ACVR1/ALK2-p21 signaling axis modulates proliferation of the venous endothelium in the retinal vasculature.

The proliferation of the endothelium is a highly coordinated process to ensure the emergence, expansion, and homeostasis of the vasculature. While Bone Morphogenetic Protein (BMP) signaling fine-tunes the behaviors of endothelium in health and disease, how BMP signaling influences the proliferation of endothelium and therefore, modulates angiogenesis remains largely unknown. Here, we evaluated the role of Activin A Type I Receptor (ACVR1/ALK2), a key BMP receptor in the endothelium, in modulating the proliferation of endothelial cells. We show that ACVR1/ALK2 is a key modulator for the proliferation of endothelium in the retinal vessels. Loss of endothelial ALK2 leads to a significant reduction in endothelial proliferation and results in fewer branches/endothelial cells in the retinal vessels. Interestingly, venous endothelium appears to be more susceptible to ALK2 deletion. Mechanistically, ACVR1/ALK2 inhibits the expression of CDKN1A/p21, a critical negative regulator of cell cycle progression, in a SMAD1/5-dependent manner, thereby enabling the venous endothelium to undergo active proliferation by suppressing CDKN1A/p21. Taken together, our findings show that BMP signaling mediated by ACVR1/ALK2 provides a critical yet previously underappreciated input to modulate the proliferation of venous endothelium, thereby fine-tuning the context of angiogenesis in health and disease.

Sox17 Deficiency Promotes Pulmonary Arterial Hypertension via HGF/c-Met Signaling.

BACKGROUND: In large-scale genomic studies, Sox17, an endothelial-specific transcription factor, has been suggested as a putative causal gene of pulmonary arterial hypertension (PAH); however, its role and molecular mechanisms remain to be elucidated. We investigated the functional impacts and acting mechanisms of impaired Sox17 (SRY-related HMG-box17) pathway in PAH and explored its potential as a therapeutic target. METHODS: In adult mice, Sox17 deletion in pulmonary endothelial cells (ECs) induced PAH under hypoxia with high penetrance and severity, but not under normoxia. RESULTS: Key features of PAH, such as hypermuscularization, EC hyperplasia, and inflammation in lung arterioles, right ventricular hypertrophy, and elevated pulmonary arterial pressure, persisted even after long rest in normoxia. Mechanistically, transcriptomic profiling predicted that the combination of Sox17 deficiency and hypoxia activated c-Met signaling in lung ECs. HGF (hepatocyte grow factor), a ligand of c-Met, was upregulated in Sox17-deficient lung ECs. Pharmacologic inhibition of HGF/c-Met signaling attenuated and reversed the features of PAH in both preventive and therapeutic settings. Similar to findings in animal models, Sox17 levels in lung ECs were repressed in 26.7% of PAH patients (4 of 15), while those were robust in all 14 non-PAH controls. HGF levels in pulmonary arterioles were increased in 86.7% of patients with PAH (13 of 15), but none of the controls showed that pattern. CONCLUSIONS: The downregulation of Sox17 levels in pulmonary arterioles increases the susceptibility to PAH, particularly when exposed to hypoxia. Our findings suggest the reactive upregulation of HGF/c-Met signaling as a novel druggable target for PAH treatment.

Exosomal miR-184 in the aqueous humor of patients with central serous chorioretinopathy: a potential diagnostic and prognostic biomarker.

