Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 66
Filter
1.
J Exp Bot ; 75(3): 1016-1035, 2024 Feb 02.
Article in English | MEDLINE | ID: mdl-37813095

ABSTRACT

Drought stress poses a serious threat to grain formation in wheat. Nitrogen (N) plays crucial roles in plant organ development; however, the physiological mechanisms by which drought stress affects plant N availability and mediates the formation of grains in spikes of winter wheat are still unclear. In this study, we determined that pre-reproductive drought stress significantly reduced the number of fertile florets and the number of grains formed. Transcriptome analysis demonstrated that this was related to N metabolism, and in particular, the metabolism pathways of arginine (the main precursor for synthesis of polyamine) and proline. Continuous drought stress restricted plant N accumulation and reallocation rates, and plants preferentially allocated more N to spike development. As the activities of amino acid biosynthesis enzymes and catabolic enzymes were inhibited, more free amino acids accumulated in young spikes. The expression of polyamine synthase genes was down-regulated under drought stress, whilst expression of genes encoding catabolic enzymes was enhanced, resulting in reductions in endogenous spermidine and putrescine. Treatment with exogenous spermidine optimized N allocation in young spikes and leaves, which greatly alleviated the drought-induced reduction in the number of grains per spike. Overall, our results show that pre-reproductive drought stress affects wheat grain numbers by regulating N redistribution and polyamine metabolism.


Subject(s)
Polyamines , Spermidine , Polyamines/metabolism , Polyamines/pharmacology , Spermidine/metabolism , Spermidine/pharmacology , Triticum/metabolism , Nitrogen/metabolism , Droughts , Edible Grain/metabolism
2.
Ophthalmology ; 2023 Dec 29.
Article in English | MEDLINE | ID: mdl-38160880

ABSTRACT

PURPOSE: Chronic kidney disease (CKD) may elevate susceptibility to age-related macular degeneration (AMD) because of shared risk factors, pathogenic mechanisms, and genetic polymorphisms. Given the inconclusive findings in prior studies, we investigated this association using extensive datasets in the Asian Eye Epidemiology Consortium. DESIGN: Cross-sectional study. PARTICIPANTS: Fifty-one thousand two hundred fifty-three participants from 10 distinct population-based Asian studies. METHODS: Age-related macular degeneration was defined using the Wisconsin Age-Related Maculopathy Grading System, the International Age-Related Maculopathy Epidemiological Study Group Classification, or the Beckman Clinical Classification. Chronic kidney disease was defined as estimated glomerular filtration rate (eGFR) of less than 60 ml/min per 1.73 m2. A pooled analysis using individual-level participant data was performed to examine the associations between CKD and eGFR with AMD (early and late), adjusting for age, sex, hypertension, diabetes, body mass index, smoking status, total cholesterol, and study groups. MAIN OUTCOME MEASURES: Odds ratio (OR) of early and late AMD. RESULTS: Among 51 253 participants (mean age, 54.1 ± 14.5 years), 5079 had CKD (9.9%). The prevalence of early AMD was 9.0%, and that of late AMD was 0.71%. After adjusting for confounders, individuals with CKD were associated with higher odds of late AMD (OR, 1.46; 95% confidence interval [CI], 1.11-1.93; P = 0.008). Similarly, poorer kidney function (per 10-unit eGFR decrease) was associated with late AMD (OR, 1.12; 95% CI, 1.05-1.19; P = 0.001). Nevertheless, CKD and eGFR were not associated significantly with early AMD (all P ≥ 0.149). CONCLUSIONS: Pooled analysis from 10 distinct Asian population-based studies revealed that CKD and compromised kidney function are associated significantly with late AMD. This finding further underscores the importance of ocular examinations in patients with CKD. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

3.
Indian J Ophthalmol ; 71(11): 3569-3570, 2023 11.
Article in English | MEDLINE | ID: mdl-37870026

ABSTRACT

Our purpose was to evaluate the efficacy of lateral canthotomy, sub-tenon anesthesia injection, and the use of modified speculum for gaining adequate surgical exposure during surgery for retinopathy of prematurity (ROP). Fourteen eyes of 10 consecutive patients undergoing microincisional vitrectomy surgery (MIVS) for stage 4 and stage 5 ROP were included. There was a significant widening of the palpebral fissure height and length using this technique. No patient developed a lens injury during the surgery. All the canthotomy incisions completely healed at a four-week follow-up visit. This is a safe and effective technique for increasing surgical exposure in cases of ROP requiring vitrectomy.


