Development and validation of prediction models for papillary thyroid cancer structural recurrence using machine learning approaches.

BACKGROUND: Although papillary thyroid cancer (PTC) patients are known to have an excellent prognosis, up to 30% of patients experience disease recurrence after initial treatment. Accurately predicting disease prognosis remains a challenge given that the predictive value of several predictors remains controversial. Thus, we investigated whether machine learning (ML) approaches based on comprehensive predictors can predict the risk of structural recurrence for PTC patients. METHODS: A total of 2244 patients treated with thyroid surgery and radioiodine were included. Twenty-nine perioperative variables consisting of four dimensions (demographic characteristics and comorbidities, tumor-related variables, lymph node (LN)-related variables, and metabolic and inflammatory markers) were analyzed. We applied five ML algorithms-logistic regression (LR), support vector machine (SVM), extreme gradient boosting (XGBoost), random forest (RF), and neural network (NN)-to develop the models. The area under the receiver operating characteristic (AUC-ROC) curve, calibration curve, and variable importance were used to evaluate the models' performance. RESULTS: During a median follow-up of 45.5 months, 179 patients (8.0%) experienced structural recurrence. The non-stimulated thyroglobulin, LN dissection, number of LNs dissected, lymph node metastasis ratio, N stage, comorbidity of hypertension, comorbidity of diabetes, body mass index, and low-density lipoprotein were used to develop the models. All models showed a greater AUC (AUC = 0.738 to 0.767) than did the ATA risk stratification (AUC = 0.620, DeLong test: P < 0.01). The SVM, XGBoost, and RF model showed greater sensitivity (0.568, 0.595, 0.676), specificity (0.903, 0.857, 0.784), accuracy (0.875, 0.835, 0.775), positive predictive value (PPV) (0.344, 0.272, 0.219), negative predictive value (NPV) (0.959, 0.959, 0.964), and F1 score (0.429, 0.373, 0.331) than did the ATA risk stratification (sensitivity = 0.432, specificity = 0.770, accuracy = 0.742, PPV = 0.144, NPV = 0.938, F1 score = 0.216). The RF model had generally consistent calibration compared with the other models. The Tg and the LNR were the top 2 important variables in all the models, the N stage was the top 5 important variables in all the models. CONCLUSIONS: The RF model achieved the expected prediction performance with generally good discrimination, calibration and interpretability in this study. This study sheds light on the potential of ML approaches for improving the accuracy of risk stratification for PTC patients. TRIAL REGISTRATION: Retrospectively registered at www.chictr.org.cn (trial registration number: ChiCTR2300075574, date of registration: 2023-09-08).

Design and analysis of a microgripper for trans-scale clamping based on a compliant multistable mechanism.

Piezoelectric actuators commonly used in microgrippers have a small stroke, and their accuracy is reduced by the transmission amplification unit, which leads to a contradiction between the clamping range and the clamping accuracy in existing piezoelectric-actuated microgrippers. This paper proposes a design scheme to divide the total clamping range of the microgripper into segments based on the compliant multistable mechanism (CMM). First, by using the stable equilibrium positions of the CMM, the total clamping range of the microgripper is divided into multiple smaller clamping sub-intervals to accommodate objects of different scales. Then, the theoretical models of the displacement amplification ratio of the microgripper amplification mechanism and the stiffness of the microgripper in different clamping sub-intervals are established, and the force-displacement characteristics of the CMM are analyzed. Next, through finite element simulation, the correctness of the theoretical analyses is verified, and it is shown that objects between 0 µm and 1.650 mm can be clamped using four clamping sub-intervals under a five times displacement amplification ratio. Finally, a microgripper of the CMM consisting of two three-segment fully compliant bistable mechanisms connected in series is designed and machined, and microgripper segmented clamping experiments are conducted. The experimental results demonstrate the feasibility of the design scheme proposed in this paper.

Temporal trend of anisometropia incidence in Chinese school-aged children before and during the COVID-19 pandemic.

