Global, regional, and national prevalence, disability adjusted life years, and time trends for refraction disorders, 1990-2019: findings from the global burden of disease study 2019.

BACKGROUND: To evaluate global burden of refraction disorders by year, age, region, gender, socioeconomic status and other national characteristics in terms of disability adjusted life years (DALYs) and prevalence from Global Burden of Disease (GBD) study 2019 and World Bank Open Data 2019. METHODS: Global, regional, and national DALY numbers, crude DALY rates, age-standardized DALY and prevalence rates of refraction disorders were acquired from the GBD study 2019. Mobile cellular subscriptions, urban population, GDP per capita, access to electricity and total fertility rate were obtained from the World Bank to explore the factors that influenced the health burden of refraction disorders. Kruskal-Wallis test, linear regression and multiple linear regression were performed to evaluate the associations between the health burden with socioeconomic levels and other national characteristics. Wilcoxon Signed-Rank Test was used to investigate the gender disparity. RESULTS: Globally, age-standardized DALY rates of refraction disorders decreased from 88.9 (95% UI: 60.5-120.3) in 1990 to 81.5 (95% UI: 55.0-114.8) in 2019, and might fall to 73.16 (95% UI: 67.81-78.51) by 2050. Age-standardized prevalence rates would also reduce to 1830 (95% UI: 1700-1960) by 2050, from 2080 (95% UI: 1870-2310) in 1990 to 1960 (95% UI: 1750-2180) in 2019. In low SDI region, age-standardized DALY rates (equation: Y = 114.05*X + 27.88) and prevalence rates (equation: Y = 3171.1*X + 403.2) were positively correlated with SDI in linear regression respectively. East Asia had the highest blindness rate caused by refraction disorders in terms of age-standardized DALY rates (11.20, 95% UI: 7.38-16.36). Gender inequality was found among different age groups and SDI regions. CONCLUSION: Health burden of refraction disorders decreased in recent years, and may continue to alleviate in the next three decades. Older ages, females and lower socioeconomic status were associated with higher refraction disorders health burden.

Quantitative Assessment of Fundus Tessellated Density and Associated Factors in Fundus Images Using Artificial Intelligence.

Purpose: This study aimed to quantitative assess the fundus tessellated density (FTD) and associated factors on the basis of fundus photographs using artificial intelligence. Methods: A detailed examination of 3468 individuals was performed. The proposed method for FTD measurements consists of image preprocessing, sample labeling, deep learning segmentation model, and FTD calculation. Fundus tessellation was extracted as region of interest and then the FTD could be obtained by calculating the average exposed choroid area of per unit area of fundus. Besides, univariate and multivariate linear regression analysis have been conducted for the statistical analysis. Results: The mean FTD was 0.14 ± 0.08 (median, 0.13; range, 0-0.39). In multivariate analysis, FTD was significantly (P < 0.001) associated with thinner subfoveal choroidal thickness, longer axial length, larger parapapillary atrophy, older age, male sex and lower body mass index. Correlation analysis suggested that the FTD increased by 33.1% (r = 0.33, P < .001) for each decade of life. Besides, correlation analysis indicated the negative correlation between FTD and spherical equivalent (SE) in the myopia participants (r = -0.25, P < 0.001), and no correlations between FTD and SE in the hypermetropia and emmetropic participants. Conclusions: It is feasible and efficient to extract FTD information from fundus images by artificial intelligence-based imaging processing. FTD can be widely used in population screening as a new quantitative biomarker for the thickness of the subfoveal choroid. The association between FTD with pathological myopia and lower visual acuity warrants further investigation. Translational Relevance: Artificial intelligence can extract valuable clinical biomarkers from fundus images and assist in population screening.

Repeatability and Reproducibility of Quantitative Assessment of the Retinal Microvasculature Using Optical Coherence Tomography Angiography Based on Optical Microangiography.

OBJECTIVE: The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography (OCTA) based on optical microangiography (OMAG) measurements of macular vessels in normal eyes. METHODS: In this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA (Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density (VAD), vessel skeleton density (VSD), vessel diameter index (VDI), vessel perimeter index (VPI), vessel complexity index (VCI), flux, and foveal avascular zone (FAZ). Coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility. RESULTS: The measurements showed high repeatability [CVs ⪕ 4.2% (intravisit) and ⪕ 4.6% (intervisit)] and interobserver reproducibility (ICCs ⪖ 0.923) for all parameters. CONCLUSION: This study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes.

