Retinopathy of prematurity (ROP) is a vision-threatening disorder that leads to pathological growth of the retinal vasculature due to hypoxia. Here, we investigated the potential effects of alamandine, a novel heptapeptide in the renin-angiotensin system (RAS), on hypoxia-induced retinal neovascularization and its underlying mechanisms. In vivo, the C57BL/6J mice with oxygen-induced retinopathy (OIR) were injected intravitreally with alamandine (1.0 μmol/kg per eye). In vitro, human retinal microvascular endothelial cells (HRMECs) were utilized to investigate the effects of alamandine (10 μg/mL) on proliferation, apoptosis, migration, and tubular formation under vascular endothelial growth factor (VEGF) stimulation. Single-cell RNA sequencing (scRNA-seq) matrix data from the Gene Expression Omnibus (GEO) database and RAS-related genes from the Molecular Signatures Database (MSigDB) were sourced for subsequent analyses. By integrating scRNA-seq data across multiple species, we identified that RAS-associated endothelial cell populations were highly related to retinal neovascularization. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis revealed a significant decrease in alamandine levels in both the serum and retina of OIR mice compared to those in the control group. Next, alamandine ameliorated hypoxia-induced retinal pathological neovascularization and physiologic revascularization in OIR mice. In vitro, alamandine effectively mitigated VEGF-induced proliferation, scratch wound healing, and tube formation of HRMECs primarily by inhibiting the hypoxia-inducible factor-1α (HIF-1α)/VEGF pathway. Further, coincubation with D-Pro⁷ (Mas-related G protein-coupled receptor D (MrgD) antagonist) hindered the beneficial impacts of alamandine on hypoxia-induced pathological angiogenesis both in vivo and in vitro. Our findings suggested that alamandine could mitigate retinal neovascularization by targeting the MrgD-mediated HIF-1α/VEGF pathway, providing a potential therapeutic agent for OIR prevention and treatment.
Animals ; Retinal Neovascularization/prevention & control* ; Mice, Inbred C57BL ; Vascular Endothelial Growth Factor A/metabolism* ; Humans ; Mice ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Oligopeptides/therapeutic use* ; Signal Transduction/drug effects* ; Cell Proliferation/drug effects* ; Endothelial Cells/drug effects* ; Retinopathy of Prematurity/drug therapy* ; Apoptosis/drug effects* ; Cell Movement/drug effects* ; Renin-Angiotensin System/drug effects* ; Cells, Cultured

PURPOSE: To evaluate the clinical presentations of focal choroidal excavation and to report long-term outcomes of cases without retinal disorders at the initial presentation. METHODS: A retrospective review of medical records was performed for patients diagnosed with focal choroidal excavation. Concomitant retinal disorders at the initial presentation were identified. In cases without retinal disorders, the development of retinal disorders during follow-up was also evaluated. RESULTS: Forty-five eyes in 45 patients were examined in this study. Focal choroidal excavation was accompanied with retinal disorders in 16 eyes (35.6%). In the remaining 29 eyes, only focal choroidal excavation was noted without any accompanying retinal disorders. The accompanying retinal disorders included choroidal neovascularization (n = 8), central serous chorioretinopathy (n = 4), epiretinal membrane (n = 1), macular hole (n = 1), branch retinal vein occlusion (n = 1), and uveitis (n = 1). Of the 29 eyes without retinal disorders, 22 were followed up for a mean period of 33.5 ± 18.2 months. Consequently, choroidal neovascularization was found to have developed in one eye at 59 months, and subretinal fluid had developed in two eyes at 17 and 28 months, respectively. CONCLUSIONS: Focal choroidal excavation was accompanied by retinal disorders in 35.6% of the included patients. In patients without retinal disorders, the development of a retinal disorder was noted in some eyes, suggesting the need for long-term regular follow-up in patients diagnosed with focal choroidal excavation.
Central Serous Chorioretinopathy ; Choroid ; Choroidal Neovascularization ; Epiretinal Membrane ; Follow-Up Studies ; Humans ; Medical Records ; Retinal Perforations ; Retinal Vein Occlusion ; Retinaldehyde ; Retrospective Studies ; Subretinal Fluid ; Uveitis