Objective: To analyze and compare the temporal trends in the incidence of anisometropia among Chinese school-aged children both before and during the COVID-19 pandemic, and to investigate the impact of the pandemic on the incidence of anisometropia. Methods: We conducted a retrospective study comprising six distinct and independent longitudinal cohorts, each including children aged 6 to 13 years who visited the Joint Shantou International Eye Center between January 2010 and December 2021. Children were grouped into cohorts based on the year of their first eye clinic visit: 2010, 2012, 2014, 2016, 2018, or 2020. Only children without anisometropia at initial visits, followed for 18 ± 6 months, were included. The cumulative incidence and risk factors of anisometropia were analyzed using Kaplan-Meier estimation and Cox proportional hazards regression models. Subgroup analyses were performed based on sex, age groups, initial refractive error status, and initial interocular SE difference. Anisometropic children were further categorized into myopic and non-myopic, with subsequent subgroup analyses conducted. Results: Of 11,235 children were recruited from six cohorts (2010: n = 1,366; 2012: n = 1,708; 2014: n = 1,896; 2016: n = 2,354; 2018: n = 2,514; 2020: n = 1,397), 869 children developed anisometropia during a mean follow-up of 17.5 ± 3.7 months. After adjustment of confounding factors, we found that the risk of anisometropia remained relatively stable before 2020 but significantly increased in the 2020 cohort (adjusted HR 2.93, 95% CI 2.23 to 3.86; p < 0.001). This trend persisted in studies of spherical anisometropia (adjusted HR 2.52, 95% CI 1.60 to 3.97; p < 0.001) and cylindrical anisometropia (adjusted HR 2.91, 95% CI 1.69 to 3.62; p < 0.001). Older age and a greater initial difference in SE between the two eyes were also significantly associated with a higher risk of developing anisometropia (p < 0.001). Subgroup analyses consistently showed increased risk in the 2020 cohort. Conclusion: This study reveals a concerning rise in anisometropia incidence among Chinese school-aged children during the period of the COVID-19 pandemic. These findings highlight the worrisome rise in anisometropia risk during the COVID-19 pandemic and emphasize the importance of early detection and management to safeguard children's visual health.

Canalicular laceration repair using a novel bicanalicular silicone stent versus traditional bicanalicular stent with nasal fixation.

PURPOSE: To compare the clinical effects of two types of lacrimal stents in the repair of canalicular lacerations. METHODS: A retrospective analysis was conducted on patients with canalicular lacerations between January 2017 and December 2022. The canalicular reconstruction was performed using either the Runshi-RS bicanalicular silicone stent or the traditional bicanalicular silicone stent with nasal fixation, under a surgical microscope. The stent was placed for 3 months, and patients were followed up for more than 3 months after extubation. The anatomical and functional success rates were compared between the two groups. Anatomical success was assessed through diagnostic probing and irrigation of lacrimal passage, while functional success was determined by the patient's subjective symptoms of epiphora. RESULTS: The study included 315 patients (315 eyes) undergoing canalicular laceration repair. The Runshi-RS stent was utilized in 147 patients (46.7%), while the traditional stent with nasal fixation was employed in 168 patients (53.3%). The anatomical success rates (99.3% vs 98.8%, P = 0.642) and functional success rates (87.2% vs 88.1%, P = 0.926) were similar between the RS group and the traditional stent group. Postoperative complications were fewer (4.1% vs 10.1%, P = 0.04) and the operation time was shorter (67.1 ± 35.3 min vs 86.1 ± 43.4 min, P < 0.001) in the RS group. CONCLUSION: The Runshi-RS tube demonstrates favorable surgical outcomes for the repair of canalicular lacerations. Compared to the traditional stent with nasal fixation, the RS stent allows for shorter operation times and fewer postoperative complications in the repair of canalicular lacerations.

Geospatial analysis of spatial distribution, patterns, and relationships of health status in the belt and road initiative.

The Health Silk Road plays a crucial role in the Belt and Road Initiative, and comprehending the health status within the participating countries is fundamental for fostering cooperation in public health. This paper collected five health indicators to represent the health status of the Belt and Road countries. Employing spatial statistics, the spatial patterns of health indicators and the associations with influencing factors were investigated. The utilized spatial statistics encompass spatial autocorrelation methods, geographical detector and spatial lag model. The results revealed obvious disparities and significant positive spatial autocorrelation of health indicators within the Belt and Road countries. Specifically, countries in Sub-Saharan Africa exhibited significant clustering of limited health indicators, while countries in Europe and Central Asia demonstrated significant clustering of robust health indicators. Furthermore, the health indicators exhibited significant spatial heterogeneity and association with the influencing factors. Universal health coverage, household air pollution, and the prevalence of undernourishment emerge as influential factors affecting health indicators. Overall, our findings highlighted complex influencing factors that contributed to the profound health inequalities across the Belt and Road countries. These factors should be duly considered in public health collaborations within the Belt and Road Initiative.

