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.

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.

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.

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 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.

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.

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.

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.

Long-term clinical effects of intravitreal injections of conbercept for the treatment of choroidal neovascularization in patients with pathological myopia.

AIM: To observe the long-term clinical efficacy of intravitreal injections of conbercept, a novel vascular growth factor inhibitor, for the treatment of pathological myopia choroidal neovascularization (PM-CNV). METHODS: A total of 67 eyes (from 67 patients; mean age, 54.90±12.7y) with PM-CNV were retrospectively researched. Based on the different schemes used for the administration of the drug, the patients were divided into two groups: group A (n=35; average age, 53.31±13.6y; average diopter, 9.25±1.72 D), which received only one injection of pro re nata (PRN; 1+PRN regimen), and group B (n=32; average age, 56.49±11.8y; average diopter, 9.63±2.24 D), which received one injection per month for 3mo (3+PRN regimen). Best-corrected visual acuity (BCVA) analysis, intraocular pressure (IOP) examination, slit-lamp microscopy, fundus examination and optical coherence tomography were performed at each follow-up. The recurrence and treatment times of CNV were recorded. The patients were followed up for at least 12mo. RESULTS: The BCVA was increased in 29 eyes (82.9%) in group A and 30 eyes (93.75%) in group B; no increase or decrease was observed in 6 (17.1%) and 2 (6.25%) eyes in groups A and B, respectively. The BCVA (logMAR) values before treatment (0.67±0.48 and 0.71±0.56) were significantly higher than those 12mo after treatment (0.31±0.26 and 0.33±0.17) in groups A and B, respectively (P<0.05). The mean central macular thickness (CMT) values had significantly decreased from 346.49±65.99 and 360.10±82.31 µm at baseline to 257.29±40.47 and 251.97±48.26 µm in groups A and B, respectively, after 12mo of treatment. A total of 21 eyes in group A needed reinjection (60%; average number of injections, 2.51±0.98); the corresponding values in group B were 6 eyes (18.75%; average number of injections, 3.74±1.22). There were no adverse ocular and systemic complications during the treatment and follow-up. CONCLUSION: Intravitreal injection of conbercept with 1+PRN or 3+PRN improve the visual acuity, reduce macular edema and reduce the level of CMT in patients with PM-CNV. The 3+PRN regimen demonstrates a lower recurrence rate of CNV than the 1+PRN regimen, but requires more treatment. However, both treatment regimens demonstrate long-term safety and efficacy for the treatment of PM-CNV.

A novel mutation in RS1 and clinical manifestations in a Chinese twin family with congenital retinoschisis.

Purpose: We aim to analyze the clinical and genetic features in a Chinese family with congenital retinoschisis by whole-exome sequencing and comprehensive clinical examination. Methods: Six members were recruited from a Chinese family. Three of them were diagnosed as congenital retinoschisis, including two twin siblings. All subjects received a full eye examination. Whole-exome sequencing (WES) and Sanger sequencing were performed on two twin probands and all participants, respectively. Results: A novel splice site mutation RS1.c.53-1G>A was identified in a Chinese congenital retinoschisis family. The mean onset age was 16.7 ± 2.4 years old. The average BCVA in patients was 0.37 ± 0.05. A typical spoke-wheel pattern was observed in all affected eyes. OCT examination results showed fovea schisis and schisis cavities were located in the inner nuclear layer in 100% eyes (6/6). ERG b/a ratio was decreased markedly, but was still more than 1 in the four eyes that were available. Conclusion: The present study discovered a new pathogenic splice cite variant of RS1 in congenital retinoschisis, which expands the mutational spectrum. In contrast to previous research, the phenotype of patients with the same mutation within one family was highly similar. Early molecular testing is crucial for early diagnosis, clinical management, and genetic counseling of patients with congenital retinoschisis.

Guideline for the treatment of no light perception eyes induced by mechanical ocular trauma.

Severe mechanical ocular trauma with no light perception (NLP) predicts a poor prognosis of visual acuity and enucleation of the eyeball. Since the innovative treatment concept of exploratory vitreoretinal surgery has developed and treatment technology has advanced, the outcomes of severe ocular trauma treatment in NLP patients have greatly improved. However, there remains a lack of unified standards for the determination, surgical indication, and timing of vitrectomy in NLP eye treatment. To address these problems, we aimed to create evidence-based medical guidelines for the diagnosis, treatment, and prognosis of mechanical ocular trauma with NLP. Sixteen relevant recommendations for mechanical ocular trauma with NLP were obtained, and a consensus was reached. Each recommendation was explained in detail to guide the treatment of mechanical ocular trauma associated with NLP.

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.

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.