Subject(s)
Lens, Crystalline , Retinal Detachment , Retinopathy of Prematurity , Infant, Newborn , Humans , Retinopathy of Prematurity/diagnosis , Retinopathy of Prematurity/surgery , Follow-Up Studies , Treatment Outcome , Vitrectomy/methods , Lens, Crystalline/surgery , Retrospective Studies , Visual Acuity , Gestational Age , Retinal Detachment/surgery
4.
J Ophthalmic Vis Res ; 18(3): 334-338, 2023.
Article in English | MEDLINE | ID: mdl-37600914

ABSTRACT

Purpose: To report a case of a young female who presented with scotoma in the right eye for few days. Case Report: Krill's disease or acute retinal pigment epithelitis (ARPE) is a self-limiting retinal disease with no specific treatment. Typical clinical and imaging features helped us to diagnose her with ARPE. Intravenous methylprednisolone (IVMP), which gives a rapid anti-inflammatory response, was advised. An SD-OCT scan post-injection showed a reduction in hyperreflectivity and height of lesion at day 3 and near total resolution by day 5. Conclusion: This case suggests rapid resolution of ARPE with the use of IVMP.

5.
Rice (N Y) ; 16(1): 19, 2023 Apr 11.
Article in English | MEDLINE | ID: mdl-37039929

ABSTRACT

BACKGROUND: As climate change events become more frequent, drought is an increasing threat to agricultural production and food security. Crop rhizosphere microbiome and root exudates are critical regulators for drought adaptation, yet our understanding on the rhizosphere bacterial communities and root exudate composition as affected by drought stress is far from complete. In this study, we performed 16S rRNA gene amplicon sequencing and widely targeted metabolomic analysis of rhizosphere soil and root exudates from two contrasting rice genotypes (Nipponbare and Luodao 998) exposed to drought stress. RESULTS: A reduction in plant phenotypes was observed under drought, and the inhibition was greater for roots than for shoots. Additionally, drought exerted a negligible effect on the alpha diversity of rhizosphere bacterial communities, but obviously altered their composition. In particular, drought led to a significant enrichment of Actinobacteria but a decrease in Firmicutes. We also found that abscisic acid in root exudates was clearly higher under drought, whereas lower jasmonic acid and L-cystine concentrations. As for plant genotypes, variations in plant traits of the drought-tolerant genotype Luodao 998 after drought were smaller than those of Nipponbare. Interestingly, drought triggered an increase in Bacillus, as well as an upregulation of most organic acids and a downregulation of all amino acids in Luodao 998. Notably, both Procrustes analysis and Mantel test demonstrated that rhizosphere microbiome and root exudate metabolomic profiles were highly correlated. A number of differentially abundant genera responded to drought and genotype, including Streptomyces, Bacillus and some members of Actinobacteria, were significantly associated with organic acid and amino acid contents in root exudates. Further soil incubation experiments showed that Streptomyces was regulated by abscisic acid and jasmonic acid under drought. CONCLUSIONS: Our results reveal that both drought and genotype drive changes in the compositions of rice rhizosphere bacterial communities and root exudates under the greenhouse condition, and that organic acid exudation and suppression of amino acid exudation to select specific rhizosphere bacterial communities may be an important strategy for rice to cope with drought. These findings have important implications for improving the adaptability of rice to drought from the perspective of plant-microbe interactions.

6.
Eur J Ophthalmol ; 33(4): 1755-1757, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36703255

ABSTRACT

AIM: To document the use of topical glycerine to reduce corneal edema in cases of retinopathy of prematurity (ROP) undergoing laser photocoagulation (PHC). METHODS: Thirty-two eyes of 16 babies (9 males) with a mean gestational age of 30 weeks, mean gestational weight of 1242 grams underwent PHC for Type 1 (zone 1 disease) retinopathy of prematurity. All babies received a single PHC session. Twenty eyes of 10 babies received intravitreal anti-VEGF injection, 1-3 weeks before PHC session. All patients received a single drop of glycerine during the PHC session to clear the corneal clouding. All patients underwent PHC to the avascular area right up to the ora serrata. Patients were seen at one week and one month to assess the adequacy of laser PHC. RESULTS: We were able to complete the PHC for all babies in a single session without any ocular or systemic adverse events. We did not find any skip lesions at follow-up, and the second session of laser PHC was not required in any eyes. CONCLUSION: Topical glycerine is safe and effective to clear corneal clouding in eyes undergoing laser PHC for retinopathy of prematurity.