BACKGROUND: Central serous chorioretinopathy (CSC) is the fourth most prevalent retinal disease leading to age-related macular degeneration (AMD) and retinal atrophy. However, CSC's pathogenesis and therapeutic target need to be better understood. RESULTS: We investigated exosomal microRNA in the aqueous humor of CSC patients using next-generation sequencing (NGS) to identify potential biomarkers associated with CSC pathogenesis. Bioinformatic evaluations and NGS were performed on exosomal miRNAs obtained from AH samples of 62 eyes (42 CSC and 20 controls). For subgroup analysis, patients were divided into treatment responders (CSC-R, 17 eyes) and non-responders (CSC-NR, 25 eyes). To validate the functions of miRNA in CECs, primary cultured-human choroidal endothelial cells (hCEC) of the donor eyes were utilized for in vitro assays. NGS detected 376 miRNAs. Our results showed that patients with CSC had 12 significantly upregulated and 17 downregulated miRNAs compared to controls. miR-184 was significantly upregulated in CSC-R and CSC-NR patients compared to controls and higher in CSC-NR than CSC-R. In vitro assays using primary cultured-human choroidal endothelial cells (hCEC) demonstrated that miR-184 suppressed the proliferation and migration of hCECs. STC2 was identified as a strong candidate for the posttranscriptional down-regulated target gene of miR-184. CONCLUSION: Our findings suggest that exosomal miR-184 may serve as a biomarker reflecting the angiostatic capacity of CEC in patients with CSC.

Dll4 Suppresses Transcytosis for Arterial Blood-Retinal Barrier Homeostasis.

RATIONALE: Central nervous system has low vascular permeability by organizing tight junction (TJ) and limiting endothelial transcytosis. While TJ has long been considered to be responsible for vascular barrier in central nervous system, suppressed transcytosis in endothelial cells is now emerging as a complementary mechanism. Whether transcytosis regulation is independent of TJ and its dysregulation dominantly causes diseases associated with edema remain elusive. Dll4 signaling is important for various vascular contexts, but its role in the maintenance of vascular barrier in central nervous system remains unknown. OBJECTIVE: To find a TJ-independent regulatory mechanism selective for transcytosis and identify its dysregulation as a cause of pathological leakage. METHODS AND RESULTS: We studied transcytosis in the adult mouse retina with low vascular permeability and employed a hypertension-induced retinal edema model for its pathological implication. Both antibody-based and genetic inactivation of Dll4 or Notch1 induce hyperpermeability by increasing transcytosis without junctional destabilization in arterial endothelial cells, leading to nonhemorrhagic leakage predominantly in the superficial retinal layer. Endothelial Sox17 deletion represses Dll4 in retinal arteries, phenocopying Dll4 blocking-driven vascular leakage. Ang II (angiotensin II)-induced hypertension represses arterial Sox17 and Dll4, followed by transcytosis-driven retinal edema, which is rescued by a gain of Notch activity. Transcriptomic profiling of retinal endothelial cells suggests that Dll4 blocking activates SREBP1 (sterol regulatory element-binding protein 1)-mediated lipogenic transcription and enriches gene sets favorable for caveolae formation. Profiling also predicts the activation of VEGF (vascular endothelial growth factor) signaling by Dll4 blockade. Inhibition of SREBP1 or VEGF-VEGFR2 (VEGF receptor 2) signaling attenuates both Dll4 blockade-driven and hypertension-induced retinal leakage. CONCLUSIONS: In the retina, Sox17-Dll4-SREBP1 signaling axis controls transcytosis independently of TJ in superficial arteries among heterogeneous regulations for the whole vessels. Uncontrolled transcytosis via dysregulated Dll4 underlies pathological leakage in hypertensive retina and could be a therapeutic target for treating hypertension-associated retinal edema.

ASSOCIATION BETWEEN EPIRETINAL MEMBRANE, EPIRETINAL PROLIFERATION, AND PROGNOSIS OF FULL-THICKNESS MACULAR HOLE CLOSURE.