Persistence of severe global inequalities in the burden of blindness and vision loss from 1990 to 2019: findings from the Global Burden of Disease Study 2019.

AIMS: To assess the global burden and economic inequalities in the distribution of blindness and vision loss between 1990 and 2019. METHODS: A secondary analysis of the Global Burden of Diseases, Injuries and Risk Factors Study (GBD) 2019. Data for disability-adjusted life-years (DALYs) due to blindness and vision loss were extracted from the GBD 2019. Data for gross domestic product per capita were extracted from the World Bank database. Slope index of inequality (SII) and concentration index were computed to assess absolute and relative cross-national health inequality, respectively. RESULTS: Countries with high, high-middle, middle, low-middle and low Socio-demographic Index (SDI) had decline of age-standardised DALY rate of 4.3%, 5.2%, 16.0%, 21.4% and 11.30% from 1990 to 2019, respectively. The poorest 50% of world citizens bore 59.0% and 66.2% of the burden of blindness and vision loss in 1990 and 2019, respectively. The absolute cross-national inequality (SII) fell from -303.5 (95% CI -370.8 to -236.2) in 1990 to -256.0 (95% CI -288.1 to -223.8) in 2019. The relative inequality (concentration index) for global blindness and vision loss remained essentially constant between 1991 (-0.197, 95% CI -0.234 to -0.160) and 2019 (-0.193, 95% CI -0.216 to -0.169). CONCLUSION: Though countries with middle and low-middle SDI were the most successful in decreasing burden of blindness and vision loss, a high level of cross-national health inequality persisted over the past three decades. More attention must be paid to the elimination of avoidable blindness and vision loss in low-income and middle-income countries.

Assessment of Peripapillary Retinal Nerve Fiber Layer Optical Density Ratios in Healthy Eyes Using Optical Coherence Tomography with Different Analytical Radii.

PURPOSE: To explore the characteristics and determinants of peripapillary retinal nerve fiber layer (RNFL) optical density (OD) by optical coherence tomography (OCT) in healthy eyes with varied analytical radii. METHODS: Peripapillary OCT scans centered at the optic disc of 150 eyes from 150 healthy subjects (64 males and 86 females) were included. Under 5 analytical circles with different radii (1.45 mm, 1.7 mm, 1.95 mm, 2.2 mm and 2.45 mm), the circumpapillary circular cross-sectional images were exported for further analysis using Image J. Peripapillary RNFL and retinal pigment epithelium (RPE) OD in different quadrants and clock-hours were obtained. RNFL optical density ratio (ODR) was then calculated as RNFL OD divided by RPE OD. A linear mixed-effects model analysis was performed to assess the relationship between RNFL ODR and analytical radius, accounting for axial length, age, spherical equivalent, thickness and image score. RESULTS: The RNFL ODRs had a double-hump pattern with peaks in the superior and inferior quadrants and troughs in the temporal and nasal areas. In the linear mixed-effects model analysis, a trend of decreasing mean RNFL ODR with increasing analytical radius was found (0.9227 ± 0.0689, 0.9063 ± 0.0620, 0.8916 ± 0.0552, 0.8729 ± 0.0553 and 0.8575 ± 0.0564 respectively, p = 0.034). RNFL ODR values was negatively correlated with age (p < 0.001), positively correlated with corresponding RNFL thickness (p < 0.001). No significant correlation was found between RFNL ODR and image score, axial length and spherical equivalent. CONCLUSIONS: RNFL ODR profile showed a comparable double-hump configuration with RNFL thickness. RNFL ODR values tended to decrease with larger analytical circles and older age, and increase with corresponding RNFL thickness. These factors should be considered when interpreting RNFL ODR in glaucoma assessment.

The association between the interval of radioiodine treatment and treatment response, and side effects in patients with lung metastases from differentiated thyroid cancer.