Subject(s)
Corneal Diseases , Corneal Opacity , Retinopathy of Prematurity , Infant, Newborn , Infant , Male , Humans , Retinopathy of Prematurity/drug therapy , Retinopathy of Prematurity/surgery , Bevacizumab/therapeutic use , Angiogenesis Inhibitors/therapeutic use , Glycerol/therapeutic use , Vascular Endothelial Growth Factor A , Retina/pathology , Laser Coagulation/adverse effects , Intravitreal Injections , Gestational Age , Corneal Diseases/etiology , Corneal Opacity/etiology , Lasers , Treatment Outcome , Retrospective Studies
7.
Lancet Glob Health ; 10(12): e1754-e1763, 2022 12.
Article in English | MEDLINE | ID: mdl-36240807

ABSTRACT

BACKGROUND: In 2021, WHO Member States endorsed a global target of a 40-percentage-point increase in effective refractive error coverage (eREC; with a 6/12 visual acuity threshold) by 2030. This study models global and regional estimates of eREC as a baseline for the WHO initiative. METHODS: The Vision Loss Expert Group analysed data from 565 448 participants of 169 population-based eye surveys conducted since 2000 to calculate eREC (met need/[met need + undermet need + unmet need]). A binary logistic regression model was used to estimate eREC by Global Burden of Disease (GBD) Study super region among adults aged 50 years and older. FINDINGS: In 2021, distance eREC was 79·1% (95% CI 72·4-85·0) in the high-income super region; 62·1% (54·7-68·8) in north Africa and Middle East; 49·5% (45·0-54·0) in central Europe, eastern Europe, and central Asia; 40·0% (31·7-48·2) in southeast Asia, east Asia, and Oceania; 34·5% (29·4-40·0) in Latin America and the Caribbean; 9·0% (6·5-12·0) in south Asia; and 5·7% (3·1-9·0) in sub-Saharan Africa. eREC was higher in men and reduced with increasing age. Global distance eREC increased from 2000 to 2021 by 19·0%. Global near vision eREC for 2021 was 20·5% (95% CI 17·8-24·4). INTERPRETATION: Over the past 20 years, distance eREC has increased in each super region yet the WHO target will require substantial improvements in quantity and quality of refractive services in particular for near vision impairment. FUNDING: WHO, Sightsavers, The Fred Hollows Foundation, Fondation Thea, Brien Holden Vision Institute, Lions Clubs International Foundation.


Subject(s)
Global Health , Refractive Errors , Adult , Male , Humans , Middle Aged , Aged , Global Burden of Disease , Africa South of the Sahara , Europe , Refractive Errors/epidemiology , Refractive Errors/therapy
8.
Front Med (Lausanne) ; 9: 957437, 2022.
Article in English | MEDLINE | ID: mdl-35911392

ABSTRACT

Background: In 2021, the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) validated a new equation for estimated glomerular filtration rate (eGFR). However, this new equation is not ethnic-specific, and prevalence of CKD in Asians is known to differ from other ethnicities. This study evaluates the impact of the 2009 and 2021 creatinine-based eGFR equations on the prevalence of CKD in multiple Asian cohorts. Methods: Eight population-based studies from China, India, Russia (Asian), Singapore and South Korea provided individual-level data (n = 67,233). GFR was estimated using both the 2009 CKD-EPI equation developed using creatinine, age, sex, and race (eGFRcr [2009, ASR]) and the 2021 CKD-EPI equation developed without race (eGFRcr [2021, AS]). CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73m2 (G3-G5). Prevalence of eGFR categories was compared within each study and within subgroups of age, sex, body mass index (BMI), diabetes, and hypertension status. The extent of reclassification was examined using net reclassification improvement (NRI). Findings: Of 67,233 adults, CKD prevalence was 8.6% (n = 5800/67,233) using eGFRcr (2009, ASR) and 6.4% (n = 4307/67,233) using eGFRcr (2021, AS). With the latter, CKD prevalence was reduced across all eight studies, ranging from -7.0% (95% CI -8.5% to -5.4%) to -0.4% (-1.3% to 0.5%), and across all subgroups except those in the BMI < 18.5% subgroup. Net reclassification index (NRI) was significant at -2.33% (p < 0.001). No individuals were reclassified as a higher (more severe) eGFR category, while 1.7%-4.2% of individuals with CKD were reclassified as one eGFR category lower when eGFRcr (2021, AS) rather than eGFRcr (2009, ASR) was used. Interpretation: eGFRcr (2021, AS) consistently provided reduced CKD prevalence and higher estimation of GFR among Asian cohorts than eGFRcr (2009, ASR). Based on current risk-stratified approaches to CKD management, more patients reclassified to lower-risk GFR categories could help reduce inappropriate care and its associated adverse effects among Asian renal patients. Comparison of both equations to predict progression to renal failure or adverse outcomes using prospective studies are warranted. Funding: National Medical Research Council, Singapore.

