Prevalence of strabismus among preschool children in eastern China and comparison at a 5-year interval: a population-based cross-sectional study.

OBJECTIVE: To update data on strabismus and evaluate the changes in prevalence and patterns among preschoolers in eastern China over a period of 5 years. DESIGN: Nanjing Eye Study, a longitudinal population-based study. SETTING: Recruitment and testing in kindergartens in Yuhuatai District, Nanjing. PARTICIPANTS: 2300 eligible children. MAIN OUTCOME MEASURES: Comprehensive ocular examinations were conducted in 1986 children aged 48-<60 months in Nanjing Eye Study (NES, 2016-2017), including visual acuity, ocular alignment, refractive error and ocular structures evaluation. The prevalence rate and pattern of strabismus were calculated and compared with those from the Nanjing Pediatric Vision Project (NPVP, 2011-2012) in children of the same age, of the same area and using the same diagnostic criteria. RESULTS: The overall prevalence rate of strabismus in NES was 5.56% (95% CI 4.54% to 6.57%), which was not significantly different from that in NPVP (4.99%, 95% CI 4.13% to 5.84%, p=0.40). The prevalence of subtypes of strabismus underwent significant changes, with significant increase in intermittent exotropia (IXT) in NES (2.78% vs 4.69%, p=0.001) and significant decrease in constant exotropia (1.17% vs 0.15%, p<0.001). Significant change in pattern was observed in IXT, where the proportion of the convergence insufficiency type (2.90% vs 27.17%) increased and exceeded the divergence excess type (20.29% vs 11.96%) to be the second common type (p<0.001). CONCLUSION: The prevalence of strabismus appeared stable in children aged 48-<60 months in eastern China at a 5-year interval. The prevalence of IXT increased significantly, and the convergence insufficiency type became more prevalent in patients with IXT. Timely detection and intervention of IXT are important among preschoolers.

MARCKS is Necessary for Oligodendrocyte Precursor Cell Maturation.

Oligodendrocyte precursor cell (OPC) development into myelinated oligodendrocytes demands vigorous membrane addition. Since myristoylated alanine-rich C-kinase substrate (MARCKS) reportedly contributes to Ras-associated protein (Rab)-10-associated vesicle insertion into neuronal membranes, we investigated the role of MARCKS in OPC maturation. We found that either knockdown of MARCKS or interruption of its interaction with Rab10 would cause a decrease of the cell membrane area during OPC development. Enhanced MARCKS phosphorylation by Nogo66 or myelin debris treatment inhibited OPC maturation, while its dephosphorylation by protein phosphatase 2 A activator D-erythro-sphingosine promoted OPC development in the presence of myelin debris. Our results demonstrated that MARCKS is involved in OPC maturation by interacting with Rab10.

Rab10 Disruption Results in Delayed OPC Maturation.

Oligodendrocyte precursor cell (OPC) maturation requires membrane addition for myelin sheath formation. Since the Rab system has been shown to contribute to membrane addition in other cell types, in this study, we explored the role of Rab in OPC maturation. SiRNA and shRNA techniques and conditional knockout mice provided in vitro and in vivo evidence that Rab10 is involved in OPC maturation and may affect myelination during OPC development.