Predict and Protect: Evaluating the Double-Layer Sign in Age-Related Macular Degeneration.

Introduction: Advanced age-related macular degeneration (AMD) is a major cause of vision loss. Therefore, there is interest in precursor lesions that may predict or prevent the onset of advanced AMD. One such lesion is a shallow separation of the retinal pigment epithelium (RPE) and Bruch's membrane (BM), which is described by various terms, including double-layer sign (DLS).

The Optical Coherence Tomography and Microperimetry Biomarker Evaluation in Patients with Geographic Atrophy (OMEGA) Study: Design and Baseline Characteristics - OMEGA Report 1.

Introduction: The aim of this study was to describe the design and the participants' baseline characteristics of a prospective natural history study of geographic atrophy (GA) secondary to age-related macular degeneration.

Methods: The optical coherence tomography (OCT) and microperimetry biomarker evaluation in patients with GA (OMEGA) study was conducted at a tertiary referral center (ClinicalTrials.gov identifier: NCT05963646).

Mapping diurnal changes in choroidal, Haller's and Sattler's layer thickness using 3-dimensional 1060-nm optical coherence tomography.

Purpose: To test the significance of diurnal changes in choroidal, Haller's and Sattler's layer thickness in healthy subjects using spatial analysis of three-dimensional (3D) 1060-nm optical coherence tomography (OCT) scans.

Methods: Automatically generated choroidal, Haller's and Sattler's layer thickness maps were statistically analyzed for 19 healthy subjects at two time points (8 a.m.

Choroid, Haller's, and Sattler's layer thickness in intermediate age-related macular degeneration with and without fellow neovascular eyes.

Purpose: To analyze choroidal, Sattler's, and Haller's layer thickness maps in age-related macular degeneration (AMD) patients having eyes with bilateral large drusen and pigment changes (intermediate AMD), in patients having intermediate AMD eyes with neovascular fellow eyes (nAMD), and in healthy subjects using three-dimensional (3D) 1060-nm optical coherence tomography (OCT).

Methods: Automatically generated choroidal thickness (ChT), retinal thickness, and Sattler's and Haller's layer thickness maps were statistically analyzed in 67 subjects consisting of intermediate AMD (n = 21), intermediate AMD (n = 22) with fellow nAMD eyes (n = 22), and healthy eyes (n = 24) with no age and axial eye length difference between groups of eyes (P > 0.05, ANOVA).

Choroidal Haller's and Sattler's layer thickness measurement using 3-dimensional 1060-nm optical coherence tomography.

Objectives: To examine the feasibility of automatically segmented choroidal vessels in three-dimensional (3D) 1060-nmOCT by testing repeatability in healthy and AMD eyes and by mapping Haller's and Sattler's layer thickness in healthy eyes.

Methods: Fifty-five eyes (from 45 healthy subjects and 10 with non-neovascular age-related macular degeneration (AMD) subjects) were imaged by 3D-1060-nmOCT over a 36°x36° field of view. Haller's and Sattler's layer were automatically segmented, mapped and averaged across the Early Treatment Diabetic Retinopathy Study grid.

Choroidal thickness in patients with reticular pseudodrusen using 3D 1060-nm OCT maps.

Purpose: To map and analyze choroidal thickness (ChT) in AMD patients with reticular pseudodrusen (RPD) using three-dimensional (3D) 1060-nm optical coherence tomography (OCT).

Methods: Fifty eyes from 25 patients with RPD were grouped according to the severity of AMD and the presence of RPD. All patients were imaged by high-speed (60,000 A-scans/s) 3D 1060-nm OCT over a 36 × 36° field of view.

Automated three-dimensional choroidal vessel segmentation of 3D 1060 nm OCT retinal data.

A fully automated, robust vessel segmentation algorithm has been developed for choroidal OCT, employing multiscale 3D edge filtering and projection of "probability cones" to determine the vessel "core", even in the tomograms with low signal-to-noise ratio (SNR). Based on the ideal vessel response after registration and multiscale filtering, with computed depth related SNR, the vessel core estimate is dilated to quantify the full vessel diameter. As a consequence, various statistics can be computed using the 3D choroidal vessel information, such as ratios of inner (smaller) to outer (larger) choroidal vessels or the absolute/relative volume of choroid vessels.

Choroidal thinning in diabetes type 1 detected by 3-dimensional 1060 nm optical coherence tomography.

Purpose: To map choroidal (ChT) and retinal thickness (RT) in patients with diabetes type 1 with and without maculopathy and retinopathy in order to compare them with healthy subjects using high speed 3-dimensional (3D) 1060 nm optical coherence tomography (OCT).

Methods: Thirty-three eyes from 33 diabetes type 1 subjects (23-57 years, 15 male) divided into groups of without pathology (NDR) and with pathology (DR; including microaneurysms, exudates, clinically significant macular-oedema and proliferative retinopathy) were compared with 20 healthy axial eye length and age-matched subjects (24-57 years, 9 male), imaged by high speed (60.000 A-scans/s) 3D 1060 nm OCT performed over 36° × 36° field of view.

