Ophthalmology (Eye & Ear Hospital) - Research Publications
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ItemSelf-refraction, ready-made glasses and quality of life among rural myopic Chinese children: a non-inferiority randomized trial(WILEY, 2017-09)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 ≥6/7.5 bilaterally, refractive error ≤-1.0 D and <2.0 D of anisometropia and astigmatism bilaterally, were randomized to receive ready-made spectacles (RM) or identical-appearing spectacles with power determined by: subjective cycloplegic retinoscopy by a university optometrist (U), a rural refractionist (R) or non-cycloplegic self-refraction (SR). Main study outcome was global score on the National Eye Institute Refractive Error Quality of Life-42 (NEI-RQL-42) after 2 months of wearing study glasses, comparing other groups with the U group, adjusting for baseline score. RESULTS: Only one child (0.18%) was excluded for anisometropia or astigmatism. A total of 426 eligible subjects (mean age 14.2 years, 84.5% without glasses at baseline) were allocated to U [103 (24.2%)], RM [113 (26.5%)], R [108 (25.4%)] and SR [102 (23.9%)] groups, respectively. Baseline and endline score data were available for 398 (93.4%) of subjects. In multiple regression models adjusting for baseline score, older age (p = 0.003) and baseline spectacle wear (p = 0.016), but not study group assignment, were significantly associated with lower final score. CONCLUSION: Quality of life wearing ready-mades or glasses based on self-refraction did not differ from that with cycloplegic refraction by an experienced optometrist in this non-inferiority trial.
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ItemEffects of Longitudinal Body Mass Index Variability on Microvasculature over 5 Years in Adult Chinese(WILEY, 2016-03)OBJECTIVE: To explore the associations of 5-year trend and fluctuation in body mass index (BMI) with retinal vascular caliber in a middle-aged and elderly Chinese population. METHODS: Participants age ≥40 years were recruited in a prospective study. Baseline BMI data were collected in 2008, and the participants were re-examined annually until 2012. Retinal vascular caliber was measured from fundus photographs collected in 2012. BMI trend was calculated as the slope of BMI against the time of examinations. BMI fluctuation was defined as the root mean square error around the regression line of BMI over time (BMI RMSE) and the coefficient of variation of BMI (BMI CV). RESULTS: Rising BMI trend was associated with narrower retinal arteriolar and wider venular calibers in the overall subjects, especially among persons with overweight and obesity (BMI ≥ 25 kg/m(2) , P = 0.004 and 0.033, respectively). Rising BMI trend was also significantly associated with narrower retinal arteriole even in nonobese individuals with BMI < 25 kg/m(2) (P = 0.017) when eliminating the effects of hypertension and diabetes. Neither BMI RMSE nor BMI CV was statistically associated with retinal vascular caliber (all P > 0.05). CONCLUSIONS: Annual rising trending BMI was associated with retinal microvascular alteration. The results suggest that weight gain probably increases the risk of cardiovascular diseases among middle-aged and elderly people.
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ItemNo Preview AvailableThe CODATwins Project: The Current Status and Recent Findings of COllaborative Project of Development of Anthropometrical Measures in Twins(CAMBRIDGE UNIV PRESS, 2019-12)The COllaborative project of Development of Anthropometrical measures in Twins (CODATwins) project is a large international collaborative effort to analyze individual-level phenotype data from twins in multiple cohorts from different environments. The main objective is to study factors that modify genetic and environmental variation of height, body mass index (BMI, kg/m2) and size at birth, and additionally to address other research questions such as long-term consequences of birth size. The project started in 2013 and is open to all twin projects in the world having height and weight measures on twins with information on zygosity. Thus far, 54 twin projects from 24 countries have provided individual-level data. The CODATwins database includes 489,981 twin individuals (228,635 complete twin pairs). Since many twin cohorts have collected longitudinal data, there is a total of 1,049,785 height and weight observations. For many cohorts, we also have information on birth weight and length, own smoking behavior and own or parental education. We found that the heritability estimates of height and BMI systematically changed from infancy to old age. Remarkably, only minor differences in the heritability estimates were found across cultural-geographic regions, measurement time and birth cohort for height and BMI. In addition to genetic epidemiological studies, we looked at associations of height and BMI with education, birth weight and smoking status. Within-family analyses examined differences within same-sex and opposite-sex dizygotic twins in birth size and later development. The CODATwins project demonstrates the feasibility and value of international collaboration to address gene-by-exposure interactions that require large sample sizes and address the effects of different exposures across time, geographical regions and socioeconomic status.
