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PurposeLess was known about globular cells which were a type of dendritic cells (DCs) in cornea. We aimed to investigate the morphological and distribution characteristics of globular cells in corneal vortex and their clinical correlations with ocular surface.MethodsCase records of patients who underwent in vivo confocal microscopy (IVCM) were evaluated retrospectively. The morphology and distribution features of globular cells in cornea nerve vortex and their co-existence status with Langerhans cells (LCs) were analyzed. Data of ocular surface symptoms and signs were collected and their correlations with globular cells distribution patterns and dendritic forms were performed. Dry eye patients without LCs were treated with preservative-free artificial tears, while patients with LCs were treated with artificial tears and fluoromethalone until the activated LCs disappeared.ResultsA total of 836 eyes from 451 individuals were included. Three distribution patterns of globular cells in vortex were investigated, type 1 scattered globular cells (57.66%), type 2 large amounts of globular cells (≥50 cells) gathering in vortex and along some fixed vortex direction horizontally (13.52%) and type 3 no globular cells (28.83%). Their location and cell count altered slightly in the follow-ups but would not disappear. LCs could co-exist with globular cells and could fade after treatment. The type 2 distribution pattern was associated with older age (p = 0.000) and higher upper eyelid Meiboscore (p = 0.006). Dendritic globular cells had higher Meiboscore than Non-dendritic forms.ConclusionsGlobular cells had characteristic distribution patterns and biological features different from LCs. They were associated with long-term irritation of the meibomian gland dysfunction.

Our purpose is to demonstrate the changes in cornea nerve parameters and symptoms and signs in dry eye disease (DED) patients after oral vitamin B1 and mecobalamin treatment. In this randomized double-blind controlled trial, DED patients were randomly assigned to either the treatment group (oral vitamin B1 and mecobalamin, artificial tears) or the control group (artificial tears). Corneal nerve parameters via in vivo confocal microscopy (IVCM), DED symptoms, and signs were assessed at baseline and 1 and 3 months post-treatment. In total, 398 eyes from 199 patients were included. In the treatment group, there were significant improvements in corneal nerve length, width, and neuromas, the sign of conjunctival congestion score (CCS), symptoms of dryness, pain, photophobia, blurred vision, total symptom score, and OSDI (OSDI) at 1/3 months post-treatment (all p < 0.05). Patients who received vitamin B1 and mecobalamin showed greater improvement in CCS, dryness scores at 1 month (p < 0.05), corneal fluorescein staining (CFS) (p = 0.012), photophobia (p = 0.032), total symptom scores (p = 0.041), and OSDI (p = 0.029) at 3 months. Greater continuous improvement in CFS (p = 0.045), dryness (p = 0.033), blurred vision (p = 0.031) and total symptom scores (p = 0.023) was demonstrated at 3 months than at 1 month post-treatment in the treatment group. We found that oral vitamin B1 and mecobalamin can improve corneal nerve length, width, reflectivity and the number of neuromas in IVCM, thereby repairing epithelial cells and alleviating some ocular symptoms. Thus, vitamin B1 and mecobalamin are potential treatment options for patients with DED.

We evaluated how different degrees of air pollution affect the ocular surface of a cohort of human subjects in Beijing by correlating in-patient test outcomes with tear cytokines. A cross-sectional study involving 221 volunteers was carried out in different districts of Beijing. Air pollution indices were recorded for 7 d (including the visit day). The indices recorded were the air quality index (AQI), which is a dimensionless measure that quantitatively describes the state of air quality, concentrations of particulate matter smaller than 2.5 μm (PM2.5) and 10 μm (PM10), sulfur dioxide (SO2), ozone (O3), and nitrogen dioxide (NO2). The Ocular Symptom Disease Index (OSDI) questionnaire provided. Subsequently, subjects underwent slit-lamp examination, which included meibomian gland examination, conjunctival congestion score, conjunctivochalasis grade, tear meniscus height (TMH), tear breakup time (TBUT), corneal fluorescein staining (CFS), Schirmer I test, and conjunctival impression cytology. The concentrations of vascular endothelial growth factor (VEGF), interleukins (IL)-1β, IL-6 and IL-8 in tears were measured by microsphere-based immunoassay analysis. According to the value of the AQI, participants are divided into a slightly polluted (SP) group (n = 103) which the AQI value is less than or equal to 100 and a heavily polluted (HP) group (n = 118) whose AQI value is more than 100. Air pollution is related to ocular discomfort based on tear cytokine concentrations. PM2.5, PM10 and NO2 were positively correlated with OSDI, MG expressibility, meibum score, meiboscore, conjunctival congestion score, Schirmer I test value, TMH, goblet-cell density, concentrations of IL-6, and VEGF were negatively correlated with TBUT. PM2.5 and PM10 appear to be the major risk factors to the ocular surface, with NO2 being another important risk factor based on this study. The symptoms and signs of eye discomfort in the SP group were significantly less severe than those in the HP group, and tear cytokine concentrations (IL-6 and VEGF) were lower. Air pollution degrees were significantly correlated with tear cytokine concentrations, indicating an alteration of cytokine balance at the ocular surface under different degrees of air pollution.

PurposeTo explore the composition of the ocular microbiome in patients with Meibomian gland dysfunction (MGD) using metagenomic nanopore sequencing.MethodsA total of 98 participants were recruited from September to December 2021, including 86 patients with MGD and 12 controls. Symptoms and signs of dry eye were assessed, and bacterial samples in the conjunctival sac (CS) and meibomian gland (MG) secretions were then identified by bacterial culture identification and metagenomic nanopore sequencing.ResultsThe positive rate of CS bacterial culture in the MGD group was significantly higher than that in the normal group. A more complex composition of bacterial genera was detected in the mild and moderate MGD groups than in the control. However, the severe MGD groups had the simplest composition of bacteria. Metagenomic nanopore sequencing detected more species of bacteria than traditional culture.ConclusionThe CS and MG of MGD patients may have different degrees of bacterial microbiota imbalance. Metagenomic nanopore sequencing technology provides a new way for us to understand the composition of “real-world” ocular surface microorganisms.