Hyperglycemia Promotes Mitophagy and Thereby Mitigates Hyperglycemia-Induced Damage.

The observation that diabetic retinopathy (DR) typically takes decades to develop suggests the existence of an endogenous system that protects from diabetes-induced damage. To investigate the existance of such a system, primary human retinal endothelial cells were cultured in either normal glucose (5 mmol/L) or high glucose (30 mmol/L; HG). Prolonged exposure to HG was beneficial instead of detrimental.

VEGFR2 Trafficking by KIF13B Is a Novel Therapeutic Target for Wet Age-Related Macular Degeneration.

Purpose: Vascular endothelial growth factor (VEGF) and its receptor VEGFR2 are promising therapeutic targets for wet age-related macular degeneration (AMD). As a topically applicable option, we developed the peptide KAI to selectively interfere with VEGFR2 trafficking to the cell surface where it receives VEGF. This study sought to determine the efficacy of KAI in the mouse model of choroidal neovascularization (CNV).

Bone-marrow mesenchymal stem-cell administration significantly improves outcome after retinal ischemia in rats.

Purpose: Ischemia-associated retinal degeneration is one of the leading causes of vision loss, and to date, there are no effective treatment options. We hypothesized that delayed injection of bone-marrow stem cells (BMSCs) 24 h after the onset of ischemia could effectively rescue ischemic retina from its consequences, including apoptosis, inflammation, and increased vascular permeability, thereby preventing retinal cell loss.

Methods: Retinal ischemia was induced in adult Wistar rats by increasing intraocular pressure (IOP) to 130-135 mmHg for 55 min.

Induction of autophagy in rats upon overexpression of wild-type and mutant optineurin gene.

Background: Optineurin is a gene associated with normal tension glaucoma and amyotrophic lateral sclerosis. It has been reported previously that in cultured RGC5 cells, the turnover of endogenous optineurin involves mainly the ubiquitin-proteasome pathway (UPP). When optineurin is upregulated or mutated, the UPP function is compromised as evidenced by a decreased proteasome β5 subunit (PSMB5) level and autophagy is induced for clearance of the optineurin protein.

Feasibility of assessment of conjunctival microvascular hemodynamics in unilateral ischemic stroke.

Since the internal carotid artery supplies blood to both the eye and the brain, ocular microvascular hemodynamics can be altered due to ischemic stroke. The purpose of the current study was to establish the feasibility of conjunctival microcirculation imaging for detection of inter-ocular differences in microvascular hemodynamics in subjects with unilateral ischemic stroke. Conjunctival microcirculation imaging was performed in both eyes of 15 healthy control subjects and 12 subjects following unilateral ischemic stroke.

Inner and outer retinal thickness mapping of nonproliferative diabetic retinopathy by spectral-domain optical coherence tomography.

Background And Objective: To report inner retinal thickness (IRT), outer retinal thickness (ORT), and total retinal thickness (TRT) mapping of nonproliferative diabetic retinopathy (DR).

Patients And Methods: Spectral-domain optical coherence tomography (SD-OCT) images were obtained in 31 study participants with nonproliferative DR. Semi-automated software generated IRT, ORT, and TRT maps.

A Method for En Face OCT Imaging of Subretinal Fluid in Age-Related Macular Degeneration.

Purpose. The purpose of the study is to report a method for en face imaging of subretinal fluid (SRF) due to age-related macular degeneration (AMD) based on spectral domain optical coherence tomography (SDOCT). Methods.

Conjunctival microvascular haemodynamics in sickle cell retinopathy.

Purpose: To determine alterations in bulbar conjunctival microvascular haemodynamics in sickle cell retinopathy (SCR) subjects with focal macular thinning (FMT).

Methods: Conjunctival microcirculation imaging and spectral domain optical coherence tomography (SD-OCT) were performed in 22 subjects (eyes) diagnosed with SCR. Based on evaluation of SD-OCT retinal thickness maps, eyes were assigned to one of the two groups: with or without FMT.

Wavefront error correction with adaptive optics in diabetic retinopathy.

Purpose: To determine the effects of diabetic retinopathy (DR), increased foveal thickness (FT), and adaptive optics (AO) on wavefront aberrations and Shack-Hartmann (SH) image quality.

Methods: Shack-Hartmann aberrometry and wavefront error correction were performed with a bench-top AO retinal imaging system in 10 healthy control and 19 DR subjects. Spectral domain optical coherence tomography was performed and central FT was measured.

Neural constraints on visual acuity in proliferative diabetic retinopathy.

Purpose: Visual acuity (VA) in normally sighted individuals is highly correlated with equivalent intrinsic blur, a measure of the amount of blur within the visual system that is generated by optical and neural sources. This study assessed the extent to which VA, equivalent intrinsic blur, optical blur, and neural blur are abnormal in subjects with proliferative diabetic retinopathy (PDR) and characterized the relationships among these parameters.

Methods: Best-corrected VA of 10 subjects with PDR (ages 25 to 68) and 10 normally sighted individuals (ages 46 to 63) was measured for tumbling E optotypes.

En face spectral-domain optical coherence tomography outer retinal analysis and relation to visual acuity.

Purpose: To describe a method of en face visualization and quantification of the photoreceptor inner segment/outer segment junction area, using spectral-domain optical coherence tomography, and association with visual acuity.

Methods: Case series of 74 eyes in 53 patients. Central 1-mm and 400-μm en face areas were analyzed with a computer algorithm.

Feasibility of a method for en face imaging of photoreceptor cell integrity.

Purpose: To report a method for en face imaging of the photoreceptor inner and outer segment junction by spectral-domain optical coherence tomography (SD OCT) and to describe findings in normal subjects and patients with various retinal diseases.