9.
Front Plant Sci ; 13: 890181, 2022.
Article in English | MEDLINE | ID: mdl-35651778

ABSTRACT

Nitrogen (N) fertilization plays a pivotal role in physiomorphological attributes and yield formation of field-grown cotton (Gossypium hirsutum L.), but little is known of its interaction with irrigation levels. Therefore, this study was conducted with an objective of evaluating the impact of irrigation and nitrogen levels on growth attributes and nitrogen use efficiency of Bt cotton (Gossypium spp.) in the hot arid region. The experiment consisted of a factorial arrangement of three irrigation levels (200, 400, and 600 mm) and four nitrogen rates (0, 75, 150, and 225 kg ha-1) in a split-plot design with three replications. Nitrogen fertilization and irrigation levels influenced cotton growth attributes and yield. The highest leaf area index, dry matter accumulation, crop growth rate, and relative growth rate were achieved at 225 kg N ha-1 and irrigation level 600 mm as compared to other experimental treatments. Similarly, nitrogen uptake and content by seed, lint, and stalk and total nitrogen uptake recorded maximum at 225 kg N ha-1 and irrigation level 600 mm. Interestingly, the treatment of 600 mm of irrigation and 150 kg N ha-1 displayed significant increase in nitrogen use efficiency indices such as agronomic efficiency of nitrogen (AEN) and recovery efficiency of nitrogen (REN), while partial factor productivity of nitrogen (PFPN) and internal nitrogen use efficiency (iNUE) were significantly higher with application of 600 mm of irrigation and nitrogen application rate of 75 kg ha-1. Application of 600 mm of irrigation along with 225 kg N ha-1 resulted in significant increase in gross return, net return, and B:C ratio than any other treatment combinations. So, application of 600 mm of irrigation along with 225 kg N ha-1 could be recommended for achieving higher growth and yield, as well as profitability of Bt cotton under hot arid region and similar agroecologies.

10.
Retin Cases Brief Rep ; 16(5): 569-571, 2022 Sep 01.
Article in English | MEDLINE | ID: mdl-32976230

ABSTRACT

PURPOSE: To report the safety and efficacy of intravitreal bevacizumab (IVB) in a case of cystoid macular edema (CME) in a silicone oil-filled eye. METHODS: A man, aged 51 years, reported with poor visual improvement in the right eye (RE) after pars plana vitrectomy with oil injection performed 2 months back for a pseudophakic, macula-off rhegmatogenous retinal detachment. His best-corrected visual acuity in the RE was counting fingers 2 m. Fundus examination of the RE showed a silicone oil-filled eye with attached retina, and CME was confirmed on spectral-domain optical coherence tomography. He was advised to undergo IVB injection, which was given a few days later. RESULTS: One week after IVB, the central macular thickness had decreased to 437 µ m. Seven weeks later, the macular edema subsided completely with a final central macular thickness of 219 µ m. His vision improved by seven lines to 6/24 and was stable for another 2 months. He underwent removal of silicone oil after 3 months, wherein his visual acuity improved further by one line to 6/18. DISCUSSION: This case demonstrates the use IVB for CME in a silicone oil-filled eye. It was found that IVB was safe and effective in CME associated with a silicone oil-filled eye.


Subject(s)
Macular Edema , Retinal Detachment , Bevacizumab/adverse effects , Humans , Macular Edema/diagnosis , Macular Edema/drug therapy , Macular Edema/etiology , Male , Retinal Detachment/diagnosis , Retinal Detachment/surgery , Retrospective Studies , Silicone Oils/adverse effects , Tomography, Optical Coherence , Vitrectomy/adverse effects , Vitrectomy/methods
11.
Br J Ophthalmol ; 106(7): 980-986, 2022 07.
Article in English | MEDLINE | ID: mdl-33622697

ABSTRACT

BACKGROUND/AIMS: Obesity is a well-known risk factor for diabetes, but its association with diabetic retinopathy (DR) is inconclusive, in particular in Asians. We aimed to assess whether body mass index (BMI) is associated with the presence and severity of DR in Asian populations with diabetes. METHODS: Pooled analysis of individual-level cross-sectional data from 10 010 adults with diabetes who participated in 12 population-based studies conducted in China, India, Japan, Russia (Asian), Singapore and South Korea that were part of the Asian Eye Epidemiology Consortium (AEEC). BMI was calculated as weight in kilograms divided by height in square metres and categorised into normal (<25 kg/m2, reference), overweight (25-29.9 kg/m2) and obese (≥30 kg/m2). Any-DR (n=1669) and vision-threatening DR (VTDR, n=489) were assessed from digital retinal photographs and graded according to standard protocols. Each study was analysed separately using multivariable logistic regression models adjusted for age, sex, haemoglobin A1c%, systolic blood pressure and diabetes duration, and the estimated odds ratios (ORs) and 95% confidence interval (CIs) from all studies were then combined using random-effects models. RESULTS: In multivariable models, obesity showed a significant inverse association with any-DR (pooled OR (95% CI) =0.74 (0.59 to 0.91)) and VTDR (0.75 (0.60 to 0.93)). Similarly, in continuous analysis, BMI showed a significant inverse association with both any-DR (0.93 (0.87 to 0.99)) and VTDR (0.79 (0.68 to 0.92) per SD increase). Overweight did not show a significant association with any-DR. CONCLUSIONS: Among Asian adults with diabetes, both BMI and obesity showed an inverse association with DR. These findings warrant confirmation in further longitudinal studies.


