MSC-Derived Small Extracellular Vesicles Alleviate Diabetic Retinopathy by Delivering miR-22-3p to Inhibit NLRP3 Inflammasome Activation.

PURPOSE: This study aimed to investigate the effect of mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEVs) on diabetic retinopathy (DR) and its underlying mechanism. METHODS: In vivo, MSC-sEVs were injected intravitreally into diabetic rats to determine the therapeutic efficacy. In vitro, MSC-sEVs with/without miR-22-3p inhibition were cocultured with advanced glycation end-products (AGEs)-induced microglia with/without NLRP3 overexpression to explore the molecular mechanism. RESULTS: In vivo, MSC-sEVs inhibited NLRP3 inflammasome activation, suppressed microglial activation, decreased inflammatory cytokines levels in the retina, and alleviated DR as evidenced by improved histological morphology and blood-retinal barrier function. Based on miRNA sequencing of MSC-sEVs, bioinformatic software, and dual-luciferase reporter assay, miR-22-3p stood out as the critical molecule for the role of MSC-sEVs in regulating NLRP3 inflammasome activation. Diabetic rats had lower level of miR-22-3p in their retina than those of control and sEV-treated rats. Confocal microscopy revealed that sEV could be internalized by microglia both in vivo and in vitro. In vitro, compared with sEV, the anti-inflammation effect of sEVmiR-22-3p(-) on AGEs-induced microglia was compromised, as they gave a lower suppression of NLRP3 inflammasome activation and inflammatory cytokines. In addition, NLRP3 overexpression in microglia damped the anti-inflammatory effect of sEV. CONCLUSION: These results indicated that MSC-sEVs alleviated DR via delivering miR-22-3p to inhibit NLRP3 inflammasome activation. Our findings indicate that MSC-sEVs might be a potential therapeutic method for DR.

Correlation between choroidal vascularity and retrobulbar ocular blood flow changes and thyroid-associated ophthalmopathy activity: a cross-sectional study.

OBJECTIVE: To evaluate the alterations in retrobulbar color Doppler imaging (CDI) parameters and retinal/choroidal optical coherence tomography angiography (OCTA) parameters and their association with the clinical activity and severity in thyroid-associated orbitopathy (TAO) patients. METHODS: In this study, the retrobulbar flow parameters including resistance index (RI), Pulsatile Index(PI), peak systolic velocity (PSV) and end diastolic velocity (EDV) in posterior ciliary artery (PCA), central retinal artery (CRA) and ophthalmic artery (OA) were determined by CDI. Moreover, the retina and choroidal vascularity including the superficial vessel density (SVD), deep vessel density (DVD), choroidal thickness (ChT) and choroidal vascularity, including total choroidal area (TCA), luminal area (LA), stromal area (SA) and Choroidal Vascularity Index (CVI), were determined by OCTA. All patients grouped as active TAO and inactive TAO based on Clinical activity score (CAS). We picked the severe eye among the subjects and compared all parameters between two groups. We analyzed the correlations among those parameters. RESULTS: There was a significant difference in CAS score, proptosis value, ChT, LA, CVI between patients with active TAO and inactive TAO. In the active group, PSV and EDV of PCA were significantly higher than the inactive group. On logistic regression analysis, CAS was closely associated with PSV-PCA. On multiple linear regression, proptosis value was closely associated with ChT, LA, SA and CVI. CONCLUSION: Choroidal vascularization and retrobulbar blood flow were concurrently higher in active TAO patients and several variables in choroid circulation was closely related to TAO clinical features.

Minimal Posterior Pole Vitrectomy and Fixing the Inverted Internal Limiting Membrane Flap with DisCoVisc for Macular Hole: No Gas or Air Tamponade.

