Retina And Quantitative

Diabetic retinopathy (DR) can cause visual impairment and blindness, and the increasing global prevalence of diabetes underscores the need for effective therapies to prevent and treat DR. Therefore, this study aimed to evaluate the protective effect of pemafibrate treatment against DR, using a Spontaneously Diabetic Torii (SDT) fatty rat model of obese type 2 diabetes. SDT fatty rats were fed either a diet supplemented with pemafibrate (0.3 mg/kg/day) for 16 weeks, starting at 8 weeks of age (Pf SDT fatty: study group), or normal chow (SDT fatty: controls)...

PURPOSE: To report a case of pitchfork sign following pars plana vitrectomy for idiopathic epiretinal membrane. STUDY DESIGN: Case report. RESULTS: A 75-year-old man was referred to the surgical retina service due to a quantitative and qualitative decline in vision in the left eye (LE) for several months. Optical coherence tomography (OCT) examination revealed the presence of a stage III epiretinal membrane (ERM) according to the Govetto classification...

PURPOSE: To characterize any differences in the vasculature and cone photoreceptor packing geometry (CPG) between subjects with diabetes without/no diabetic retinopathy (NDR) and healthy controls. METHODS: Eight NDR and five controls were enrolled. Optical coherence tomography angiography (OCTA) taken at the macula was used to measure vessel density, vessel length density, and vessel density index (VDI) in three vascular plexuses, namely, the superficial vascular plexus, intermediate capillary plexus, and deep capillary plexus (DCP)...

PURPOSE: To examine retinal feature dynamics in eyes with neovascular age-related macular degeneration (nAMD) treated with anti-vascular endothelial growth factor (anti-VEGF) therapy and the relationship of these features with visual acuity. DESIGN: Post hoc analysis of the phase 3, randomized, HAWK nAMD clinical trial. PARTICIPANTS: Participants randomized to the brolucizumab 6 mg or aflibercept 2 mg arms of the trial. METHODS: Spectral domain optical coherence tomography (OCT) scans collected at 4-week intervals were analyzed using an automated machine learning-enhanced segmentation and feature-extraction platform with manual verification...

OBJECTIVES: To investigate the association between peripheral non-perfusion index (NPI) on ultrawide-field fluorescein angiography (UWF-FA) and quantitative OCT-Angiography (OCT-A) metrics in the macula. METHODS: In total, 48 eyes with UWF-colour fundus photos (CFP), UWF-FA (California, Optos) and OCT-A (Spectralis, Heidelberg) were included. OCT-A (3 × 3 mm) was used to determine foveal avascular zone (FAZ) parameters and vessel density (VD), perfusion density (PD), fractal dimension (FD) on superficial capillary plexus (SCP)...

BI-X, a therapeutic protein under development for the treatment of human ocular disease via intravitreal administration, binds to its therapeutic targets and endogenous albumin in the vitreous humor. A monkey ocular pharmacokinetic (PK) study following BI-X administration was conducted to measure drug and albumin levels in plasma, the vitreous humor, the aqueous humor, and retina tissue at various timepoints post-dose. A comprehensive bioanalytical approach was implemented in support of this study. Five immunocapture-LC-MS/MS assays were developed and qualified for quantitating BI-X in different matrices, while ELISA was used for albumin measurement...

The oriental armyworm, Mythimna separata (Walker), is a well-known nocturnal migratory pest that relies on its exceptional nocturnal vision for navigation during long-distance flights. In this study, we investigated the ultrastructure of the compound eyes of adult M. separata using transmission electron microscopy and quantitatively evaluated adaptational changes in the retina under light and dark conditions. The compound eyes of M. separata are superposition eyes with a clear zone. The retina shows remarkable anatomical differences under light and dark adaptation, primarily characterized by distinct patterns of rhabdoms within the clear zone: the rhabdoms are nearly absent under light adaptation, but become more voluminous under dark adaptation...

AIMS: To find potential relation between retrobulbar vessels and fundus microvessels and to detect sensitive and effective clinical indicators in predicting the progress of diabetic retinopathy (DR), ocular hemodynamics were measured using superb microvascular imaging (SMI) and ultrawide-field optical coherence tomography angiography (UWF-OCTA). METHODS: Observational, cross-sectional study evaluating ocular hemodynamics in patients with DR by SMI (Aplio i900, Canon Medical) and UWF-OCTA (BM-400 K BMizar, Tupai Medical Technology)...

INTRODUCTION: This study aimed to explore the effect and molecular mechanism of Tetrandrine (Tet) onlipopolysaccharide (LPS)-induceduveitis andoptic nerve injury in vivo and in vitro . METHODS: Uveitis was induced by LPS injected into the hindlimb foot pad of Wistar rats and was intervened by retroeyeball injection of Tet (100 nM, 1 μM or 10 μM).The anterior segment inflammation was observed by slit lamp. Tunelassay was used to detect the survival state of ganglion cells and nuclear layers of inner and outer...