Subject(s)
Diabetes Mellitus, Type 2 , Diabetic Retinopathy , Adult , Asian People , Body Mass Index , Cross-Sectional Studies , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/epidemiology , Diabetic Retinopathy/epidemiology , Humans , Obesity/complications , Obesity/epidemiology , Overweight/complications , Overweight/epidemiology , Risk Factors
12.
Maturitas ; 154: 46-54, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34736579

ABSTRACT

Obesity and chronic kidney disease (CKD) are major public health problems worldwide. However, the association between body mass index (BMI) and CKD is inconclusive in Asians. In this meta-analysis, eight population-based studies, from China, India, Russia (Asian), Singapore and South Korea, provided individual-level data (n=50037). CKD was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m2. BMI was analyzed both as a continuous variable and in three categories: <25kg/m2, normal; 25-29.9kg/m2, overweight; and ≥30kg/m2, obese. The association between BMI and CKD was evaluated in each study using multivariable logistic regression models and individual estimates were pooled using random-effect meta-analysis to obtain the pooled odds ratio (OR) and 95% confidence interval (CI). Associations were also evaluated in subgroups of age, gender, smoking, diabetes, and hypertension status. Of 50037 adults, 4258 (8.5%) had CKD. 13328 (26.6%) individuals were overweight while 4440 (8.9%) were obese. The prevalence of any CKD ranged from 3.5% to 29.1% across studies. In pooled analysis, both overweight and obesity were associated with increased odds of CKD, with pooled OR (95% CI) of 1.15 (1.03-1.29) and 1.23 (1.06-1.42), respectively. In subgroup analyses, significant associations between BMI and CKD were observed in adult males, non-smokers, and those with diabetes and arterial hypertension (all p<0.05). When evaluated as a continuous variable, BMI was not significantly associated with CKD. If confirmed in longitudinal studies, these results may have clinical implications in risk stratification and preventive measures, given that obesity and CKD are two major chronic diseases with substantial public health burden worldwide.


Subject(s)
Asian People/statistics & numerical data , Body Mass Index , Overweight/complications , Renal Insufficiency, Chronic/ethnology , Adult , Aged , Female , Glomerular Filtration Rate , Humans , Male , Middle Aged , Obesity/complications , Obesity/epidemiology , Overweight/epidemiology , Renal Insufficiency, Chronic/etiology , Risk Factors
13.
Lancet Digit Health ; 3(5): e317-e329, 2021 05.
Article in English | MEDLINE | ID: mdl-33890579

ABSTRACT

BACKGROUND: By 2050, almost 5 billion people globally are projected to have myopia, of whom 20% are likely to have high myopia with clinically significant risk of sight-threatening complications such as myopic macular degeneration. These are diagnoses that typically require specialist assessment or measurement with multiple unconnected pieces of equipment. Artificial intelligence (AI) approaches might be effective for risk stratification and to identify individuals at highest risk of visual loss. However, unresolved challenges for AI medical studies remain, including paucity of transparency, auditability, and traceability. METHODS: In this retrospective multicohort study, we developed and tested retinal photograph-based deep learning algorithms for detection of myopic macular degeneration and high myopia, using a total of 226 686 retinal images. First we trained and internally validated the algorithms on datasets from Singapore, and then externally tested them on datasets from China, Taiwan, India, Russia, and the UK. We also compared the performance of the deep learning algorithms against six human experts in the grading of a randomly selected dataset of 400 images from the external datasets. As proof of concept, we used a blockchain-based AI platform to demonstrate the real-world application of secure data transfer, model transfer, and model testing across three sites in Singapore and China. FINDINGS: The deep learning algorithms showed robust diagnostic performance with areas under the receiver operating characteristic curves [AUC] of 0·969 (95% CI 0·959-0·977) or higher for myopic macular degeneration and 0·913 (0·906-0·920) or higher for high myopia across the external testing datasets with available data. In the randomly selected dataset, the deep learning algorithms outperformed all six expert graders in detection of each condition (AUC of 0·978 [0·957-0·994] for myopic macular degeneration and 0·973 [0·941-0·995] for high myopia). We also successfully used blockchain technology for data transfer, model transfer, and model testing between sites and across two countries. INTERPRETATION: Deep learning algorithms can be effective tools for risk stratification and screening of myopic macular degeneration and high myopia among the large global population with myopia. The blockchain platform developed here could potentially serve as a trusted platform for performance testing of future AI models in medicine. FUNDING: None.


