Histopathology and electron microscopy evaluation of the sildenafil effect on diabetic rats' retinae.

Purpose: Although there is increasing evidence that phosphodiesterase-5 (PDE-5) inhibitors modify the effect of diabetes on different tissues, its effect on diabetic retinopathy is not well studied.

Methods: Forty male Sprague-Dawley (SD) rats were divided into four groups: group I = control group that received no treatment; group II (diabetic group), in which diabetes was induced by a single streptozotocin injection; group III (sildenafil small dose, SSD), in which diabetes was similarly introduced (however, rats received daily oral 1 mg/kg sildenafil citrate (SC) for 3 months); and group IV (sildenafil large dose, SLD), which was as in group 3, but SC was 2.5 mg/kg.

Chronic sildenafil citrate use decreases retinal vascular endothelial growth factor expression in diabetic rats: a pilot study.

Background: Sildenafil citrate (SC) attenuates endothelial dysfunction. However, its effects on diabetic retinopathy (DR), which is mainly a microvascular disease, remain unclear. Vascular endothelial growth factor (VEGF) is known to be a critical mediator of DR.

Persistent diabetic macular edema: Definition, incidence, biomarkers, and treatment methods.

Intravitreal antivascular endothelial growth factor (anti-VEGF) treatment has drastically improved the visual and anatomical outcomes in patients with diabetic macular edema (DME); however, success is not always guaranteed, and a proportion of these eyes demonstrate persistent DME (pDME) despite intensive treatment. While standardized criteria to define these treatment-resistant eyes have not yet been established, many studies refer to eyes with no clinical response or an unsatisfactory partial response as having pDME. A patient is considered to have pDME if the retinal thickness improves less than 10-25% after 6 months of treatment.

Evaluation of Urgent Retinal Practice and Safety Measures for Physicians and Patients During COVID-19 Pandemic.

Purpose: To assess the impact of the COVID-19 pandemic on urgent retina practice and factors influencing adherence of physicians and patients to safety measures.

Methods: In this clinical audit, urgent or emergent vitreoretinal surgical disorders that presented to our hospital during the period of 15th March-15th May 2020 were compared with the period just before the pandemic declaration (15th December 2019-15th February 2020). Additionally, two questionnaires assessing the adherence to safety measures were circulated to the medical personnel and a sample of patients.

Influence of narrow-band ultraviolet B therapy on sirtuin 1 expression in lesional skin of patients with chronic plaque psoriasis: Relation to clinical improvement and interferon-γ expression.

Background: Reduced sirtuin 1 (Sirt1) expression in psoriasis was previously reported, and its activation was associated with disease improvement. Narrow-band ultraviolet B (NB-UVB) downregulates several pro-inflammatory cytokines such as interferon-γ (IFN-γ) and influences keratinocyte differentiation in psoriasis.

Objectives: The aim of this study was to study the in vivo influence NB-UVB treatment on Sirt1 expression in psoriatic skin in relation to disease improvement and IFN-γ expression.

Optical Coherence Tomography Angiography Biomarkers Predict Anatomical Response to Bevacizumab in Diabetic Macular Edema.

Purpose: To identify biomarkers that may predict an early anatomical response to the treatment of diabetic macular edema (DME) with intravitreal bevacizumab (IVB) by means of optical coherence tomography angiography (OCTA).

Methods: This study is a retrospective study of treatment-naïve patients with DME who underwent 6 × 6 mm OCTA imaging of the macula at baseline and after three monthly IVB injections. Thirty-six eyes of 23 patients were included.

Incidence and Risk Factors for Retinopathy of Prematurity (ROP) in Biggest Neonatal Intensive Care Unit in Itay Elbaroud City, Behera Province, Egypt.

Aim Of The Work: To evaluate the incidence and risk factors for development of retinopathy of prematurity (ROP) in the biggest neonatal intensive care unit (NICU) in Itay Elbaroud City, Behera province, Egypt.

Methods: We studied data of 240 newly born infants with gestational age (GA) ≤34 weeks or birth weight (BW) ≤2000 g or infants with unstable course who were admitted to the biggest NICU in Itay Elbaroud City, Behera province, Egypt, 
between October 1, 2018 and October 31, 2020. There is no standard screening system in Egypt.

Mean macular intercapillary area in eyes with diabetic macular oedema after anti-vascular endothelial growth factor therapy and its association with treatment response.

Background: To evaluate the changes in the mean macular intercapillary area (ICA) from sequential enface optical coherence tomography angiography (OCTA) images following intravitreal anti-vascular endothelial growth factor (VEGF) therapy in initially treatment-naïve eyes with diabetic macular oedema (DME).

