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Retina (Philadelphia, Pa.) Apr 2013To analyze the morphology of microaneurysms before and after direct photocoagulation using spectral domain optical coherence tomography.
PURPOSE
To analyze the morphology of microaneurysms before and after direct photocoagulation using spectral domain optical coherence tomography.
METHODS
In 13 eyes of diabetic patients who underwent focal photocoagulation for clinically significant macular edema, microaneurysms were evaluated before, immediately after, 1 month after, and 2 months after photocoagulation with spectral domain optical coherence tomography. The microaneurysms were also evaluated by fluorescein angiography and color fundus photography. The patients underwent focal photocoagulation for microaneurysm.
RESULTS
The microaneurysms before photocoagulation in spectral domain optical coherence tomography were observed as circular or elliptical structures with hyperreflective foci within vessel walls. Immediately after photocoagulation, the microaneurysms were changed to indistinct lesions with hyperreflectivity around the microaneurysms. Acoustic shadows developed on the choroidal side of the microaneurysms. If photocoagulation for microaneurysms was appropriately done, retinal changes were limited to within the inner retina around the microaneurysms and no changes were observed in retinal pigment epithelium. Within 2 months after photocoagulation, the microaneurysms changed into fine scars and the retinal structure normalized. Average retinal thickness of the fovea was 432 ± 70 μm before the procedure but reduced to 373 ± 84 μm at 2 months post surgery.
CONCLUSION
Focal photocoagulation may be a less invasive method for treating microaneurysms, and spectral domain optical coherence tomography is useful for evaluating the efficacy of photocoagulation.
Topics: Aneurysm; Diabetic Retinopathy; Female; Fluorescein Angiography; Humans; Laser Coagulation; Macular Edema; Male; Middle Aged; Retinal Vessels; Retrospective Studies; Tomography, Optical Coherence; Treatment Outcome
PubMed: 23478291
DOI: 10.1097/IAE.0b013e3182753960 -
Clinical Ophthalmology (Auckland, N.Z.) 2020To analyze the effects on microaneurysm (MA) and perifoveal perfusion in nonproliferative diabetic retinopathy (NPDR) patients with macular edema (ME) after early...
Prospective, Single-Center, Six-Month Study of Intravitreal Ranibizumab for Macular Edema with Nonproliferative Diabetic Retinopathy: Effects on Microaneurysm Turnover and Non-Perfused Retinal Area.
PURPOSE
To analyze the effects on microaneurysm (MA) and perifoveal perfusion in nonproliferative diabetic retinopathy (NPDR) patients with macular edema (ME) after early intensive treatment using intravitreal ranibizumab (IVR) injections.
PATIENTS AND METHODS
Prospectively, 25 eyes of 25 type 2 diabetes mellitus patients with ME were included between August 2016 and February 2019. For 6 months, patients were administered 0.5-mg IVR injections monthly. Ocular evaluation, including best-corrected visual acuity (BCVA; using the Early Treatment Diabetic Retinopathy Study chart), central retinal thickness (CRT; using optical coherence tomography), fundus photography, and fluorescein angiography, was performed for all participants. Results obtained at baseline were compared to those observed after 6 months.
RESULTS
Mean BCVA increased significantly from 67.6±3.29 letters at baseline to 76.36±1.61 letters after 6 months (P=0.002) of IVR therapy. CRT decreased significantly from 479.12±16.66 µm at baseline to 369.12±13.02 µm at 6 months. Similarly, the total number of MAs decreased significantly from 5.68±3.41 to 1.60±1.73 (<0.0001). MA turnover, calculated by adding the MA formation rate to the MA disappearance rate (both calculated as MA number/month) also decreased significantly from 6.88±3.83 to 1.92±1.75 after treatment (<0.0001). Perifoveal non-perfused area decreased from 2.517±0.456 mm at baseline to 2.495±0.293 mm at 6 months, but the results were not statistically significant (=0.954).