PURPOSE: To demonstrate the effects of epiretinal membrane (ERM) and epiretinal proliferation on surgical outcomes for full-thickness macular hole. METHODS: Nested case-control study with propensity score matching. Patients operated on for full-thickness macular hole between January 2011 and March 2020 were enrolled. The primary outcome was failure of the macular hole closure, and the secondary outcome was unfavorable hole closure (V or λ type closure) at 6 months after the surgery. RESULTS: Five hundred and thirty-four eyes of 534 patients met the inclusion criteria. After 1:1 propensity score matching (127 pairs), patients demonstrating ERM were more likely to have a failure of hole closure (adjusted odds ratio, 2.71; 95% confidence interval, 1.19-6.14) and unfavorable hole closure (adjusted odds ratio, 2.07; 95% confidence interval, 1.16-3.71). Epiretinal membrane spanning the hole margin (hole marginal ERM) greatly increased the likelihood of unfavorable hole closure (adjusted odds ratio, 2.13; 95% confidence interval, 1.12-4.07). Patients with hole marginal-ERM + epiretinal proliferation were more likely to have a failure of hole closure (38.4%) compared with those with no ERM (11.8%). CONCLUSION: Patients with ERM had a higher risk for adverse surgical outcomes for full-thickness macular hole closure. The location of the ERM relative to the macular hole and the presence of epiretinal proliferation might affect the surgical outcomes for full-thickness macular hole closure.

Physical activity and the risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related mortality in South Korea: a nationwide cohort study.

PURPOSE: To determine the potential associations between physical activity and risk of SARS-CoV-2 infection, severe illness from COVID-19 and COVID-19 related death using a nationwide cohort from South Korea. METHODS: Data regarding 212 768 Korean adults (age ≥20 years), who tested for SARS-CoV-2, from 1 January 2020 to 30 May 2020, were obtained from the National Health Insurance Service of South Korea and further linked with the national general health examination from 1 January 2018 to 31 December 2019 to assess physical activity levels. SARS-CoV-2 positivity, severe COVID-19 illness and COVID-19 related death were the main outcomes. The observation period was between 1 January 2020 and 31 July 2020. RESULTS: Out of 76 395 participants who completed the general health examination and were tested for SARS-CoV-2, 2295 (3.0%) were positive for SARS-CoV-2, 446 (0.58%) had severe illness from COVID-19 and 45 (0.059%) died from COVID-19. Adults who engaged in both aerobic and muscle strengthening activities according to the 2018 physical activity guidelines had a lower risk of SARS-CoV-2 infection (2.6% vs 3.1%; adjusted relative risk (aRR), 0.85; 95% CI 0.72 to 0.96), severe COVID-19 illness (0.35% vs 0.66%; aRR 0.42; 95% CI 0.19 to 0.91) and COVID-19 related death (0.02% vs 0.08%; aRR 0.24; 95% CI 0.05 to 0.99) than those who engaged in insufficient aerobic and muscle strengthening activities. Furthermore, the recommended range of metabolic equivalent task (MET; 500-1000 MET min/week) was associated with the maximum beneficial effect size for reduced risk of SARS-CoV-2 infection (aRR 0.78; 95% CI 0.66 to 0.92), severe COVID-19 illness (aRR 0.62; 95% CI 0.43 to 0.90) and COVID-19 related death (aRR 0.17; 95% CI 0.07 to 0.98). Similar patterns of association were observed in different sensitivity analyses. CONCLUSION: Adults who engaged in the recommended levels of physical activity were associated with a decreased likelihood of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related death. Our findings suggest that engaging in physical activity has substantial public health value and demonstrates potential benefits to combat COVID-19.

Severe clinical outcomes of COVID-19 associated with proton pump inhibitors: a nationwide cohort study with propensity score matching.