Is whole-body hydration an important consideration in dry eye?

Purpose: To identify if whole-body hydration plays an important role in dry eye (DE). We hypothesized that individuals classified as DE have higher plasma osmolality (Posm), indicating suboptimal hydration, compared with those classified as non-DE.

Methods: Using a hospital-based observational cross-sectional design, assessment of DE and hydration was performed upon admission in 111 participants (N = 56 males and 55 females; mean ± SD age 77 ± 8 years).

Automated choroidal segmentation of 1060 nm OCT in healthy and pathologic eyes using a statistical model.

A two stage statistical model based on texture and shape for fully automatic choroidal segmentation of normal and pathologic eyes obtained by a 1060 nm optical coherence tomography (OCT) system is developed. A novel dynamic programming approach is implemented to determine location of the retinal pigment epithelium/ Bruch's membrane /choriocapillaris (RBC) boundary. The choroid-sclera interface (CSI) is segmented using a statistical model.

Retinal and choroidal thickness in early age-related macular degeneration.

Purpose: To compare retinal thickness and choroidal thickness at increasing retinal eccentricity in individuals with early age-related macular degeneration (AMD) and in healthy controls using enhanced choroidal penetration, 3-dimensional optical coherence tomography at 1060 nm.

Design: Cross-sectional study.

Methods: Individuals with early AMD (n = 16; mean age, 71.

Mapping choroidal and retinal thickness variation in type 2 diabetes using three-dimensional 1060-nm optical coherence tomography.

Purpose: To map choroidal (ChT) and retinal thickness (RT) in healthy subjects and patients with diabetes with and without maculopathy using three dimensional 1060-nm optical coherence tomography (3D-1060nm-OCT).

Methods: Sixty-three eyes from 42 diabetic subjects (41-82 years of age; 11 females) grouped according to a custom scheme using Early Treatment Diabetic Retinopathy Study definitions for pathology within 1 disc-diameter of fovea (without pathology [NDR], microaneurysms [M1], exudates [M2], clinically significant macular edema [CSME]) and 16 eyes from 16 healthy age matched subjects (38-79 years of age; 11 females) were imaged by 3D-1060nm-OCT performed over a 36° × 36° field of view. Axial length, 45° fundus photographs, body mass index, plasma glucose, and blood pressure measurements were recorded.

Tear fluid osmolarity as a potential marker of hydration status.

Unlabelled: It has been suggested that tear fluid is isotonic with plasma, and plasma osmolality (P(osm)) is an accepted, albeit invasive, hydration marker. Our aim was to determine whether tear fluid osmolarity (T(osm)) assessed using a new, portable, noninvasive, rapid collection and measurement device tracks hydration.

Purpose: This study aimed to compare changes in T(osm) and another widely used noninvasive marker, urine specific gravity (USG), with changes in P(osm) during hypertonic-hypovolemia.

Three-dimensional 1060-nm OCT: choroidal thickness maps in normal subjects and improved posterior segment visualization in cataract patients.

Purpose: To evaluate the performance and potential clinical role of three-dimensional (3D) 1060-nm OCT by generating choroidal thickness (ChT) maps in patients of different ages with different degrees of ametropia and axial lengths and to investigate the effect of cataract grade on OCT retinal imaging quality.

Methods: Axial lengths (ALs) and 45° fundus photographs were acquired from 64 eyes (34 healthy subjects, 19 to 80 years, ametropia +3 to -10 D). 3D 1060-nm OCT was performed over a 36° × 36° field of view with ∼7-μm axial resolution and up to 70 frames/s (512 A-scans/frame).

Impact of enhanced resolution, speed and penetration on three-dimensional retinal optical coherence tomography.

: Recent substantial developments in light source and detector technology have initiated a paradigm shift in retinal optical coherence tomography (OCT) performance. Broad bandwidth light sources in the 800 nm and 1060 nm wavelength region enable axial OCT resolutions of 2-3 mum and 5-7 mum, respectively. Novel high speed silicon based CMOS cameras at 800 nm and InGaAs based CCD cameras in combination with frequency domain OCT technology enable data acquisition speeds of up to 47,000 A-scans/s at 1060 nm and up to 312,500 A-scans/s at 800 nm.

Tear sample collection using cellulose acetate absorbent filters.

Purpose: To assess the use of cellulose acetate filter rods as a technique for tear collection.

Method: The cellulose acetate rod (CR) was compared with the 'standard' glass capillary tube (CT), in a series of experiments, to assess: sample collection by collected volume size; the effect of tear stimulation on total tear protein concentration and major tear protein concentrations; and technique invasiveness.

Results: No difference was found in concentrations for total protein, IgA (secretory immunoglobulin A), lactoferrin and lysozyme (p > 0.

The neonatal tear film.

The importance of the tear film for the integrity of the ocular surface is well established. Full-term neonates produce tears normally, but low spontaneous blink rates during early life raises important questions regarding tear dynamics and stability. Although an afferent neural pathway that could potentially detect tear break-up is in place at birth, there is indirect evidence that the neonatal tear film is adapted to resist evaporation-mediated tear thinning.