- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Investigation of inner ear anatomy in mouse using X-ray phase contrast tomography
摘要： A thorough understanding of inner ear anatomy is important for investigators. However, investigation of the mouse inner ear is difficult due to the limitations of imaging techniques. X-ray phase contrast tomography increases contrast 100–1,000 times compared with conventional X-ray imaging. This study aimed to investigate inner ear anatomy in a fresh post-mortem mouse using X-ray phase contrast tomography and to provide a comprehensive atlas of microstructures with less tissue deformation. All experiments were performed in accordance with our institution's guidelines on the care and use of laboratory animals. A fresh mouse cadaver was scanned immediately after sacrifice using an inline phase contrast tomography system. Slice images were reconstructed using a filtered back-projection (FBP) algorithm. Standardized axial and coronal planes were adjusted with a multi-planar reconstruction method. Some three-dimensional (3D) objects were reconstructed by surface rendering. The characteristic features of microstructures, including otoconia masses of the saccular and utricular maculae, superior and inferior macula cribrosae, single canal, modiolus, and osseous spiral lamina, were described in detail. Spatial positions and relationships of the vestibular structures were exhibited in 3D views. This study investigated mouse inner ear anatomy and provided a standardized presentation of microstructures. In particular, otoconia masses were visualized in their natural status without contrast for the first time. The comprehensive anatomy atlas presented in this study provides an excellent reference for morphology studies of the inner ear.
关键词： saccular macula,phase contrast imaging,inner ear,utricular macula,otoconia
更新于2025-09-23 15:23:52
-
Microvascular changes in macula and optic nerve head after femtosecond laser-assisted LASIK: an optical coherence tomography angiography study
摘要： To measure the microcirculation change of macula and optic nerve head before and after femtosecond laser assisted laser in situ keratomileusis. In total 45 eyes from 45 subjects, who underwent FS-LASIK during June 2017 to December 2017 in Guangdong Provincial People’s Hospital, were recruited in this study. Vessel density in macula and optic nerve head were measured by optical coherence tomography angiography before and after transient elevation in intraocular pressure caused by application of suction ring during surgery. Vessel density (VD) at superficial (SCP) plexus of macular region did not differ after surgery (F(3,132) = 1.41, P = 0.24), while the deep (DCP) plexus of macular region significantly decreased 1 day after surgery (P = 0.001) but returned to its baseline value 1 month postoperatively (P = 0.1). Vessel density of optic nerve head region had no significant changes after surgery (F(2.51,95.18) = 0.6, P = 0.59). A short-term temporary decrease of vessel density at deep layer of macular region was observed in eyes undergoing FS-LASIK. However, the retinal capillary density went back to preoperative level 1 month after surgery. Therefore, transient IOP spike during FS-LASIK did not cause long-term decline of retinal microcirculation.
关键词： Optical coherence tomography angiography,Femtosecond laser-assisted LASIK,Microvascular changes,Macula,Optic nerve head
更新于2025-09-23 15:19:57
-
[IEEE 2019 IEEE Fourth Ecuador Technical Chapters Meeting (ETCM) - Guayaquil, Ecuador (2019.11.11-2019.11.15)] 2019 IEEE Fourth Ecuador Technical Chapters Meeting (ETCM) - Deterministic and stochastic optimization-based decision-making approaches for effectively coping with residential photovoltaic micro-systems sizing problem under net-metering schemes
摘要： This paper intends to present a Web-based application to collect and manage clinical data and clinical trials together in a unique tool. I-maculaweb is a user-friendly Web-application designed to manage, share, and analyze clinical data from patients affected by degenerative and vascular diseases of the macula. The unique and innovative scientific and technological elements of this project are the integration with individual and population data, relevant for degenerative and vascular diseases of the macula. Clinical records can also be extracted for statistical purposes and used for clinical decision support systems. I-maculaweb is based on an existing multilevel and multiscale data management model, which includes general principles that are suitable for several different clinical domains. The database structure has been specifically built to respect laterality, a key aspect in ophthalmology. Users can add and manage patient records, follow-up visits, treatment, diagnoses, and clinical history. There are two different modalities to extract records: one for the patient’s own center, in which personal details are shown and the other for statistical purposes, where all center’s anonymized data are visible. The Web-platform allows effective management, sharing, and reuse of information within primary care and clinical research. Clear and precise clinical data will improve understanding of real-life management of degenerative and vascular diseases of the macula as well as increasing precise epidemiologic and statistical data. Furthermore, this Web-based application can be easily employed as an electronic clinical research file in clinical studies.