OBJECTIVE: The adverse effects of proton pump inhibitors (PPIs) have been documented for pneumonia; however, there is no consensus regarding whether the use of PPIs might be harmful regarding the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In this regard, we aimed to measure the potential associations of the current use of PPIs with the infection rates of COVID-19 among patients who underwent SARS-CoV-2 testing. DESIGN: Data were derived from a Korean nationwide cohort study with propensity score matching. We included 132 316 patients older than 18 years who tested for SARS-CoV-2 between 1 January and 15 May 2020. Endpoints were SARS-CoV-2 positivity (primary) and severe clinical outcomes of COVID-19 (secondary: admission to intensive care unit, administration of invasive ventilation or death). RESULTS: In the entire cohort, there were 111 911 non-users, 14 163 current PPI users and 6242 past PPI users. After propensity score matching, the SARS-CoV-2 test positivity rate was not associated with the current or past use of PPIs. Among patients with confirmed COVID-19, the current use of PPIs conferred a 79% greater risk of severe clinical outcomes of COVID-19, while the relationship with the past use of PPIs remained insignificant. Current PPI use starting within the previous 30 days was associated with a 90% increased risk of severe clinical outcomes of COVID-19. CONCLUSION: Patients taking PPIs are at increased risk for severe clinical outcomes of COVID-19 but not susceptible to SARS-CoV-2 infection. This suggests that physicians need to assess benefit-risk assessments in the management of acid-related diseases amid the COVID-19 pandemic.

Non-alcoholic Fatty Liver Disease and COVID-19 Susceptibility and Outcomes: a Korean Nationwide Cohort.

BACKGROUND: Evidence for the association between underlying non-alcoholic fatty liver disease (NAFLD), the risk of testing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positive, and the clinical consequences of coronavirus disease 2019 (COVID-19) is controversial and scarce. We aimed to investigate the association between the presence of NAFLD and the risk of SARS-CoV-2 infectivity and COVID-19-related outcomes. METHODS: We used the population-based, nationwide cohort in South Korea linked with the general health examination records between January 1, 2018 and July 30, 2020. Data for 212,768 adults older than 20 years who underwent SARS-CoV-2 testing from January 1 to May 30, 2020, were obtained. The presence of NAFLDs was defined using three definitions, namely hepatic steatosis index (HSI), fatty liver index (FLI), and claims-based definition. The outcomes were SARS-CoV-2 test positive, COVID-19 severe illness, and related death. RESULTS: Among 74,244 adults who completed the general health examination, there were 2,251 (3.0%) who were SARS-CoV-2 positive, 438 (0.6%) with severe COVID-19 illness, and 45 (0.06%) COVID-19-related deaths. After exposure-driven propensity score matching, patients with pre-existing HSI-NAFLD, FLI-NAFLD, or claims-based NAFLD had an 11-23% increased risk of SARS-CoV-2 infection (HSI-NAFLD 95% confidence interval [CI], 1-28%; FLI-NAFLD 95% CI, 2-27%; and claims-based NAFLD 95% CI, 2-31%) and a 35-41% increased risk of severe COVID-19 illness (HSI-NAFLD 95% CI, 8-83%; FLI-NAFLD 95% CI, 5-71%; and claims-based NAFLD 95% CI, 1-92%). These associations are more evident as liver fibrosis advanced (based on the BARD scoring system). Similar patterns were observed in several sensitivity analyses including the full-unmatched cohort. CONCLUSION: Patients with pre-existing NAFLDs have a higher likelihood of testing SARS-CoV-2 positive and severe COVID-19 illness; this association was more evident in patients with NAFLD with advanced fibrosis. Our results suggest that extra attention should be given to the management of patients with NAFLD during the COVID-19 pandemic.

Allergic disorders and susceptibility to and severity of COVID-19: A nationwide cohort study.

BACKGROUND: There is inconclusive and controversial evidence of the association between allergic diseases and the risk of adverse clinical outcomes of coronavirus disease 2019 (COVID-19). OBJECTIVE: We sought to determine the association of allergic disorders with the likelihood of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test result and with clinical outcomes of COVID-19 (admission to intensive care unit, administration of invasive ventilation, and death). METHODS: A propensity-score-matched nationwide cohort study was performed in South Korea. Data obtained from the Health Insurance Review & Assessment Service of Korea from all adult patients (age, >20 years) who were tested for SARS-CoV-2 in South Korea between January 1, 2020, and May 15, 2020, were analyzed. The association of SARS-CoV-2 test positivity and allergic diseases in the entire cohort (n = 219,959) and the difference in clinical outcomes of COVID-19 were evaluated in patients with allergic diseases and SARS-CoV-2 positivity (n = 7,340). RESULTS: In the entire cohort, patients who underwent SARS-CoV-2 testing were evaluated to ascertain whether asthma and allergic rhinitis were associated with an increased likelihood of SARS-CoV-2 test positivity. After propensity score matching, we found that asthma and allergic rhinitis were associated with worse clinical outcomes of COVID-19 in patients with SARS-CoV-2 test positivity. Patients with nonallergic asthma had a greater risk of SARS-CoV-2 test positivity and worse clinical outcomes of COVID-19 than patients with allergic asthma. CONCLUSIONS: In a Korean nationwide cohort, allergic rhinitis and asthma, especially nonallergic asthma, confers a greater risk of susceptibility to SARS-CoV-2 infection and severe clinical outcomes of COVID-19.