Design: Observational case series.

Methods: SD OCT images were acquired from 6 normal subjects (mean age, 44 ± 11 years) and from 5 subjects with retinal diseases (mean age, 66 ± 22 years).

Contributions of optical and non-optical blur to variation in visual acuity.

Purpose: To determine the relative contributions of optical and non-optical sources of intrinsic blur to variations in visual acuity (VA) among normally sighted subjects.

Methods: Best-corrected VA of 16 normally sighted subjects was measured using briefly presented (59 ms) tumbling E optotypes that were either unblurred or blurred through convolution with Gaussian functions of different widths. A standard model of intrinsic blur was used to estimate each subject's equivalent intrinsic blur (σint) and VA for the unblurred tumbling E (MAR0).

Thickness mapping of retinal layers by spectral-domain optical coherence tomography.

Purpose: To report normal baseline thickness maps for 6 retinal layers generated by segmentation of spectral-domain optical coherence tomography (SD-OCT) images in normal subjects. Intersubject thickness variability and thickness variations in 9 macular sectors were established.

Design: Prospective cross-sectional study.

Differential macular morphology in patients with RPE65-, CEP290-, GUCY2D-, and AIPL1-related Leber congenital amaurosis.

Purpose: To evaluate genotypic and macular morphologic correlations in patients with RPE65-, CEP290-, GUCY2D-, or AIPL1-related Leber congenital amaurosis (LCA) using spectral-domain optical coherence tomography (SD-OCT).

Methods: SD-OCT macular scans were performed in 21 patients, including 10 with RPE65, 7 with CEP290, 3 with GUCY2D, and 1 with AIPL1 mutations. An image processing software was used to manually draw segmentation lines by three observers.

Correlation between microaneurysms and retinal thickness in diabetic macular edema.

Purpose: Microaneurysms commonly are believed to be related causally to retinal thickening in diabetic retinopathy, especially by leaking. The hypothesis that thicker areas of retina in diabetic retinopathy have more microaneurysms per unit area than areas that are not as thick was tested.

Methods: Retinal thickness analysis was performed with a prototype instrument for 27 eyes of 27 diabetic patients and 22 normal eyes of 22 healthy subjects.

Thickness profiles of retinal layers by optical coherence tomography image segmentation.

Purpose: To report an image segmentation algorithm that was developed to provide quantitative thickness measurement of six retinal layers in optical coherence tomography (OCT) images.

Design: Prospective cross-sectional study.

Methods: Imaging was performed with time- and spectral-domain OCT instruments in 15 and 10 normal healthy subjects, respectively.

A method for three-dimensional imaging of the retina in human eyes.

Background And Objectives: An optical system for three-dimensional imaging of the retinal tissue in human eyes is described.

Patients And Methods: A laser beam was projected at an oblique angle on the retina and scanned to acquire 40 optical section images in a 1.0 x 1.

Nerve fiber layer thickness in glaucoma patients with asymmetric hemifield visual field loss.

Purpose: To investigate the presence of retinal nerve fiber layer (RNFL) thinning and determine the relationship between RNFL thickness and visual field sensitivity loss in glaucoma patients with asymmetric hemifield visual field loss.

Patients And Methods: Thirty glaucoma patients with asymmetric hemifield visual field loss and 30 normal control subjects were included in the study. RNFL thickness was measured by optical coherence tomography and visual field sensitivity was measured by automated perimetry.

A method for differentiating ocular higher-order aberrations from light scatter applied to retinitis pigmentosa.

Purpose: The purpose of this study is to report a method for differentiating ocular higher-order aberrations and intraocular light scatter based on a deconvolution technique.

Methods: An optical system was used to image a laser slit on the retina and also to perform Shack-Hartmann wavefront sensing. From the laser slit image, the line spread function, incorporating both ocular higher-order aberrations and light scatter, was derived.

Higher-order wavefront aberrations in retinitis pigmentosa.

Purpose: The purpose of this study was to characterize higher-order wavefront aberrations associated with posterior subcapsular (PSC) cataracts in patients with retinitis pigmentosa (RP).

Methods: Wavefront aberrations were measured by Shack-Hartmann (SH) aberrometry in eight patients with RP who had PSC cataracts, 10 patients with RP who had minimal or no PSC cataracts, and 16 age-equivalent visually normal control subjects. Higher-order wavefront aberrations for 3-mm and 6-mm pupil diameters were defined as the root mean square (RMS) of the wavefront aberration functions.

Quantitative thickness measurement of retinal layers imaged by optical coherence tomography.

Purpose: To report an image analysis algorithm that was developed to provide quantitative thickness measurement of retinal layers on optical coherence tomography (OCT) images.

Design: Prospective cross-sectional study.

Methods: Imaging was performed with an OCT3 commercial instrument in 10 visually normal healthy subjects.

Optical section retinal imaging and wavefront sensing in diabetes.

Purpose: To investigate differences in higher-order ocular aberrations and in optical section retinal image resolution between healthy normal and diabetic subjects.

Methods: An optical imaging system was established for combined retinal optical section imaging and wavefront sensing. A laser beam was expanded and focused to a point on the retina by the optics of the eye.

Feasibility of noninvasive imaging of chorioretinal oxygenation.

Background And Objective: The feasibility of an optical system for noninvasive imaging of chorioretinal oxygenation was evaluated. Due to its depth discrimination, this optical section imaging technique has potential for differential imaging of oxygen tension in the chorioretinal vasculatures.

Materials And Methods: The method consisted of projecting a narrow laser line obliquely on the retina after intravenous injection of an oxygen-sensitive probe and imaging the phosphorescence emission.