Relationship between Refractive Error and Ocular Biometrics in Twin Children:the Guangzhou Twin Eye Study

Purpose:A cross-sectional study was conducted to explore the relationship between refractive error and ocular biometrics in children from the Guangzhou twin eye study.Methods:.Twin participants aged 7-15 years were selected from Guangzhou Twin Eye Study..Ocular examinations included visual acuity measurement, ocular motility evaluation, autorefraction under cycloplegia, and anterior segment, media, and fundus examination...Axial length(AL),..anterior cham ber depth(ACD), and corneal curvature radius were measured using partial coherence laser interferometry. A multivariate linear regression model was used for statistical analysis.Results:.Twin children from Guangzhou city showed a decreased spherical equivalent with age,.whereas both AL and ACD were increased and corneal curvature radius remained unchanged. When adjusted by age and gender, the data from77% of twins presenting with spherical equivalent changes indicated that these were caused by predictable variables.(R2=0.77, P<0.001). Primary factors affecting children's refraction included axial length(β=-0.97,P<0.001), ACD(β=0.33,P<0.001), and curvature radius(β=2.10,P<0.001). Girls had a higher tendency for myopic status than did boys(β=-0.26,P<0.001)..Age exerted no effect upon the changes in refraction(β=-0.01, P=0.25).Conclusion:.Refraction is correlated with ocular biometrics.Refractive status is largely determined by axial length as the major factor.

Efficacy of Progressive Addition Lenses in the Treatment of Ametropia after the Single Eye's IOL Implantation

Purpose: To investigate the efficacy of progressive addition lenses on the treatment of ametropia and loss of accomodation after the single eye's IOL implantation. Methods:.Eighty four patients undergoing IOL implantation in single eyes were prescribed with progressive addition lenses for ametropia correction and regularly followed up to observe subsequent correction effect. Results:.Among these 84 patients,.72 could comfortably adapt to the use of progressive addition lenses to improve visual acuity and accomondation,while the remaining 12 patients failed to accomodate the usage of progressive addition lenses. Conclusion:.Wearing progressive addition lenses acts as a relatively feasible approach to improve visual acuity and alleviate disorders of accomodation for patients who underwent IOL implantation in single eyes..The patients should be prescribed with progressive lenses under professional instructions and guidance.

Eliminating doubts of time outdoors as a significant intervention to reduce the prevalence of myopia

We thank Dr.Li Deng et al.and Dr.Enis Kocak et al.for their comments on our previous study of outdoor time and myopia development.Clearly,as noted in Dr.Li Deng et al.’s paper,we did not measure the academic performance of subjects or near work time in the trial.Though these are important confounders of myopia,their effect may be considerably reduced by randomization in

Re:Commentary on ten-year incidence of cataract surgery in urban south China:the Liwan Eye Study

We would like to thank Koo et al.for their comments regarding our study on the 10-year incidence of cataract surgery and its associations in an urban adult Chinese population aged 50 years and older(1).Our study indicated that although the annual incidence of cataract surgery in our study(0.9%)was higher than that previously reported by the Beijing Eye Study,it was notably lower than those in other high-income countries,especially for those aged 75 years and older.Participants with higher income,higher education levels,and diabetes at baseline were more likely to have cataract surgery during the 10-year follow-up period.

Longitudinal Relationship between Axial Length and Height in Chinese Children:Guangzhou Twin Eye Study

Purpose:.To understand the growth model of axial length(AL) and height, and to explore the relationship between the two with the passage of time.Methods:.We followed twins in the Guangzhou Twin Eye Study for five years..The AL of both eyes was measured by partial coherence interferometry, and height was measured by a standard scale during each visit..A multivariate multilevel mixed model was adopted for data analysis.Results:.A total of 1217 children were included in the study.Both AL and height increased, but the rate of growth slowed down with age..The mitigation rate of height growth was-0.34 cm / year;.while that of AL growth was-0.01 mm / year.AL was positively related to height,.with a relevant coefficient of R=0.22(Cov [height intercept, AL intercept] =1.56, 95%CI=1.14 to 1.99). The growth rates of AL and height were also positively related, with a relevant coefficient of R =0.18(Cov [height slope, AL slope] =0.03, 95%CI=0.01 to 0.05).However, taller children had slower rates of height increases,with a relevant coefficient of R=-0.12(Cov[height intercept,height slope]=-1.33,95%CI=-2.25 to-0.42); but had faster AL growth,.with a relevant coefficient of R =(Cov [height intercept, AL slope] =0.02, 95%CI=-0.05 to 0.08, R=0.02).AL and its growth rate were positively related to each other,with a relevant coefficient of R=(Cov [AL intercept,.AL slope]=0.04, 95%CI=0.03 to 0.05, R=0.3); while the growth rates of AL and height were negatively related to each other, with a relevant coefficient of R=(Cov [AL intercept, height slope]=--0.03 95%CI=-0.16 to 0.1, R=-0.02).Conclusion:.The increase in children's AL is relevant to their height increases..The faster their height increases,.the faster their AL increases.