Asymptomatic Transmission of SARS-CoV-2 on Evacuation Flight.

We conducted a cohort study in a controlled environment to measure asymptomatic transmission of severe acute respiratory syndrome coronavirus 2 on a flight from Italy to South Korea. Our results suggest that stringent global regulations are necessary for the prevention of transmission of this virus on aircraft.

SoxF Transcription Factors Are Positive Feedback Regulators of VEGF Signaling.

RATIONALE: Vascular endothelial growth factor (VEGF) signaling is a key pathway for angiogenesis and requires highly coordinated regulation. Although the Notch pathway-mediated suppression of excessive VEGF activity via negative feedback is well known, the positive feedback control for augmenting VEGF signaling remains poorly understood. Transcription factor Sox17 is indispensable for angiogenesis, but its association with VEGF signaling is largely unknown. The contribution of other Sox members to angiogenesis also remains to be determined. OBJECTIVE: To reveal the genetic interaction of Sox7, another Sox member, with Sox17 in developmental angiogenesis and their functional relationship with VEGF signaling. METHODS AND RESULTS: Sox7 is expressed specifically in endothelial cells and its global and endothelial-specific deletion resulted in embryonic lethality with severely impaired angiogenesis in mice, substantially overlapping with Sox17 in both expression and function. Interestingly, compound heterozygosity for Sox7 and Sox17 phenocopied vascular defects of Sox7 or Sox17 homozygous knockout, indicating that the genetic cooperation of Sox7 and Sox17 is sensitive to their combined gene dosage. VEGF signaling upregulated both Sox7 and Sox17 expression in angiogenesis via mTOR pathway. Furthermore, Sox7 and Sox17 promoted VEGFR2 (VEGF receptor 2) expression in angiogenic vessels, suggesting a positive feedback loop between VEGF signaling and SoxF. CONCLUSIONS: Our findings demonstrate that SoxF transcription factors are indispensable players in developmental angiogenesis by acting as positive feedback regulators of VEGF signaling.

Effect of diquafosol tetrasodium 3% on the conjunctival surface and clinical findings after cataract surgery in patients with dry eye.

PURPOSE: To investigate the effects of diquafosol tetrasodium (DT) 3% on conjunctival impression cytologic findings in addition to clinical symptoms and signs after cataract surgery in patients with preexisting dry eye disease (DED). METHODS: Ninety-four eyes of 94 patients with DED who underwent uneventful cataract surgery were included. In total, 50 patients were treated with DT 3% (group A), while 44 patients were treated with sodium hyaluronate 0.1% (group B) postoperatively, along with topical antibiotics and steroids. Conjunctival impression cytology was performed at baseline and at 4 and 12 weeks after surgery. Visual acuity, ocular surface disease index (OSDI), tear film breakup time (TBUT), keratoepitheliopathy score, Schirmer's test, and tear clearance rate were measured at baseline and at 1, 4, and 12 weeks, and corneal aberration was analyzed at baseline and at 4 and 12 weeks. RESULTS: The grade of conjunctival squamous metaplasia was lower at 12 weeks, and goblet cell density was higher at 4 and 12 weeks in group A than in group B (P < 0.05). Compared with group B, group A showed significantly lower OSDI scores at 4 and 12 weeks, longer TBUT at 1, 4, and 12 weeks, lower keratoepitheliopathy scores at 1 and 12 weeks, and lower total root-mean-square score and spherical aberrations at 4 weeks after surgery (P < 0.05). CONCLUSIONS: DT 3% eye drops application after cataract surgery was effective in improving conjunctival epithelial morphology and goblet cell density as well as clinical findings in patients with DED.

