their complications, and owing to elevated vascular endothelial growth factor production from hemangioblastoma, hamartoma, and retinal vascular proliferative tumors, increasing interest in this line of therapy has been conducted although research is still ongoing in this area.
Topics: Hemangioblastoma; Humans; Neurocutaneous Syndromes; Retinal Neoplasms; Vascular Endothelial Growth Factor A; von Hippel-Lindau Disease
PubMed: 33755531
DOI: 10.1080/08820538.2021.1900284 -
La Tunisie MedicaleTo analyze microcirculatory abnormalities, central avascular area and capillary density in OCT-angiography in retinal venous occlusions (RVO).
AIM
To analyze microcirculatory abnormalities, central avascular area and capillary density in OCT-angiography in retinal venous occlusions (RVO).
METHODS
This is a descriptive study of 35 patients (35 eyes) with RVO who consulted at the ophthalmology department of Farhat Hached Hospital in Sousse between January 2014 and July 2018. The diagnosis of retinal venous occlusion was established on clinical examination, fundus photography and fluorescein angiography. All patients underwent OCT-angiography and OCT B-scan.
RESULTS
Our study includes a total of 35 patients (35 eyes). Of these patients, 20 (57.1%) had branch retinal vein occlusion and 15 (42.8%) had central retinal vein occlusion. The loss or rarefaction of the capillary plexus concerned the deep capillary plexus (DCP) more than the superficial one (SCP). This rarefaction was observed in 25 eyes (71.42%) in both DCP and SCP. The widening of the central avascular zone and the rupture of the peri-foveolar anastomotic mesh were better or as visible as fluorescein angiography. Vascular tortuosity was easy to analyze and was more evident in the SCP than the DCP. Twenty-six (74.28%) patients had vascular tortuosity in DCP and 30 patients (85.71%) had this vascular tortuosity in SCP. Capillary dilatation and microaneurysms were better visible in the DCP than the SCP. These vascular abnormalities were found in 26 cases (74.28%) in the DCP and in 17 cases (48.57%) in the SCP.
CONCLUSIONS
OCT-A is a non-invasive examination that allows very precise analysis and follow-up of both macular edema and superficial and deep capillary plexus architecture during retinal vein occlusions.
Topics: Fluorescein Angiography; Fundus Oculi; Humans; Microcirculation; Retinal Vein Occlusion; Retinal Vessels; Retrospective Studies; Tomography, Optical Coherence; Visual Acuity
PubMed: 35244903
DOI: No ID Found -
Translational Vision Science &... May 2024To identify progression of nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes by combining optical coherence tomography angiography (OCTA)...
PURPOSE
To identify progression of nonproliferative diabetic retinopathy (NPDR) in patients with type 2 diabetes by combining optical coherence tomography angiography (OCTA) metrics and color fundus photography (CFP) images.
METHODS
This study was a post hoc analysis of a prospective longitudinal cohort study (CORDIS, NCT03696810) with 2-year duration. This study enrolled 122 eyes. Ophthalmological examinations included OCTA and CFP. OCTA metrics included skeletonized vessel density (SVD) and perfusion density (PD) at the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Microaneurysm turnover analysis and Early Treatment Diabetic Retinopathy Study (ETDRS) grading for diabetic retinopathy (DR) severity assessment were performed on 7-field CFP.
RESULTS
Eyes graded as ETDRS level 20 showed significant capillary nonperfusion predominantly in the inner ring area in the SCP (P < 0.001), whereas eyes graded as ETDRS level 35 and ETDRS levels 43 and 47 showed significant capillary nonperfusion in both the SCP and DCP in both inner and outer rings (P < 0.001). When evaluating rates of progression in capillary nonperfusion for the 2-year period of follow-up, changes were found predominantly in the DCP for SVD and PD and were better identified in the outer ring area. Microaneurysm turnover contributes to the characterization of NPDR progression by discriminating ETDRS level 35 from ETDRS levels 43 and 47 (P < 0.001), which could not be achieved using only OCTA metrics.
CONCLUSIONS
Patterns of progression of NPDR can be identified combining OCTA examinations of the superficial and deep retinal capillary plexi of central retina and determination of microaneurysm turnover from fundus photographs.
TRANSLATIONAL RELEVANCE
Our study reports results from a registered clinical trial that advances understanding of disease progression in NPDR.
Topics: Humans; Diabetic Retinopathy; Disease Progression; Male; Female; Middle Aged; Tomography, Optical Coherence; Prospective Studies; Retinal Vessels; Aged; Fluorescein Angiography; Diabetes Mellitus, Type 2; Photography
PubMed: 38780953
DOI: 10.1167/tvst.13.5.22 -
Sensors (Basel, Switzerland) Jan 2022In diabetic retinopathy (DR), the early signs that may lead the eyesight towards complete vision loss are considered as microaneurysms (MAs). The shape of these MAs is...
In diabetic retinopathy (DR), the early signs that may lead the eyesight towards complete vision loss are considered as microaneurysms (MAs). The shape of these MAs is almost circular, and they have a darkish color and are tiny in size, which means they may be missed by manual analysis of ophthalmologists. In this case, accurate early detection of microaneurysms is helpful to cure DR before non-reversible blindness. In the proposed method, early detection of MAs is performed using a hybrid feature embedding approach of pre-trained CNN models, named as VGG-19 and Inception-v3. The performance of the proposed approach was evaluated using publicly available datasets, namely "E-Ophtha" and "DIARETDB1", and achieved 96% and 94% classification accuracy, respectively. Furthermore, the developed approach outperformed the state-of-the-art approaches in terms of sensitivity and specificity for microaneurysms detection.