CONCLUSION
Treatment with early intensive IVR therapy in NPDR patients with ME not only improved BCVA and CRT but also decreased MA turnover. However, in the study period of 6 months, IVR therapy did not show significant improvement in perifoveal non-perfused area.
PubMed: 32606576
DOI: 10.2147/OPTH.S248529 -
Ophthalmology Jul 2017To evaluate detection of hemorrhage and/or microaneurysm (H/Ma) using ultrawide field (UWF) retinal imaging as compared with standard Early Treatment Diabetic... (Comparative Study)
Comparative Study
OBJECTIVE
To evaluate detection of hemorrhage and/or microaneurysm (H/Ma) using ultrawide field (UWF) retinal imaging as compared with standard Early Treatment Diabetic Retinopathy Study (ETDRS) 7-field photographs (ETDRS photos).
DESIGN
Single-site comparative study of UWF images and ETDRS photos.
PARTICIPANTS
One hundred twenty-six eyes of 69 patients with no diabetic retinopathy (DR) or mild or moderate nonproliferative DR (NPDR).
METHODS
Stereoscopic 200° UWF images and stereoscopic 35mm 30° 7-field color photographs were acquired on the same visit. Images were graded for severity and distribution of H/Ma. H/Mas were counted in ETDRS fields 2 to 7 in both ETDRS photos and UWF images. H/Mas in the UWF peripheral fields were also counted.
MAIN OUTCOME MEASURES
Kappa (κ) and weighted κ statistics for agreement. Number of H/Ma within and outside ETDRS fields identified in UWF images and ETDRS photos.
RESULTS
Distribution of DR severity by ETDRS photos was 24 (19.0%) no DR, 48 (38.1%) mild NPDR, and 54 (42.9%) moderate NPDR. A total of 748 of 756 fields (98.9%) were gradable for H/Mas on ETDRS photos and UWF images. Simple κ/weighted κ statistics for severity of H/Ma: all fields 0.61/0.69, field 2 0.70/0.77, field 3 0.62/0.73, field 4 0.50/0.62, field 5 0.54/0.65, field 6 0.64/0.70, and field 7 0.58/0.63 with overall exact agreement in 81.3% and within 1 step in 97.9% of fields. A greater proportion of fields was graded a more severe H/Ma level in UWF images than in the corresponding ETDRS photos (UWF: 12.7% vs.
ETDRS
6.5%). Evaluating comparable areas in UWF images and ETDRS photos (fields 2-7), a mean of 42.8 H/Mas were identified using ETDRS photos and 48.8 in UWF images (P = 0.10). An additional mean of 21.3 H/Mas (49.8% increase, P < 0.0001) were identified in the peripheral fields of the UWF images.
CONCLUSIONS
There is good to excellent agreement between UWF images and ETDRS photos in determining H/Ma severity, with excellent correlation of H/Ma counts within ETDRS photo fields. UWF peripheral fields identified 49.8% more H/Ma, suggesting a more severe H/Ma in 12.7% of eyes. Given the additional lesions detected in peripheral fields and the known risks associated with H/Ma and peripheral lesions, quantification of H/Ma using UWF images may provide a more accurate representation of DR disease activity and potential greater accuracy in predicting DR progression.
Topics: Diabetic Retinopathy; Disease Progression; Follow-Up Studies; Humans; Microaneurysm; Photography; Prospective Studies; ROC Curve; Retina; Retinal Hemorrhage; Severity of Illness Index; Time Factors
PubMed: 28336057
DOI: 10.1016/j.ophtha.2017.02.012 -
IEEE Transactions on Medical Imaging Sep 2006Screening programs using retinal photography for the detection of diabetic eye disease are being introduced in the UK and elsewhere. Automatic grading of the images is...