PURPOSE: To investigate an alternative surgical method for macular hole repair without fluid-air exchange, gas tamponade, and prone positioning. METHODS: Eighteen eyes of 17 patients with macular holes underwent minimal posterior pole vitrectomy with an inverted internal limiting membrane flap technique. Ophthalmic viscosurgical device was used to fix the inverted internal limiting membrane flap in the balanced salt solution. No fluid-air exchange, gas tamponade, or prone positioning was needed. Follow-ups were performed at 1 day, 1 week, and the last visit (ranging from 3 to 6 months) after surgery. Optical coherence tomography examination, intraocular pressure, and best-corrected visual acuity measurements were performed preoperatively and at every follow-up, postoperatively. RESULTS: Primary closure of the macular hole was observed in all 18 eyes (100%). Optical coherence tomography showed U-type closure in 12 eyes, V-type closure in five eyes, and W-type closure in one eye. Preoperative, postoperative 1 week, and last follow-up best-corrected visual acuity were 0.90 (Snellen equivalent 20/159) ± 0.31 LogMAR, 0.72 (Snellen equivalent 20/105) ± 0.33 LogMAR, and 0.48 (Snellen equivalent 20/60) ± 0.32 LogMAR, respectively. Postoperative visual acuity was significantly improved compared with preoperative values ( F = 19.250, P = 0.000). No significant difference in intraocular pressure was found compared with preoperative values ( F = 1.933, P = 0.168). No significant complications were observed. CONCLUSION: This surgical method can effectively close macular holes, improve visual acuity, enhance surgical efficiency, reduce surgical complications, and improve patients' postoperative experience without the need for fluid-air exchange, gas tamponade, or prone positioning.

Resolvin D1 protects against Aspergillus fumigatus keratitis in diabetes by blocking the MAPK-NF-κB pathway.

Fungal keratitis (FK) is one of the main causes of blindness in China. People with diabetes are susceptible to corneal epithelial disease, even fungal keratitis. At present, there are few studies on this disease. Resolvins (Rv) has been reported as a mediators that exert crucial anti-inflammatory and immune regulation roles in serval diseases. In order to investigate the roles and underlying mechanism of Resolvins D1 (RvD1) on the Aspergillus fumigatus (A. fumigatus) keratitis in diabetes, we established in vivo and in vitro models of A. fumigatus keratitis, which were then exposed to high glucose. The expression levels of RvD1, 5-lipoxygenase (5-LOX), and 15-lipoxygenase (15-LOX) in A. fumigatus keratitis patients with diabetes were determined through Enzyme Linked Immunosorbent Assay (ELISA), Western blot and immunohistochemistry. Reactive Oxygen Species (ROS) production, ELISA, flow cytometry, Hematoxylin-Eosin (HE) staining and fungal loading determination were conducted to evaluate the severity of A. fumigatus infection. Lymphangiogenesis and angiogenesis were examined by immunofluorescence assay. Western blot was applied to detect the proteins of the MAPK-NF-κB pathway. The results showed that RvD1 diminished the high glucose-induced oxidative stress and inflammatory response, as evidenced by the reduction of ROS production, Interleukin-6 (IL-6), Interleukin-8 (IL-8), Heme Oxygenase-1 (HMOX-1), and the elevation of Cyclooxygenase-2 (COX2), Superoxide Dismutase (SOD-1), and Glutathione Peroxidase-2 (GPX2) levels in A. fumigatus-infected Human Corneal Endothelial Cells (HCECs). Additionally, lymphangiogenesis and angiogenesis prominently decreased after intervention with RvD1. Furthermore, RvD1 significantly reduced the levels of p-MEK1/2 and p-ERK1/2, and restrained the NF-κB and GPR32 activation. The above results showed that RvD1 protects against A. fumigatus keratitis in diabetes by suppressing oxidative stress, inflammatory response, fungal growth, and immunoreaction via modulating MAPK-NF-κB pathway. RvD1 provides clues for the therapeutic targets of Fungal keratitis complicated with diabetes.

Macular pucker, an atypical clinical presentation of ocular toxoplasmosis: a case report.