PURPOSE: To report a rare case of Sjögren's reticular retinal dystrophy. CASE SUMMARY: A 54-year-old male presented with blurred vision and metamorphopsia in both eyes since a few years prior to his initial visit. There was a bilateral reticular network of yellow deposits throughout the posterior pole on fundus examination, which was hyperautofluorescent in fundus autofluorescence photographs. The pigment alterations were more visible with fluorescein angiography, which showed hypofluorescent lesions with hyperfluorescent borders. Spectral-domain optical coherence tomography showed elevations of the outer retina associated with the presence of subretinal hyperreflective material. Based on the conclusive correlation with clinical features, we diagnosed Sjögren's reticular retinal dystrophy. CONCLUSIONS: Sjögren's reticular retinal dystrophy is characterized by its specific pigment changes at the level of clinical manifestations and the retinal pigment epithelium. In cases of Sjögren's reticular retinal dystrophy, close monitoring is required because it has a lifetime risk of choroidal neovascularization.
Choroidal Neovascularization ; Fluorescein Angiography ; Humans ; Macular Degeneration ; Male ; Middle Aged ; Retina ; Retinal Dystrophies ; Retinal Pigment Epithelium ; Retinaldehyde ; Tomography, Optical Coherence ; Vision Disorders

PURPOSE: To evaluate the relationship between pericytes and endothelial cells in retinal neovascularization through histological and immunofluorescent studies. METHODS: C57BL/6J mice were exposed to hyperoxia from postnatal day (P) 7 to P12 and were returned to room air at P12 to induce a model of oxygen-induced retinopathy (OIR). The cross sections of enucleated eyes were processed with hematoxylin and eosin. Immunofluorescent staining of pericytes, endothelial cells, and N-cadherin was performed. Microfluidic devices were fabricated out of polydimethylsiloxane using soft lithography and replica molding. Human retinal microvascular endothelial cells, human brain microvascular endothelial cells, human umbilical vein endothelial cells and human placenta pericyte were mixed and co-cultured. RESULTS: Unlike the three-layered vascular plexus found in retinal angiogenesis of a normal mouse, angiogenesis in the OIR model is identified by the neovascular tuft extending into the vitreous. Neovascular tufts and the three-layered vascular plexus were both covered with pericytes in the OIR model. In this pathologic vascularization, N-cadherin, known to be crucial intercellular adhesion molecule, was also present. Further evaluation using the microfluidic in vitro model, successfully developed a microvascular network of endothelial cells covered with pericytes, mimicking normal retinal angiogenesis within 6 days. CONCLUSIONS: Pericytes covering endothelial cells were observed not only in vasculature of normal retina but also pathologic neovascularization of OIR mouse at P17. Factors involved in the endothelial cell-pericyte interaction can be evaluated as an attractive novel treatment target. These future studies can be performed using microfluidic systems, which can shorten the study time and provide three-dimensional structural evaluation.
Animals ; Brain ; Cadherins ; Endothelial Cells ; Eosine Yellowish-(YS) ; Fungi ; Hematoxylin ; Human Umbilical Vein Endothelial Cells ; Humans ; Hyperoxia ; In Vitro Techniques ; Lab-On-A-Chip Devices ; Mice ; Microfluidics ; Microvessels ; Neovascularization, Pathologic ; Pericytes ; Placenta ; Retina ; Retinal Neovascularization ; Retinaldehyde

PURPOSE: To report a case of choroidal osteoma (CO) complicated by extensive subretinal hemorrhage treated with intravitreal bevacizumab and aflibercept injections. CASE SUMMARY: A 42-year-old female patient presented with decreased visual acuity and a temporal visual field defect in the left eye. The patient had a history of retinal hemorrhage in the left eye 3 years prior, which improved without any treatment. The patient's visual acuity had decreased to 0.6 at the initial visit. On fundus examination, orange-colored elevated lesions involving the superior peripapillary area with massive subretinal hemorrhage extending to the macular area were revealed. Optical coherence tomography, fluorescein angiography, and B-scan ultrasonography results indicated CO complicated by choroidal neovascularization (CNV). With multiple intravitreal injections of bevacizumab and aflibercept (bevacizumab ×1, aflibercept ×2), the patient's visual acuity improved and the CNV lesion was kept stable without recurrence as of the 1-year follow-up visit. CONCLUSIONS: Intravitreal bevacizumab and aflibercept injections can be helpful in the treatment of CO complicated by CNV, by improving visual acuity and the retinal anatomy.
Adult ; Bevacizumab ; Choroid ; Choroidal Neovascularization ; Female ; Fluorescein Angiography ; Follow-Up Studies ; Hemorrhage ; Humans ; Intravitreal Injections ; Osteoma ; Recurrence ; Retinal Hemorrhage ; Retinaldehyde ; Tomography, Optical Coherence ; Ultrasonography ; Visual Acuity ; Visual Fields