Subject(s)
Algorithms , Artificial Intelligence , Blockchain , Deep Learning , Macular Degeneration/diagnosis , Myopia/diagnosis , Retina/diagnostic imaging , Area Under Curve , Biomedical Research/instrumentation , Biomedical Research/methods , Cohort Studies , Datasets as Topic , Humans , Proof of Concept Study , ROC Curve , Reproducibility of Results , Retrospective Studies
14.
Lancet Digit Health ; 3(1): e29-e40, 2021 01.
Article in English | MEDLINE | ID: mdl-33735066

ABSTRACT

BACKGROUND: In current approaches to vision screening in the community, a simple and efficient process is needed to identify individuals who should be referred to tertiary eye care centres for vision loss related to eye diseases. The emergence of deep learning technology offers new opportunities to revolutionise this clinical referral pathway. We aimed to assess the performance of a newly developed deep learning algorithm for detection of disease-related visual impairment. METHODS: In this proof-of-concept study, using retinal fundus images from 15 175 eyes with complete data related to best-corrected visual acuity or pinhole visual acuity from the Singapore Epidemiology of Eye Diseases Study, we first developed a single-modality deep learning algorithm based on retinal photographs alone for detection of any disease-related visual impairment (defined as eyes from patients with major eye diseases and best-corrected visual acuity of <20/40), and moderate or worse disease-related visual impairment (eyes with disease and best-corrected visual acuity of <20/60). After development of the algorithm, we tested it internally, using a new set of 3803 eyes from the Singapore Epidemiology of Eye Diseases Study. We then tested it externally using three population-based studies (the Beijing Eye study [6239 eyes], Central India Eye and Medical study [6526 eyes], and Blue Mountains Eye Study [2002 eyes]), and two clinical studies (the Chinese University of Hong Kong's Sight Threatening Diabetic Retinopathy study [971 eyes] and the Outram Polyclinic Study [1225 eyes]). The algorithm's performance in each dataset was assessed on the basis of the area under the receiver operating characteristic curve (AUC). FINDINGS: In the internal test dataset, the AUC for detection of any disease-related visual impairment was 94·2% (95% CI 93·0-95·3; sensitivity 90·7% [87·0-93·6]; specificity 86·8% [85·6-87·9]). The AUC for moderate or worse disease-related visual impairment was 93·9% (95% CI 92·2-95·6; sensitivity 94·6% [89·6-97·6]; specificity 81·3% [80·0-82·5]). Across the five external test datasets (16 993 eyes), the algorithm achieved AUCs ranging between 86·6% (83·4-89·7; sensitivity 87·5% [80·7-92·5]; specificity 70·0% [66·7-73·1]) and 93·6% (92·4-94·8; sensitivity 87·8% [84·1-90·9]; specificity 87·1% [86·2-88·0]) for any disease-related visual impairment, and the AUCs for moderate or worse disease-related visual impairment ranged between 85·9% (81·8-90·1; sensitivity 84·7% [73·0-92·8]; specificity 74·4% [71·4-77·2]) and 93·5% (91·7-95·3; sensitivity 90·3% [84·2-94·6]; specificity 84·2% [83·2-85·1]). INTERPRETATION: This proof-of-concept study shows the potential of a single-modality, function-focused tool in identifying visual impairment related to major eye diseases, providing more timely and pinpointed referral of patients with disease-related visual impairment from the community to tertiary eye hospitals. FUNDING: National Medical Research Council, Singapore.


Subject(s)
Algorithms , Deep Learning , Eye Diseases/complications , Vision Disorders/diagnosis , Vision Disorders/etiology , Aged , Area Under Curve , Asian People , Female , Humans , Male , Middle Aged , Photography/methods , Proof of Concept Study , ROC Curve , Sensitivity and Specificity , Singapore/epidemiology
15.
Br J Ophthalmol ; 105(8): 1140-1148, 2021 08.
Article in English | MEDLINE | ID: mdl-32878826

