Photoreceptor outer segment reflectivity with ultrahigh resolution visible light optical coherence tomography in systemic hydroxychloroquine use.

Purpose: To evaluate outer retinal organization in normal subjects and those using hydroxychloroquine (HCQ) with ultrahigh resolution visible light optical coherence tomography (VIS-OCT).

Methods: Forty eyes of 22 adult subjects were recruited from a tertiary care retina practice including controls (20 eyes, 12 subjects, mean age 40±22yrs, mean logMAR BCVA 0.19, 90% female) and subjects with a history of HCQ use (20 eyes, 10 subjects, mean age 62±17yrs, mean logMAR BCVA 0.

Biological and Methodological Variability in Retinal Nerve Fiber Layer OCT: The Framingham Heart Study.

Objective: To explore participant-level biological attributes and scan-level methodological attributes associated with retinal nerve fiber layer (RNFL) thickness variability in a population-based sample of elderly United States adults.

Design: Cross-sectional analysis using data from the Framingham Heart Study.

Participants: One thousand three hundred forty-seven eyes from 825 participants with ≥1 OCT scan and axial length data were included.

Rigid alignment method for secondary analyses of optical coherence tomography volumes.

Optical coherence tomography (OCT) provides micron level resolution of retinal tissue and is widely used in ophthalmology. Millions of pre-existing OCT images are available from research and clinical databases. Analysis of this data often requires or can benefit significantly from image registration and reduction of speckle noise.

Long-term Follow-up of a Phase 1/2a Clinical Trial of a Stem Cell-Derived Bioengineered Retinal Pigment Epithelium Implant for Geographic Atrophy.

Purpose: To report long-term results from a phase 1/2a clinical trial assessment of a scaffold-based human embryonic stem cell-derived retinal pigmented epithelium (RPE) implant in patients with advanced geographic atrophy (GA).

Design: A single-arm, open-label phase 1/2a clinical trial approved by the United States Food and Drug Administration.

Participants: Patients were 69-85 years of age at the time of enrollment and were legally blind in the treated eye (best-corrected visual acuity [BCVA], ≤ 20/200) as a result of GA involving the fovea.

The role of poroelastic diffusion in the transient wetting behavior of hydrogels.

Wetting and water absorption of hydrogels is often encountered in many applications. We seek to understand how wetting behavior can be affected by the time-dependent swelling of hydrogels. We measured the advancing contact angles of water droplets on hydrogels of varying thicknesses where thicker gels absorbed water more slowly.

Retinal perfusion is linked to cognition and brain MRI biomarkers in Black Americans.

Introduction: We investigated whether retinal capillary perfusion is a biomarker of cerebral small vessel disease and impaired cognition among Black Americans, an understudied group at higher risk for dementia.

Methods: We enrolled 96 Black Americans without known cognitive impairment. Four retinal perfusion measures were derived using optical coherence tomography angiography.

Retinotopic degeneration of the retina and optic tracts in autosomal dominant Alzheimer's disease.

Introduction: We investigated the correlation between retinal thickness and optic tract integrity in subjects with autosomal dominant Alzheimer's disease (ADAD) causing mutations.

Methods: Retinal thicknesses and diffusion tensor images (DTI) were obtained using optical coherence tomography and magnetic resonance imaging, respectively. The association between retinal thickness and DTI measures was adjusted for age, sex, retinotopy, and correlation between eyes.

Alterations in Retinal Vascular and Oxygen Metrics in Treated and Untreated Proliferative Diabetic Retinopathy: A Case Report.

Proliferative diabetic retinopathy (PDR) is a vision-threatening complication of diabetes. Panretinal photocoagulation (PRP) and anti-vascular endothelial growth factor (anti-VEGF) are approved treatment modalities aimed at regressing neovascularization. Data are lacking about abnormalities in retinal vascular and oxygen metrics before and after combination treatments.

Variability of Vascular Reactivity in the Retina and Choriocapillaris to Oxygen and Carbon Dioxide Using Optical Coherence Tomography Angiography.

Purpose: To investigate the regional and layer-specific vascular reactivity of the healthy human retina and choriocapillaris to changes in systemic carbon dioxide or oxygen.

Methods: High-resolution 3 × 3-mm2 optical coherence tomography angiography (OCTA) images were acquired from the central macula, temporal macula, and peripapillary retina while participants were exposed to three gas breathing conditions-room air, 5%CO2, and 100% O2. OCTA from all three regions were extracted and the apparent skeletonized vessel density (VSD) was assessed.