Objective: Repeat radioiodine (RAI) treatment has been widely implemented for RAI-avid lung metastases and is clinically effective for lung metastatic differentiated thyroid cancer (DTC). We aim to investigate the association between the interval of RAI treatment and short-term response, and the side effects in patients with lung metastases from DTC and to identify predictors for non-effective response to the next RAI treatment. Methods: A total of 282 course pairs from 91 patients were established and categorized into two groups by the interval of neighboring RAI treatment (<12 and ≥12 months), and the characteristics and treatment response between the two groups were compared. Multivariate logistic regression was used to identify predictors associated with treatment response. The side effects in the former course and the latter course were compared while taking into account the interval. Results: No significant difference was found between the two groups in treatment response in the latter course (p > 0.05). In the multivariate analysis, age ≥ 55 years (OR = 7.29, 95% CI = 1.66-33.35, p = 0.008), follicular thyroid cancer (OR = 5.00, 95% CI = 1.23-22.18, p = 0.027), and a second RAI treatment as the former course (OR = 4.77, 95% CI = 1.42-18.61, p = 0.016) were significantly associated with a non-effective response. There was no significant difference in the side effects in the former and latter courses between the two groups (p > 0.05). Conclusion: The interval of RAI treatment does not affect short-term response and side effects of DTC patients with RAI-avid lung metastases. It was feasible to defer repeat evaluation and treatment with an interval of at least 12 months to obtain an effective response and reduce the risk of side effects.

Evaluation and comparison of ocular biometric parameters obtained with Tomey OA-2000 in silicone oil-filled aphakic eyes.

PURPOSE: To evaluate a new non-contact instrument (OA-2000) measuring the ocular biometry parameters of silicone oil (SO)-filled aphakic eyes, as compared with IOLMaster 700. METHODS: Forty SO-filled aphakic eyes of 40 patients were enrolled in this cross-sectional clinical trial. The axial length (AL), central corneal thickness (CCT), keratometry ((flattest keratometry) Kf and (steep keratometry, 90° apart from Kf) Ks), and axis of the Kf (Ax1) were measured with OA-2000 and IOLMaster 700. The coefficient of variation (CoV) was calculated to assess the repeatability. The correlation was evaluated by the Pearson coefficient. Bland-Altman analysis and paired t test were used to analyze the agreements and differences of parameters measured by the two devices, respectively. RESULTS: The mean AL obtained with the OA-2000 was 23.57 ± 0.93 mm (range: 21.50 to 25.68 mm), and that obtained with the IOLMaster 700 was 23.69 ± 0.94 mm (range: 21.85 to 25.86 mm), resulting in a mean offset of 0.124 ± 0.125 mm (p < 0.001). The mean offset of CCT measured by OA-2000 and IOLMaster 700 was 14.6 ± 7.5 µm (p < 0.001). However, the Kf, Ks and Ax1 values from the two devices were comparable (p > 0.05). All the measured parameters of the two devices showed strong linear correlations (all r ≥ 0.966). The Bland-Altman analysis showed a narrow 95% limits of agreement (LoA) of Kf, Ks and AL, but 95%LoA of CCT and Ax1 was wide, which were - 29.3 ~ 0.1 µm and-25.9 ~ 30.7°respectively. The CoVs of the biometric parameters obtained with OA-2000 were lower than 1%. CONCLUSION: In SO-filled aphakic eyes, the ocular parameters (including AL, Kf, Ks, Ax1, and CCT) measured by the OA-2000 and IOLMaster 700 had a good correlation. Two devices had an excellent agreement on ocular biometric measurements of Kf, Ks and AL. The OA-2000 provided excellent repeatability of ocular parameters in SO-filled aphakic eyes.

Assessment of nitrogen and phosphorus in the soil of longitudinal direction affected by in-situ oxidation remediation.

The application of in-situ chemical oxidative remediation for contaminated soils has attracted extensive attention, but the effects of remediation processes on soil physical and chemical properties are rarely studied. Herein, a ferrous-activated persulphate oxidation system for remediating dibutyl phthalate (DBP)-polluted soil was simulated in the soil column to explore the effects of in-situ oxidative remediation on soil properties in the longitudinal direction. The DBP content in the soil column was used as an indicator of oxidation strength and the correlation between N, P, soil particle size and oxidation strength was analysed. The experiment results showed that the settling performance of polluted soil after remediation improved and the distribution of the soil particle size at 128 nm disappeared after oxidation, indicating that the suspended solids in the experimental soil were mainly fine clay particles. The oxidation system can promote the conversion of organic nitrogen to inorganic nitrogen and migration characteristics of nitrogen and phosphorus, to aggravate the loss of TN and TP in the soil. The average soil particle size (d50), TN, NH4-N, available phosphorus (Ava-P), exchangeable phosphorus (Ex-P) and organic phosphorus(Or-P) were significantly correlated with oxidation strength; and stable pH in the soil column (pH = 3), showing that the changes in the longitudinal direction of d50 (smaller), TN, NH4-N, Ava-P, Ex-P, and Or-P resulted from the weakening of the longitudinal oxidation strength in the direction of the soil column.

Global, regional, and national burden of multiple sclerosis from 1990 to 2019: Findings of global burden of disease study 2019.