ABSTRACT

AIMS: To determine the prevalence and predictors of myopic macular degeneration (MMD) in a consortium of Asian studies. METHODS: Individual-level data from 19 885 participants from four population-based studies, and 1379 highly myopic participants (defined as axial length (AL) >26.0 mm) from three clinic-based/school-based studies of the Asian Eye Epidemiology Consortium were pooled. MMD was graded from fundus photographs following the meta-analysis for pathologic myopia classification and defined as the presence of diffuse choroidal atrophy, patchy chorioretinal atrophy, macular atrophy, with or without 'plus' lesion (lacquer crack, choroidal neovascularisation or Fuchs' spot). Area under the curve (AUC) evaluation for predictors was performed for the population-based studies. RESULTS: The prevalence of MMD was 0.4%, 0.5%, 1.5% and 5.2% among Asians in rural India, Beijing, Russia and Singapore, respectively. In the population-based studies, older age (per year; OR=1.13), female (OR=2.0), spherical equivalent (SE; per negative diopter; OR=1.7), longer AL (per mm; OR=3.1) and lower education (OR=1.9) were associated with MMD after multivariable adjustment (all p<0.001). Similarly, in the clinic-based/school-based studies, older age (OR=1.07; p<0.001), female (OR=2.1; p<0.001), longer AL (OR=2.1; p<0.001) and lower education (OR=1.7; p=0.005) were associated with MMD after multivariable adjustment. SE had the highest AUC of 0.92, followed by AL (AUC=0.87). The combination of SE, age, education and gender had a marginally higher AUC (0.94). CONCLUSION: In this pooled analysis of multiple Asian studies, older age, female, lower education, greater myopia severity and longer AL were risk factors of MMD, and myopic SE was the strongest single predictor of MMD.


Subject(s)
Asian People/ethnology , Macular Degeneration/ethnology , Myopia, Degenerative/ethnology , Adolescent , Adult , Aged , Aged, 80 and over , Area Under Curve , Axial Length, Eye/pathology , China/epidemiology , Cross-Sectional Studies , Female , Humans , India/epidemiology , Macular Degeneration/diagnosis , Male , Middle Aged , Myopia, Degenerative/diagnosis , Prevalence , ROC Curve , Refraction, Ocular/physiology , Republic of Korea/epidemiology , Risk Factors , Singapore/epidemiology , Visual Acuity/physiology
17.
Ophthalmology ; 127(10): 1371-1381, 2020 10.
Article in English | MEDLINE | ID: mdl-32344073

ABSTRACT

PURPOSE: Although there have been many population-based studies of age-related macular degeneration (AMD), only limited information is available in Asia on the epidemiology of geographic atrophy (GA). We aimed to determine the prevalence and patterns of GA through an analysis of multiple studies conducted within the Asian Eye Epidemiology Consortium (AEEC). DESIGN: Cross-sectional meta-analyses. PARTICIPANTS: A total of 97 213 individuals aged 40 years and older. METHODS: Data from 22 population-based studies from countries belonging to the AEEC were included. In all studies, AMD was defined on the basis of standardized grading systems. Geographic atrophy was defined as an area of pallor in the fundus with visibility of the underlying choroidal blood vessels and sharply defined borders. Random-effects meta-analysis was performed to estimate overall and age-, gender-, and region-specific pooled prevalence of GA. MAIN OUTCOME MEASURES: Prevalence of GA per 1000 persons. RESULTS: The mean age was 60.8 ± 10.0 years, and 42 673 (43.9%) were male. Overall, a total of 223 individuals (0.2%) had GA. The pooled overall prevalence of GA was 1.57 per 1000 persons (95% confidence interval [CI], 1.04-2.10), which was 3 times less than that of neovascular AMD of 5.20 per 1000 persons (95% CI, 3.97-6.43). Compared with those aged 50 to 59 years, the prevalence of GA increased from 0.34 per 1000 persons (95% CI, 0.07-0.62) to 2.90 per 1000 persons (95% CI, 1.55-4.25) in those aged ≥70 years. The GA prevalence per 1000 persons was similar between urban (2.22; 95% CI, 1.22-3.23) and rural residents (1.33; 95% CI, 0.70-1.96). Geographic atrophy was more prevalent in South Asia (based on studies from India and Nepal, 3.82 per 1000 persons; 95% CI, 1.72-5.93) compared with East Asia (based on studies from China, Korea, Hong Kong, Taiwan, and Japan, and the Singapore Chinese Eye Study, 0.76 per 1000 persons; 95% CI, 0.31-1.22, P = 0.005). CONCLUSIONS: Geographic atrophy is uncommon in Asian populations compared with those of European ancestry. Even within Asia, geographic differences in GA prevalence were seen. The findings of this meta-analysis suggest that better dissection of risk factors in the Asian population for GA may provide insights into the biological pathways that drive these late-stage manifestations, thus suggesting better targets for prevention.