Postural effects on intraocular pressure and ocular perfusion pressure in patients with non-arteritic anterior ischemic optic neuropathy.

BACKGROUND: To investigate postural effects on intraocular pressure (IOP) and ocular perfusion pressure (OPP) in patients with non-arteritic ischemic optic neuropathy (NAION). METHODS: IOP and blood pressure (BP) were measured in 20 patients with unilateral NAION 10 min after changing to each of the following positions sequentially: sitting, supine, right lateral decubitus position (LDP), supine, left LDP, and supine. IOP was measured using a rebound tonometer and OPP was calculated using formulas based on mean BP. The dependent LDP (DLDP) was defined as the position when the eye of interest (affected or unaffected eye) was placed on the dependent side in the LDP. RESULTS: IOPs were significantly higher (P = 0.020) and OPPs were significantly lower (P = 0.041) in the affected eye compare with the unaffected eye, with the affected eye in DLDP. Compared with the mean IOP of the unaffected eyes, the mean IOP of the affected eyes increased significantly (+2.9 ± 4.4 versus +0.7 ± 3.1 mmHg, respectively; P = 0.003) and the mean OPP decreased significantly (-6.7 ± 9.4 versus -4.9 ± 8.0 mmHg, respectively; P = 0.022) after changing positions from supine to DLDP. In addition, changing position from supine to DLDP showed significantly larger absolute changes in IOP (4.13 ± 3.19 mmHg versus 2.51 ± 1.92 mmHg, respectively; P = 0.004) and OPP (9.86 ± 5.69 mmHg versus 7.50 ± 5.49 mmHg, respectively; P = 0.009) in the affected eye compared with the unaffected eye. In the affected eye, there was a significant positive correlation between absolute change in IOP and OPP when changing position from supine to DLDP (Rho = 0.512, P = 0.021). CONCLUSIONS: A postural change from supine to DLDP caused significant fluctuations in IOP and OPP of the affected eye, and may significantly increase IOP and decrease OPP. Posture-induced IOP changes may be a predisposing factor for NAION development.

A novel TRPM8 agonist relieves dry eye discomfort.

BACKGROUND: Physical cooling of the eye surface relieves ocular discomfort, but translating this event to drug treatment of dry eye discomfort not been studied. Here, we synthesized a water-soluble TRPM8 receptor agonist called cryosim-3 (C3, 1-diisopropylphosphorylnonane) which selectively activates TRPM8 (linked to cooling) but not TRPV1 or TRPA1 (linked to nociception) and tested C3 in subjects with mild forms of dry eye disease. METHODS: A set of 1-dialkylphosphoryalkanes were tested for activation of TRPM8, TRPV1 and TRPA1 receptors in transfected cells. The bioactivity profiles were compared by perioral, topical, and intravenous delivery to anesthetized rats. The selected lead candidate C3 or vehicle (water) was applied with a cotton gauze pad to upper eyelids of patients with dry eye disease (n = 30). Cooling sensation, tear film break-up time (TBUT), basal tear secretion, and corneal staining were evaluated. C3 was then applied four times daily for 2 weeks to patients using a pre-loaded single unit applicator containing 2 mg/mL of C3 in water (n = 20) or water only. TBUT, basal tear secretion, and corneal staining, and three questionnaires surveys of ocular discomfort (VAS scale, OSDI, and CVS symptoms) were analyzed before and at 1 and 2 weeks thereafter. RESULTS: C3 was a selective and potent TRPM8 agonist without TRPV1 or TRPA1 activity. In test animals, the absence of shaking behavior after C3 perioral administration made it the first choice for further study. C3 increased tear secretion in an animal model of dry eye disease and did not irritate when wiped on eyes of volunteers. C3 singly applied (2 mg/ml) produced significant cooling in <5 min, an effecting lasting 46 min with an increase in tear secretion for 60 min. C3 applied for 2 weeks also significantly increased basal tear secretion with questionnaire surveys of ocular discomfort indices clearly showing improvement of symptoms at 1 and 2 weeks. No complaints of irritation or pain were reported by any subject. CONCLUSIONS: C3 is a promising candidate for study of TRPM8 function on the eye surface and for relief of dry eye discomfort. TRIAL REGISTRATION: ISRCTN24802609 and ISRCTN13359367 . Registered 23 March 2015 and 2 September 2015.