Background: The global rising prevalence and incidence of multiple sclerosis (MS) has been reported during the past decades. However, details regarding the evolution of MS burden have not been fully studied. This study aimed to investigate the global, regional, and national burden and temporal trends in MS incidence, deaths, and disability-adjusted life years (DALYs) from 1990 to 2019 using the age-period-cohort analysis. Methods: We performed a secondary comprehensive analysis of incidence, deaths, and DALYs of MS by calculating the estimated annual percentage change from 1990 to 2019 obtained from the Global Burden of Disease (GBD) 2019 study. The independent age, period, and birth cohort effects were evaluated by an age-period-cohort model. Results: In 2019, there were 59,345 incident MS cases and 22,439 MS deaths worldwide. The global number of incidences, deaths, and DALYs of MS followed an upward trend, whereas the age-standardized rates (ASR) slightly declined from 1990 to 2019. High socio-demographic index (SDI) regions had the highest ASR of incidences, deaths, and DALYs in 2019, while the rate of deaths and DALYs in medium SDI regions are the lowest. Six regions which include high-income North America, Western Europe, Australasia, Central Europe, and Eastern Europe had higher ASR of incidences, deaths, and DALYs than other regions in 2019. The age effect showed that the relative risks (RRs) of incidence and DALYs reached the peak at ages 30-39 and 50-59, respectively. The period effect showed that the RRs of deaths and DALYs increased with the period. The cohort effect showed that the later cohort has lower RRs of deaths and DALYs than the early cohort. Conclusion: The global cases of incidence, deaths, and DALYs of MS have all increased, whereas ASR has declined, with different trends in different regions. High SDI regions such as European countries have a substantial burden of MS. There are significant age effects for incidence, deaths, and DALYs of MS globally, and period effects and cohort effects for deaths and DALYs.

Smartphone ophthalmoscope as a tool in teaching direct ophthalmoscopy: a crossover randomized controlled trial.

To evaluate the effectiveness of smartphone ophthalmoscope (SO) in teaching ophthalmoscopy, compared with direct ophthalmoscope (DO). In this cross-over study, 45 final-year medical students attending sessions at a single institution were randomly allocated to two groups (A and B). Both groups attended two training sessions. In the first session, Group A students were taught ophthalmoscopy using DO and Group B students using SO. In the second session, the training sessions were crossed over. A series of eye models with 10 letters placed on the inner surface were designed to assess the students' skill on ophthalmoscopy. Students performed ophthalmoscopy on the eye models, recorded their findings, and completed a questionnaire of feedback on DO and SO. The main outcome measure was the score of ophthalmoscopy, assessed by the student correctly recording each letter (score 1 for each letter). For Group A, the mean score of ophthalmoscopy on the eye model using DO and SO was 3.9±2.4 and 8.2±2.2, respectively. For Group B, the mean score of ophthalmoscopy on the eye model using SO and DO 8.7±1.8 and 5.7±3.5 . Students scored significantly higher in ophthalmoscopy when using SO than DO (P<0.001). They expressed better visualization of the fundus using SO than DO (4.49±0.65 vs 4.13±0.81, P=0.004). Students' performance of ophthalmoscopy was better when SO was used compared with DO. The use of SO as an adjunctive tool is recommended to improve the effectiveness of teaching ophthalmoscopy.

Preoperative geometric parameters predict the outcome of lamellar keratoscleroplasty in patients with limbal dermoids.

