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Yuichiro Ogura - One of the best experts on this subject based on the ideXlab platform.
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six month results of intravitreal ranibizumab for macular edema after branch retinal vein occlusion in a single center prospective study visual outcomes and Microaneurysm formation
Clinical Ophthalmology, 2018Co-Authors: Mihoko Kawamura, Yoshio Hirano, Munenori Yoshida, Tsutomu Yasukawa, Takeshi Mizutani, Kazuhiko Sugitani, Yuichiro OguraAbstract:Purpose The aim of this study is to report the 6-month results after one intravitreal ranibizumab (IVR) injection followed by pro re nata dosing for macular edema (ME) after branch retinal vein occlusion. Patients and methods The inclusion criteria included a minimal patient age of 18 years, 20 letters or more best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] score, 77 letters or less), and central retinal thickness (CRT) of 250 microns or more. The primary outcome measure was the mean BCVA change from baseline at month 6; the secondary outcomes were mean changes in CRT, residual ME, and Microaneurysm formation. Results Twenty patients were enrolled from March 2014 through October 2016 at Nagoya City University Hospital. The baseline mean ETDRS letters and CRT were 63.1 and 500 microns, respectively; mean time from symptom onset to initial therapy was 1.80 months; and mean ETDRS gain and CRT reduction were 15.2 letters and 230 microns, respectively. The percentages of patients with Snellen equivalent BCVAs of 20/40 (70 ETDRS letters) or better and 20/20 (85 ETDRS letters) were 90% and 15%, respectively. Residual ME and Microaneurysms were observed in 85% and 35% of patients. Microaneurysm formation was associated with delayed initial therapy. Conclusion Prompt initiation of IVR injection provided a better visual prognosis at month 6 and suppressed the Microaneurysm formation.
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Microaneurysms cause refractory macular edema in branch retinal vein occlusion
Scientific reports, 2016Co-Authors: Taneto Tomiyasu, Yoshio Hirano, Munenori Yoshida, Norihiro Suzuki, Takeshi Nishiyama, Akiyoshi Uemura, Tsutomu Yasukawa, Yuichiro OguraAbstract:Intravitreal anti-vascular endothelial growth factor (VEGF) agents can treat macular edema (ME) in branch retinal vein occlusion (BRVO). However, refractory ME, the mechanism of which is not well elucidated, occurs frequently. Sixty-six eyes with ME secondary to BRVO were enrolled in this retrospective observational case-control study. Twenty eyes received a sub-Tenon's capsule injection of triamcinolone acetonide (STTA), 22 eyes an intravitreal anti-VEGF injection (ranibizumab), 16 eyes were switched from STTA to ranibizumab, 4 eyes underwent vitrectomy, and 4 eyes were untreated. Multiple regression analysis and multivariate logistic regression analysis were conducted, respectively, to identify independent predictors of visual acuity (VA) prognosis and risk factors for refractory ME longer than 1 year. The mechanism of refractory ME and therapeutic approaches for identified risk factors also were investigated. Thirty-four (52%) eyes had refractory ME for over 1 year. Microaneurysms were identified as risk factors for refractory ME, leading to poor final VA. Ranibizumab suppressed Microaneurysm formation and refractory ME, with early administration more effective. For already formed Microaneurysms, laser photocoagulation reduced additional treatments. Microaneurysms may cause refractory ME in BRVO. Alternative therapy to suppress Microaneurysms should be considered to prevent refractory ME in patients with BRVO.
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New Insights Into Microaneurysms in the Deep Capillary Plexus Detected by Optical Coherence Tomography Angiography in Diabetic Macular Edema.