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ItemNo Preview AvailableTwin's Birth-Order Differences in Height and Body Mass Index From Birth to Old Age: A Pooled Study of 26 Twin Cohorts Participating in the CODATwins Project(CAMBRIDGE UNIV PRESS, 2016-04)We analyzed birth order differences in means and variances of height and body mass index (BMI) in monozygotic (MZ) and dizygotic (DZ) twins from infancy to old age. The data were derived from the international CODATwins database. The total number of height and BMI measures from 0.5 to 79.5 years of age was 397,466. As expected, first-born twins had greater birth weight than second-born twins. With respect to height, first-born twins were slightly taller than second-born twins in childhood. After adjusting the results for birth weight, the birth order differences decreased and were no longer statistically significant. First-born twins had greater BMI than the second-born twins over childhood and adolescence. After adjusting the results for birth weight, birth order was still associated with BMI until 12 years of age. No interaction effect between birth order and zygosity was found. Only limited evidence was found that birth order influenced variances of height or BMI. The results were similar among boys and girls and also in MZ and DZ twins. Overall, the differences in height and BMI between first- and second-born twins were modest even in early childhood, while adjustment for birth weight reduced the birth order differences but did not remove them for BMI.
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ItemPrevalence and risk profile of retinopathy in non-diabetic subjects: National Health and Nutrition Examination Survey 2005 to 2008(WILEY, 2019-12)IMPORTANCE: Recent US national population-based data on the prevalence of retinopathy in non-diabetic participants is limited. BACKGROUND: To assess the prevalence and risk factors of retinopathy in a representative US population without diabetes. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: A total of 4354 non-diabetic participants 40 years and older with valid fundus photographs in the 2005 to 2008 National Health and Nutrition Examination Survey. METHODS: Diabetes mellitus was defined as glycosylated haemoglobin (HbA1c) ≥6.5%, physician diagnosis of diabetes mellitus or use of diabetic medication. Retinopathy level was based on the Modified Airlie House adaptation from the Early Treatment Diabetic Retinopathy Study (ETDRS) protocol. Risk profile was assessed from standardized interviews, clinical examinations and laboratory measurements. MAIN OUTCOME MEASURES: Prevalence and risk profile of retinopathy in non-diabetic participants. RESULTS: The overall weighted prevalence of retinopathy was 6.7% (n = 341). Among them, 98.2% (n = 331) had signs of minimal-to-mild non-proliferative retinopathy (ETDRS level 14-31) while only 1.8% (n = 10) had moderate-to-severe non-proliferative retinopathy (ETDRS level 41-51). After adjusting for multiple covariates, retinopathy signs in non-diabetic participants were associated with male gender (odds ratio [OR] 1.54; 95% confidence interval [CI] 1.22-1.93), systolic blood pressure (OR per 10 mmHg increase 1.11; 95% CI 1.03-1.19), HbA1c (OR per % increase 1.43; 95% CI 1.01-2.05) and history of stroke (OR 2.39; 95% CI 1.14-5.04). CONCLUSIONS AND RELEVANCE: Consistent with previous studies, signs of retinopathy are common in US persons without diabetes. Risk factors for retinopathy signs include gender, blood pressure, HbA1c and history of stroke.
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ItemDevelopment and validation of a deep-learning algorithm for the detection of neovascular age-related macular degeneration from colour fundus photographs(WILEY, 2019-11)IMPORTANCE: Detection of early onset neovascular age-related macular degeneration (AMD) is critical to protecting vision. BACKGROUND: To describe the development and validation of a deep-learning algorithm (DLA) for the detection of neovascular age-related macular degeneration. DESIGN: Development and validation of a DLA using retrospective datasets. PARTICIPANTS: We developed and trained the DLA using 56 113 retinal images and an additional 86 162 images from an independent dataset to externally validate the DLA. All images were non-stereoscopic and retrospectively collected. METHODS: The internal validation dataset was derived from real-world clinical settings in China. Gold standard grading was assigned when consensus was reached by three individual ophthalmologists. The DLA classified 31 247 images as gradable and 24 866 as ungradable (poor quality or poor field definition). These ungradable images were used to create a classification model for image quality. Efficiency and diagnostic accuracy were tested using 86 162 images derived from the Melbourne Collaborative Cohort Study. Neovascular AMD and/or ungradable outcome in one or both eyes was considered referable. MAIN OUTCOME MEASURES: Area under the receiver operating characteristic curve (AUC), sensitivity and specificity. RESULTS: In the internal validation dataset, the AUC, sensitivity and specificity of the DLA for neovascular AMD was 0.995, 96.7%, 96.4%, respectively. Testing against the independent external dataset achieved an AUC, sensitivity and specificity of 0.967, 100% and 93.4%, respectively. More than 60% of false positive cases displayed other macular pathologies. Amongst the false negative cases (internal validation dataset only), over half (57.2%) proved to be undetected detachment of the neurosensory retina or RPE layer. CONCLUSIONS AND RELEVANCE: This DLA shows robust performance for the detection of neovascular AMD amongst retinal images from a multi-ethnic sample and under different imaging protocols. Further research is warranted to investigate where this technology could be best utilized within screening and research settings.