Recommendations for OCT Angiography Reporting in Retinal Vascular Disease: A Delphi Approach by International Experts.

Purpose: To develop a consensus nomenclature for reporting OCT angiography (OCTA) findings in retinal vascular disease (e.g., diabetic retinopathy, retinal vein occlusion) by international experts.

Stem cell-derived retinal pigment epithelium transplantation in age-related macular degeneration: recent advances and challenges.

Purpose Of Review: Age-related macular degeneration (AMD) is one of the leading causes of irreversible vision loss in the world with more than 80% of the prevalence accounted for by the nonneovascular (NNAMD) or 'dry' form of the disease. NNAMD does not have any definitive treatment once vision loss has ensued and presents a major unmet medical need. This review will highlight stem cell-based therapies that are a promising form of treatment for advanced NNAMD.

OCTA Derived Vessel Skeleton Density Versus Flux and Their Associations With Systemic Determinants of Health.

Purpose: To examine the associations of optical coherence tomography angiography (OCTA)-derived retinal capillary flux with systemic determinants of health.

Methods: This is a cross-sectional study of subjects recruited from the African American Eye Disease Study. A commercially available swept-source (SS)-OCTA device was used to image the central 3 × 3 mm macular region.

Capillary density and caliber as assessed by optical coherence tomography angiography may be significant predictors of diabetic retinopathy severity.

Purpose: To validate retinal capillary density and caliber associations with diabetic retinopathy (DR) severity in different clinical settings.

Methods: This cross-sectional study assessed retinal capillary density and caliber in the superficial retinal layer of 3-mm OCTA scans centered on the fovea. Images were collected from non-diabetic controls and subjects with mild or referable DR (defined DR worse than mild DR) between February 2016 and December 2019 at secondary and tertiary eye care centers.

Ocular and systemic determinants of perifoveal and macular vessel parameters in healthy African Americans.

Purpose: To determine the relationship of various systemic and ocular characteristics with perifoveal and macular vessel density in healthy African American eyes.

Design: A population-based cross-sectional study of prospectively recruited African Americans ≥40 years of age. Participants underwent 3×3 mm and 6×6 mm macula scans using spectral-domain optical coherence tomography angiography (OCTA), clinical examinations and clinical questionnaires.

Optical Coherence Tomography Angiography-Derived Flux As a Measure of Physiological Changes in Retinal Capillary Blood Flow.

Purpose: To compare optical coherence tomography angiography (OCTA)-derived flux with conventional OCTA measures of retinal vascular density in assessment of physiological changes in retinal blood flow.

Methods: Healthy subjects were recruited, and 3 × 3-mm2 fovea-centered scans were acquired using commercially available swept-source OCTA (SS-OCTA) while participants were breathing room air, 100% O2, or 5% CO2. Retinal perfusion was quantified using vessel area density (VAD) and vessel skeleton density (VSD), as well as novel measures of retinal perfusion, vessel area flux (VAF) and vessel skeleton flux (VSF).

Relating Retinal Vascular Oxygen Saturation and Microvasculature Morphology at Progressive Stages of Diabetic Retinopathy.

Purpose: Diabetic retinopathy (DR) is a common cause of vision loss in working age adults and presents changes in retinal vessel oxygenation and morphology. The purpose of this study was to test the hypothesis that there is an association of retinal vessel oxygen saturation with vessel density (VD) and tortuosity in DR.

Methods: Ninety-five subjects were classified in the following groups: nondiabetic control (N = 25), no DR (N = 28), mild nonproliferative DR (NPDR; N = 21), moderate to severe NPDR (N = 14), or treated proliferative DR (PDR; N = 7).

Retinal imaging demonstrates reduced capillary density in clinically unimpaired ε4 gene carriers.

Introduction: Apolipoprotein E () ε4, the strongest non-Mendelian genetic risk factor for Alzheimer's disease (AD), has been shown to affect brain capillaries in mice, with potential implications for AD-related neurodegenerative disease. However, human brain capillaries cannot be directly visualized in vivo. We therefore used retinal imaging to test ε4 effects on human central nervous system capillaries.

Phenotypic Identification and Genotypic Characterization of Plasmid-Mediated AmpC β-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae Isolates in Iran.

One of the mechanisms of Klebsiella pneumoniae and Escherichia coli resistance to β-lactam antibiotics is the production of β-lactamase enzymes. Among these are the AmpC β-lactamases, which confer resistance to a class of antibiotics. However, little is known about the AmpC β-lactamases of K.