Investigative ophthalmology & visual science, 2016Co-Authors: Norio Hasegawa, Munenori Yoshida, Miho Nozaki, Noriaki Takase, Yuichiro OguraAbstract:Purpose: To study the association between the distributions of Microaneurysms detected by en face optical coherence tomography angiography (OCTA) and diabetic macular edema (DME). Methods: The study design was a retrospective chart review of 27 patients (33 eyes) with DME. The eyes were scanned using OCTA (6 × 6 mm) and spectral-domain (SD) OCT macular cube. Each of the images of the capillary plexus was overlaid onto the image of the topographic map, and the densities of the Microaneurysms were measured by ImageJ software. The association between the distribution of Microaneurysms and macular edema was evaluated. Results: For Microaneurysms in areas with and without edema, 77.3 ± 8.1% of these Microaneurysms were located in the deep capillary plexuses (DCP). However, in areas of edema where the retinal thickness was more than 400 μm, 91.3 ± 9.1% of the Microaneurysms were found in the DCP. This difference was statistically significant (P < 0.001). In the macular edema area, there was a significantly higher density of Microaneurysms in the DCP compared to the superficial capillary plexuses (1.71/mm2 vs. 0.17/mm2, P < 0.001). There was also a significant correlation between the macular volume and the density of Microaneurysms in the DCP in edema (r = 0.63, P < 0.001). Conclusions: Our study demonstrated a high proportion of Microaneurysms in the DCP, as well as a novel association between the distributions of Microaneurysms detected by OCTA and DME. Results also indicated that Microaneurysms located in the DCP contribute to the pathogenesis of DME.
Munenori Yoshida - One of the best experts on this subject based on the ideXlab platform.
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six month results of intravitreal ranibizumab for macular edema after branch retinal vein occlusion in a single center prospective study visual outcomes and Microaneurysm formation
Clinical Ophthalmology, 2018Co-Authors: Mihoko Kawamura, Yoshio Hirano, Munenori Yoshida, Tsutomu Yasukawa, Takeshi Mizutani, Kazuhiko Sugitani, Yuichiro OguraAbstract:Purpose The aim of this study is to report the 6-month results after one intravitreal ranibizumab (IVR) injection followed by pro re nata dosing for macular edema (ME) after branch retinal vein occlusion. Patients and methods The inclusion criteria included a minimal patient age of 18 years, 20 letters or more best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] score, 77 letters or less), and central retinal thickness (CRT) of 250 microns or more. The primary outcome measure was the mean BCVA change from baseline at month 6; the secondary outcomes were mean changes in CRT, residual ME, and Microaneurysm formation. Results Twenty patients were enrolled from March 2014 through October 2016 at Nagoya City University Hospital. The baseline mean ETDRS letters and CRT were 63.1 and 500 microns, respectively; mean time from symptom onset to initial therapy was 1.80 months; and mean ETDRS gain and CRT reduction were 15.2 letters and 230 microns, respectively. The percentages of patients with Snellen equivalent BCVAs of 20/40 (70 ETDRS letters) or better and 20/20 (85 ETDRS letters) were 90% and 15%, respectively. Residual ME and Microaneurysms were observed in 85% and 35% of patients. Microaneurysm formation was associated with delayed initial therapy. Conclusion Prompt initiation of IVR injection provided a better visual prognosis at month 6 and suppressed the Microaneurysm formation.
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Microaneurysms cause refractory macular edema in branch retinal vein occlusion
Scientific reports, 2016Co-Authors: Taneto Tomiyasu, Yoshio Hirano, Munenori Yoshida, Norihiro Suzuki, Takeshi Nishiyama, Akiyoshi Uemura, Tsutomu Yasukawa, Yuichiro OguraAbstract:Intravitreal anti-vascular endothelial growth factor (VEGF) agents can treat macular edema (ME) in branch retinal vein occlusion (BRVO). However, refractory ME, the mechanism of which is not well elucidated, occurs frequently. Sixty-six eyes with ME secondary to BRVO were enrolled in this retrospective observational case-control study. Twenty eyes received a sub-Tenon's capsule injection of triamcinolone acetonide (STTA), 22 eyes an intravitreal anti-VEGF injection (ranibizumab), 16 eyes were switched from STTA to ranibizumab, 4 eyes underwent vitrectomy, and 4 eyes were untreated. Multiple regression analysis and multivariate logistic regression analysis were conducted, respectively, to identify independent predictors of visual acuity (VA) prognosis and risk factors for refractory ME longer than 1 year. The mechanism of refractory ME and therapeutic approaches for identified risk factors also were investigated. Thirty-four (52%) eyes had refractory ME for over 1 year. Microaneurysms were identified as risk factors for refractory ME, leading to poor final VA. Ranibizumab suppressed Microaneurysm formation and refractory ME, with early administration more effective. For already formed Microaneurysms, laser photocoagulation reduced additional treatments. Microaneurysms may cause refractory ME in BRVO. Alternative therapy to suppress Microaneurysms should be considered to prevent refractory ME in patients with BRVO.
