CNN-Based Device-Agnostic Feature Extraction From ONH OCT Scans.

Purpose: Optical coherence tomography (OCT)-derived measurements of the optic nerve head (ONH) from different devices are not interchangeable. This poses challenges to patient follow-up and collaborative studies. Here, we present a device-agnostic method for the extraction of OCT biomarkers using artificial intelligence.

Detection of capillary abnormalities in early diabetic retinopathy using scanning laser ophthalmoscopy and optical coherence tomography combined with adaptive optics.

This study tested if a high-resolution, multi-modal, multi-scale retinal imaging instrument can provide novel information about structural abnormalities in vivo. The study examined 11 patients with very mild to moderate non-proliferative diabetic retinopathy (NPDR) and 10 healthy subjects using fundus photography, optical coherence tomography (OCT), OCT angiography (OCTA), adaptive optics scanning laser ophthalmoscopy (AO-SLO), adaptive optics OCT and OCTA (AO-OCT(A)). Of 21 eyes of 11 patients, 11 had very mild NPDR, 8 had mild NPDR, 2 had moderate NPDR, and 1 had no retinopathy.

Multi-modal and multi-scale clinical retinal imaging system with pupil and retinal tracking.

We present a compact multi-modal and multi-scale retinal imaging instrument with an angiographic functional extension for clinical use. The system integrates scanning laser ophthalmoscopy (SLO), optical coherence tomography (OCT) and OCT angiography (OCTA) imaging modalities and provides multi-scale fields of view. For high resolution, and high lateral resolution in particular, cellular imaging correction of aberrations by adaptive optics (AO) is employed.

Tear Film Surface Quality in Modern Daily Disposable Contact Lens Wear.

Objectives: As reported previously, tear film surface quality (TFSQ) should be considered in contact lens (CL) fitting. This study followed noninvasive keratograph tear film break-up time (NIKBUT) in CL wearers for 12 months to validate its clinical utility in predicting CL performance.

Methods: Fifty-five subjects (M/F=17/38) aged 26±4 years were prescribed silicone hydrogel or hydrogel CLs.

Combination of snapshot hyperspectral retinal imaging and optical coherence tomography to identify Alzheimer's disease patients.

Introduction: The eye offers potential for the diagnosis of Alzheimer's disease (AD) with retinal imaging techniques being explored to quantify amyloid accumulation and aspects of neurodegeneration. To assess these changes, this proof-of-concept study combined hyperspectral imaging and optical coherence tomography to build a classification model to differentiate between AD patients and controls.

Methods: In a memory clinic setting, patients with a diagnosis of clinically probable AD (n = 10) or biomarker-proven AD (n = 7) and controls (n = 22) underwent non-invasive retinal imaging with an easy-to-use hyperspectral snapshot camera that collects information from 16 spectral bands (460-620 nm, 10-nm bandwidth) in one capture.

Assessing Corneal Speckle in Optical Coherence Tomography: A New Look at Glaucomatous Eyes.

Significance: Optical coherence tomography speckle is used here in an unconventional way as the indirect source of information on tissue microstructure. The study reveals that the corneal speckle of glaucoma suspects has a similar relationship between the parameters of scattering exhibited in glaucoma patients.

Purpose: The purpose of this study was to evaluate the potential of optical coherence tomography imaging of the cornea in early diagnosis of glaucoma.

Heterogeneity in arterial hypertension and ocular perfusion pressure definitions: Towards a consensus on blood pressure-related parameters for glaucoma studies.

Purpose: Glaucoma studies have long taken into account the blood pressure (BP) status of patients. This study summarizes and evaluates the impact of the different criteria that have been used for BP-related variables in glaucoma research.

Methods: Studies included in two meta-analyses that reviewed the role of BP in glaucoma were analyzed.

Quantitative automated circumpapillary microvascular density measurements: a new angioOCT-based methodology.

Purpose: To develop a new methodology to detect glaucoma damage based on circumpapillary microvascular density (cpmVD) as measured by optical coherence tomography angiography (angioOCT).