PURPOSE: To find preoperative simple geometric parameters to predict the outcome of lamellar keratoscleroplasty in patients with corneal limbal dermoids. METHODS: We retrospectively analyzed the data of 30 patients with limbal dermoids who underwent lamellar keratoscleroplasty and were followed up for more than 6 months. Seven geometric parameters were used to analyze the relationship with postoperative visual acuity, astigmatism, and scar formation and investigated for their influence on postoperative outcome. These seven parameters included the cornea-invaded area of dermoid, dermoid area, the cornea-invaded length of dermoid, the corneal limbus invaded length of dermoid, dermoid size, bed size, graft size. Furthermore, we divided patients with corneal limbal dermoids into amblyopia group and non-amblyopia group, and analyzed the clinical characteristics of the amblyopia group. RESULTS: The mean age of the patients at surgery was 10.6 ± 5.83 years. The 7 geometric parameters, preoperative and postoperative astigmatism of the amblyopia group were higher than those of the non-amblyopia group (all P < 0.05). Among the geometric parameters analyzed, the r coefficients between the cornea-invaded length of dermoid and postoperative visual acuity and astigmatism were the highest (r = 0.854, r = 0.714). The r coefficient between the corneal limbus invaded length of dermoid and the postoperative scar was the highest (r = 0.375). The r coefficient between age and postoperative steroid-induced high intraocular pressure was the highest (r = - 0.416). In univariate regression analysis, the cornea-invaded length of dermoid was significantly correlated with postoperative visual acuity (ß = 0.270, P < 0.001) and postoperative astigmatism (ß = 1.362, P < 0.001). Among the geometric parameters analyzed, the cornea-invaded length of dermoid had best stratified patients in grouping with or without amblyopia (cutoff > 2.24). CONCLUSION: The cornea-invaded length of dermoid was the most important related factor of postoperative visual acuity, astigmatism, and amblyopia. The corneal limbus invaded length of dermoid was the most important related factor of postoperative scar formation. The geometric parameters and astigmatism in patients with amblyopia were larger than those in patients without amblyopia.

Radioactive Iodine Therapy Decreases the Recurrence of Intermediate-Risk PTC With Low Thyroglobulin Levels.

CONTEXT: Whether radioactive iodine therapy (RAIT) is necessary for intermediate-risk papillary thyroid cancer (PTC) after total thyroidectomy is still lacking reliable evidence, especially for patients with low postoperative thyroglobulin (Tg) levels. OBJECTIVE: This study conducted a propensity score matching (PSM) analysis to investigate whether RAIT is effective in reducing the recurrence of intermediate-risk PTC with low Tg levels. METHODS: In total, 1487 patients with intermediate-risk PTC with unstimulated Tg ≤ 1 ng/mL or stimulated Tg ≤ 10 ng/mL after total thyroidectomy were enrolled retrospectively. The clinicopathological characteristics were compared between the non-RAIT and RAIT groups before and after PSM (1:4 matching). The impact of RAIT on biochemical recurrence and structural recurrence was evaluated. RESULTS: Overall, 1349 (90.7%) patients underwent RAIT, and 138 (9.3%) did not. After a median follow-up time of 51 months, 30 patients presented with recurrence, including 11 structural and 19 biochemical recurrences. After PSM, the non-RAIT group had a higher rate of structural recurrence (5/138 vs 5/552, P = .046) and biochemical recurrence (6/138 vs 4/552, P = .005) than the RAIT group. Multivariate analysis showed that not receiving RAIT was an independent risk factor for structural recurrence (hazard ratio [HR] 10.572, 95% CI 2.439-45.843, P = .002) and biochemical recurrence (HR 16.568, 95% CI 3.670-74.803, P < .001). Kaplan-Meier analysis showed that the non-RAIT group had more unfavorable recurrence-free survival (structural and biochemical, all P < .05). CONCLUSION: RAIT could decrease the recurrence risk of intermediate-risk PTC in patients with unstimulated Tg ≤ 1 ng/mL or stimulated Tg ≤ 10 ng/mL. Further prospective randomized studies are needed to confirm these findings.

Prevalence of myopia and uncorrected myopia among 721 032 schoolchildren in a city-wide vision screening in southern China: the Shantou Myopia Study.

AIMS: To explore the prevalence and risk factors for myopia and uncorrected myopia in schoolchildren in southern China. METHODS: The government-led Shantou Myopia Study was conducted from September 2020 to June 2021. Non-cycloplegic refraction was performed. Uncorrected visual acuity (UCVA) was measured along with presenting visual acuity if participants wore spectacles. Spherical equivalent refraction (SER) is defined as the spherical dioptres added to half of the cylindrical dioptres. Myopia is defined as SER <-0.50 dioptre with UCVA of <20/20 in at least one eye. RESULTS: This study enrolled 724 828 schoolchildren (77.8% of all schoolchildren in Shantou) from 901 schools. Data from 721 032 schoolchildren (99.5%) were analysed (mean age 11.53±3.13 years, 6-20 years, 373 230 boys and 347 802 girls). Among them, 373 459 (51.8%) had myopia: 37.1% of 465 696 children in primary schools, 75.4% of 170 164 children in junior high schools and 84.8% of 85 172 children in senior high schools. The prevalence of myopia increases non-linearly with age. Older age, female and urban living environment were independently associated with myopia prevalence and myopic SER. Among the 373 459 children with myopia, 60.0% had no refractive correction: 74.9%, 53.9% and 35.5% in primary, junior high and senior high schools, respectively. CONCLUSION: The overall prevalence of myopia among schoolchildren in Shantou was 51.8%, higher than the national average in China. The proportion of uncorrected myopia is high, especially in primary schools. Our results indicate the need for public education on eye care among schoolchildren even in a municipal city.