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New Insights Into Microaneurysms in the Deep Capillary Plexus Detected by Optical Coherence Tomography Angiography in Diabetic Macular Edema.
Investigative ophthalmology & visual science, 2016Co-Authors: Norio Hasegawa, Munenori Yoshida, Miho Nozaki, Noriaki Takase, Yuichiro OguraAbstract:Purpose: To study the association between the distributions of Microaneurysms detected by en face optical coherence tomography angiography (OCTA) and diabetic macular edema (DME). Methods: The study design was a retrospective chart review of 27 patients (33 eyes) with DME. The eyes were scanned using OCTA (6 × 6 mm) and spectral-domain (SD) OCT macular cube. Each of the images of the capillary plexus was overlaid onto the image of the topographic map, and the densities of the Microaneurysms were measured by ImageJ software. The association between the distribution of Microaneurysms and macular edema was evaluated. Results: For Microaneurysms in areas with and without edema, 77.3 ± 8.1% of these Microaneurysms were located in the deep capillary plexuses (DCP). However, in areas of edema where the retinal thickness was more than 400 μm, 91.3 ± 9.1% of the Microaneurysms were found in the DCP. This difference was statistically significant (P < 0.001). In the macular edema area, there was a significantly higher density of Microaneurysms in the DCP compared to the superficial capillary plexuses (1.71/mm2 vs. 0.17/mm2, P < 0.001). There was also a significant correlation between the macular volume and the density of Microaneurysms in the DCP in edema (r = 0.63, P < 0.001). Conclusions: Our study demonstrated a high proportion of Microaneurysms in the DCP, as well as a novel association between the distributions of Microaneurysms detected by OCTA and DME. Results also indicated that Microaneurysms located in the DCP contribute to the pathogenesis of DME.
John V. Forrester - One of the best experts on this subject based on the ideXlab platform.
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Automated Measurement of Microaneurysm Turnover
Investigative ophthalmology & visual science, 2003Co-Authors: Keith A Goatman, Michael J. Cree, John V. Forrester, Jim Olson, Peter F. SharpAbstract:PURPOSE. An automated system for the measurement of Microaneurysm (MA) turnover was developed and compared with manual measurement. The system analyses serial fluorescein angiogram (FA) or red-free (RF) fundus images; fluorescein angiography was used in this study because it is the more sensitive test for MAs. Previous studies have shown that the absolute number of MAs observed does not reflect the dynamic temporal nature of the MA population. In this study, almost half of the MAs present at baseline had regressed after a year and been replaced by new lesions elsewhere. METHODS. Two clinical datasets were used to evaluate the performance of the automated turnover measurement system. The first consisted of 10 patients who had two fluorescein angiograms acquired a year apart. These data were analyzed, both manually and using the automated system, to investigate the inter- and intraobserver variations associated with manual measurement and to assess the performance of the automated system. The second dataset contained FAs from a further 25 patients. This dataset was analyzed only with the automated system to investigate some properties of Microaneurysm turnover, in particular the differing detection sensitivities of new, static and regressed Microaneurysms. RESULTS. Manual measurements exhibited large inter- and intraobserver variation. The sensitivity and specificity of the automated system were similar to those of the human observers. However, the automated measurements were more consistent—an important condition for accurate turnover quantification. Regressed MAs were more difficult to detect reliably than new MAs, which were themselves more difficult to detect reliably than static MAs.