Screening programs using retinal photography for the detection of diabetic eye disease are being introduced in the UK and elsewhere. Automatic grading of the images is being considered by health boards so that the human grading task is reduced. Microaneurysms (MAs) are the earliest sign of this disease and so are very important for classifying whether images show signs of retinopathy. This paper describes automatic methods for MA detection and shows how image contrast normalization can improve the ability to distinguish between MAs and other dots that occur on the retina. Various methods for contrast normalization are compared. Best results were obtained with a method that uses the watershed transform to derive a region that contains no vessels or other lesions. Dots within vessels are handled successfully using a local vessel detection technique. Results are presented for detection of individual MAs and for detection of images containing MAs. Images containing MAs are detected with sensitivity 85.4% and specificity 83.1%.
Topics: Algorithms; Aneurysm; Artificial Intelligence; Diabetic Retinopathy; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Information Storage and Retrieval; Pattern Recognition, Automated; Reproducibility of Results; Retinal Vessels; Retinoscopy; Sensitivity and Specificity
PubMed: 16967807
DOI: 10.1109/tmi.2006.879953 -
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 -
Eye (London, England) Jan 2021The introduction of optical coherence tomography angiography (OCTA) has remarkably expanded our knowledge of the ocular vascular alterations occurring in diabetes. In... (Review)
Review
The introduction of optical coherence tomography angiography (OCTA) has remarkably expanded our knowledge of the ocular vascular alterations occurring in diabetes. In this article, a review of the prominent OCTA findings in diabetes is followed by a description of salient histological and anatomical features of microaneurysms, essential for the proper interpretation of in vivo imaging of these retinal vascular abnormalities. The recent employment of a three-dimensional (3D) visualization in OCTA imaging is also discussed. The latter imaging technique has granted a detailed characterization of microaneurysms in vivo.
Topics: Diabetes Mellitus; Diabetic Retinopathy; Fluorescein Angiography; Humans; Microaneurysm; Retinal Vessels; Tomography, Optical Coherence
PubMed: 32887935
DOI: 10.1038/s41433-020-01173-7 -
Annual International Conference of the... Jul 2018Microaneurysms (MAs) are common signsof several diseases, appearing as small circular darkish spots in color fundus images. The presence of even a single MA may suggest...
Microaneurysms (MAs) are common signsof several diseases, appearing as small circular darkish spots in color fundus images. The presence of even a single MA may suggest diseases (e.g. diabetic retinopathy), thus, their reliable recognition is a critical issue in both human clinical practice and computer-aided systems. As for their automatic recognition, deep learning techniques became very popular in the recent years. In this paper, we also apply such deep convolutional neural network (DCNN) based techniques; however, we organize them into a supernetwork with a fusionbased approach. The combination of the member DCNNs is achieved with interconnecting them in a joint fully-connected layer. The advantage of the method is that this large architecture can be trained as a single neural network, and thus, the member DCNNs are also trained with taking the predictions of the other members into consideration. The competitiveness of our approach is also validated with experimental studies, where the ensemble-based system outperformed each member DCNN. As a primary application domain with strong clinical motivation, the methodology was tested for image-level classification. More specifically, a retinal image is divided into subimages to provide the required inputs for the DCNN-based architecture, and the whole image is labeled as a positive case, if the presence of MA is predicted in any of the subimages. Additionally, we also demonstrate how our architecture can be trained to accurately localize MAs with training only the local neighborhoods of the lesions; empirical tests showing solid performance are also enclosed.
Topics: Deep Learning; Diabetic Retinopathy; Fundus Oculi; Humans; Microaneurysm; Neural Networks, Computer
PubMed: 30441176
DOI: 10.1109/EMBC.2018.8513035 -
Annual International Conference of the... 2011In this paper, results of a diabetic retinopathy screening experiment are presented which is based solely on the findings of a microaneurysm detector. For this purpose,...
In this paper, results of a diabetic retinopathy screening experiment are presented which is based solely on the findings of a microaneurysm detector. For this purpose, an ensemble-based algorithm developed by our research group was used; this provided promising results in our earlier experiments. At its best, the 1200 image of the Messidor database is classified by this detector with a sensitivity of 96%, a specificity of 51% and achieved an AUC of 0.87. As anticipated, larger microaneurysm counts are recognized with higher level of certainty. Therefore, this approach might be expected to have good performance in relation to the severity of the disease.
