Visual impairment and refractive error in school children in Bhutan: The findings from the Bhutan School Sight Survey (BSSS 2019).

Purpose: To estimate the nationwide prevalence of visual impairment and associated refractive error in school children in Bhutan.

Methods: The sample of this prospective cross-sectional national survey comprised of randomly selected classes in levels IV-IX (age 10 to 15 years) from schools throughout Bhutan. The examination included measurement of visual acuity (VA), evaluation of ocular motility, refraction under cycloplegia, examination of the external eye, media and fundus.

Influence of Distance and Near Visual Impairment on Self-Reported Near Visual Functioning in a Multinational Study.

Purpose: To assess the influence of distance and near visual impairment on self-reported near visual functioning (VF) in a multinational study.

Design: Population-based cross-sectional study.

Participants: Participants aged 35 years or older were selected randomly with cluster sampling at 7 sites: rural sites in Nepal (Kaski) and India (Madurai), a semirural site in China (Shunyi), semiurban sites in South Africa (Durban) and Niger (Dosso), and urban sites in the United States (Los Angeles) and China (Guangzhou).

Prevalence and causes of blindness and vision impairment: magnitude, temporal trends and projections in South and Central Asia.

Background: To assess prevalence and causes of vision loss in Central and South Asia.

Methods: A systematic review of medical literature assessed the prevalence of blindness (presenting visual acuity<3/60 in the better eye), moderate and severe vision impairment (MSVI; presenting visual acuity <6/18 but ≥3/60) and mild vision impairment (MVI; presenting visual acuity <6/12 and ≥6/18) in Central and South Asia for 1990, 2010, 2015 and 2020.

Results: In Central and South Asia combined, age-standardised prevalences of blindness, MSVI and MVI in 2015 were for men and women aged 50+years, 3.

Meeting the need for corrective spectacles in visually impaired Chinese school children: the potential of ready-made spectacles.

Purpose: To assess the potential of ready-made (spherical) spectacles (RMS) in meeting the need for refractive correction in visually impaired children in China.

Methods: Eligible children aged 5-17 years were identified from the three study sites in China. Distance visual acuity was measured with a retroilluminated logarithm of the minimum angle of resolution chart with tumbling E optotypes.

Causes of Visual Impairment and Blindness in the 2006 and 2014 Nine-Province Surveys in Rural China.

Purpose: To investigate the primary causes of visual impairment and blindness in rural China.

Design: Population-based, cross-sectional study.

Methods: Geographic cluster sampling was used in randomly selecting residents from a rural county/district within 9 provinces in the East Coast, Inland Middle, and West regions of mainland China.

Cataract Surgical Coverage and Visual Acuity Outcomes in Rural China in 2014 and Comparisons With the 2006 China Nine-Province Survey.

Purpose: To estimate surgical coverage of cataract-related vision impairment and blindness and visual acuity outcomes in operated eyes in rural China in 2014 with comparisons with the 2006 Nine-Province Survey.

Design: Population-based, cross-sectional study.

Methods: Geographical cluster sampling was used in randomly selecting residents from a rural county or semi-rural district within 9 provinces: Beijing, Jiangsu, Guangdong, Heilongjiang, Jiangxi, Hebei, Ningxia, Chongqing, and Yunnan.

Prevalence of Vision Impairment in Older Adults in Rural China in 2014 and Comparisons With the 2006 China Nine-Province Survey.

Purpose: To estimate the prevalence of vision impairment and blindness in 2014 among older adults in rural China with comparisons with the 2006 Nine-Province Survey.

Design: Population-based, cross-sectional study.

Methods: Geographical cluster sampling was used in randomly selecting residents from a rural county or semi-rural district within 9 provinces: Beijing, Jiangsu, Guangdong, Heilongjiang, Jiangxi, Hebei, Ningxia, Chongqing, and Yunnan.

Progression of Near Vision Loss and Incidence of Near Vision Impairment in an Adult Chinese Population.

Purpose: To investigate the progression of near vision loss and the cumulative incidence of near vision impairment (NVI) 6 years after initial examination of an urban Chinese cohort.

Design: Population-based, prospective cohort study.

Participants: People aged ≥35 years examined at baseline in the Yuexiu District of Guangzhou, China.

Toward translating near-infrared spectroscopy oxygen saturation data for the non-invasive prediction of spatial and temporal hemodynamics during exercise.

Image-based computational fluid dynamics (CFD) studies conducted at rest have shown that atherosclerotic plaque in the thoracic aorta (TA) correlates with adverse wall shear stress (WSS), but there is a paucity of such data under elevated flow conditions. We developed a pedaling exercise protocol to obtain phase contrast magnetic resonance imaging (PC-MRI) blood flow measurements in the TA and brachiocephalic arteries during three-tiered supine pedaling at 130, 150, and 170 % of resting heart rate (HR), and relate these measurements to non-invasive tissue oxygen saturation [Formula: see text] acquired by near-infrared spectroscopy (NIRS) while conducting the same protocol. Local quantification of WSS indices by CFD revealed low time-averaged WSS on the outer curvature of the ascending aorta and the inner curvature of the descending aorta (dAo) that progressively increased with exercise, but that remained low on the anterior surface of brachiocephalic arteries.

Self-refraction, ready-made glasses and quality of life among rural myopic Chinese children: a non-inferiority randomized trial.

Purpose: To study, for the first time, the effect of wearing ready-made glasses and glasses with power determined by self-refraction on children's quality of life.

Methods: This is a randomized, double-masked non-inferiority trial. Children in grades 7 and 8 (age 12-15 years) in nine Chinese secondary schools, with presenting visual acuity (VA) ≤6/12 improved with refraction to ≥6/7.