Comparison of Topical Cyclosporine and Diquafosol Treatment in Dry Eye.

PURPOSE: To compare the treatment effects of topical cyclosporine A (CsA) and diquafosol sodium (DQS) for the treatment of moderate to severe dry eye disease (DED). METHODS: This prospective, nonrandomized, comparative study involved 60 eyes of 60 patients with moderate to severe DED who were treated with topical CsA 0.05% (group 1, 31 patients) or DQS 3% (group 2, 29 patients) in addition to artificial tears for 3 months. Before treatment, and at 1 and 3 months after treatment, the Ocular Surface Disease Index, tear breakup time, Schirmer score, tear clearance rate, and corneal and conjunctival staining scores were compared. RESULTS: Significant improvements in Ocular Surface Disease Index score, tear clearance rate, and corneal staining score were observed 1 month after treatment in group 2 (p = 0.014, p = 0.002, and p < 0.001, respectively), when compared with group 1. However, no significant differences were observed between the two groups 3 months after treatment (p > 0.05). Tear breakup times were significantly higher in group 2 compared with group 1 for the duration of the study (p < 0.001). Three months after treatment, Schirmer score was significantly higher and conjunctival staining score was significantly lower in group 1 compared with group 2 (p < 0.001). CONCLUSIONS: Both topical CsA 0.05% and DQS 3% are effective in patients with moderate to severe DED. However, the timing and degree of therapeutic effects on tear film and ocular surface parameters, as well as symptoms, can be different between the two treatments.

Early resolved acute syphilitic posterior placoid chorioretinitis.

PURPOSE: Acute syphilitic posterior placoid chorioretinitis (ASPPC) is a rare ocular manifestation of syphilis, and its natural course is not well understood. We herein present two unusual cases of ASPPC in which there was almost total resolution of the fundus and optical coherence tomography (OCT) findings during the early presentation before treatment was initiated. CASE REPORTS: Patient 1: A 44-year-old man presented with a 4-day history of decreased visual acuity in his left eye. Dilated fundus examination revealed a yellowish subretinal placoid lesion in the posterior pole, and OCT images showed subretinal fluid and irregular or granular hyperreflectivity of the retinal pigment epithelium. Ten days later, the yellowish placoid lesion had dramatically improved and the OCT findings showed absence of the subretinal fluid and hyperreflective lesion without any treatment. Patient 2: A 35-year-old man presented with a 3-day history of decreased visual acuity in his right eye. Dilated fundus examination showed a yellow submacular placoid lesion, and OCT images showed a small amount of subretinal fluid with disruption of the inner segment/outer segment junction. Four days after presentation, the fundus and OCT findings had markedly resolved without definitive treatment. In both cases, serologic test results confirmed the diagnosis of syphilis, and the patients were referred to the Department of Infectious Disease for systemic antibiotic treatment. After treatment, the patients' visual acuities were improved, but the disruption of the inner segment/outer segment junction on OCT images remained. CONCLUSIONS: In patients with ASPPC, fundus and OCT findings can spontaneously recover during the early clinical course before treatment.