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ItemAssociations of retinal microvascular caliber with intermediate phenotypes of large arterial function and structure: A systematic review and meta-analysis(WILEY, 2019-10)OBJECTIVE: Intermediate phenotypes of microcirculation (retinal microvascular caliber) are associated with cardiovascular (CV) risk factors and independently predict CV events. However, the effect of microcirculation variation on the vascular system is unclear. We conducted a systematic review and meta-analysis of observational studies to quantify associations of retinal microvascular caliber (arteriolar, venular caliber, arteriole-to-venule ratio) and preclinical CV measures (large arterial function and structure). METHODS: We identified studies in MEDLINE, EMBASE, and PubMed (1946 to March 2018) studying (a) general population samples and (b) patients with cardiometabolic disease. Study-specific correlation estimates were combined into meta-analysis where possible. RESULTS: Of 1294 studies identified, 26 met inclusion criteria (general population 16, patients 10), of which five studies were included in meta-analysis. Most studied middle-aged adults cross-sectionally, with one childhood study. Large arterial function and structure were predominantly assessed by pulse wave velocity and carotid intima-media thickness, respectively. Only arteriolar caliber was consistently associated with arterial function and structure, with stronger associations observed in cardiometabolic patients. Narrower (worse) arteriolar caliber was associated with faster (poorer) pulse wave velocity (correlation coefficient (r) -0.17, 95% CI -0.25 to -0.10) and greater (poorer) intima-media thickness (r -0.05, 95%CI -0.09 to -0.02) across all adult participants. CONCLUSIONS: Retinal arteriolar, but not venular caliber, was modestly associated with large arterial function and weakly associated with large arterial structure, with stronger evidence in patients with cardiometabolic disease. This suggests that preclinical changes in large arteries and the microcirculation have some shared but mainly unique pathways to associate with cardiovascular disease.
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ItemReal-world assessment of topical glaucoma medication persistence rates based on national pharmaceutical claim data in a defined population(WILEY, 2019-09)IMPORTANCE: The rate and determinants of persistence to topical glaucoma medications are important for identifying patients at high risk of discontinuing medications and designing targeted approaches to improve persistence. BACKGROUND: To evaluate the rate and determinants of persistence to topical glaucoma medications among middle-aged and older Australian adults. DESIGN: Population-based cohort study. PARTICIPANTS: Participants in need of persistent topical glaucoma medications in the 45 and Up Study. METHODS: The 45 and Up Study is a large-scale population-based cohort study. Participants were classified as needing persistent topical glaucoma medications if at least three claims with related prescriptions were recorded. Persistence was defined as topical glaucoma medications were filled within 90 days. MAIN OUTCOME MEASURES: The rates and determinants of medication persistence at 2-year follow-up. RESULTS: A total of 12 899 patients requiring persistent topical glaucoma medications were identified. Among them, 9019 (69.9%) had persisted with their glaucoma medications for at least 2 years. Multiple logistic regression analysis documented significant effects of patient-related factors (gender, socioeconomic status, language spoken at home, lifestyle and comorbidities) and drug-related factors (total number and drug class) on the persistence rate. Those most at risk groups of non-persistence were those patients living in remote areas (odds ratio, OR: 0.59, 95% confidence interval, CI: 0.37-0.92), having family income over 70 000 AUD/year (OR: 0.53, 95% CI: 0.45-0.62), speaking other languages at home (OR: 0.61, 95% CI: 0.53-0.68), and using cholinergic classes of medications (OR: 0.55, 95% CI: 0.38-0.79). CONCLUSIONS AND RELEVANCE: Our data has shown a medium level of persistence to topical glaucoma medication among middle-aged and older Australian adults. However, efforts are still needed to improve the rate of persistence.
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ItemIncidence and correction of vision impairment among elderly population in southern urban China(WILEY, 2019-05)IMPORTANCE: Data on the incidence of presenting vision impairment (PVI) and spectacle coverage rate (SCR) in urban China is limited. BACKGROUND: To estimate the 6-year incidence and risk factors for PVI and the SCR in urban Southern China. DESIGN: Population-based cohort study. PARTICIPANTS: A total of 1817 participants aged ≥35 years were identified from Guangzhou in 2008 at baseline and 1427 attended follow-up examination in 2014. METHODS: Presenting visual acuity (PVA) was measured using the ETDRS chart with habitual spectacles. Participants with PVA ≤20/40 underwent subjective refraction at the follow-up visit. Incidence of PVI was calculated using the WHO and US criteria, respectively. The met-need SCR was defined as the percentage of participants with PVA <20/40 that had been improved to ≥20/40 after correction. MAIN OUTCOME MEASURES: Incidence of PVI and SCR. RESULTS: Incidence of PVI was 8.3% (95%CI, 6.9-9.8) and 12.2% (95%CI, 10.5-14.0) based on the WHO and US definition, respectively. Older age, female, lower education level, more myopic spherical equivalent and worse PVA at baseline were significantly related to a higher PVI incidence based on the WHO criteria, with similar associations identified using the US criteria except for gender. The overall met-need SCR was 42.5%, and was lower among the elderly, more hyperopic participants or participants with lower education level. CONCLUSIONS AND RELEVANCE: The incidence of PVI is high in urban Southern China and spectacle wearing is available in less than half of those in need. This highlights the needs to promote spectacle coverage even in the urban population.