Subject(s)
Geographic Atrophy/epidemiology , Visual Acuity , Asia/epidemiology , Geographic Atrophy/physiopathology , Humans , Prevalence
18.
Br J Ophthalmol ; 104(9): 1298-1303, 2020 09.
Article in English | MEDLINE | ID: mdl-31959588

ABSTRACT

AIM: To comprehensively examine the association between kidney function and primary open angle glaucoma (POAG) in a large consortium of multiple Asian population-based studies. METHODS: 28 925 participants (57 340 eyes) from 9 population-based studies (from China, Hong Kong, India, Korea, Russia, Singapore) of the Asian Eye Epidemiology Consortium were included. Across all studies, POAG was defined based on the International Society of Geographical and Epidemiological Ophthalmology criteria. Estimated glomerular filtration rate (eGFR) was calculated from serum creatinine. Chronic kidney disease (CKD) was defined as eGFR<60 mL/min/1.73 m2. Eye-specific data were pooled from each study. Multivariable regression analysis with generalised estimating equation models was performed to evaluate the associations between kidney function with POAG and intraocular pressure (IOP). RESULTS: After adjusting for age, gender, study group, hypertension, diabetes, hyperlipidaemia, body mass index, smoking status and IOP, lower eGFR (per 10 mL/min/1.73 m2 decrease) was not significantly associated with POAG (OR=1.01; p=0.77). Presence of CKD was also not significantly associated with POAG (OR=1.01; p=0.739). Furthermore, lower eGFR and presence of CKD were not associated with IOP (all p≥0.12), However, in the subgroup of combined Korean and Chinese individuals, significant associations between lower eGFR (OR=1.09; 95% CI 1.00 to 1.18; p=0.048) and severe kidney function decline (<45 mL/min/1.73 m2; OR=2.57; 95% CI 1.34 to 4.93; p=0.004) with POAG, were observed. CONCLUSION: In this large pooled-analysis of multiple Asian population-based studies, our findings suggest that the association between CKD and POAG may only be present in East Asians specifically but not in the overall Asian population. Further evaluation in Japanese population is warranted to confirm this observation.


Subject(s)
Glaucoma, Open-Angle/physiopathology , Kidney/physiopathology , Adult , Aged , Asia/epidemiology , Asian People/statistics & numerical data , Cross-Sectional Studies , Epidemiologic Studies , Female , Glaucoma, Open-Angle/epidemiology , Glomerular Filtration Rate , Humans , Intraocular Pressure/physiology , Male , Middle Aged , Renal Insufficiency, Chronic/epidemiology , Renal Insufficiency, Chronic/physiopathology , Tonometry, Ocular , Visual Field Tests , Visual Fields/physiology
19.
Br J Ophthalmol ; 103(7): 871-877, 2019 07.
Article in English | MEDLINE | ID: mdl-30409914

ABSTRACT

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, 3.72% (80% uncertainty interval (UI): 1.39-6.75) and 4.00% (80% UI: 1.41-7.39), 16.33% (80% UI: 8.55-25.47) and 17.65% (80% UI: 9.00-27.62), 11.70% (80% UI: 4.70-20.32) and 12.25% (80% UI:4.86-21.30), respectively, with a significant decrease in the study period for both gender. In South Asia in 2015, 11.76 million individuals (32.65% of the global blindness figure) were blind and 61.19 million individuals (28.3% of the global total) had MSVI. From 1990 to 2015, cataract (accounting for 36.58% of all cases with blindness in 2015) was the most common cause of blindness, followed by undercorrected refractive error (36.43%), glaucoma (5.81%), age-related macular degeneration (2.44%), corneal diseases (2.43%), diabetic retinopathy (0.16%) and trachoma (0.04%). For MSVI in South Asia 2015, most common causes were undercorrected refractive error (accounting for 66.39% of all cases with MSVI), followed by cataract (23.62%), age-related macular degeneration (1.31%) and glaucoma (1.09%). CONCLUSIONS: One-third of the global blind resided in South Asia in 2015, although the age-standardised prevalence of blindness and MSVI decreased significantly between 1990 and 2015.


Subject(s)
Blindness , Vision Disorders , Asia, Central/epidemiology , Asia, Southeastern/epidemiology , Blindness/epidemiology , Blindness/etiology , Humans , Prevalence , Risk Factors , Vision Disorders/epidemiology , Vision Disorders/etiology
20.
Indian J Ophthalmol ; 66(7): 916-920, 2018 07.
Article in English | MEDLINE | ID: mdl-29941730

ABSTRACT

Diabetic retinopathy (DR) and glaucoma are emerging causes of blindness and visual impairment in India and the world. Both diseases do not have any early warning symptoms, and once the symptoms appear, the diseases are reasonably advanced. Because of the long-standing nature of the diseases, one cannot adopt the cataract detection and treatment model so successfully developed in India. It requires an altogether different approach for screening and related infrastructure including human capital development. The solutions developed to reduce the burden of DR/glaucoma should be customized to urban, semi-urban, and rural areas. Greater advocacy, improving the health-seeking behavior, development of infrastructure and skilled personnel appropriate for the points of care, and an emphasis in comprehensive eye care are some of the solutions.


Subject(s)
Community Networks , Consensus , Diabetic Retinopathy/therapy , Disease Management , Glaucoma/therapy , Humans , India
SELECTION OF CITATIONS
SEARCH DETAIL
...