Affordable ultra-widefield smartphone PedCam for comprehensive pediatric retinal examination.

Widefield fundus photography is critical for the detection, documentation, and management of pediatric eye diseases. Existing clinical pediatric fundus cameras offer a limited field of view (FOV) and suboptimal image contrast, hindering comprehensive peripheral retina examination. Additionally, the high cost and lack of portability of commercial devices restrict their use in resource-limited settings.

Evaluation of carotid intima-media thickness measurements in patients with central serous chorioretinopathy.

Background: Central serous chorioretinopathy (CSC) is a systemic disease more than a disease localized to the eye, and there may be vascular involvement in its pathogenesis.

Objective: This study aimed to evaluate the carotid intima-media thickness (IMT) of patients with CSC, to compare it with that of healthy individuals, and to explore whether there might be an association between CSC and subclinical carotid atherosclerotic disease.

Materials And Methods: Adult patients with CSC (n = 30) and healthy individuals (n = 30) were included in this prospective study.

Evaluating spatial dependency of the spectral efficiency in trans-palpebral illumination for widefield fundus photography.

Multi-spectral widefield fundus photography is valuable for the clinical diagnosis and management of ocular conditions that may impact both central and peripheral regions of the retina and choroid. Trans-palpebral illumination has been demonstrated as an alternative to transpupillary illumination for widefield fundus photography without requiring pupil dilation. However, spectral efficiency can be complicated due to the spatial variance of the light property through the palpebra and sclera.

Light color efficiency-balanced trans-palpebral illumination for widefield fundus photography of the retina and choroid.

A wide-field fundus camera, which can selectively evaluate the retina and choroid, is desirable for better detection and treatment evaluation of eye diseases. Trans-palpebral illumination has been demonstrated for wide-field fundus photography, but its application for true-color retinal imaging is challenging due to the light efficiency delivered through the eyelid and sclera is highly wavelength dependent. This study is to test the feasibility of true-color retinal imaging using efficiency-balanced visible light illumination, and to validate multiple spectral imaging (MSI) of the retina and choroid.

Understanding the relationship between visual-angle and eye-angle for reliable determination of the field-of-view in ultra-wide field fundus photography.

Visual-angle has been used as the conventional unit to determine the field-of-view (FOV) in traditional fundus photography. Recently emerging usage of eye-angle as the unit in wide field fundus photography creates confusion about FOV interpretation in instrumentation design and clinical application. This study aims to systematically derive the relationship between the visual-angle θ and eye-angle θ, and thus to enable reliable determination of the FOV in wide field fundus photography.

Portable ultra-widefield fundus camera for multispectral imaging of the retina and choroid.

Multispectral imaging (MSI) of the retina and choroid has increasing interest for better diagnosis and treatment evaluation of eye diseases. However, currently available MSI systems have a limited field of view (FOV) to evaluate the peripheral retina. This study is to validate trans-pars-planar illumination for a contact-mode ultra-widefield MSI system.

Transfer Learning for Automated OCTA Detection of Diabetic Retinopathy.

Purpose: To test the feasibility of using deep learning for optical coherence tomography angiography (OCTA) detection of diabetic retinopathy.

Methods: A deep-learning convolutional neural network (CNN) architecture, VGG16, was employed for this study. A transfer learning process was implemented to retrain the CNN for robust OCTA classification.

Holographic waveguide based optometer for the quantitative monitoring of ocular refractive error.

Oculomotor disorders are known to have profound impacts on a patients' quality of life. However, current clinical practice lacks the capability to provide simultaneous assessment of three tightly coupled oculomotor control components, i.e.

Trans-pars-planar illumination enables a 200° ultra-wide field pediatric fundus camera for easy examination of the retina.

This study is to test the feasibility of using trans-pars-planar illumination for ultra-wide field pediatric fundus photography. Fundus examination of the peripheral retina is essential for clinical management of pediatric eye diseases. However, current pediatric fundus cameras with traditional trans-pupillary illumination provide a limited field of view (FOV), making it difficult to access the peripheral retina adequately for a comprehensive assessment of eye conditions.