BACKGROUND: Ocular toxoplasmosis caused by Toxoplasma gondii is an infectious disease which is widely distributed around the world and can present with various clinic manifestations. We are here reporting an unusual case presented with epiretinal membrane (ERM), i.e., macular pucker. CASE PRESENTATION: A 16-year old male patient visited our outpatient clinic complaining of decreased vision for about 8 years in his left eye. The best-corrected visual acuity (BCVA) was 20/20 OD and 20/400 OS. There was sensory exotropia in his left eye. No inflammatory cells or flare were found in his anterior chamber or vitreous cavity OU. An ERM involving his left macular area was found on his dilated fundus exam, which was confirmed by Optical Coherence Tomography (OCT). The ERM was found to involve his left macular area with his foveal ellipsoid zone absent. The right eye was found to be within normal limit. After a thorough discussion with the patient and his parents about treatment options and surgical benefits, risks and alternatives, we performed vitrectomy, peeled off the ERM and collected the vitreous sample for parasite testing during the procedure. Patient's blood also was drawn for serological testing. Vitreous sample analysis and serological tests confirmed ocular toxoplasmosis OS as his final diagnosis. Unfortunately, the BCVA of this patient was not improved after the surgery, but the exotropia disappeared. CONCLUSION: ERM is an unusual clinical presentation of ocular toxoplasmosis. We may add Toxoplasma gondii infection as a differential diagnosis when encountering ERM cases.

Multimodal imaging of spontaneous subretinal hemorrhage in a young male: a case report.

BACKGROUND: Spontaneous subretinal hemorrhage (SSRH) is a rare disease that severely affects the visual function, and is difficult to diagnose. This study aimed to describe the multimodality imaging characteristics of SSRH in a young male patient. CASE PRESENTATION: A 28-year-old male was presented to our hospital with "sudden drop of left eye vision for one week." Three weeks ago, he was admitted to other hospital due to sudden severe pain and unclear vision in the left eye for 1 h. The intraocular pressure was 69 mmHg, and the blood pressure was 230/120 mmHg. Skull CT and MRI detected abnormal signal shadows in the left eye and no abnormalities in the brain. B-ultrasonography indicated occupying lesions in the left eye. Two weeks later, the patient came to our hospital for treatment as the vision of the left eye had decreased sharply. Admission examination: blood pressure was 200/120 mmHg, best-corrected visual acuity was 20/20 in the right eye and hand motion in the left eye. Fundus details could not be evaluated in the left eye because of hemorrhage in the vitreous cavity. B-ultrasonography of the left eye revealed a dense, diffuse intravitreal hemorrhage. Skull MRI showed an abnormal signal shadow in the left eyeball, suggesting intraocular hemorrhage. Vitrectomy revealed a dome-shaped lesion in the peripheral part of the inferotemporal region during the operation. Postoperative indocyanine green angiography (ICGA) of the lesion showed hypofluorescence and no leakage or altered morphology during the whole imaging process. Follow-up showed gradual reabsorption of SSRH. CONCLUSIONS: In this case, SSRH was considered to be associated with high blood pressure. Multimodal imaging provides accurate data for the diagnosis and follow-up of the disease.

Macular hole secondary to Valsalva retinopathy after doing push-up exercise.

BACKGROUND: Valsalva retinopathy and traumatic macular hole are common conditions, but macular hole secondary to Valsalva retinopathy is rarely reported. CASE PRESENTATION: A 34-year-old healthy man suffered Valsalva retinopathy after doing push-up exercise. During his follow-up visits, the best-corrected visual acuity (BCVA) measurements, fundus examinations and spectral-domain optical coherence tomography (SD-OCT) tests were performed. Three months later, the premacular hemorrhage was noticeably absorbed with an improvement of visual acuity. SD-OCT showed a lamellar macular hole with intact but thickened internal limiting membrane (ILM) with vitreal tractions on surface of the macular. Nine months after the first visit, his vision acuity was 20/25. The fundus examination showed a complete absorption of the macular hemorrhage. SD-OCT showed that the lamellar macular hole has enlarged, with thickened ILM on the surface. Seventeen months after the onset, the BCVA, fundus examination results and OCT findings were stable. CONCLUSIONS: Macular hole secondary to Valsalva retinopathy had been rarely reported and its mechanism needs further understanding. SD-OCT can be used to observe the evolvement of Valsalva retinopathy.

