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Multimodal macula mapping by deformable image registration
Published in João Manuel, R. S. Tavares, R. M. Natal Jorge, Computational Modelling of Objects Represented in Images, 2018
P. Baptista, J. Ferreira, R. Bernardes, J. Dias, J. Cunha-Vaz
Multimodal macula mapping is the combination of a variety of diagnostic imaging modalities to examine the macular region in order to obtain information on its structure and function. The macula is located in the posterior pole of the retina and is responsible for detailed and color vision, thus constituting an important area for human vision, as any macular alteration will, sooner or later, affect visual acuity (Bernardes, Lobo, and Cunha-Vaz 2002). Currently, a wealth of retina imaging modalities exists, either on daily clinical practice or research environments, such as color fundus photography, red-free fundus photography, fluorescein angiography, indocyanine green angiography, optical coherence tomography, retina flowmeter, fundus autofluorescence, leakage analysis, multifocal electroretinography, etc. The potential for multimodal macular mapping was demonstrated in (Bernardes, Lobo, and Cunha-Vaz 2002).
From Vision Science to Design Practice
Published in Marcelo M. Soares, Francisco Rebelo, Ergonomics in Design Methods & Techniques, 2016
Cristina Pinheiro, Fernando Moreira da Silva
Rods are colorblind and converge on the retina's bipolar cells. As a result, they have poor acuity but they support our perception in low lighting levels (scotopic vision). Cones, sensitive to color information, are responsible for acuity and vision in daylight conditions (photopic vision). The posterior pole of the retina is constituted by macula lutea, region of the retina responsible for central vision, where most of the cones are located.
Laser Personnel Medical Surveillance
Published in D. C. Winburn, Practical Laser Safety, 2017
Documented use of lasers at the Los Alamos National Laboratory dates back to 1964. Procedures were established by the Health Research Division to provide laser personnel with an examination of the eye by an ophthalmologist. Fundus photography of the posterior pole was performed after examination of the retinal surface with an opthalmoscope.
Intelligent identification and classification of diabetic retinopathy using fuzzy inference system
Published in Computer Methods in Biomechanics and Biomedical Engineering: Imaging & Visualization, 2023
Jyoti Prakash Medhi, R. Sandeep, Pranami Datta, Tousif Khan Nizami
To assess the performance of the FIS algorithm, the standard MESSIDOR dataset Decencière et al. (2014) containing annotated colour fundus images is used Salamat et al. (2019). Along with MESSIDOR, images from local hospitals, namely Guwahati Eye Institute (GEI) and Sri Sankaradeva Nethralaya (NETRALAYA), are collected to analyse the performance of the algorithm on real-time images. The classification of dataset images into a set of four stages is tabulated and shown in Table 2. eye fundus colour images are collected by three ophthalmologic departments using a colour video 3CCD camera placed on the Topcon TRC NW6 non-mydriatic retinograph with a field of view to form the posterior pole of the MESSIDOR database. 8-bits per colour plane at a resolution of or pixels are taken Salamat et al. (2019). Images having few microaneurysms are classified as Stage 1, images having both microaneurysms and HMs are categorised as Stage 2, and images having high microaneurysms and HMs are designated as Stage 3. The GEI database consists of a 120-colour fundus image with a resolution of 1078 × 933 pixels in JPEG format. The NETRALAYA database consists of a 280-colour fundus image with a resolution of 768 × 576 pixels in TIFF format.
Recent advances in wide field and ultrawide field optical coherence tomography angiography in retinochoroidal pathologies
Published in Expert Review of Medical Devices, 2021
Gagan Kalra, Francesco Pichi, Nitin Kumar Menia, Daraius Shroff, Nopasak Phasukkijwatana, Kanika Aggarwal, Aniruddha Agarwal
In summary, WF and UWF OCTA have been employed in few retinochoroidal diseases thus far. The literature on the advantages and disadvantages of wider FOV in OCTA is still evolving. While this technology may not provide additional beneficial information in diseases limited to the posterior pole or central macula such as age-related macular degeneration, evaluation of diseases with peripheral retinal involvement may be improved. With the availability of several commercial devices that have differences in terms of FOV, resolution, speed and scan algorithms, the financial liability of vitreoretinal diagnostics has also increased. Another major issue that exists is the limitations in the data storage capacity of commercially available OCTA devices. The hard drives provided by the devices have limited storage and computer systems meant for viewing the images may also have limitations in handling large volumes of data. This is especially a problem in large volume centers. As better technology and data storage solutions are being developed, this is one area which needs attention. In the future, it is hoped that better diagnostic tools will ultimately provide clinical benefit to the patients.
Recent advances in imaging technologies for assessment of retinal diseases
Published in Expert Review of Medical Devices, 2020
Taha Soomro, Neil Shah, Magdalena Niestrata-Ortiz, Timothy Yap, Eduardo M. Normando, M. Francesca Cordeiro
The images can suffer from distortion in the antero-posterior [23] and horizontal axes, with stretching of the retina peripherally. The peripheral retina can also appear relatively magnified compared with the posterior pole [18].This has been improved with new stereographic projection software algorithms [24]. There can also be issues with image contrast with images taken through a miotic pupil [18] and eyelash artifacts, the latter of which can be minimized with the use of a speculum [25].