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automated detection of Microaneurysms in digital red free photographs a diabetic retinopathy screening tool
Diabetic Medicine, 2000Co-Authors: J H Hipwell, K. C. Mchardy, F Strachan, J A Olson, P F Sharp, John V. ForresterAbstract:Aims To develop a technique to detect Microaneurysms automatically in 50 degrees digital red-free fundus photographs and evaluate its performance as a tool for screening diabetic patients for retinopathy,Methods Candidate Microaneurysms are extracted, after the image has been modified to remove variations In background intensity, by algorithms that enhance small round features. Each Microaneurysm candidate is then classified according to its intensity and size by the application of a sec of rules derived from a training set of 102 images.Results When 3783 individual images were analysed and the results compared with the opinion of a clinical research fellow examining the same images, the program achieved a sensitivity of 81% and a specificity of 93% for the detection of images containing Microaneurysms, Nine hundred and twenty-five sets of 4 images per patient were then analysed and the total number of Microaneurysms detected compared with the overall patient retinopathy grade derived by the clinician examining the same images. In this context, intended to mimic a screening situation, the program achieved a sensitivity of 85% and a specificity of 76% for the detection of patients with (any) retinopathy (positive predictive value 0.71, negative predictive value 0,88),Conclusions An automated technique was developed to detect retinopathy in digital red-free fundus images that can form part of a diabetic retinopathy screening programme. It is believed that it can perform a useful role in this context identifying images worthy of closer inspection or eliminating 50% or more of the screening population who have no retinopathy.
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A fully automated comparative Microaneurysm digital detection system.
Eye, 1997Co-Authors: Michael J. Cree, John A Olson, K. C. Mchardy, Peter F. Sharp, John V. ForresterAbstract:A fully automated digital image processing system, which provides an objective and repeatable way to quantify Microaneurysms in digitised fluorescein angiograms, has been developed. The automated computer processing includes registration of same-eye retinal images for serial studies, cutting of regions-of-interest centred on the fovea, the detection of Microaneurysms and the comparison of serial images for Microaneurysm turnover. The Microaneurysm detector was trained against a database of 68 images of patients with diabetes containing 394 true Microaneurysms, as identified by an ophthalmologist. The Microaneurysm detector achieved 82% sensitivity with 2.0 false-positives per image. An independent test set, comprising 20 images containing 297 true Microaneurysms, was used to compare the Microaneurysm detector with clinicians. The Microaneurysm detector achieved a sensitivity of 82% for 5.7 false-positives per image, whereas the clinician receiver-operator-characteristic (ROC) curve gives 3.2 false-positives per image at a sensitivity of 82%. It is concluded that the computer system can reliably detect Microaneurysms. The advantages of the computer system include objectivity, repeatability, speed and full automation.
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automated Microaneurysm detection
International Conference on Image Processing, 1996Co-Authors: Michael J. Cree, John A Olson, K. C. Mchardy, John V. Forrester, Peter F. SharpAbstract:A digital image processing system has been developed to quantify and monitor the presence of Microaneurysms in retinal fluorescein angiograms. The system is fully automated (except for the initial digitisation), and includes stages for preprocessing, registration of same-eye images obtained at different visits, fovea detection for placement of regions-of-interest, and detection of Microaneurysms and Microaneurysm turnover. The system achieves 82% sensitivity for detecting Microaneurysms with a specificity of 84%. Preliminary investigations indicate a high Microaneurysm turnover for most patients with diabetic retinopathy, which may have significant clinical implications.