Methods: AngioOCT scans from a random eye of 40 healthy subjects (aged 63 ± 14 years) and 82 glaucoma patients (aged 66 ± 9 years with an average visual field loss of -7.8 ± 6.

The utility of measuring tear film break-up time for prescribing contact lenses.

Purpose: To evaluate the clinical value of non-invasive keratograph tear film breakup time (NIKBUT) in the assessment of pre-corneal and pre-lens tear film quality for prescribing contact lenses (CLs).

Methods: Forty-six subjects aged 25.5±4.

Influence of eye biometrics and corneal micro-structure on noncontact tonometry.

Purpose: Tonometry is widely used as the main screening tool supporting glaucoma diagnosis. Still, its accuracy could be improved if full knowledge about the variation of the corneal biomechanical properties was available. In this study, Optical Coherence Tomography (OCT) speckle statistics are used to infer the organisation of the corneal micro-structure and hence, to analyse its influence on intraocular pressure (IOP) measurements.

Assessment of corneal properties based on statistical modeling of OCT speckle.

A new approach to assess the properties of the corneal micro-structure based on the statistical modeling of speckle obtained from Optical Coherence Tomography (OCT) is presented. A number of statistical models were proposed to fit the corneal speckle data obtained from OCT raw image. Short-term changes in corneal properties were studied by inducing corneal swelling whereas age-related changes were observed analyzing data of sixty-five subjects aged between twenty-four and seventy-three years.

Precise measurement of scleral radius using anterior eye profilometry.

Purpose: To develop a new and precise methodology to measure the scleral radius based on anterior eye surface.

Methods: Eye Surface Profiler (ESP, Eaglet-Eye, Netherlands) was used to acquire the anterior eye surface of 23 emmetropic subjects aged 28.1±6.

On the Methods for Estimating the Corneoscleral Limbus.

Objective: The aim of this study was to develop computational methods for estimating limbus position based on the measurements of three-dimensional (3-D) corneoscleral topography and ascertain whether corneoscleral limbus routinely estimated from the frontal image corresponds to that derived from topographical information.

Methods: Two new computational methods for estimating the limbus position are proposed: One based on approximating the raw anterior eye height data by series of Zernike polynomials and one that combines the 3-D corneoscleral topography with the frontal grayscale image acquired with the digital camera in-built in the profilometer. The proposed methods are contrasted against a previously described image-only-based procedure and to a technique of manual image annotation.

Principles of operation, accuracy and precision of an Eye Surface Profiler.

Purpose: To introduce a newly developed instrument for measuring the topography of the anterior eye, provide principles of its operation and to assess its accuracy and precision.

Methods: The Eye Surface Profiler is a new technology based on Fourier transform profilometry for measuring the anterior eye surface encompassing the corneo-scleral area. Details of technical principles of operation are provided for the particular case of sequential double fringe projection.

Simplifying numerical ray tracing for two-dimensional non circularly symmetric models of the human eye.

Ray tracing is a powerful technique to understand the light behavior through an intricate optical system such as that of a human eye. The prediction of visual acuity can be achieved through characteristics of an optical system such as the geometrical point spread function. In general, its precision depends on the number of discrete rays and the accurate surface representation of each eye's components.

Age-related changes of the corneal speckle by Optical Coherence Tomography.

Ageing of the population has several consequences for the human visual system. The corneal tissue which is responsible for two thirds of the total optical power is not an exception, suffering structural and anatomical changes with the age. In this study, we have explored the usefulness of Optical Coherence Tomography (OCT) speckle to study the age-related changes in corneal stroma.

Using ultrasound backscattering signals and Nakagami statistical distribution to assess regional cataract hardness.

This study aims to analyze the protein aggregates spatial distribution for different cataract degrees, and correlate this information with the lens acoustical parameters and by this way, assess the cataract regional hardness. Different cataract degrees were induced ex vivo in porcine lenses. A 25 MHz ultrasonic transducer was used to obtain the acoustical parameters (velocity, attenuation, and backscattering signals).