Vision loss in diabetic retinopathy (DR) is ascribed primarily to retinal vascular abnormalities—including hyperpermeability, hypoperfusion, and neoangiogenesis—that eventually lead to anatomical and functional alterations in retinal neurons and glial cells. Recent advances in retinal imaging systems using optical coherence tomography technologies and pharmacological treatments using anti-vascular endothelial growth factor drugs and corticosteroids have revolutionized the clinical management of DR. However, the cellular and molecular mechanisms underlying the pathophysiology of DR are not fully determined, largely because hyperglycemic animal models only reproduce limited aspects of subclinical and early DR. Conversely, non-diabetic mouse models that represent the hallmark vascular disorders in DR, such as pericyte deficiency and retinal ischemia, have provided clues toward an understanding of the sequential events that are responsible for vision-impairing conditions. In this review, we summarize the clinical manifestations and treatment modalities of DR, discuss current and emerging concepts with regard to the pathophysiology of DR, and introduce perspectives on the development of new drugs, emphasizing the breakdown of the blood-retina barrier and retinal neovascularization.
Adrenal Cortex Hormones ; Angiopoietins ; Animals ; Diabetic Retinopathy* ; Endothelial Cells ; Endothelial Growth Factors ; Ischemia ; Macular Edema ; Mice ; Models, Animal ; Neuroglia ; Pericytes ; Retinal Neovascularization ; Retinal Neurons ; Retinaldehyde ; Tomography, Optical Coherence ; Vascular Endothelial Growth Factors

OBJECTIVETo explore the effects of rat bone mesenchymal stem cell (BMSC) transplantation on retinal neovascularization, and to observe the changes of hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factors (VEGF) in rats with oxygen-induced retinopathy (OIR).

METHODSSeventy-two seven-day-old Sprague-Dawley rats were randomly divided into three groups: normal control (CON), model (OIR) and BMSC transplantation. In the BMSC transplantation group, BMSCs were transplanted 5 days after oxygen conditioning. The phosphate buffered saline of the same volume was injected in the CON and OIR groups. The OIR model was prerpared according to the classic hyperoxygen method. At seven days after transplantation, retinal neovascularization was examined by retinal flat-mount staining and hematoxylin eosin (HE) staining. The expression of HIF-1α and VEGF proteins was examined by immunohistochemistry staining and Western blot analysis.

RESULTSThe retinal flat-mount staining results showed that the vessels were well organized in the CON group, but the vessels were irregularly organized, and lots of nonperfusion areas were observed in the OIR group. The large vessels were a bit circuitous, the retinal vessels were relatively organized, and less nonperfusion areas were noted in the BMSC transplantation group. The HE staining results showed that many neovessels and preretinal neovascular (pre-RNC) cells were observed on the internal limiting membrane in the OIR group. There were less pre-RNC cells in the BMSC transplantation group compared with the OIR group (P<0.01). The immunohistochemistry analysis showed that more HIF-1αand VEGFcells were observed in the OIR group compared with the CON group, and less HIF-1αand VEGFcells were observed in the BMSC transplantation group compared with OIR group (P<0.05). The Western blot analysis showed the expression of HIF-1α and VEGF proteins in the OIR group was significantly higher than that in the CON group. The expression of HIF-1α and VEGF proteins in the BMSC transplantation group was lower than that in the OIR group (P<0.01).

CONCLUSIONSBMSC transplantation therapy could alleviate retinal neovascularization in OIR rats, and its mechanisms might be associated with the inhibition of the expression of HIF-1α and VEGF proteins.

Animals ; Animals, Newborn ; Female ; Hypoxia-Inducible Factor 1, alpha Subunit ; analysis ; Male ; Mesenchymal Stem Cell Transplantation ; Rats ; Rats, Sprague-Dawley ; Retina ; chemistry ; Retinal Neovascularization ; prevention & control ; Retinopathy of Prematurity ; metabolism ; therapy ; Vascular Endothelial Growth Factor A ; analysis

PURPOSE: To report a case of full-thickness macular hole following intravitreal aflibercept injection in a patient with wet age-related macular degeneration (AMD). CASE SUMMARY: A 70-year-old man presented to our department with gradually decreasing vision in his left eye. Best-corrected visual acuity was measured as 0.8 in the right eye and 0.2 in the left eye. Fundus examination, fluorescein angiography, and optical coherence tomography (OCT) showed occult choroidal neovascularization associated with subretinal fluid in the left eye. The patient received several intravitreal ranibizumab and bevacizumab injections in his left eye but responded poorly to the treatment. The patient was switched to intravitreal aflibercept injection. After 1 month, the best corrected visual acuity in the left eye was decreased to 0.05. Although the fundus examination was indistinct, OCT confirmed the presence of a full-thickness macular hole. The patient underwent pars plana vitrectomy with internal limiting membrane peeling and fluid-gas exchange, 20% SF6 gas injection, phacoemulsification, and posterior chamber intraocular lens implantation. One month after the operation, the best corrected visual acuity was 0.2. The macular hole was closed completely, as confirmed by OCT. CONCLUSIONS: Although the occurrence of a full-thickness macular hole after intravitreal aflibercept injection in the treatment of choroidal neovascularization with wet AMD is uncommon, physicians should pay attention for this complication.
Aged ; Bevacizumab ; Choroidal Neovascularization ; Fluorescein Angiography ; Humans ; Lens Implantation, Intraocular ; Macular Degeneration* ; Membranes ; Phacoemulsification ; Ranibizumab ; Retinal Perforations* ; Subretinal Fluid ; Tomography, Optical Coherence ; Visual Acuity ; Vitrectomy