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An image-processing strategy for the segmentation and quantification of Microaneurysms in fluorescein angiograms of the ocular fundus
Computers and biomedical research an international journal, 1996Co-Authors: Timothy Spencer, John A Olson, Peter F. Sharp, Kenneth C. Mchardy, John V. ForresterAbstract:Digital image-processing techniques can provide an objective and highly repeatable way of quantifying retinal pathology. This study describes an image-processing strategy which detects and quantifies Microaneurysms present in digitized fluorescein angiograms. After preprocessing stages, a bilinear top-hat transformation and matched filtering are employed to provide an initial segmentation of the images. Thresholding this processed image results in a binary image containing candidate Microaneurysms. A novel region-growing algorithm fully delineates each marked object and subsequent analysis of the size, shape, and energy characteristics of each candidate results in the final segmentation of Microaneurysms. The technique is assessed by comparing the computer's results with Microaneurysm counts carried out by five clinicians, using Receiver Operating Characteristic (ROC) curves. The performance of the automated technique matched that of the clinicians' analyses. This strategy is valuable in providing a way of accurately monitoring the progression of diabetic retinopathy.
Tsutomu Yasukawa - One of the best experts on this subject based on the ideXlab platform.
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six month results of intravitreal ranibizumab for macular edema after branch retinal vein occlusion in a single center prospective study visual outcomes and Microaneurysm formation
Clinical Ophthalmology, 2018Co-Authors: Mihoko Kawamura, Yoshio Hirano, Munenori Yoshida, Tsutomu Yasukawa, Takeshi Mizutani, Kazuhiko Sugitani, Yuichiro OguraAbstract:Purpose The aim of this study is to report the 6-month results after one intravitreal ranibizumab (IVR) injection followed by pro re nata dosing for macular edema (ME) after branch retinal vein occlusion. Patients and methods The inclusion criteria included a minimal patient age of 18 years, 20 letters or more best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] score, 77 letters or less), and central retinal thickness (CRT) of 250 microns or more. The primary outcome measure was the mean BCVA change from baseline at month 6; the secondary outcomes were mean changes in CRT, residual ME, and Microaneurysm formation. Results Twenty patients were enrolled from March 2014 through October 2016 at Nagoya City University Hospital. The baseline mean ETDRS letters and CRT were 63.1 and 500 microns, respectively; mean time from symptom onset to initial therapy was 1.80 months; and mean ETDRS gain and CRT reduction were 15.2 letters and 230 microns, respectively. The percentages of patients with Snellen equivalent BCVAs of 20/40 (70 ETDRS letters) or better and 20/20 (85 ETDRS letters) were 90% and 15%, respectively. Residual ME and Microaneurysms were observed in 85% and 35% of patients. Microaneurysm formation was associated with delayed initial therapy. Conclusion Prompt initiation of IVR injection provided a better visual prognosis at month 6 and suppressed the Microaneurysm formation.
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Microaneurysms cause refractory macular edema in branch retinal vein occlusion
Scientific reports, 2016Co-Authors: Taneto Tomiyasu, Yoshio Hirano, Munenori Yoshida, Norihiro Suzuki, Takeshi Nishiyama, Akiyoshi Uemura, Tsutomu Yasukawa, Yuichiro OguraAbstract:Intravitreal anti-vascular endothelial growth factor (VEGF) agents can treat macular edema (ME) in branch retinal vein occlusion (BRVO). However, refractory ME, the mechanism of which is not well elucidated, occurs frequently. Sixty-six eyes with ME secondary to BRVO were enrolled in this retrospective observational case-control study. Twenty eyes received a sub-Tenon's capsule injection of triamcinolone acetonide (STTA), 22 eyes an intravitreal anti-VEGF injection (ranibizumab), 16 eyes were switched from STTA to ranibizumab, 4 eyes underwent vitrectomy, and 4 eyes were untreated. Multiple regression analysis and multivariate logistic regression analysis were conducted, respectively, to identify independent predictors of visual acuity (VA) prognosis and risk factors for refractory ME longer than 1 year. The mechanism of refractory ME and therapeutic approaches for identified risk factors also were investigated. Thirty-four (52%) eyes had refractory ME for over 1 year. Microaneurysms were identified as risk factors for refractory ME, leading to poor final VA. Ranibizumab suppressed Microaneurysm formation and refractory ME, with early administration more effective. For already formed Microaneurysms, laser photocoagulation reduced additional treatments. Microaneurysms may cause refractory ME in BRVO. Alternative therapy to suppress Microaneurysms should be considered to prevent refractory ME in patients with BRVO.