Integration of Massive Open Online Course (MOOC) in Ophthalmic Skills Training for Medical Students: Outcomes and Perspectives.

PURPOSE: To integrate a massive open online course (MOOC) into conventional clinical ophthalmology teaching and investigate its impact on the skills of medical students. METHODS: This was a nonrandomized, prospective, and comparative study. Seventy-six medical students were assigned to 2 groups before their clinical teaching. Some were asked to follow a MOOC for slitlamp microscope examination but used textbook for preview of visual acuity test (SLMM group, n=39), while others were required to take a MOOC for visual acuity test and previewed slitlamp microscopy using textbook (VATM group, n=37). All the students then underwent conventional clinical ophthalmology teaching on slitlamp microscopy and visual acuity test. Their performance was evaluated using Direct Observation of Procedural Skills (DOPS). Students were also asked to complete a 5-item questionnaire about their learning experience and comment on the MOOC. RESULTS: Students in the SLMM group obtained overall higher scores in the slitlamp practical skills (47.64±4.01 vs 44.68±5.99, P=0.013), while those in the VATM group performed better in the visual acuity test (46.45±4.90 vs 43.78±4.94, P=0.004). MOOC was deemed to increase learning interests (4.13 of 5 points) and motivation (4.01 of 5 points) but was more preferred as an additional tool to traditional teaching methods (4.34 of 5 points) rather than to replace them (2.92 of 5 points). CONCLUSIONS: MOOC offers an added benefit in improving clinical skills and is worth advocating as an additional tool for clinical ophthalmic education.

Teachers' assessment literacy improves teaching efficacy: A view from conservation of resources theory.

Recent revisions to the Conservation of Resources theory have not only reclassified categories of resources, but have also acknowledged the conceptual importance of "gain spirals" and "resource caravans" in enriching the theoretical understanding of resources. Given that teachers' assessment literacy is a prominent yet underexplored personal constructive resource in teaching, this paper examines its role in teaching efficacy. In addition, personal energy resources (e.g., psychological capital and professional identity) are studied as antecedents to teaching efficacy. To this end, a survey based on the Chinese versions of the Teacher Assessment Literacy Scale, the Teaching Efficacy Scale, the Psychological Capital Scale, and the Teacher Professional Identity Scale was administered to secondary school teachers in Henan Province, China, and 351 completed, valid surveys were returned. The findings indicated that the teachers' assessment literacy and teaching efficacy were positively correlated, verifying that assessment literacy can influence teaching efficacy through the separate and chain mediation effects of psychological capital and professional identity. The identification of such mediating pathways has confirmed that resources owned by teachers can lead to gain spirals and full resource caravans, thus expanding the Conservation of Resources theory by positing that resources can be nested within one another. This study has theoretical implications for teaching efficacy research and the Conservation of Resources theory as well as practical implications regarding how to boost teachers' constructive and energy resources and professional development.

The Topographic Relationship Between Choroidal Microvascular Dropout and Glaucomatous Damage in Primary Angle-Closure Glaucoma.

Purpose: To study the topographic relationship between parapapillary choroidal microvasculature dropout (MvD) and parapapillary retinal nerve fiber layer (RNFL) defect in primary angle-closure glaucoma (PACG) eyes. Methods: This cross-sectional study was carried out in a glaucoma clinic. Patients with PACG and healthy controls were consecutively enrolled. Each subject underwent optical coherence tomography angiography (OCTA) and OCT testing; additionally, visual field (VF) tests were also conducted in the patients with PACG. MvD was determined when choroidal layer images in OCTA showed a complete loss of the microvasculature. The study included 55 patients with PACG and 30 healthy controls. Results: Fifty-five eyes in 55 patients with PACG and 30 eyes in 30 healthy controls were recruited. MvD was found in 26 PACG eyes (47.3%), but no MvD was found in the healthy eyes. Compared with PACG eyes without MvD, eyes with MvD had thinner average RNFL (P < 0.001), worse VF mean deviation (P = 0.006), and lower peripapillary vessel density (P < 0.001). Between MvD and RNFL defects, there was good topographic consistency in angular circumference (Bland-Altman 95% confidence interval [CI], -24.9° to 21.0°) and position (Bland-Altman 95% CI, -18.6° to 20.6°). There was a significant correlation between the MvD angular circumference and the average peripapillary vessel density (r = -0.505; P = 0.014), average RNFL thickness (r = -0.742; P < 0.001), and VF mean deviation (r = -0.572; P = 0.004). Conclusions: In patients with PACG, the MvD angular circumference and position were highly topographic consistent with those of the peripapillary RNFL defect area. This study suggests that there is a significant correlation between MvD and glaucoma optic nerve injury. Translational Relevance: Given the vascular etiology for glaucoma, the current research suggests that the MvD angular circumference may serve as a potential supplementary clue of glaucoma disease severity.