Blindness poses a growing global challenge, with approximately 26% of cases attributed to degenerative retinal diseases. While gene therapy, optogenetic tools, photosensitive switches, and retinal prostheses offer hope for vision restoration, these high-cost therapies will benefit few patients. Understanding retinal diseases is therefore key to advance effective treatments, requiring in vitro models replicating pathology and allowing quantitative assessments for drug discovery. Pluripotent stem cells (PSCs) provide a unique solution given their limitless supply and ability to differentiate into light-responsive retinal tissues encompassing all cell types...

BACKGROUND: Hypertension influences the inflammatory pathological changes in the retina. The function of the inflammasomes is significant. To see if Sirtuin 1 (SIRT1) regulates angiotensin II (Ang II)-induced hypertensive retinopathy and inflammation by modulating NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome activation and the potential protective effects of fucoidan (FO) in mouse retinal vascular endothelial cells (mRECs) and mice retina. METHODS: The diagnosis of hypertensive retinopathy was made after three weeks of Ang II infusion (3000 ng/kg/min)...

BACKGROUND: Qualitative and quantitative assessment of retinal perfusion using optical coherence tomography angiography (OCTA) has shown to be effective in the treatment and management of various retinal and optic nerve diseases. However, manual analyses of OCTA images to calculate metrics related to Foveal Avascular Zone (FAZ) morphology, and retinal vascular density and morphology are costly, time-consuming, subject to human error, and are exposed to both inter and intra operator variability...

PURPOSE: To validate the quantitative assessment of metamorphopsia in rhegmatogenous retinal detachment(RRD) using M-CHARTS by determining its correlation with subjective reporting of metamorphopsia with a validated metamorphopsia questionnaire(modified MeMoQ). METHODS: Research Ethics Board approved, prospective observational study carried out at St. Michael's Hospital, Toronto, Canada. Patients with primary, unilateral RRD and healthy controls were included. Metamorphopsia at 3-months was assessed with modified MeMoQ and M-CHARTS...

PURPOSE: To assess the retinal vasculature changes quantitatively using wide-field optical coherence tomography angiography (OCTA) in systemic lupus erythematosus (SLE), and explore its correlation with systemic clinical features. DESIGN: Prospective, cross-sectional, observational study. PARTICIPANTS AND CONTROLS: Patients with SLE who presented to the Ophthalmology Department of Peking Union Medical College Hospital from November 2022 to April 2023 were collected...

PURPOSE: To investigate the incidence and morphological biomarkers to predict the exudative conversion in eyes with type 1 nonexudative macular neovascularization (MNV) using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: MNVs were detected using the retinal pigment epithelium (RPE)-to-RPE-fit slab of SS-OCTA scan. Depending on whether exudation developed within a year, the eyes were divided into two groups: active and silent. Qualitative and quantitative OCTA parameters of the two groups were evaluated to discriminate the biomarkers associated with exudative conversion...

Myopia is widely recognized as an epidemic. Studies have found a link between Transforming Growth Factor-beta (TGF-β) and myopia, but the specific molecular mechanisms are not fully understood. In this study, a monocular model in tree shrews (Tupaia belangeri) was established to verify the molecular mechanism of TGF-β in myopia. The results indicated that there were significant changes in TGF-βs during the treatment of myopia, which could enhance the refractive ability and axial length of the eye...

BACKGROUND AND OBJECTIVE: We sought to establish normative quantitative contrast sensitivity function (qCSF) values in healthy adult eyes and investigate the effect of age on qCSF. PATIENTS AND METHODS: Healthy eyes underwent qCSF testing (adaptive sensory technology) and Snellen's visual acuity (VA). Descriptive statistics and mixed-effects multivariable linear regressions were evaluated. RESULTS: A total of 334 eyes (290 patients) with median age 61 years (range 21 to 88) had qCSF values as follows: area under the log contrast sensitivity function curve: 1...

PURPOSE: Thyroid-associated ophthalmopathy (TAO) may result in increased metabolism and abnormalities in microcirculation. The fractal dimension (Df) of retinal vessels has been shown to be related to the pathology of a number of ophthalmic disorders, but it hasn't been investigated in TAO. METHODS: We analyzed 1078 participants aged 18 to 72 (548 healthy volunteers and 530 TAO). Images were captured using a non-mydriatic 45-degree fundus camera. Baseline retinal characteristics, such as vessel width, tortuosity, and Df were measured using semiautomated software from fundus images...

PURPOSE: To analyze the alterations at the level of the inner retina in patients affected by Stargardt disease (STGD1). METHODS: Cross-sectional investigation involving STGD1 patients with genetically confirmed diagnosis, who underwent optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), and microperimetry. RESULTS: Overall, 31 patients (62 eyes) with genetically confirmed STGD1 were included in the study. Mean inner retinal thickness, vessel density of plexa, and retinal sensitivity resulted significantly reduced in STGD patients, compared with healthy controls ( p  < 0...

Oculocutaneous albinism (OCA) is characterized by reduced melanin biosynthesis affecting the retina, thus impairing visual function. The disease pathology of OCA is poorly understood at the cellular level due to unavailability of suitable biological model systems. This study aimed to develop a disease-specific in vitro model for OCA type 1A, the most severe form caused by TYR (tyrosinase) gene mutations, using retinal pigment epithelium (RPE) differentiated from patient-derived human-induced pluripotent stem cells (hiPSCs)...