Yoshio Hirano - One of the best experts on this subject based on the ideXlab platform.
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six month results of intravitreal ranibizumab for macular edema after branch retinal vein occlusion in a single center prospective study visual outcomes and Microaneurysm formation
Clinical Ophthalmology, 2018Co-Authors: Mihoko Kawamura, Yoshio Hirano, Munenori Yoshida, Tsutomu Yasukawa, Takeshi Mizutani, Kazuhiko Sugitani, Yuichiro OguraAbstract:Purpose The aim of this study is to report the 6-month results after one intravitreal ranibizumab (IVR) injection followed by pro re nata dosing for macular edema (ME) after branch retinal vein occlusion. Patients and methods The inclusion criteria included a minimal patient age of 18 years, 20 letters or more best-corrected visual acuity (BCVA) (Early Treatment Diabetic Retinopathy Study [ETDRS] score, 77 letters or less), and central retinal thickness (CRT) of 250 microns or more. The primary outcome measure was the mean BCVA change from baseline at month 6; the secondary outcomes were mean changes in CRT, residual ME, and Microaneurysm formation. Results Twenty patients were enrolled from March 2014 through October 2016 at Nagoya City University Hospital. The baseline mean ETDRS letters and CRT were 63.1 and 500 microns, respectively; mean time from symptom onset to initial therapy was 1.80 months; and mean ETDRS gain and CRT reduction were 15.2 letters and 230 microns, respectively. The percentages of patients with Snellen equivalent BCVAs of 20/40 (70 ETDRS letters) or better and 20/20 (85 ETDRS letters) were 90% and 15%, respectively. Residual ME and Microaneurysms were observed in 85% and 35% of patients. Microaneurysm formation was associated with delayed initial therapy. Conclusion Prompt initiation of IVR injection provided a better visual prognosis at month 6 and suppressed the Microaneurysm formation.
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Microaneurysms cause refractory macular edema in branch retinal vein occlusion
Scientific reports, 2016Co-Authors: Taneto Tomiyasu, Yoshio Hirano, Munenori Yoshida, Norihiro Suzuki, Takeshi Nishiyama, Akiyoshi Uemura, Tsutomu Yasukawa, Yuichiro OguraAbstract:Intravitreal anti-vascular endothelial growth factor (VEGF) agents can treat macular edema (ME) in branch retinal vein occlusion (BRVO). However, refractory ME, the mechanism of which is not well elucidated, occurs frequently. Sixty-six eyes with ME secondary to BRVO were enrolled in this retrospective observational case-control study. Twenty eyes received a sub-Tenon's capsule injection of triamcinolone acetonide (STTA), 22 eyes an intravitreal anti-VEGF injection (ranibizumab), 16 eyes were switched from STTA to ranibizumab, 4 eyes underwent vitrectomy, and 4 eyes were untreated. Multiple regression analysis and multivariate logistic regression analysis were conducted, respectively, to identify independent predictors of visual acuity (VA) prognosis and risk factors for refractory ME longer than 1 year. The mechanism of refractory ME and therapeutic approaches for identified risk factors also were investigated. Thirty-four (52%) eyes had refractory ME for over 1 year. Microaneurysms were identified as risk factors for refractory ME, leading to poor final VA. Ranibizumab suppressed Microaneurysm formation and refractory ME, with early administration more effective. For already formed Microaneurysms, laser photocoagulation reduced additional treatments. Microaneurysms may cause refractory ME in BRVO. Alternative therapy to suppress Microaneurysms should be considered to prevent refractory ME in patients with BRVO.