Quantitative optical coherence tomography angiography: A review.

Unlabelled: As a new optical coherence tomography (OCT) modality, OCT angiography (OCTA) provides a noninvasive method to detect microvascular distortions correlated with eye conditions. By providing unparalleled capability to differentiate individual plexus layers in the retina, OCTA has demonstrated its excellence in clinical management of diabetic retinopathy, glaucoma, sickle cell retinopathy, diabetic macular edema, and other eye diseases. Quantitative OCTA analysis of retinal and choroidal vasculatures is essential to standardize objective interpretations of clinical outcome.

Is age-related macular degeneration a local manifestation of systemic disorder? Changes in nailfold capillaries at age-related macular degeneration.

Aims: Determining whether nailfold capillary involvement is present in patients with Age-related macular degeneration (AMD) and whether there are different nailfold capillaroscopy findings between wet and dry types.

Methods: From January 2016 to December 2017, with an initial diagnosis of AMD, 53 consecutive adult patients (AMD group) and 91 age- and sex-matched healthy individuals were studied prospectively. There was no history of any other ocular disease and other disease affecting nailfold capillaries.

Near infrared oximetry-guided artery-vein classification in optical coherence tomography angiography.

Unlabelled: Differential artery–vein analysis is valuable for early detection of diabetic retinopathy and other eye diseases. As a new optical coherence tomography imaging modality, optical coherence tomography angiography provides capillary level resolution for accurate examination of retinal vasculatures. However, differential artery–vein analysis in optical coherence tomography angiography particularly for macular region in which blood vessels are small is challenging.

OCT feature analysis guided artery-vein differentiation in OCTA.

Differential artery-vein analysis promises better sensitivity for retinal disease detection and classification. However, clinical optical coherence tomography angiography (OCTA) instruments lack the function of artery-vein differentiation. This study aims to verify the feasibility of using OCT intensity feature analysis to guide artery-vein differentiation in OCTA.

Differential Artery-Vein Analysis Improves the Performance of OCTA Staging of Sickle Cell Retinopathy.

Purpose: We test if differential artery-vein analysis can increase the performance of optical coherence tomography angiography (OCTA) detection and classification of sickle cell retinopathy (SCR).

Method: This observational case series was conducted in a tertiary-retina practice. Color fundus and OCTA images were collected from 20 control and 48 SCR subjects.

Color Fundus Image Guided Artery-Vein Differentiation in Optical Coherence Tomography Angiography.

Purpose: This study aimed to develop a method for automated artery-vein classification in optical coherence tomography angiography (OCTA), and to verify that differential artery-vein analysis can improve the sensitivity of OCTA detection and staging of diabetic retinopathy (DR).

Methods: For each patient, the color fundus image was used to guide the artery-vein differentiation in the OCTA image. Traditional mean blood vessel caliber (m-BVC) and mean blood vessel tortuosity (m-BVT) in OCTA images were quantified for control and DR groups.

Spontaneous Macular Hole Closure after Valsalva Retinopathy and Nd:YAG Laser Treatment.

Purpose: The purpose of this report is to present a case who had spontaneous macular hole closure after Nd:YAG laser membranotomy applied to premacular haemorrhage associated with Valsalva retinopathy.

Methods: Case report.

Results: A 19-year-old young male patient presented to our clinic with sudden vision loss in his right eye, which had occurred 2 weeks before, following push-up and sit-up exercise.

Automated classification and quantitative analysis of arterial and venous vessels in fundus images.

It is known that retinopathies may affect arteries and veins differently. Therefore, reliable differentiation of arteries and veins is essential for computer-aided analysis of fundus images. The purpose of this study is to validate one automated method for robust classification of arteries and veins (A-V) in digital fundus images.

A New Objective Parameter in Hydroxychloroquine-Induced Retinal Toxicity Screening Test: Macular Retinal Ganglion Cell-Inner Plexiform Layer Thickness.