Methods: In this multicentre retrospective study, 6 × 6 and 3 × 3 mm customised, total retinal projection enface OCTA images were collected and processed for quantitative assessment of ICA by a customised MATLAB software. Measurements were done in concentric regions centred on the fovea-with the exclusion of foveal avascular zone (FAZ)-in 0.

Intravitreal injections of anti-VEGF agents during COVID-19 pandemic: clinical audit from Tanta University Hospital.

Background: The aims of this study were to provide real-life data about the effect of COVID-19 pandemic on the practice of anti-VEGF injections and to evaluate the safety of the modifications in the injection protocol imposed during the ongoing pandemic on the anatomical and functional outcome of patients.

Methods: All patients attending Tanta University hospital for receiving intravitreal anti-VEGF injections were screened. Patients who were previously deferred according to a modified protocol implemented in the hospital in response to the pandemic or who demonstrated deviation from it were included for further analysis.

Trichoscopic signs of tinea capitis: a guide for selection of appropriate antifungal.

Background: Tinea capitis is the most common pediatric dermatophyte infection. Optimal treatment regimen differs according to the type of the dermatophyte involved.

Objectives: The aim of this work was to study the trichoscopic signs in relation to isolated organism in a sample of Egyptian patients with tinea capitis and the possibility of using them as a guide for selection of appropriate antifungal.

Differential Modulation of Autophagy Contributes to the Protective Effects of Resveratrol and Co-Enzyme Q10 in Photoaged Mice.

Background: In photoaging, the accumulation of ultraviolet (UV)-induced oxidative damage leads to the characteristic hallmarks of aging. Here arises the importance of autophagy as a cellular degradation process that cleans the cells of defective or aged organelles and macromolecules, thus maintaining cellular homeostasis. In spite of this, the exact impact of autophagy in photoaging is still elusive.

Visual and anatomic outcomes of sustained single agent anti-VEGF treatment versus double anti-VEGF switching in the treatment of persistent diabetic macular edema.

Background: To compare the anatomical and visual outcomes in eyes with persistent diabetic macular edema (DME) after initial anti-VEGF therapy that were retreated continuously with the same anti-VEGF drug versus those that underwent two successive cycles of medication change in anti-VEGF drugs (double anti-VEGF switch).

Methods: Retrospective review of eyes with persistent DME after 3 initial consecutive monthly anti-VEGF injections. This cohort was divided into two groups: Group 1 continued to receive the same initial anti-VEGF drug for at least 18 months while group 2 eyes were switched to different anti-VEGF medications twice.

Morphological changes in intraretinal microvascular abnormalities after anti-VEGF therapy visualized on optical coherence tomography angiography.

Background: To examine the baseline morphological characteristics and alterations in intraretinal microvascular abnormalities (IRMAs) in response to anti-vascular endothelial growth factor (anti-VEGF) treatment, documented by optical coherence tomography angiography (OCTA) in diabetic eyes.

Methods: In this retrospective study, IRMAs were evaluated with multimodal imaging (fundus photography, fluorescein angiography, OCTA) in treatment-naïve diabetic eyes before and after anti-VEGF treatment for diabetic macular edema (DME) and/or proliferative diabetic retinopathy (PDR) and compared to diabetic control eyes with similar diabetic retinopathy (DR) severity that did not receive anti-VEGF therapy. The morphological characteristics of IRMAs on enface OCTA imaging were graded by masked readers at baseline, then after anti-VEGF therapy in treated eyes or after observation in control eyes.

Topographic analysis of macular choriocapillaris flow deficits in diabetic retinopathy using swept-source optical coherence tomography angiography.

Background: The purpose of this study was to investigate the association between diabetic retinopathy (DR) severity and macular choriocapillaris (CC) flow deficit percentage (FD %) in different macular regions using swept-source optical coherence tomography angiography (SS-OCTA).

Methods: Diabetic patients with SS-OCTA images were graded by severity and retrospectively assessed. CC FD % was calculated in four different regions of the OCTA image: inner, middle, outer, and full-field region.

Global Analysis of Macular Choriocapillaris Perfusion in Dry Age-Related Macular Degeneration using Swept-Source Optical Coherence Tomography Angiography.

Purpose: Swept-source optical coherence tomography angiography (SS-OCTA) was used to investigate if the clinical stage of dry age-related macular degeneration (AMD) was correlated with global and regional macular choriocapillaris (CC) perfusion.

Methods: In this retrospective, cross-sectional study, 6 × 6-mm SS-OCTA images from eyes with early, intermediate, and advanced dry AMD (56 eyes, 41 patients) were analyzed using algorithms described in the literature to assess regional flow deficit percentage (FD%) and average flow deficit size. Regions were defined by concentric areas centered on the fovea: a 1-mm-diameter area, 3-mm-diameter ring, 5-mm-diameter area, 5-mm-diameter ring, and 6 × 6-mm whole image.

