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AIM: To evaluate the imaging characteristics of dense automatic real time B-scan optical coherence tomography angiography(DART-OCTA)in macular-involved branch retinal vein occlusion(BRVO)and the diagnostic value of capillary perfusion imaging in the macular area.METHODS: From June 2020 to December 2020, there were 51 cases of 51 eyes with BRVO diagnosed in Eye Hospital, Wenzhou Medical University. Imaging characteristics of the BRVO macular area were observed by fluorescein angiography(FA), optical coherence tomography angiography(OCTA)and DART-OCTA examination, respectively. According to the retinal capillary perfusion status, the included patients were divided into capillary and non-imaging groups, comparing the results of capillary perfusion imaging in the BRVO macular area among the three examination methods.Furthermore, quantitative analysis of capillary perfusion density in the lesion involved area and the lesion non-involved area was performed in DART-OCTA images. RESULTS: Patients with 51 eyes were included in this study, FA identified 10 eyes of capillary perfusion imaging, OCTA identified 14 eyes of capillary perfusion imaging, DART-OCTA identified 34 eyes of the capillary perfusion imaging.Comparison of the three test methods for capillary perfusion imaging findings in the BRVO macular area showed that DART-OCTA was more sensitive compared to FA and OCTA for capillary perfusion imaging in the ischemic area. In DART-OCTA examination, retinal capillary blood flow density was lower in the lesion-involved areas in both the capillary perfusion imaging group and the non-imaging groups(0.65±0.20/mm vs 1.16±0.31/mm,0.41±0.16/mm vs 1.06±0.38/mm, all P<0.0001).CONCLUSION: DART-OCTA can provide clearer tomographic imaging of retinal capillary perfusion. And the imaging with its observation of BRVO involving the macular area is least affected by macular hemorrhage and it is an important complementary method for BRVO patients with significant retinal hemorrhage.
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The advances in treating blinding conditions often depends on the development of new techniques that allows early detection, treatment, and follow-up of the disease. Functional changes often precede structural changes in many retinal disorders. Therefore, detecting these changes helps in early diagnosis and management, with the intention of preventing permanent morbidity. The Retinal Functional Imager (RFI) is a non-invasive imaging system that allows us to assess the various functional parameters of the retina. The RFI quantitatively measures the retinal blood-flow velocity, oxygen saturation, metabolic demand and generates a non-invasive capillary perfusion map that provides details similar to a fluorescein angiography. All of these parameters correlate with the health of the retina, and are known to get deranged in retinal disease. This article is a brief review of published literature on the clinical utility of the RFI.
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Abstract Introduction A new method for segmenting and quantifying the macular area based on morphological alternating sequential filtering (ASF) is proposed. Previous studies show that persons with diabetes present alterations in the foveal avascular zone (FAZ) prior to the appearance of retinopathy. Thus, a proper characterization of FAZ using a method of automatic classification and prediction is a supportive and complementary tool for medical evaluation of the macular region, and may be useful for possible early treatment of eye diseases in persons without diabetic retinopathy. Methods We obtained high-resolution retinal images using a non-invasive functional imaging system called Retinal Function Imager to generate a series of combined capillary perfusion maps. We filtered sequentially the macular images to reduce the complexity by ASF. Then we segmented the FAZ using watershed transform from an automatic selection of markers. Using Hu's moment invariants as a descriptor, we can automatically classify and categorize each FAZ. Results The FAZ differences between non-diabetic volunteers and diabetic subjects were automatically distinguished by the proposed system with an accuracy of 81%. Conclusion This is an innovative method to classify FAZ using a fully automatic algorithm for segmentation (based on morphological operators) and for the classification (based on descriptor formed by Hu's moments) despite the presence of edema or other structures. This is an alternative tool for eye exams, which may contribute to the analysis and evaluation of FAZ morphology, promoting the prevention of macular impairment in diabetics without retinopathy.
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PURPOSE: The goal of wound managements are to prevent further tissue injury during dressing changes, and absorb the excessive exudates, provide moist condition, reduce the infection. But the usual dressing methods have several limitations to serve the information about wound surface environment. Moist, pressure, temperature, pH are the important factors that give us the information about the healing process phase, speed of healing, & the risk of infection. METHODS: We made full thickness wounds & burn on porcine model, then assessed the surface temperature intermittently until repithelialization were completed, and size measurement were done with Image Pro Plus 6.0. RESULTS: In wound areas, the surface temperature was lowest at post operation #1 day, then slightly increased till POD #21 days, and again down slope curvature. In burn area, the surface temperature was highest at POD #1 day, then slightly decreased till POD # 21 days, and more fall curvature. Modern sensing technology along with wireless radio frequency communication technology is posed to make significant advances in wound management. Our result will be a basic data for the future researches about the surface temperature monitor to detect the early infection and the intervention to modulate the surface temperature to increase the rate of epithelialization. CONCLUSION: The result of the correlation between the surface temperature and area reduction have weak or moderate negative Pearson correlation coefficient.