Application of optical coherence tomography angiography in assessment of posterior scleral reinforcement for pathologic myopia.

AIM: To investigate the effect of posterior scleral reinforcement (PSR) on circulation of pathologic myopia eyes with posterior staphyloma by optical coherence tomography angiography (OCTA). METHODS: The study included 30 pathologic myopia eyes with posterior staphyloma which underwent PSR (PSR group) for 6 to 18mo ago, and 30 age and myopia matched eyes without PSR surgery as control group. Macular, choriocapillaris and radial peripapillary capillary (RPC) flow density were measured by OCTA, and the measurements were compared between groups. RESULTS: OCTA found no significant differences in macular flow density between PSR and control groups. For the superficial flow, whole enface flow density (WED), fovea density (FD), and parafoveal density (PD) were 46.55%±5.19% vs 47.29%±4.12% (P=0.542), 31.45%±6.35% vs 31.17%±4.48% (P=0.841), and 48.82%±5.66% vs 49.21%±4.15% (P=0.756) in PSR and control groups, respectively. For the deep flow, WED, FD, and PD were 52.07%±5.78% vs 53.95%±4.62% (P=0.168), 29.62%±6.55% vs 29.50%±6.38% (P=0.940), and 56.93%±6.17% vs 58.15%±5.13% (P=0.407) in PSR and control groups, respectively. The choriocapillary flow density was 61.18±3.25% in PSR group vs 60.88%±2.56% in control group (P=0.692). Also, OCTA found no significant differences in RPCs flow density between PSR and control groups. The optic disc WED, inside disc flow density and peripapillary flow density were 48.47%±4.77% vs 48.11%±4.57% (P=0.813), 45.47%±11.44% vs 46.68%±9.02% (P=0.709), 54.32%±5.29% vs 52.47%±6.62% (P=0.349) in PSR and control groups, respectively. CONCLUSION: OCTA provides a non-invasive and quantitative approach for monitoring macular and papillary blood flow in pathologic myopia. PSR can not improve but may maintain the circulation of pathologic myopia eyes with posterior staphyloma.

[Clinical investigation of the Heidelberg retina tomograph II in assessment of macular edema].

OBJECTIVE: To evaluate the significance of detecting macular edema by the Retina Module of the Heidelberg retina tomograph II (HRTII). METHODS: Comparative clinical study, One hundred and twenty-six eyes were divided into two groups according to FFA results, one with macular edema and the other without macular edema. Morphological changes in macular edema were observed by HRTII and e (edema index) in two areas of each eye were determined. E value in these two groups and the correlation of e with retinal thickness, BCVA, amplitude and latency of N1 and P1 by multifocal electroretinogram were analyzed. RESULTS: HRTII-RM scan could distinguish different kinds of macular edema (cystoid, local and diffused) and the difference of e between these two groups was significant (e1: t = -19.238, e2: t = -12.436; P < 0.01). The best critical value of e was 1.475 and 1.411 (e1 = 1.475, e2 = 1.411). The sensitivity of e was 92.9% and 91.8% (e1 = 92.9%, e2 = 91.8%). The specificity of e was 97.6% and 95.1% (e1 = 97.6%, e2 = 95.1%). The correlation coefficient between e and retinal thickness was 0.816 and 0.587 (e1: r = 0.816, e2: r = 0.587; P < 0.01); was -0.658 and -0.640 (e1: r = -0.658, e2: r = -0.640; P < 0.01) between e and BCVA; was 0.266 and 0.312 (e1: r = 0.266, e2: r = 0.312; P < 0.01) between e and latency of N1; was -0.609 and -0.586 (e1: r = -0.609, e2: r = -0.586; P < 0.01) between e and amplitude of N1; was 0.529 and 0.431 (e1: r = 0.529, e2: r = 0.431; P < 0.01) between e and latency of P1 and was -0.783 and -0.714 (e1: r = -0.783, e2: r = -0.714; P < 0.01) between e and amplitude of P1, respectively. CONCLUSIONS: There are characteristic changes in the appearance of macular edema as examined by HRT II-RM. The quantitative index e value also shows remarkable changes. HRT II-RM not only detects morphological changes, but also relates to functional changes. This method is capable for evaluating the macular edema.