关键词： multi-level and multi-scale data management model,Macula diseases,Web based clinical data collection for reuse
更新于2025-09-23 15:19:57
-
Analyse glaukombedingter Makulaver?nderungen mittels optischer Koh?renztomografie
摘要： Background In glaucoma, progressive retinal nerve fibre loss can be measured in the peripapillary and macular regions using optical coherence tomography (OCT). The goal of this study was to evaluate the impact of glaucoma on all measurable retinal layers using the spectral domain OCT (SD-OCT). Materials and Methods SD-OCT scans using automated retinal layer segmentation were performed in both eyes of primary open-angle glaucoma patients with strictly monocular absolute visual field scotoma in the central 10° of their visual field. The same measurements were performed in one eye per person in a healthy age-matched control group. The mean thickness of all retinal layers in the central 24 × 24° of the macular region was compared between groups. Results SD-OCT scans were performed in 24 eyes of 12 glaucoma patients (10 female, 2 male) with a mean age of 72.3 ± 8.1 years and in 12 eyes of 12 healthy controls (9 female, 3 male) with a mean age of 66.0 ± 7.6 years. Statistically significant thickness differences between the glaucomatous and the healthy eyes could be demonstrated for the retinal nerve fibre layer, the ganglion cell layer, the inner plexiform layer and the complete retinal thickness, with lower mean thicknesses in the glaucoma group. Conclusion Using SD-OCT, single retinal layers of the macular region can be scanned and measured automatically. In glaucoma, a decrease in thickness of the inner retinal layers containing ganglion cells and their axons or dendrites could be demonstrated compared to healthy eyes. No corresponding difference in thickness could be found for the outer retinal layers using SD-OCT measurements.
关键词： scotoma,retina,glaucoma,optical coherence tomography,macula
更新于2025-09-19 17:15:36
-
A practical approach to estimating optic disc dose and macula dose without treatment planning in ocular brachytherapy using 125I COMS plaques
摘要： Background: It has been reported that proximity of the tumor to the optic disc and macula, and radiation dose to the critical structures are substantial risk factors for vision loss following plaque brachytherapy. However, there is little dosimetry data published on this. In this study, therefore, the relationship between distance from tumor margin and radiation dose to the optic disc and macula in ocular brachytherapy using 125I Collaborative Ocular Melanoma Study (COMS) plaques was comprehensively investigated. From the information, this study aimed to allow for estimation of optic disc dose and macula dose without treatment planning. Methods: An in-house brachytherapy dose calculation program utilizing the American Association of Physicists in Medicine Task Group-43 U1 formalism with a line source approximation in a homogenous water phantom was developed and validated against three commercial treatment planning systems (TPS). Then optic disc dose and macula dose were calculated as a function of distance from tumor margin for various tumor basal dimensions for seven COMS plaques (from 10 mm to 22 mm in 2 mm increments) loaded with commercially available 125I seeds models (IAI-125A, 2301 and I25.S16). A prescribed dose of 85 Gy for an irradiation time of 168 h was normalized to a central-axis depth of 5 mm. Dose conversion factors for each seed model were obtained by taking ratios of total reference air kerma per seed at various prescription depths (from 1 mm to 10 mm in 1 mm intervals) to that at 5 mm. Results: The in-house program demonstrated relatively similar accuracy to commercial TPS. Optic disc dose and macula dose decreased as distance from tumor margin and tumor basal dimension increased. Dose conversion factors increased with increasing prescription depth. There existed dose variations (<8%) among three 125I seed models. Optic disc dose and macula dose for each COMS plaque and for each seed model are presented in a figure format. Dose conversion factors for each seed model are presented in a tabular format. Conclusions: The data provided in this study would enable clinicians in any clinic using 125I COMS plaques to estimate optic disc dose and macula dose without dose calculations.