Glycemic Control and Retinal Microvascular Changes in Type 2 Diabetes Mellitus Patients without Clinical Retinopathy.

Background: To investigate the association of glycemic control and retinal microvascular changes in patients with type 2 diabetes mellitus (T2DM) without diabetic retinopathy (DR). Methods: This retrospective, observational, cohort study included patients with T2DM without DR. The patients were categorized into intensive control (IC; mean glycosylated hemoglobin [HbA1c] ≤7.0%) and moderate control (MC; mean HbA1c >7.0%) groups. Optical coherence tomography (OCT) and swept-source OCT angiography (OCTA) image parameters were compared between three groups, including healthy controls. Results: In total, 259 eyes of 259 participants (88 IC, 81 MC, and 90 controls) were included. The foveal avascular zone area was significantly larger in the MC group than IC and control groups (all P<0.05). The IC group had lower vessel density in the superficial retinal layer and deep retinal layer than the controls (all P<0.05). The choriocapillaris (CC) flow deficit (FD) was significantly greater in the MC group than in the IC and control groups (18.2%, 16.7%, and 14.2%, respectively; all P<0.01). In multivariate regression analysis, CC-FD was associated with the mean HbA1c level (P=0.008). There were no significant differences in OCT parameters among the groups. Conclusion: OCTA revealed that early CC impairment is associated with HbA1c levels; the CC changes precede clinically apparent DR. The OCTA parameters differed among the groups according to the degree of glycemic control. Our results suggest that microvascular changes precede DR and are closely related to glycemic control.

Deciphering perivascular macrophages and microglia in the retinal ganglion cell layers.

Introduction: The classically defined two retinal microglia layers are distributed in inner and outer plexiform layers. Although there are some reports that retinal microglia are also superficially located around the ganglion cell layer (GCL) in contact with the vitreous, there has been a lack of detailed descriptions and not fully understood yet. Methods: We visualized the microglial layers by using CX3CR1-GFP (C57BL6) transgenic mice with both healthy and disease conditions including NaIO3-induced retinal degeneration models and IRBP-induced auto-immune uveitis models. Result: We found the GCL microglia has two subsets; peripheral (pph) microglia located on the retinal parenchyma and BAM (CNS Border Associated Macrophage) which have a special stretched phenotype only located on the surface of large retinal veins. First, in the pph microglia subset, but not in BAM, Galectin-3 and LYVE1 are focally expressed. However, LYVE1 is specifically expressed in the amoeboid or transition forms, except the typical dendritic morphology in the pph microglia. Second, BAM is tightly attached to the surface of the retinal veins and has similar morphology patterns in both the healthy and disease conditions. CD86+ BAM has a longer process which vertically passes the proximal retinal veins. Our data helps decipher the basic anatomy and pathophysiology of the retinal microglia in the GCL. Discussion: Our data helps decipher the basic anatomy and pathophysiology of the retinal microglia in the GCL.

Visuomotor anomalies in achiasmatic mice expressing a transfer-defective Vax1 mutant.

In binocular animals that exhibit stereoscopic visual responses, the axons of retinal ganglion cells (RGCs) connect to brain areas bilaterally by forming a commissure called the optic chiasm (OC). Ventral anterior homeobox 1 (Vax1) contributes to the formation of the OC, acting endogenously in optic pathway cells and exogenously in growing RGC axons. Here, we generated Vax1AA/AA mice expressing the Vax1AA mutant, which is incapable of intercellular transfer. We found that RGC axons cannot take up Vax1AA protein from the Vax1AA/AA mouse optic stalk (OS) and grow slowly to arrive at the hypothalamus at a late stage. The RGC axons of Vax1AA/AA mice connect exclusively to ipsilateral brain areas after failing to access the midline, resulting in reduced visual acuity and abnormal oculomotor responses. Overall, our study provides physiological evidence for the necessity of intercellular transfer of Vax1 and the importance of the bilateral RGC axon projection in proper visuomotor responses.