Retinal Nonperfusion Relationship to Arteries or Veins Observed on Widefield Optical Coherence Tomography Angiography in Diabetic Retinopathy.

Purpose: To evaluate whether retinal capillary nonperfusion is found predominantly adjacent to arteries or veins in eyes with diabetic retinopathy (DR).

Methods: Sixty-three eyes from 44 patients with proliferative DR (PDR) or non-PDR (NPDR) were included. Images (12 × 12-mm) foveal-centered optical coherence tomography (OCT) angiography (OCTA) images were taken using the Zeiss Plex Elite 9000.

DISTINGUISHING INTRARETINAL MICROVASCULAR ABNORMALITIES FROM RETINAL NEOVASCULARIZATION USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

Purpose: With the increasing prevalence of diabetes, fast, noninvasive identification of proliferative diabetic retinopathy (PDR) becomes essential. This study evaluated the utility of optical coherence tomography angiography (OCTA) to characterize intraretinal microvascular abnormalities (IRMA) and retinal neovascularization (NV).

Methods: Patients with severe non-PDR or PDR were imaged with fluorescein angiography and widefield swept-source OCTA (Zeiss Plex Elite 9000; Carl Zeiss Meditec, Dublin, CA).

Accuracy and Reliability in Differentiating Retinal Arteries and Veins Using Widefield En Face OCT Angiography.

Purpose: To evaluate the accuracy and reliability in differentiating retinal arteries from veins using widefield optical coherence tomography angiography (OCTA).

Methods: Ten healthy eyes and 12 eyes from diabetic patients were included. Foveal-centered swept-source OCTA images (12 × 12 mm) were obtained using the PLEX Elite 9000.

Optical coherence tomography angiography analysis of macular vessel density before and after anti-VEGF therapy in eyes with diabetic retinopathy.

Purpose: To evaluate changes in macular vessel density following intravitreal anti-VEGF injection in patients with diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR).

Methods: In this retrospective case series, optical coherence tomography angiography (OCTA) images from 55 eyes of 35 patients with either DME (46 eyes) or PDR (9 eyes) were included. Macular capillary vessel density at the level of the superficial retinal capillary plexus (SCP), deep retinal capillary plexus (DCP) and total retinal capillary plexus (TCP) before and after anti-VEGF treatment was calculated.

Impact of Binarization Thresholding and Brightness/Contrast Adjustment Methodology on Optical Coherence Tomography Angiography Image Quantification.

Purpose: Binarization is a critical technique in optical coherence tomography angiography (OCTA) image analysis, but there is no consistency in the method used in published OCTA studies. This study assessed whether differences in OCTA binarization and brightness and contrast adjustments affect quantification measurements.

Design: Prospective cross-sectional validity study.

Optical coherence tomography angiography (OCTA) flow speed mapping technology for retinal diseases.

Introduction: Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality for depth-resolved visualization of retinal vasculature. Angiographic data couples with structural data to generate a cube scan, from which en-face images of vasculature can be obtained at various axial positions. OCTA has expanded understanding of retinal vascular disorders and has primarily been used for qualitative analysis.

White and yellow dots as new trichoscopic signs of severe female androgenetic alopecia in dark skin phototypes.

Background: Androgenetic alopecia or female pattern hair loss is the condition that most commonly leads to hair loss in adult females. The trichoscope is used for the early diagnosis of the disease. The study aims at finding a possible association between trichoscopic signs and disease severity in dark-skinned females.

Gamma Knife radiosurgery for locally recurrent choroidal melanoma following plaque radiotherapy.

Background: For the majority of eyes with choroidal melanoma, radiation therapy is the treatment of choice. Local recurrence after radiation therapy can occur, however, and when it does, salvaging the globe with useful vision is atypical.

Case Presentation: We report a case of late, local failure 7 years following previous brachytherapy successfully managed with Gamma Knife radiosurgery (GKR).

Use of OCTA, FA, and Ultra-Widefield Imaging in Quantifying Retinal Ischemia: A Review.

As ischemia remains a key prognostic factor in the management of various diseases including diabetic retinopathy, an increasing amount of research has been dedicated to its quantification as a potential biomarker. Advancements in the quantification of retinal ischemia have been made with the imaging modalities of fluorescein angiography (FA), ultra-widefield imaging (UWF), and optical coherence tomography angiography (OCTA), with each imaging modality offering certain benefits over the others. FA remains the gold standard in assessing the extent of ischemia.