An update of the Guangzhou Twin Eye Study

The Guangzhou Twin Eye Study(GTES)is a population-based study of young twins residing in Guangzhou City.The major aim of GTES is to explore the impact of genes,environmental factors and gene-environment interactions on common eye diseases.From 2006,for more than 1,300 twin pairs,age 7-26 years old,progressive ocular phenotypes,such as refraction,ocular biometrics,weight,and height were collected annually,while non-progressive phenotypes such as parental refraction,corneal thickness,retinal fundus,intraocular pressure and DNA only collected at baseline.In the current study,we summarize the major findings on the etiology of myopia in recent decades.

Correlation between Lens Thickness and Central Anterior Chamber Depth

Purpose:.To investigate gender differences in lens thickness (LT) and central anterior chamber depth (ACD) in normal subjects,.and to assess age associated changes in these measures. Methods:.The anterior chamber depth (ACD), and lens thickness (LT), of 150 normal subjects (150 eyes) was measured by anterior segment optical coherence tomography (AS- OCT)..Gender differences were assessed by independent t-test,.and correlation analysis was used to examine the effect of age. Results:.The mean values of ACD and LT were 2.69±0.32 mm and 4.85±0.43 mm, respectively. Women had a significantly lower Mean ACD as compared to men (2.56±0.33 mm vs 2.85±0.29 mm; P﹤0.05). No statistically significant difference was found in LT between male and female subjects (P>0.05)..Correlation analysis findings suggest that LT increases with age (r=0.83,P﹤0.05), and that ACD decreases with age (r=-0.57,P﹤0.05). After controlling for LT, no significant correlation was observed between age and ACD (P>0.05). Conclusion:.The ACD of female subjects was,.on average, shallower than that of their male counterparts..Aging was associated with increasing LT,.and the observed narrowing of ACD with age,.might be partially mediated by the increasing LT.

Inter-ethnic variation of ocular traits——design and methodology of comparison study among American Caucasians,American Chinese and mainland Chinese

Purpose:To summarize the design and methodology of a multi-center study.With the existed ethnic differences of glaucoma,this survey will explore the differences with regard to anterior and posterior ocular segment parameters between Caucasians and Chinese.Methods:In this study,four cohorts including American Caucasians and American Chinese from San Francisco,southern mainland Chinese from Guangzhou,and northern mainland Chinese from Beijing were prospectively enrolled for a series of eye examinations and tests from May 2008 to December 2010.A total of 120 subjects including 15 of each gender in each age decade from 40s to 70s were recruited for each group.Data of the following tests were collected:a questionnaire eliciting systemic and ocular disease history,blood pressure,presenting and best corrected visual acuity,auto-refraction,Goldmann applanation tonometry,go nioscopy,A-scan,anterior segment optical coherence tomography (ASOCT),ultrasound biomicroscopy (UBM),visual field (VF),Heidel berg retinal tomography (HRT),OCT for optic nerve,and digital fundus photography.Conclusion:this study will provide insights to the etiologies of glaucoma especially PACG through inter-ethnic comparisons of relevant ocular anatomic and functional parameters.