Six-point scleral fixation of a three-looped haptics one-piece posterior chamber intraocular lens by a single suture.

To evaluate a novel technique for six-point scleral fixation of a three-looped haptics posterior chamber intraocular lens (PCIOL) by a single suture. Nine eyes of nine patients were studied from September 2021 to March 2023. All patients had undergone vitrectomy. Only a single 9-0 polypropylene suture was used for scleral fixation. The three looped haptics were fixed at 12, 4, and 8 o'clock with six-point scleral fixation. The entire procedure took about 30 min. Among the nine patients, eight (88.8%) eyes had a significant improvement in best-corrected visual acuity, whereas one (11.2%) eye showed no change. No intraoperative or postoperative complications were observed. By ultrasonic biomicroscopy examination, intraocular lenses were well positioned and stable with no tilt in the horizontal and vertical axis. The method of six-point scleral fixation of a three-looped haptics PCIOL by a single suture is safe and effective.

MSC-derived small extracellular vesicles mitigate diabetic retinopathy by stabilizing Nrf2 through miR-143-3p-mediated inhibition of neddylation.

Diabetic retinopathy (DR) is a highly hazardous and widespread complication of diabetes mellitus (DM). The accumulated reactive oxygen species (ROS) play a central role in DR development. The aim of this research was to examine the impact and mechanisms of mesenchymal stem cell (MSC)-derived small extracellular vesicles (sEV) on regulating ROS and retinal damage in DR. Intravitreal injection of sEV inhibited Cullin3 neddylation, stabilized Nrf2, decreased ROS, reduced retinal inflammation, suppressed Müller gliosis, and mitigated DR. Based on MSC-sEV miRNA sequencing, bioinformatics software, and dual-luciferase reporter assay, miR-143-3p was identified to be the key effector for MSC-sEV's role in regulating neural precursor cell expressed developmentally down-regulated 8 (NEDD8)-mediated neddylation. sEV were able to be internalized by Müller cells. Compared to advanced glycation end-products (AGEs)-induced Müller cells, sEV coculture decreased Cullin3 neddylation, activated Nrf2 signal pathway to combat ROS-induced inflammation. The barrier function of endothelial cells was impaired when endothelial cells were treated with the supernatant of AGEs-induced Müller cells, but was restored when treated with supernatant of AGEs-induced Müller cells cocultured with sEV. The protective effect of sEV was, however, compromised when miR-143-3p was inhibited in sEV. Moreover, the protective efficacy of sEV was diminished when NEDD8 was overexpressed in Müller cells. These findings showed MSC-sEV delivered miR-143-3p to inhibit Cullin3 neddylation, stabilizing Nrf2 to counteract ROS-induced inflammation and reducing vascular leakage. Our findings suggest that MSC-sEV may be a potential nanotherapeutic agent for DR, and that Cullin3 neddylation could be a new target for DR therapy.

Mesenchymal Stem Cells Regulate Microglial Polarization via Inhibition of the HMGB1/TLR4 Signaling Pathway in Diabetic Retinopathy.

Diabetic retinopathy (DR) is recognized as the most prevalent retinal degenerative disorder. Inflammatory response usually precedes microvascular alteration and is the primary factor of diabetic retinopathy. Activated microglia express many pro-inflammatory cytokines that exacerbate retina inflammation and disruption. In the present study, we found that MSCs alleviated blood-retina barrier (BRB) breakdown in diabetic rats, as evidenced by reduced retinal edema, decreased vascular leakage, and increased occludin expression. The MSC-treated retinal microglia exhibited reduced expression of M1-phenotype markers in the diabetic rats, including inducible nitric oxide synthase (iNOS), CD16, and pro-inflammatory cytokines. On the other hand, MSCs increased the expression of M2-phenotype markers, such as arginase-1 (Arg-1), CD206, and anti-inflammatory cytokines. HMGB1/TLR4 signaling pathway is activated in DR and inhibited after MSC treatment. Consistent with in vivo evidence, MSCs drove BV2 microglia toward M2 phenotype in vitro. Overexpression of HMGB1 in microglia reversed the effects of MSC treatment, suggesting HMGB1/TLR4 pathway is necessary for MSCs' regulatory effects on microglia polarization. Collectively, MSCs exert beneficial effects on DR by polarizing microglia from M1 toward M2 phenotype via inhibiting the HMGB1/TLR4 signaling pathway.