Topics: Algorithms; Deep Learning; Diabetic Retinopathy; Fundus Oculi; Humans; Microaneurysm; Sensitivity and Specificity
PubMed: 35062506
DOI: 10.3390/s22020542 -
Ophthalmologica. Journal International... 2020In the last decades, significant changes have been taking place regarding the pathogenesis of diabetic retinopathy (DR) and the complex mechanisms that eventually lead... (Review)
Review
In the last decades, significant changes have been taking place regarding the pathogenesis of diabetic retinopathy (DR) and the complex mechanisms that eventually lead to the various manifestations of the disease, including diabetic macular edema (DME). DR was first considered a pure microvascular disease, due to the evident capillary structural changes (microaneurysms), fluid extravasation, and lipid exudation. With the advent of fundus fluorescein angiography, the concept of ischemia and the correlation between peripheral nonperfusion and neovascularization has been introduced, which was eventually followed by the advent of new therapeutic strategies, such as peripheral photocoagulation. Nowadays, thanks to more advanced imaging techniques, namely optical coherence tomography (OCT), OCT angiography, and wide-field imaging (imaging up to 200° of the retina in a single shot), it became clear that other elements participate in the occurrence of DR and DME, including inflammation and neurodegeneration. In the future, integration of standard investigations with new diagnostic devices would allow the prompt recognition of DR even before clinical signs of the disease are ophthalmoscopically evident, and the development of personalized treatment for both retinopathy and DME will be available.
Topics: Diabetic Retinopathy; Fluorescein Angiography; History, 18th Century; History, 19th Century; History, 20th Century; Humans; Tomography, Optical Coherence
PubMed: 32015239
DOI: 10.1159/000506312 -
Journal of Digital Imaging Apr 2018Automated microaneurysm (MA) detection is still an open challenge due to its small size and similarity with blood vessels. In this paper, we present a novel method which...
Automated microaneurysm (MA) detection is still an open challenge due to its small size and similarity with blood vessels. In this paper, we present a novel method which is simple, efficient, and real-time for segmenting and detecting MA in color fundus images (CFI). To do this, a novel set of features based on statistics of geometrical properties of connected regions, that can easily discriminate lesion and non-lesion pixels are used. For large-scale evaluation proposed method is validated on DIARETDB1, ROC, STARE, and MESSIDOR dataset. It proves robust with respect to different image characteristics and camera settings. The best performance was achieved on per-image evaluation on DIARETDB1 dataset with sensitivity of 88.09 at 92.65% specificity which is quite encouraging for clinical use.
Topics: Databases, Factual; Diabetic Retinopathy; Diagnostic Techniques, Ophthalmological; Fundus Oculi; Humans; Image Interpretation, Computer-Assisted; Microaneurysm; Sensitivity and Specificity
PubMed: 28785874
DOI: 10.1007/s10278-017-0008-0 -
Klinische Monatsblatter Fur... Nov 2020Using mobile OCT equipment and remote ophthalmological diagnosis of n = 1538 diabetics in 17 diabetes practices in Germany, we found diabetic macular edema in 10.1%...
Using mobile OCT equipment and remote ophthalmological diagnosis of n = 1538 diabetics in 17 diabetes practices in Germany, we found diabetic macular edema in 10.1% of the patients and retinal bleedings or microaneurysms in 15.6%. In 1.62% of the diabetics examined, the size of the edema was > 0.4 mm², in 7% the retinal thickness was > 300 µm and thus in need of treatment. An intravitreal anti-VEGF injection was administered prior to the examination in only 10% of the patients with diabetic macular edema. By means of mobile tele-eye consultation and remote ophthalmological diagnosis using the cloud-based patient file certified as medical device IIa, patients with diabetic macular edema were identified and informed on site quickly and definitively. The data and images were made available to all attending physicians and ophthalmic surgeons.
Topics: Diabetes Mellitus; Diabetic Retinopathy; Humans; Intravitreal Injections; Macular Edema; Retina; Tomography, Optical Coherence
PubMed: 33202460
DOI: 10.1055/a-1194-5211 -
Stroke Jun 2022
Topics: Cerebral Hemorrhage; Humans; Magnetic Resonance Imaging; Microaneurysm
PubMed: 35450437
DOI: 10.1161/STROKEAHA.122.038785 -
Diabetes Research and Clinical Practice Aug 2018Diabetic retinopathy (DR) is one of the most common diabetic complications, which has become a leading cause for vision loss, mainly because of macular edema and... (Review)
Review
Diabetic retinopathy (DR) is one of the most common diabetic complications, which has become a leading cause for vision loss, mainly because of macular edema and vitreous hemorrhage. Optical coherence tomography (OCT) angiography is a novel technique to visualize vascular changes including microaneurysm, non-perfusion area, intraretinal microvascular abnormalities, and neovascularization. Recently, it is possible to quantify vascular density, foveal avascular zone area, non-perfusion area objectively using OCT angiography. In addition, OCT angiography also provides an alternative method to evaluate the effect of anti-vascular endothelial growth factor (VEGF) treatments by providing high resolution images of macular microcirculatory abnormalities. Thus OCT angiography is an effective method to investigate the vascular changes of the disease, and can also be potentially applied in the diagnosis, treatment, and follow up of DR.
Topics: Diabetic Retinopathy; Female; Fluorescein Angiography; Humans; Male; Tomography, Optical Coherence
PubMed: 29879494
DOI: 10.1016/j.diabres.2018.05.043