Objectives: This study aims to detect hydroxychloroquine (HCQ)-induced retinal toxicity at an earlier stage through the use of spectral-domain optical coherence tomography device, especially by measuring macular retinal ganglion cell-inner plexiform layer (RGC-IPL) thickness.

Patients And Methods: In this study, 92 eyes of 46 Caucasian female patients (mean age 53.6±8.

Contact-free trans-pars-planar illumination enables snapshot fundus camera for nonmydriatic wide field photography.

In conventional fundus photography, trans-pupillary illumination delivers illuminating light to the interior of the eye through the peripheral area of the pupil, and only the central part of the pupil can be used for collecting imaging light. Therefore, the field of view of conventional fundus cameras is limited, and pupil dilation is required for evaluating the retinal periphery which is frequently affected by diabetic retinopathy (DR), retinopathy of prematurity (ROP), and other chorioretinal conditions. We report here a nonmydriatic wide field fundus camera employing trans-pars-planar illumination which delivers illuminating light through the pars plana, an area outside of the pupil.

Near-infrared light-guided miniaturized indirect ophthalmoscopy for nonmydriatic wide-field fundus photography.

A portable fundus imager is essential for emerging telemedicine screening and point-of-care examination of eye diseases. However, existing portable fundus cameras have limited field of view (FOV) and frequently require pupillary dilation. We report here a miniaturized indirect ophthalmoscopy-based nonmydriatic fundus camera with a snapshot FOV up to 67° external angle, which corresponds to a 101° eye angle.

Functional optical coherence tomography of neurovascular coupling interactions in the retina.

Quantitative evaluation of retinal neurovascular coupling is essential for a better understanding of visual function and early detection of eye diseases. However, there is no established method to monitor coherent interactions between stimulus-evoked neural activity and hemodynamic responses at high resolution. Here, we report a multimodal functional optical coherence tomography (OCT) imaging methodology to enable concurrent intrinsic optical signal (IOS) imaging of stimulus-evoked neural activity and hemodynamic responses at capillary resolution.

Combining ODR and Blood Vessel Tracking for Artery-Vein Classification and Analysis in Color Fundus Images.

Purpose: This study aims to develop a fully automated algorithm for artery-vein (A-V) and arteriole-venule classification and to quantify the effect of hypertension on A-V caliber and tortuosity ratios of nonproliferative diabetic retinopathy (NPDR) patients.

Methods: We combine an optical density ratio (ODR) analysis and blood vessel tracking (BVT) algorithm to classify arteries and veins and arterioles and venules. An enhanced blood vessel map and ODR analysis are used to determine the blood vessel source nodes.

Smartphone-based imaging of the corneal endothelium at sub-cellular resolution.

This aim of this study was to test the feasibility of smartphone-based specular microscopy of the corneal endothelium at a sub-cellular resolution. Quantitative examination of endothelial cells is essential for evaluating corneal disease such as determining a diagnosis, monitoring progression and assessing treatment. Smartphone-based technology promises a new opportunity to develop affordable devices to foster quantitative examination of endothelial cells in rural and underserved areas.

WIDE-FIELD SMARTPHONE FUNDUS VIDEO CAMERA BASED ON MINIATURIZED INDIRECT OPHTHALMOSCOPY.

Purpose: This study is to develop a low-cost, easy-to-use, wide-field smartphone fundus video camera to enable affordable point-of-care examination and telemedicine.

Methods: The wide-field smartphone fundus camera is based on a unique design of miniaturized indirect ophthalmoscopy. For proof-of-concept prototype, we used a Samsung Galaxy S6 smartphone and all off-the-shelf components.

Wide-field fundus imaging with trans-palpebral illumination.

In conventional fundus imaging devices, transpupillary illumination is used for illuminating the inside of the eye. In this method, the illumination light is directed into the posterior segment of the eye through the cornea and passes the pupillary area. As a result of sharing the pupillary area for the illumination beam and observation path, pupil dilation is typically necessary for wide-angle fundus examination, and the field of view is inherently limited.