A modified 23-G trocar and cannula system with lateral micropores for drainage of vitreous humor.

When primary angle-closure glaucoma occurs during an acute attack, routine phacoemulsification is challenging because of the high intra-ocular pressure (IOP) and shallow anterior chamber (AC). To reduce IOP and deepen the AC before phacoemulsification, a portion of the vitreous body is often removed. In this report, we introduce an extended trocar/cannula system with lateral micropores to drain the liquid vitreous before routine phacoemulsification to solve this problem. A modified trocar was used to drain the liquefied vitreous before routine phacoemulsification. We demonstrated that this novel trocar/cannula system is safe and effective for draining liquefied vitreous before routine phacoemulsification. It also facilitates the transition to smooth phacoemulsification.

Glaucoma in rural China (the Rural Epidemiology for Glaucoma in China (REG-China)): a national cross-sectional study.

OBJECTIVE: This study aimed to investigate the prevalence of glaucoma with associated factors in the rural populations of 10 provinces in China. DESIGN: A population-based cross-sectional study. METHODS: All participants aged 6 years or older from 10 provinces completed visual acuity testing, slit-lamp examination, ophthalmoscopy and non-contact tonometry. Glaucoma suspects underwent fundus photography, Goldmann applanation tonometry, visual field testing and gonioscopy. Glaucoma was determined according to the International Society of Geographical and Epidemiological Ophthalmology classification scheme. Associations of demographics and medical factors with glaucoma were assessed using multiple logistic regression models. RESULTS: From June 2017 to October 2018, 48 398 of 52 041 participants were included in the final analyses. The age-standardised prevalence of glaucoma was 1.7% (95% CI 1.55% to 1.78%) among the participants older than 6 years, which was 2.1% (95% CI 1.93% to 2.23%) in participants aged over 40 years. The constituent ratios of glaucoma were: 44.4% primary angle-closure glaucoma (PACG), 34.7% primary open-angle glaucoma, 2.6% congenital glaucoma and 18.3% other types of glaucoma. Increasing age, smoking, cerebral stroke, type 2 diabetes, higher education (college or more) and higher personal income were significant risk factors for PACG. The unilateral and bilateral blindness rates in the entire study population were 4.692% and 1.068%, respectively. A family history of glaucoma was a significant risk factor for the prevalence of glaucoma and blindness in at least one eye. CONCLUSIONS: Rural populations have a high prevalence of glaucoma, which should be included in chronic disease management programmes in China for long-term care.

[Chinese herbal medicine Lingqi Huangban Granule protects retinal pigment epithelial cells against oxidative stress-induced injury in vitro].

