Three-dimensional Vascular Imaging of Proliferative Diabetic Retinopathy by Doppler Optical Coherence Tomography

PurposeTo evaluate the 3-dimensional architecture of neovascularization in proliferative diabetic retinopathy using Doppler optical coherence tomography (OCT).DesignProspective, nonrandomized clinical trial.MethodsSeventeen eyes of 14 patients with proliferative diabetic retinopathy were prospectively studied. Prototype Doppler OCT was used to evaluate the 3-dimensional vascular architecture at vitreoretinal adhesions.ResultsProliferative membranes were detected in all eyes with proliferative diabetic retinopathy by standard OCT images. Doppler OCT images detected blood flow by neovascularization of the disc in 12 eyes and neovascularization elsewhere in 11 eyes. Doppler OCT images showed the 3-dimensional extent of new vessels at various stages of neovascularization, and the extent of new vessels could be clearly confirmed at vitreoretinal adhesions.ConclusionsDoppler OCT is useful for the detection and evaluation of the 3-dimensional vascular structure of neovascularization, and can assist in the noninvasive assessment of proliferative diabetic retinopathy

Evaluation of intraretinal migration of retinal pigment epithelial cells in age-related macular degeneration using polarimetric imaging

The purpose of the present study was to evaluate the intraretinal migration of the retinal pigment epithelium (RPE) cells in age-related macular degeneration (AMD) using polarimetry. We evaluated 155 eyes at various AMD stages. Depolarized light images were computed using a polarization-sensitive scanning laser ophthalmoscope (PS-SLO), and the degree of polarization uniformity was calculated using polarization-sensitive optical coherence tomography (OCT). Each polarimetry image was compared with the corresponding autofluorescence (AF) images at 488 nm (SW-AF) and at 787 nm (NIR-AF). Intraretinal RPE migration was defined by the presence of depolarization at intraretinal hyperreflective foci on PS-SLO and PS-OCT images, and by the presence of hyper-AF on both NIR-AF and SW-AF images. RPE migration was detected in 52 of 155 eyes (33.5%) and was observed in drusenoid pigment epithelial detachment (PED) and serous PED with significantly higher frequencies than in other groups (P = 0.015). The volume of the migrated RPE cluster in serous PED was significantly correlated with the volume of the PED (R2 = 0.26; P = 0.011). Overall, our results showed that intraretinal RPE migrations occurred in various AMD stages, and that they occurred more commonly in eyes with serous and drusenoid PED

Polarization-Sensitive Optical Coherence Tomographic Documentation of Choroidal Melanin Loss in Chronic Vogt–Koyanagi–Harada Disease

Purpose: Vogt–Koyanagi–Harada (VKH) disease is a systemic autoimmune disorder that affects organs with melanocytes. The sunset glow fundus (SGF) in VKH disease was evaluated with polarization-sensitive optical coherence tomography (PS-OCT).Methods: The study involved 28 eyes from 14 patients with chronic VKH disease, 21 eyes from 21 age-matched controls, and 22 eyes from 22 high-myopic patients with a tessellated fundus. VKH eyes were grouped into sunset or non-sunset groups on the basis of color fundus images. The presence of melanin in the choroid was determined by using the degree of polarization uniformity (DOPU) obtained by PS-OCT. The sunset glow index (SGI) was calculated by using color fundus images. Presence of an SGF was evaluated by using DOPU, SGI, subfoveal choroidal thicknesses, near-infrared images, and autofluorescence images at 488 nm (SW-AF) and 785 nm (NIR-AF).Results: There were 16 eyes in the sunset group and 12 eyes in the non-sunset group. For all eyes in the sunset group, the disappearance of choroidal melanin was clearly detected with PS-OCT. Percentage areas of low DOPU in the choroidal interstitial stroma of the sunset group were significantly lower than those of other groups and showed no overlap with other groups. The distribution of choroidal thicknesses and SGI in the sunset group substantially overlapped with other groups. The subjective analyses of the sunset and non-sunset groups, using near infrared, SW-AF, or NIR-AF, showed substantial inconsistencies with the PS-OCT results.Conclusions: PS-OCT provides an in vivo objective evaluation of choroidal melanin loss of the SGF in chronic VKH disease

Evaluation of focal damage in the retinal pigment epithelium layer in serous retinal pigment epithelium detachment

The purpose of this study was to evaluate focal damage in the retinal pigment epithelium (RPE) layer in serous retinal pigment epithelium detachment (PED) with multi-contrast optical coherence tomography (OCT), which is capable of simultaneous measurement of OCT angiography, polarization-sensitive OCT and standard OCT images. We evaluated 37 eyes with age-related macular degeneration that had serous PED. Focal RPE damage was indicated by hyper-transmission beneath the RPE-Bruch’s membrane band in standard OCT images. Distribution of RPE melanin was calculated using the dataset from multi-contrast OCT. Twenty-four points with hyper-transmission were detected in 21 of the 37 eyes. Standard OCT images failed to show disruption of the RPE-Bruch’s membrane band at 5 of the 24 hyper-transmission points. Conversely, multi-contrast OCT images clearly showed melanin defects in the RPE-Bruch’s membrane band at all points. Areas of melanin defects with disruption of the RPE-Bruch’s membrane band were significantly larger than those without disruption. The volume of intraretinal hyper-reflective foci was significantly larger in eyes with hyper-transmission than that in eyes without hyper-transmission. Multi-contrast OCT is more sensitive than standard OCT for displaying changes at the RPE-Bruch’s membrane band when there are small areas of RPE damage

Design and Evaluation of Behavior Control Algorithm for Multiple-Mobile-Robot System in Panel Cruising Problem

In this paper, we describe the design and evaluation of a behavior control algorithm for a multiple-mobile-robot system in a panel cruising problem. In order to achieve given tasks, fundamental functions such as path planning, path tracking, obstacle avoidance, and energy conservation are required for each mobile robot. Therefore, we propose an intelligent behavior control algorithm that was derived by analyzing the operator's manipulation data. In particular, we focus on the implementation of decision-making skills making it possible to maintain a balance between selfish and altruistic behaviors in a multiple-mobile-robot system, and confirm the usefulness of the proposed behavior control algorithm from several computer simulations

カンキョウ ニンシキ キノウ オ ユウスル ニンゲン キョウゾンガタ キャクシキ ロボット ノ カイハツ

This paper describes a human beings coexistence type quadruped robot with environment recognition functions. To develop the excellent quadruped robot, thea daptive gait patterns on the level and unleveled walking environments are required. In this research, CPGs (Central Pattern Generators) are introduced to generate the gait pattern on level walking environment. The CPGs are mutually connected each other, and the sets of the coupling parameters are adjusted by genetic algorithm so that the quadruped robot can realize stable and adequate gait patterns. As ar esult of generation，the suitable CPG networks for aw alking straight, a right and a left rotation gait patterns is obtained on the level walking environment. On the other hand, the geometric calculations method is introduced to keep the quadruped robot stable on unleveled walking environment. Experimental results demonstrate that effectiveness of the proposed schemes on both environments