摘要 :
Purpose To provide the prevalence of vision impairment and blindness among 250,000 school children aged 6 to 17 years, screened in Tamil Nadu, India. Methods The study was conducted between 2016 and 2019 as a part of the school ey...
展开
Purpose To provide the prevalence of vision impairment and blindness among 250,000 school children aged 6 to 17 years, screened in Tamil Nadu, India. Methods The study was conducted between 2016 and 2019 as a part of the school eye screening program in Kanchipuram district, Tamil Nadu. The clinical examination included basic vision testing, objective refraction, subjective acceptance, spectacle dispensing, and a posterior segment evaluation. The prevalence of vision impairment, blindness, low vision, and the association with other demographic variables using logistic regression were calculated. Results A total of 250,052 children were screened in 1047 schools and the prevalence of vision impairment, blindness, and low vision in Kanchipuram district was 3.83%, 0.01%, 0.19%, respectively. The major causes for vision impairment, blindness, and low vision were refractive errors (3.05%), high myopia (0.002%), and refractive amblyopia (0.04%), respectively. Vision impairment was significantly associated with urban location (OR = 1.42, 95% CI 1.36-1.48, p < .0001), females (OR = 1.11, 95%CI - 1.08-1.15, p < .0001), private schools (OR = 2.43, 95%CI - 2.35-2.42, p < .0001), higher secondary class grade (OR = 1.69, 95%CI - 1.61-1.77, p = .001), high-school class grade (OR = 1.65, 95%CI - 1.58-1.72, p = .001) and middle school class grade (OR = 1.53, 95%CI - 1.47-1.59, p = .001). Conclusion This large-scale school eye screening reports a comparatively lower prevalence of vision impairment, blindness, and low vision when compared to other studies conducted around the world. Although the overall prevalence is relatively low, the causes are mostly refractive. Urban, female, private school-going children aged 11-17 are at higher risk.
收起
摘要 :
Purpose: Previously, we showed that tear fluid protects corneal epithelial cells against Pseudomonas aeruginosa without suppressing bacterial viability. Here, we studied how tear fluid affects bacterial gene expression. Methods: R...
展开
Purpose: Previously, we showed that tear fluid protects corneal epithelial cells against Pseudomonas aeruginosa without suppressing bacterial viability. Here, we studied how tear fluid affects bacterial gene expression. Methods: RNA-sequencing was used to study the P. aeruginosa transcriptome after tear fluid exposure (5 h, 37 degrees C). Outcomes were further investigated by biochemical and physiological perturbations to tear fluid and tear-like fluid (TLF) and assessment of bacterial viability following tear/TLF pretreatment and antibiotic exposure. Results: Tear fluid deregulated similar to 180 P. aeruginosa genes >= 8 fold versus PBS including downregulating lasI, rhlI, qscR (quorum sensing/virulence), oprH, phoP, phoQ (antimicrobial resistance) and arnBCADTEF (polymyxin B resistance). Upregulated genes included algF (biofilm formation) and hemO (iron acquisition). qPCR confirmed tear down-regulation of oprH, phoP and phoQ. Tear fluid pre-treatment increased P. aeruginosa resistance to meropenem similar to 5-fold (4 mu g/ml), but enhanced polymyxin B susceptibility similar to 180-fold (1 mu g/ml), the latter activity reduced by dilution in PBS. Media containing a subset of tear components (TLF) also sensitized bacteria to polymyxin B, but only similar to 22.5-fold, correlating with TLF/tear fluid Ca2+ and Mg2+ concentrations. Accordingly, phoQ mutants were not sensitized by TLF or tear fluid. Superior activity of tear fluid versus TLF against wild-type P. aeruginosa was heat resistant but proteinase K sensitive. Conclusion: P. aeruginosa responds to human tear fluid by upregulating genes associated with bacterial survival and adaptation. Meanwhile, tear fluid down-regulates multiple virulence-associated genes. Tears also utilize divalent cations and heat resistant/proteinase K sensitive component(s) to enhance P. aeruginosa sensitivity to polymyxin B.
收起
摘要 :
Purpose We explored the experiences of working-age and older adults with acquired vision impairment who pursued braille rehabilitation training, and the facilitators and barriers they encountered throughout this process. Methods S...
展开
Purpose We explored the experiences of working-age and older adults with acquired vision impairment who pursued braille rehabilitation training, and the facilitators and barriers they encountered throughout this process. Methods Semi-structured interviews of up to 90 min in length were conducted with 14 participants from across Canada who learned braille between the ages of 33 and 67 (Mdn = 46). Transcripts were analyzed by two researchers using interpretive phenomenological analysis. Results A variety of personal, social and institutional factors characterize the adult braille learning experience. Among these, participants highlight the role of prior identity and experience, the impact of access to resources and the cost of materials and devices needed to maintain braille skills. Findings also emphasize invisible barriers, including the role of societal perceptions towards braille, the level of support provided by family and friends, and the influence of unconscious biases towards braille and aging held by both adult learners and those around them. Conclusions These findings provide important context to improve policies and practice in adult braille rehabilitation. As the prevalence of age-related vision impairment continues to increase, it will become imperative to understand the unique needs of working-age and older adults with acquired vision impairment who pursue braille.
收起
摘要 :
SIGNIFICANCE Adaptive-optics scanning-laser-ophthalmoscopy (AOSLO) retinal imaging of the retinal nerve fiber layer (RNFL) helps predict the severity of perimetric damage based on absence of fibers and projection of the defects in...
展开
SIGNIFICANCE Adaptive-optics scanning-laser-ophthalmoscopy (AOSLO) retinal imaging of the retinal nerve fiber layer (RNFL) helps predict the severity of perimetric damage based on absence of fibers and projection of the defects in en face images of the RNFL from spectral-domain optical coherence tomography (SD-OCT). PURPOSE En face images of the RNFL reveal reflectance defects in patients with glaucoma and predict locations of perimetric defects. These defects could arise from either loss of retinal nerve fiber bundles or reduced bundle reflectance. This study used AOSLO to assess presence of bundles in areas with RNFL reflectance defects on SD-OCT. METHODS Adaptive-optics scanning laser ophthalmoscopy was used to image a vertical strip of RNFL measuring approximately 30 x 3 degrees between the optic disc and the fovea. Fifteen patients with glaucoma who had SD-OCT reflectance defects that passed through this region were chosen. Four patients had reflectance defects in both superior and inferior hemifields, so presence of bundles on AOSLO was assessed for 19 hemifields. Where bundles were present, the hemifield was scored for whether bundles seemed unusual (low contrast and/or low density). Perimetric defects were considered deep when sensitivity was below 15 dB. RESULTS Ten hemifields had a region with no fibers present on AOSLO; all had a corresponding deep perimetric defect. The other nine hemifields had no region in the AOSLO image without fibers: four with normal fibers and five with unusual fibers. The only one of these nine hemifields with a deep perimetric defect was one with low-contrast fibers and overall thin RNFL. CONCLUSIONS Retinal nerve fiber layer reflectance defects, which were associated with deep perimetric defects, usually had a region with absence of fibers on AOSLO images of RNFL. Ability to predict severity of perimetric damage from en face SD-OCT RNFL reflectance images could benefit from quantification that differentiated between absence of fibers and unusual fibers.
收起
原文获取