Multi-dimension Aspiration Control Mode in Phacoemulsification

Purpose: Multi-dimension aspiration control mode was put forward in this study.Accuracy of multi-dimension aspiration control model was compared to simple traditional pedal control model.Methods: Induced by high aspiration pressure (200～250 mmHg), hard nucleus (≥Grade Ⅲ ) of senile cataract was chopped before phacoemulsification in 170 patients (174 eyes). Ninety-one patients (94 eyes) accepted multi-dimension aspiration control model in which aspiration direction, distance and targets prevention were adjusted by phaco-tip besides traditional pedal control. Another 79 patients (80 eyes) were compared as reviewed group, aspiration of which was controlled simply by traditional pedal control. Postcapsular rupture rates (PCRR) were compared between two groups.Results: Multi-dimension control model could make the terminal effects cooperate with phacoemulsification more precisely and protect post capsular from damage (x2 =5.41, P ＜ 0.02).Conclusion: Multi-dimension control model could improve the accuracy of aspiration effects and protect postcapsular from damage.

How to screen diabetic retinopathy within communities

Diabetic retinopathy(DR)remains a leading cause of irreversible vision loss in adult populations around the globe.Despite growing evidence of the effectiveness of routine assessments and early intervention,DR screening strategies are not widely implemented largely due to an inadequate availability of resources to cope with the growing burden of diabetes.Advances in technology in the field of DR screening are clearly warranted and the recent emergence of deep learning-based artificial intelligence(AI)grading of retinal pathology offers significant potential benefits including an increased efficiency,accessibility and affordability of screening programmes.

Identification of novel loci influencing refractive error in East Asian populations using an extreme phenotype design

The global "myopia boom" has raised significant international concerns. Despite a higher myopia prevalence in Asia, previous large-scale genome-wide association studies(GWASs) were mostly based on European descendants. Here, we report a GWAS of spherical equivalent(SE) in 1852 Chinese Han individuals with extreme SE from Guangzhou(631 <-6.00 D and 574 > 0.00 D) and Wenzhou(593 <-6.00 D and54 >-1.75 D), followed by a replication study in two independent cohorts with totaling 3538 East Asian individuals. The discovery GWAS and meta-analysis identify three novel loci, which show genome-wide significant associations with SE, including 1 q25.2 FAM163 A, 10 p11.22 NRP1/PRAD3, and 10 p11.21 ANKRD30 A/MTRNR2 L7, together explaining 3.34% of SE variance. 10 p11.21 is successfully replicated.The allele frequencies of all three loci show significant differences between major continental groups(P < 0.001). The SE reducing(more myopic) allele of rs10913877(1 q25.2 FAM163 A) demonstrates the highest frequency in East Asians and much lower frequencies in Europeans and Africans(EAS = 0.60,EUR = 0.20, and AFR = 0.18). The gene-based analysis additionally identifies three novel genes associated with SE, including EI24, LHX5, and ARPP19. These results provide new insights into myopia pathogenesis and indicate the role of genetic heterogeneity in myopia epidemiology among different ethnicities.

A deep learning model for generating fundus autofluorescence images from color fundus photography

Background:Fundus Autofluorescence(FAF)is a valuable imaging technique used to assess metabolic alterations in the retinal pigment epithelium(RPE)associated with various age-related and disease-related changes.The practical uses of FAF are ever-growing.This study aimed to evaluate the effectiveness of a generative deep learning(DL)model in translating color fundus(CF)images into synthetic FAF images and explore its potential for enhancing screening of age-related macular degeneration(AMD).Methods:A generative adversarial network(GAN)model was trained on pairs of CF and FAF images to generate synthetic FAF images.The quality of synthesized FAF images was assessed objectively by common generation metrics.Additionally,the clinical effectiveness of the generated FAF images in AMD classification was evaluated by measuring the area under the curve(AUC),using the LabelMe dataset.Results:A total of 8410 FAF images from 2586 patients were analyzed.The synthesized FAF images exhibited an impressive objectively assessed quality,achieving a multi-scale structural similarity index(MS-SSIM)of 0.67.When evaluated on the LabelMe dataset,the combination of generated FAF images and CF images resulted in a noteworthy improvement in AMD classification accuracy,with the AUC increasing from 0.931 to 0.968.Conclusions:This study presents the first attempt to use a generative deep learning model to create authentic and high-quality FAF images from CF images.The incorporation of the translated FAF images on top of CF images improved the accuracy of AMD classification.Overall,this study presents a promising approach to enhance largescale AMD screening.