Topics: Algorithms; Aneurysm; Diabetic Retinopathy; Humans; Image Enhancement; Image Interpretation, Computer-Assisted; Pattern Recognition, Automated; Reproducibility of Results; Retinal Artery; Retinoscopy; Sensitivity and Specificity
PubMed: 22255693
DOI: 10.1109/IEMBS.2011.6091469 -
Biomedicine & Pharmacotherapy =... Nov 2018Diabetic Retinopathy (DR) is an outcome of prolonged diabetes which directly or indirectly affect the human vision. DR is asymptomatic in its early stages and the late... (Review)
Review
Diabetic Retinopathy (DR) is an outcome of prolonged diabetes which directly or indirectly affect the human vision. DR is asymptomatic in its early stages and the late diagnosis lead to undeviating loss of vision. The computer aided diagnosis with the assistance of medical images helps in timely and accurate treatment. Microaneurysms (MA) mark the onset of DR, thus a vital point in screening of this disease. This review discuses various state of the art methods available till date for automated computer aided analysis of microaneurysms and haemorrhages. The paper also highlights qualitative and quantitative comparison of the existing literature with limitations for analysis of microaneurysms and haemorrhages. It is an attempt to systematize the available algorithms for an easy gathering and guidance to researchers working in this domain for future research.
Topics: Algorithms; Deep Learning; Diabetic Retinopathy; Humans; Image Processing, Computer-Assisted; Microaneurysm
PubMed: 30130729
DOI: 10.1016/j.biopha.2018.07.175 -
The British Journal of Ophthalmology Apr 1995Although microaneurysms are a clinicopathological hallmark of diabetic retinopathy, there have been few ultrastructural studies of these important lesions. As a result,...
BACKGROUND
Although microaneurysms are a clinicopathological hallmark of diabetic retinopathy, there have been few ultrastructural studies of these important lesions. As a result, knowledge of the mechanisms involved in the pathogenesis of microaneurysms remains fragmentary. This study provides histological and ultrastructural evidence of various stages in microaneurysm formation within the retinal vasculature.
METHODS
The eyes of three type II diabetic patients, obtained within 24 hours of death, were studied by the trypsin digest technique. Eyes from two further type II diabetics were fixed in 2.5% glutaraldehyde within 12 hours of death and processed for electron microscopy.
RESULTS
In the trypsin digest preparations, small saccular and fusiform microaneurysms were observed in the peripheral retinal. In the central retina, the microaneurysms ranged in morphology from thin walled, cellular forms to dense, acellular, hyalinised forms. Ultrastructurally, four distinct groups of microaneurysm were observed. Type I showed an extensive accumulation of polymorphonuclear cells into the lumen. The endothelium remained intact, although pericytes were invariably absent. Type II microaneurysms were typified by large numbers of red blood cells (RBCs) in the lumen. Endothelial cells and pericytes were completely absent. The type III microaneurysm was also non-perfused and contained aggregates of irregularly shaped RBC profiles and RBC breakdown products. Recanalisation by new vessels into the occluded lumen was observed in one microaneurysm. Type IV microaneurysms were almost or completely sclerosed, with extensive fibrosis and lipid infiltration into the lumen and basement membrane wall.
CONCLUSION
This investigation describes several distinctive stages in the formation of microaneurysms during diabetic retinopathy. With reference to the pathogenesis of retinal microaneurysms, the interaction of various cell types is discussed and the significance of vascular cell death and localised hypertensive events highlighted.
Topics: Aneurysm; Diabetes Mellitus, Type 2; Diabetic Retinopathy; Erythrocytes; Humans; Microscopy, Electron; Neutrophils; Retinal Vessels
PubMed: 7742285
DOI: 10.1136/bjo.79.4.362