OBJECTIVE: To observe the protective effects of drug-contained serum of Lingqi Huangban Granule (LQHBG), a compound traditional Chinese herbal medicine, on oxidative stress-induced injury in rabbit retinal pigment epithelial (RPE) cells in vitro. METHODS: The oxidative stress of rabbit RPE cells in vitro was induced with hydrogen peroxide (500µmol/L) and different concentrations of LQHBG were administered to rats to prepare medicated serum. RPE cells were randomized into normal control group (no hydrogen peroxide), model group (hydrogen peroxide), model plus serum group (hydrogen peroxide and 10% control serum), model plus low-dose LQHBG group (hydrogen peroxide and low-dose LQHBG-medicated serum) and model plus high-dose LQHBG group (hydrogen peroxide and high-dose LQHBG-medicated serum). Teminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and flow cytometry (FCM) were used to measure apoptosis of cultured rabbit RPE cells. Protein expressions of caspase-3 and Bcl-X(L) were observed by Western blot method. RESULTS: FCM results showed that the apoptotic rates of the normal control group, model group, control serum group and serum containing low- and high-dose LQHBG groups were (4.85±0.26)%, (20.02±1.37)%, (21.84±0.94)%, (13.56±0.55)%, and (8.58±0.39)%, respectively; compared with the model group, the apoptotic rates of RPE cells in the low- and high-dose LQHBG groups were obviously reduced in a dose-related manner (P<0.05). TUNEL results showed that nuclei of apoptotic cells were stained brown; the number of apoptotic cells in the low- and high-dose LQHBG groups was obviously less than that in the model group. The protein expression of caspase-3 was up-regulated in the model and control serum groups, which was higher than that in the high-dose LQHBG group (P<0.05). The protein expression of Bcl-X(L) was down-regulated in the model and control serum groups, which was lower than that in the low- and high-dose LQHBG groups (P<0.01). CONCLUSION: Drug-contained serum of LQHBG obviously reduces apoptosis and partly protects rabbit RPE cells from oxidative stress-induced injury. The protective function is due to an improvement in antioxidant abilities, down-regulation of the expression of caspase-3 and up-regulation of the expression of Bcl-X(L).

Endostatin Inhibits Blood-Retinal Barrier Breakdown in Diabetic Rats by Increasing the Expression of ICAM-1 and VCAM-1 and Decreasing the Expression of VEGF.

Objective: Endostatin has become the strongest endogenous angiogenesis inhibitor due to suppressing VEGF expression. The purpose of this study was to assess the impact of endostatin on the blood-retinal barrier (BRB) in diabetic rats. Methods: SD rats were induced to develop diabetes by streptozotocin, and endostatin was administrated by intravitreal injection. The body weight, the level of blood glucose, the expressions of C-reactive protein (CRP), adhesion molecules intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), junction proteins (occludin, claudin-5, and zonula occluden-1), and VEGF were measured in rats' retinas of diabetes. The BRB breakdown was evaluated using Evans blue. Results: The level of CRP and adhesion molecules (ICAM-1 and VCAM-1) was increased in retinas of diabetic rats, while endostatin significantly inhibited the upregulation of these. Diabetes increased the BRB permeability and retinal thickness. Diabetes also decreased the levels of occludin, claudin-5, and ZO-1 in retinals. These changes were inhibited by endostatin treatment. Upregulation of vascular endothelial growth factor (VEGF), transforming growth factor-ß (TGF-ß), and protein kinase C- (PKC-) ß2 was also reversed by endostatin in retinas of diabetic rats. Conclusions: Endostatin provides protection against diabetic retinopathy, which may involve its barrier-enhancing effects.

Report of Four Cases of Endogenous Klebsiella Pneumoniae Endophthalmitis Originated from Liver Abscess with Eye Complaints as the Initial Presentations.

PURPOSE: To report four cases of endogenous endophthalmitis (EE) secondary to Klebsiella pneumoniae liver abscess, and discuss their clinic features and outcomes. METHODS: Clinical data were collected by reviewing the medical records of four patients diagnosed with endogenous Klebsiella Pneumoniae endophthalmitis (EKPE) secondary to liver abscess. RESULTS: Four patients were diagnosed with EE. Two males and two females, with ages ranging from 33 to 63 years old. All patients presented with ocular symptoms initially. Liver abscesses were diagnosed during hospitalization. All cases were caused by Klebsiella Pneumoniae confirmed by blood or tissue cultures. All patients were treated with intravitreal antibiotic injection, and two of the patients had vitrectomy. At the end, all affected eyes underwent evisceration. One patient died of septic shock with multiple organ failures. CONCLUSION: EE secondary to liver abscess with metastatic spread is a severe sight-threatening condition. The delayed discovery of liver abscess may hinder the diagnosis and treatment of the disease, which may be related to poor prognosis.