关键词： Ocular brachytherapy,Optic disc dose,COMS plaques,125I,Macula dose
更新于2025-09-11 14:15:04
-
[IEEE 2018 37th Chinese Control Conference (CCC) - Wuhan (2018.7.25-2018.7.27)] 2018 37th Chinese Control Conference (CCC) - Computer Aided Diagnosis for Diabetic Retinopathy based on Fundus Image
摘要： Diabetic Retinopathy (DR) is an eye abnormality caused by long term diabetes, which can lead to vision defects or even blindness. Performing retinal screening examinations on all diabetic patients is a hard work due to the limited number of specialists cannot keep up with the increasing prevalence of diabetes, and hence there are many undiagnosed and untreated cases of DR. Computer aided diagnosis (CAD) is a good way to save the patient’s vision and to help the ophthalmologists in mass screening of diabetes sufferers. The main purpose of the proposed study is to design an automated grading approach for DR screening, using a publicly available database of retinal images, which can evaluate the fundus images like human experts while achieving a high sensitivity for the detection of DR. This paper gives a summary of the results obtained by our previous studies. Together with these results and the DR grading schemes, we provide an automatic analysis approach for the risk of macular edema and the retinopathy grade. Experimental results indicate that the performance of our approach on this database is comparable to that of human experts.
关键词： Optic disc,Macula,Diabetic Retinopathy,Pattern Recognition,Exudates
更新于2025-09-10 09:29:36
-
A Novel Approach for Diagnosing Diabetic Retinopathy in Fundus Images
摘要： In recent years the medical profession has seen an ever increasing demand for diagnosis and a permanent cure for illnesses caused by climatic-changes, unwholesome food and environmental pollution. Also the appearances of hitherto unknown viral diseases have caused eye diseases, which have prompted surgeons to monitor the health of the eyes. Potential new therapies that may help in preserving sight in the growing population of diabetic patients into the 21st Century. Early detection of diseases affecting the eyes reduces the risk of permanent damage. Some of the serious conditions which warrant early diagnosis are: Glaucoma, floaters, macula degradation and diabetic retinopathy. In the early stages, a choice of treatment options exist, which dwindles as the disease spreads. A visual inspection of the optic disc, macula and the blood vessels of the eye requires to be done routinely. Diabetic patients run the risk of damage to retinal vessels, which are referred to as diabetic retinopathy. This may further be classified as: Non-proliferative diabetic retinopathy and proliferative diabetic retinopathy. In scientific literatures, feature extraction method has been reported for diagnosis and classification. In this study a systematic Decide, Detect, Determine and Do approach for analyzing diabetic retinopathy images has been taken up. The proposed approach gives a clearer picture of the abnormality, its type (NPDR or PDR), its status (viz., mild, moderate or severe) and finally the appropriate treatment.
关键词： Macula,Diabetic Retinopathy,PDR,Blood Vessels,NPDR,Optic Disc
更新于2025-09-10 09:29:36
-
Segmentation and Classification of Optic Disc in Retinal Images
摘要： Image segmentation plays a vital role in image analysis for diagnosis of various retinopathy diseases. For the detection of glaucoma and diabetic retinopathy, manual examination of the optic disc is the standard clinical procedure. The proposed method makes use of the circular transform to automatically locate and extract the Optic Disc (OD) from the retinal fundus images. The circular transform operates with radial line operator which uses the multiple radial line segments on every pixel of the image. The maximum variation pixels along each radial line segments are taken to detect and segment OD. The input retinal images are preprocessed before applying circular transform. The optic disc diameter and the distance from optic disc to macula are found for a sample of 20 images. An Extreme Learning Machine classifier is used to train the neural network to classify the images as normal or abnormal. Its performance is compared with Support Vector Machine in terms of computation time and accuracy. It is found that computation time is less than 0.1 sec and accuracy is 97.14% for Extreme Learning Machine classifier.