Image-based quantification of 3D morphology for bifurcations in the left coronary artery: Application to stent design.

Background: Improved strategies for stent-based treatment of coronary artery disease at bifurcations require a greater understanding of artery morphology.

Objective: We developed a workflow to quantify morphology in the left main coronary (LMCA), left anterior descending (LAD), and left circumflex (LCX) artery bifurcations.

Methods: Computational models of each bifurcation were created for 55 patients using computed tomography images in 3D segmentation software.

Prevalence of Amblyopia in School-Aged Children and Variations by Age, Gender, and Ethnicity in a Multi-Country Refractive Error Study.

Purpose: To estimate the age-, gender-, and ethnicity-specific prevalence of amblyopia in children aged 5 to 15 years using data from the multi-country Refractive Error Study in Children (RESC).

Design: Population-based, cross-sectional study.

Participants: Among 46 260 children aged 5 to 15 years who were enumerated from 8 sites in the RESC study, 39 551 had a detailed ocular examination and a reliable visual acuity (VA) measurement in 1 or both eyes.

Bifurcation study of blood flow control in the kidney.

Renal blood flow is maintained within a narrow window by a set of intrinsic autoregulatory mechanisms. Here, a mathematical model of renal hemodynamics control in the rat kidney is used to understand the interactions between two major renal autoregulatory mechanisms: the myogenic response and tubuloglomerular feedback. A bifurcation analysis of the model equations is performed to assess the effects of the delay and sensitivity of the feedback system and the time constants governing the response of vessel diameter and smooth muscle tone.

Immersive visualization for enhanced computational fluid dynamics analysis.

Modern biomedical computer simulations produce spatiotemporal results that are often viewed at a single point in time on standard 2D displays. An immersive visualization environment (IVE) with 3D stereoscopic capability can mitigate some shortcomings of 2D displays via improved depth cues and active movement to further appreciate the spatial localization of imaging data with temporal computational fluid dynamics (CFD) results. We present a semi-automatic workflow for the import, processing, rendering, and stereoscopic visualization of high resolution, patient-specific imaging data, and CFD results in an IVE.

Uptake, Barriers and Outcomes in the Follow-up of Patients Referred for Free-of-Cost Cataract Surgery in the Sao Paulo Eye Study.

Purpose: To determine uptake, barriers and outcomes in the follow-up of patients referred for free-of-charge, expedited cataract surgery in the Sao Paulo Eye Study (SPES).

Methods: SPES was a population-based study of urban, low-middle income residents aged ≥50 years. Presenting visual acuity (PVA), best-corrected visual acuity, refraction, and slit-lamp examination were performed in 3677 participants.

[Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Shuangcheng City of Heilongjiang Province: the China Nine-Province Survey].

Objective: To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Shuangcheng City of Heilongjiang Province, China.

Methods: It was a population-based cross-section study. Geographically defined cluster sampling was used in randomly selecting 5 841 individuals aged 50 years or above in 28 basic sample units in Shuangcheng City from September to December 2006.

[Prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province: the China Nine-Province Survey].

Objective: To investigate the prevalence of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yangxi County of Guangdong Province, China.

Methods: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5 531 individuals aged 50 years or above in Yangxi County from September 2006 to January 2007.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Luxi County of Yunnan Province: the China Nine-Province survey].

Objective: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Luxi County of Yunnan Province, China.

Methods: It was a population-based cross-section study. Geographically defined cluster sampling was used in randomly selecting 5575 individuals aged ≥ 50 years in Luxi County.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Changji City of Xinjiang Uygur Autonomous Region: the China Nine-Province survey].

Objective: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Changji City of Xinjiang Uygur Autonomous Region, China.

Methods: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5714 individuals aged ≥ 50 years in Changji City.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Longyao County of Hebei Province:the China Nine-Province survey].

Objective: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged ≥ 50 years in Longyao County, Hebei Province, China.

Methods: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5527 individuals aged ≥ 50 years in Longyao County.

[Prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yongchuan District of Chongqing City: the China Nine-Province survey].

Objective: To investigate the prevalence and causes of blindness and moderate and severe visual impairment among adults aged 50 years or above in Yongchuan of Chongqing City, China.

Methods: It was a population-based cross-section study.Geographically defined cluster sampling was used in randomly selecting 5663 individuals aged ≥ 50 years in Yongchuan District.

Age-related prevalence and met need for correctable and uncorrectable near vision impairment in a multi-country study.

Purpose: To estimate the prevalence, potential determinants, and proportion of met need for near vision impairment (NVI) correctable with refraction approximately 2 years after initial examination of a multi-country cohort.

Design: Population-based, prospective cohort study.

Participants: People aged ≥35 years examined at baseline in semi-rural (Shunyi) and urban (Guangzhou) sites in China; rural sites in Nepal (Kaski), India (Madurai), and Niger (Dosso); a semi-urban site (Durban) in South Africa; and an urban site (Los Angeles) in the United States.

Patient-specific modeling of cardiovascular and respiratory dynamics during hypercapnia.

This study develops a lumped cardiovascular-respiratory system-level model that incorporates patient-specific data to predict cardiorespiratory response to hypercapnia (increased CO(2) partial pressure) for a patient with congestive heart failure (CHF). In particular, the study focuses on predicting cerebral CO(2) reactivity, which can be defined as the ability of vessels in the cerebral vasculature to expand or contract in response CO(2) induced challenges. It is difficult to characterize cerebral CO(2) reactivity directly from measurements, since no methods exist to dynamically measure vasomotion of vessels in the cerebral vasculature.