Repeatability and Reproducibility of Quantitative Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography Based on Optical Microangiography / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography (OCTA) based on optical microangiography (OMAG) measurements of macular vessels in normal eyes.</p><p><b>METHODS</b>In this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA (Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density (VAD), vessel skeleton density (VSD), vessel diameter index (VDI), vessel perimeter index (VPI), vessel complexity index (VCI), flux, and foveal avascular zone (FAZ). Coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility.</p><p><b>RESULTS</b>The measurements showed high repeatability [CVs ⪕ 4.2% (intravisit) and ⪕ 4.6% (intervisit)] and interobserver reproducibility (ICCs ⪖ 0.923) for all parameters.</p><p><b>CONCLUSION</b>This study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes.</p>

Quantitative parameter character of choroidal melanoma in contrast-enhanced ultrasound / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Choroidal melanoma is the most common intraocular malignant tumor in adults. It threatens not only the visual function but also the patient's life. Therefore, it is important to find a non-traumatic, quantitative and repetitive diagnostic method. This study investigated the value of quantitative analysis of contrast-enhanced ultrasound (CEUS) in the diagnosis of choroidal melanoma.</p><p><b>METHODS</b>CEUS were performed in 51 cases of choroidal melanoma, which were diagnosed either pathologically or clinically and in 14 cases of choroidal hemangioma. The characteristics of the time-intensity curve of the contrast agent were analyzed. For the quantitative analysis, the following parameters of the contrast agent in the lesion were included: rising time (RT), time to peak (TTP), maximum intensity (MI) and the mean transit time (MTT).</p><p><b>RESULTS</b>Choroidal melanoma had the following characteristics on CEUS: Choroidal lesions were completely filled with contrast agent. The typical filling pattern was centripetal, with the peripheral of the choroidal lesion filled with the contrast agent first and then the center of the lesion. In some cases, areas with contrast agent filling defect were observed in the lesions. The contrast agent filled the lesion slower than the normal eye and orbital tissue but faded faster in the lesion. Quantitative analysis showed that in choroidal melanoma, MI of contrast agent (191.31% ± 146.90%) was significantly more than that of the normal tissue (100.00% ± 0.00%) (P < 0.05) and MTT ((63.56 ± 26.04) seconds) was significantly less than that of the normal tissue ((149.87 ± 182.68) seconds) (P < 0.05). TTP (22.80 ± 9.85) was less than that of the normal tissue ((29.57 ± 24.76) seconds) and RT ((18.52 ± 7.09) seconds) was less than that of the normal tissue ((26.45 ± 21.83) seconds). Both the differences of TTP and RT were not statistically significant though. Logistic regression showed that to predict choroidal melanoma and choroidal hemangioma with MI and MTT, the sensitivity was 90.5% and the specific degrees was 85.7%.</p><p><b>CONCLUSIONS</b>CEUS is a new method to diagnose tumors in the eye. Choroidal melanoma may be diagnosed objectively and accurately by combining the graphic characteristics on CEUS and the time-intensity curve quantitative analysis.</p>