关键词： extreme learning machine,Circular transform,optic disc,segmentation,macula
更新于2025-09-09 09:28:46
-
Evaluation of a Region-of-Interest Approach for Detecting Progressive Glaucomatous Macular Damage on Optical Coherence Tomography
摘要： Purpose: To evaluate a manual region-of-interest (ROI) approach for detecting progressive macular ganglion cell complex (GCC) changes on optical coherence tomography (OCT) imaging. Methods: One hundred forty-six eyes with a clinical diagnosis of glaucoma or suspected glaucoma with macular OCT scans obtained at least 1 year apart were evaluated. Changes in the GCC thickness were identified using a manual ROI approach (ROIM), whereby region(s) of observed or suspected glaucomatous damage were manually identified when using key features from the macular OCT scan on the second visit. Progression was also evaluated using the global GCC thickness and an automatic ROI approach (ROIA), where contiguous region(s) that fell below the 1% lower normative limit and exceeded 288 lm2 in size were evaluated. Longitudinal signal-to-noise ratios (SNRs) were calculated for progressive changes detected by each of these methods using individualized estimates of test–retest variability and age-related changes, obtained from 303 glaucoma and 394 healthy eyes, respectively. Results: On average, the longitudinal SNR for the global thickness, ROIA and ROIM methods were (cid:2)0.90 y(cid:2)1, (cid:2)0.91 y(cid:2)1, and (cid:2)1.03 y(cid:2)1, respectively, and was significantly more negative for the ROIM compared with the global thickness (P ? 0.003) and ROIA methods (P ? 0.021). Conclusions: Progressive glaucomatous macular GCC changes were optimally detected with a manual ROI approach. Translational Relevance: These findings suggests that an approach based on a qualitative evaluation of OCT imaging information and consideration of known patterns of damage can improve the detection of progressive glaucomatous macular damage.
关键词： progression,optical coherence tomography,macula,glaucoma
更新于2025-09-04 15:30:14
-
Evaluation of the Structure–Function Relationship in Glaucoma Using a Novel Method for Estimating the Number of Retinal Ganglion Cells in the Human Retina
摘要： PURPOSE. We developed a simple method for estimating the number of retinal ganglion cells (RGCs) in the human retina using optical coherence tomography (OCT), compared it to a previous approach, and demonstrated its potential for furthering our understanding of the structure–function relationship in glaucoma. METHODS. Swept-source (ss) OCT data and 10-2 visual ?elds (VFs) were obtained from 43 eyes of 36 healthy controls, and 50 eyes of 50 glaucoma patients and suspects. Using estimates of RGC density from the literature and relatively few assumptions, estimates of the number of RGCs in the macula were obtained based on ssOCT-derived RGC layer thickness measurements. RESULTS. The RGC estimates were in general agreement with previously published values derived from histology, whereas a prior method based on VF sensitivity did not agree as well with histological data and had signi?cantly higher (P ? 0.001) and more variable (P < 0.001) RGC estimates than the new method based on ssOCT. However, the RGC estimates of the new approach were not zero for extreme VF losses, suggesting that a residual, non-RGC contribution needs to be added. Finally, the new ssOCT-derived RGC estimates were signi?cantly (P < 0.001 to P ? 0.018) related to VF sensitivity (Spearman’s q ? 0.26–0.47), and, in contrast to claims made in prior studies, statistically signi?cant RGC loss did not occur more often than statistically signi?cant visual loss. CONCLUSIONS. The novel method for estimating RGCs yields values that are closer to histological estimates than prior methods, while relying on considerably fewer assumptions. Although the value added for clinical applications is yet to be determined, this approach is useful for assessing the structure–function relationship in glaucoma.
关键词： visual ?elds,glaucoma,retinal ganglion cells,structure versus function,macula,optical coherence tomography
更新于2025-09-04 15:30:14