Myopia is a common disorder affecting 38.7%-73.1% of the total population in East Asian countries. A high prevalence of myopia is associated with an increased risk of sight-threatening problems, such as retinal detachment, retinal tears, glaucoma, and choroidal neovascularization. Slowing progression of myopia could benefit many children in East Asia. However, only a few methods used for myopia control have proven to be effective. The most effective methods are topical pharmaceutical agents such as atropine, orthokeratology lens (Ortho-K lens), and outdoor activity. To minimize its side effects, a lower dose of atropine instillation is recommended. An Ortho-K lens can be a good option in mild myopia. Increasing outdoor activity and light exposure prevent myopia onset and development, as well as axial growth. Conventional methods such as pin-hole glasses, ocular movement exercise, and bifocal or multifocal glasses have all been proven to be ineffective. This lecture provides an overview of the prevention of myopia progression available in the literature, so that we can learn the methods that might lower the risk of sight-threatening complications in myopic children.
Asian Continental Ancestry Group ; Atropine ; Child ; Choroidal Neovascularization ; Contact Lenses ; Eyeglasses ; Far East ; Glass ; Glaucoma ; Humans ; Myopia* ; Prevalence ; Retinal Detachment ; Retinal Perforations

OBJECTIVETo investigate whether propranolol application as collyrium or intraperitoneal (IP) injection can promote the recovery of oxygen-induced retinopathy (OIR).

METHODThirty-six 7-day-old mice were divided into the following 6 groups: normal control, propranolol eye drops, propranolol IP injection, eye drops negative control, IP injection negative control, and pathological model with 6 mice in each. In a typical model of OIR, litters of mice pups with their nursing mothers were exposed to an infant incubator to high oxygen concentration (75 ± 5)% between postnatal day (PD) 7 and PD12, prior to returning to room air. Two routes of propranolol treatment were assessed from PD12 to PD17: IP injection and eye drop, with doses 2 mg/(kg·time), three times a day. Another three groups were given citric acid buffer eye drops, IP injection of citric acid buffer, and negative control were not treated with any drug. Neonatal mice fed in normal conditions served as normal control. Mice were sacrificed at PD17 to evaluate the morphological changes of retinal vessels by fluorescein isothiocyanate-dextran perfusion and retinal whole mount. The retinal neovascularization was evaluated by counting the number of nuclei of the endothelial cell breaking through the internal limiting membrane (ILM).

RESULTCompared with the oxygen-exposed group, the branches of retinal vessels went normal with a less un-perfused area in the propranolol eye drops and propranolol IP injection groups [(38.9 ± 9.9)% and (5.6 ± 2.3)% vs. (16.2 ± 10.0)% and (2.2 ± 0.8)%, (25.9 ± 5.0)% and (2.1 ± 2.7)%, F=36.12 and 14.55, P both<0.001]. The number of nuclei of endothelial cells breaking through the ILM on the retinal cross-section in the propranolol eye drops group decreased (14.2 ± 5.1) per slide, which was less than that in the oxygen-exposed group (49.1 ± 8.9) per slide and the propranolol IP injection group (18.0 ± 5.9) per slide; it was also less than that in the eye drops negative control group (47.4 ± 8.1) per slide (F=187.60, P<0.05). Moreover, the number of nuclei of endothelial cells breaking through the ILM on the retinal cross-section in the propranolol IP injection group was less than that in the IP injection negative control group (49.9 ± 7.1) per slide (P<0.05).

CONCLUSIONPropranolol could effectively inhibit the formation of retinal neovascularization in mice; the eye drops was more effective than the IP injection.

Animals ; Dextrans ; Disease Models, Animal ; Endothelial Cells ; Fluorescein-5-isothiocyanate ; analogs & derivatives ; Injections, Intraperitoneal ; Mice ; Ophthalmic Solutions ; Oxygen ; adverse effects ; Propranolol ; therapeutic use ; Retina ; drug effects ; Retinal Neovascularization ; chemically induced ; drug therapy ; prevention & control ; Retinal Vessels ; drug effects