Retinopathy of prematurity (ROP) and proliferative diabetic retinopathy (PDR) are ischemic retinal diseases caused by insufficient vascular network formation and vascular regression in addition to aberrant angiogenesis. We examined the role of angiopoietin-1 (Ang1) in retinal vascular network formation during postnatal development using Ang1 gain- and loss-of-function mouse models, and tested the effects of intraocular administration of Ang1 in an oxygen-induced retinopathy (OIR) mouse model that mimics cardinal features of ROP and PDR. We observed that Ang1 plays a substantial role in the formation of the retinal vascular network during postnatal development and that Ang1 supplementation can rescue vascular retinopathies by simultaneously promoting healthy vascular network formation and inhibiting subsequent abnormal angiogenesis, vascular leakage, and neuronal dysfunction in the retinas of the OIR model. We attribute these Ang1-induced effects to a dual signaling pathway-Tie2 signaling in the vascular region and integrin αvβ5 signaling in the astrocytes. The activation of integrin αvβ5 signaling promoted fibronectin accumulation and radial distribution along the sprouting endothelial cells, which consequently stimulated guided angiogenesis in the retina. These findings shed light on the role of Ang1 in the recovery of ischemic retinopathies such as ROP, PDR, and retinal vascular occlusive disease.
Age-related macular degeneration (AMD) is a major cause of blindness, but presents differently in Europeans and Asians. Here, we perform a genome-wide and exome-wide association study on 2,119 patients with exudative AMD and 5,691 controls, with independent replication in 4,226 patients and 10,289 controls, all of East Asian descent, as part of The Genetics of AMD in Asians (GAMA) Consortium. We find a strong association between CETP Asp442Gly (rs2303790), an East Asian-specific mutation, and increased risk of AMD (odds ratio (OR)=1.70, P=5.60 × 10−22). The AMD risk allele (442Gly), known to protect from coronary heart disease, increases HDL cholesterol levels by 0.17 mmol l−1 (P=5.82 × 10−21) in East Asians (n=7,102). We also identify three novel AMD loci: C6orf223 Ala231Ala (OR=0.78, P=6.19 × 10−18), SLC44A4 Asp47Val (OR=1.27, P=1.08 × 10−11) and FGD6 Gln257Arg (OR=0.87, P=2.85 × 10−8). Our findings suggest that some of the genetic loci conferring AMD susceptibility in East Asians are shared with Europeans, yet AMD in East Asians may also have a distinct genetic signature.
Ang1 supplementation can be established as a therapeutic strategy to suppress the CNV formation and vascular leakage by inhibiting the recruitment of angiogenic macrophages and tightening the endothelial junctions.
Purpose
The term “pachychoroid” refers to a newly described phenotype in which functional and structural choroidal changes are thought to play a key pathogenic role in a spectrum of related retinal disorders. A more detailed understanding of how the choroid is involved within this spectrum and a better knowledge of the most relevant clinical signs of the pachychoroid phenotype are important to differentiate these disorders from other retinal conditions. Our objectives are to provide a literature review of pachychoroid and the commonalities that may be present across pathologies included in the spectrum, and to provide details on the examination, monitoring, and management of these disorders.
Methods
We searched the PubMed web platform to identify relevant studies using the following keywords: pachychoroid, pachychoroid pigment epitheliopathy, pachychoroid neovasculopathy, aneurysmal type 1 neovascularization, focal choroidal excavation, peripapillary pachychoroid syndrome, vasculopathy pachysclera, pachychoroid geographic atrophy, and pachydrusen. We selected 157 publications and identified the most important features related to pachychoroid.
Results
The presence of hypertrophic or congested vessels in the choroid, not thickened choroid per se, under an area of reduced or absent choriocapillaris in the posterior pole seems to be the most salient feature of pachychoroid. However, other qualitative/quantitative features are needed to differentiate the uncomplicated pachychoroid from the pathological pachychoroid clinical spectrum, which may be associated with exudation, neovascularization, and/or retinal pigment epithelium and photoreceptor atrophy.
Conclusions
The most salient feature of pachychoroid appears to be the presence of large vessels under an area of reduced or absent choriocapillaris. Knowledge of the features and pathogenesis of the different disorders in the pachychoroid spectrum may assist in the management of patients.
PurposeTo investigate fixed-dosing aflibercept for treating polypoidal choroidal vasculopathy (PCV).MethodsThis phase IV, prospective, single-arm, interventional case series was conducted in eight centers. Forty treatment-naïve PCV patients were administered three monthly doses of intravitreal aflibercept (2.0 mg) and an injection every 2 months thereafter. Best-corrected visual acuity (BCVA) and central subfield macular thickness (CSMT) were measured at each visit. Fluorescein and indocyanine green angiography (ICGA) were performed at baseline, 3 and 12 months. The primary outcome measure was the proportion of patients who maintained BCVA (<15 letters loss) at 12 months. Changes in BCVA, macular appearance, and polypoidal lesion appearance were also examined.ResultsThirty-five eyes (87.5 %) had maintained BCVA at 12 months. Average BCVA was significantly higher at 12 months (20/53, 64.2 letters) than at baseline (20/80, 55.1 letters, 9-letter gain; P < .001). Mean CSMT was significantly lower at 12 months (253.6 μm) than at baseline (365.2 μm, P < .001). The macula was dry in 32 (76.2 %), 27 (64.3 %), and 24 eyes (60.0 %) at 3, 6, and 12 months respectively. Fourteen eyes (33.3 %) had a fluid recurrence or increase at 6 months, and they had a significantly lower vision gain (P = .005) than other patients at 12 months. Complete polyp regression occurred in 26 eyes (66.7 %) at 12 months.ConclusionsFixed-dosing aflibercept showed favorable outcomes in PCV patients at 12 months. However, some patients had worse outcomes because of fluid recurrence during maintenance dosing, and these patients would require additional treatments.
In our patient cohort, there was no statistically significant association between response to anti-VEGF therapy and the genotype in both positive-responder and negative-responder groups. Larger studies with more power are necessary to further determine whether a pharmacogenetic association exists between wet age-related macular degeneration and anti-VEGF therapy.
We report 3 cases of circumscribed choroidal hemangioma (CCH) effectively managed with intravitreal bevacizumab. One patient (case 1) who had recurrent CCH (1.6 mm in thickness) with prior laser photocoagulation was treated with intravitreal bevacizumab alone. Two patients (case 2 and 3) who had CCH (2.4 mm and 2.2 mm in thickness, respectively) with recent visual impairment were treated with bevacizumab followed by photodynamic therapy (PDT). Ophthalmic evaluations included visual acuity, ophthalmoscopic examination, fluorescein angiography, ultrasonography, and optical coherence tomography. Patients were followed up for 6-9 months. After therapy, all patients showed improved visual acuity due to complete resorption of subretinal fluid and macular edema. Ultrasonography demonstrated a reduction of the thickness of CCH in case 1 and complete regression of the lesions in case 2 and 3. No patient showed tumor recurrence. Intravitreal bevacizumab, alone or in combination therapy with PDT, may be a useful alternative for the treatment of symptomatic CCH with subretinal fluid.
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