Potential productivity loss from uncorrected and under-corrected presbyopia in low- and middle-income countries: A life table modeling study.

Objective: To estimate the burden of potential productivity losses due to uncorrected and under-corrected presbyopia in LMICs among the working-age population in both the cross-sectional and longitudinal manner. Methods: We extracted data for the prevalence of presbyopia from the Global Burden of Diseases (GBD), Injuries, and Risk Factors Study 2019. Data for the gross domestic product (GDP) per capita were extracted from the World Bank database and Central Intelligence Agency's World Factbook. We introduced life table models to construct age cohorts (in 5-year age groups) of the working-age population (aged from 40 to 64 years old) in LMICs, with simulated follow-up until 65 years old in people with and without uncorrected presbyopia. The differences in productivity-adjusted life years (PALYs) lived and productivity between these two cohorts were calculated. The potential productivity loss was estimated based on GDP per capita. The WHO standard 3% annual discount rate was applied to all years of life and PALYs lived. Results: In 2019, there were 238.40 million (95% confidence interval [CI]: 150.92-346.78 million) uncorrected and under-corrected presbyopia cases in LMICs, resulting in 54.13 billion (current US dollars) (95% confidence interval [CI]: 34.34-79.02 billion) potential productivity losses. With simulated follow-up until retirement, those with uncorrected and under-corrected presbyopia were predicted to experience an additional loss of 155 million PALYs (an average loss of 0.7 PALYs per case), which was equivalent to a total loss of US$ 315 billion (an average loss of US$ 1453.72 per person). Conclusions: Our findings highlight the considerable productivity losses due to uncorrected and under-corrected presbyopia in LMICs, especially in a longitudinal manner. There is a great need for the development of enabling eye care policies and programs to create access to eye care services, and more healthcare investment in the correction of presbyopia in the working-age population in LMICs. This study could provide evidences for some potential health-related strategies for socio-economic development.

Assessment of the influence of keratometry on intraocular lens calculation formulas in long axial length eyes.

PURPOSE: Hyperopic surprises tend to occur in axial myopic eyes and other factors including corneal curvature have rarely been analyzed in cataract surgery, especially in eyes with long axial length (≥ 26.0 mm). Thus, the purpose of our study was to evaluate the influence of keratometry on four different formulas (SRK/T, Barrett Universal II, Haigis and Olsen) in intraocular lens (IOL) power calculation for long eyes. METHODS: Retrospective case series. A total of 180 eyes with axial length (AL) ≥ 26.0 mm were divided into 3 keratometry (K) groups: K ≤ 42.0 D (Flat), K ≥ 46.0 D (Steep), 42.0 < K < 46.0 D (Average), and all the eyes were underwent phacoemulsification cataract surgery with Rayner (Hove, UK) 920H IOL implantation. Prediction errors (PE) were compared between different formulas to assess the accuracy of different formulas. Multiple regression analysis was performed to investigate factors associated with the PE. RESULTS: The mean absolute error was higher for all evaluated formulas in Steep group (ranging from 0.66 D to 1.02 D) than the Flat (0.34 D to 0.67 D) and Average groups (0.40 D to 0.74D). The median absolute errors predicted by Olsen formula were significantly lower than that predicted by Haigis formula (0.42 D versus 0.85 D in Steep and 0.29 D versus 0.69 D in Average) in Steep and Average groups (P = 0.012, P < 0.001, respectively). And the Olsen formula demonstrated equal accuracy to the Barrett II formula in Flat and Average groups. The predictability of the SRK/T formula was affected by the AL and K, while the predictability of Olsen and Haigis formulas was affected by the AL only. CONCLUSIONS: Steep cornea has more influence on the accuracy of IOL power calculation than the other corneal shape in long eyes. Overall, both the Olsen and Barrett Universal II formulas are recommended in long eyes with unusual keratometry.