Investigation of Choroidal Blood Flow and Thickness Changes Induced by Near Work in Young Adults.

PURPOSE: This research aimed to determine the effects of near work on macular choroidal blood flow and thickness in young adults. METHODS: A total of 109 participants (19-28 years old) were recruited from Capital Medical University in China. The participants spent 40 min reading a book text at a distance of 33 cm. Swept-source optical coherence tomography/optical coherence tomography angiography (SS-OCT/OCTA) was performed to measure the changes in choriocapillaris perfusion area (CCPA) and choroidal thickness (ChT) after 40 min of near work. The SS-OCT/OCTA data covered an area of 6 mm × 6 mm, which centered on the fovea. RESULTS: The baseline ChT and CCPA before near work were negatively correlated with AL, while positively correlated with the magnitude of spherical equivalent (p < .001). Total CCPA decreased significantly by 6 mm × 6 mm macular area after near work compared to that before near work (24.26 ± 1.96 vs. 24.63 ± 1.61 mm2, p<.001). The macular ChT was lower after 40 min of reading than that before 40 min of reading, but no significant difference was observed (302.25 ± 77.69 vs. 304.92 ± 79.73 µm, p = .078). The extent of choroidal thinning was significantly positively correlated with the magnitude of CCPA reduction (p < .001). The decline in CCPA after near work was significantly positively correlated with axial length (AL; p < .001). CONCLUSION: This study demonstrated that near work significantly decreased CCPA. The extent of CCPA reduction after near work was associated with higher severity of myopia and choroidal thinning. The baseline CCPA and ChT decreased gradually with AL.

Effect of Atropine 0.01% Eye Drops on the Difference in Refraction and Axial Length between Right and Left Eyes.

INTRODUCTION: This study sought to determine whether the application of 0.01% atropine eye drops could impact the disparity in refraction and axial length (AL) between the right and left eyes in Chinese children. METHODS: The study was designed as a double-blind, placebo-controlled randomized trial. A total of 220 children aged 6-12 years were recruited from the Beijing Tongren Hospital in Beijing, China. Participants were randomized in a 1:1 ratio and were prescribed 0.01% atropine or placebo eye drops to be administered once a night to both eyes for the duration of 1 year. The cycloplegic refraction and AL were recorded including baseline, 6 months, and again at the 12 months. RESULTS: After 1-year follow-up period, 76 (69%) and 83 (75%) subjects of the initial 220 participants were identified as the 0.01% atropine and placebo groups, respectively. The inter-ocular difference in spherical equivalent refraction (SER) and AL demonstrated stable values in the 0.01% atropine treatment group (SER: p = 0.590; AL: p = 0.322) analyzed after 1 year, but found a significant increase (SER: p < 0.001; AL: p = 0.001) in the placebo group. Furthermore, over 1 year, eyes with greater myopia in the atropine group exhibited slower myopia progression (0.45 ± 0.44 D) than the lesser myopic eye (0.56 ± 0.44 D) (p = 0.003). CONCLUSION: This study demonstrated that 0.01% atropine could maintain the inter-ocular SER and AL difference. And 0.01% atropine appeared to be more effective in delaying the progression of myopia in eyes with more myopia than in the less myopic eyes.

Effect of low-dose atropine eyedrops on pupil metrics: results after half a year of treatment and cessation.

PURPOSE: To evaluate the effect of low-dose atropine eyedrops on pupil metrics. METHODS: This study was based on a randomized, double-masked, placebo-controlled, and cross-over trial in mainland China. In phase 1, subjects received 0.01% atropine or placebo once nightly. After 1 year, the atropine group switched to placebo (atropine-placebo group), and the placebo group switched to atropine (placebo-atropine group). Ocular parameters were measured at the crossover time point (at the 12th month) and the 18th month. RESULTS: Of 105 subjects who completed the study, 48 and 57 children were allocated into the atropine-placebo and placebo-atropine groups, respectively. After cessation, the photopic pupil diameter (PD) and mesopic PD both decreased (- 0.46 ± 0.47 mm, P < 0.001; - 0.30 ± 0.74 mm, P = 0.008), and the constriction ratio (CR, %) increased (4.39 ± 7.54, P < 0.001) compared with values at the crossover time point of the atropine-placebo group; pupil metrics of the atropine-placebo group had no difference from the values at the crossover time point of the placebo-atropine group. After 6 months of treatment, the photopic PD and the mesopic PD increased (0.54 ± 0.67 mm, P < 0.001; 0.53 ± 0.89 mm, P < 0.001), the CR (%) decreased (- 2.53 ± 8.64, P < 0.001) compared with values at the crossover time point of the placebo-atropine group. There was no significant relationship between pupil metrics and myopia progression during 0.01% atropine treatment. CONCLUSION: Pupil metrics and the CR could return to pre-atropine levels after cessation. Pupil metrics had no significant effect on myopia progression during treatment.

The effect of atropine 0.01% eyedrops on relative peripheral refraction in myopic children.

BACKGROUND: Relative peripheral refraction (RPR) is a significant factor that participates in myopic development. Here, we evaluated the effects of atropine 0.01% eyedrops, as an antimyopia drug, on RPR. METHODS: Seventy-three children were enrolled from a randomized, double-blinded, placebo-0.01% atropine eyedrops cross-over trial. The study group had used the placebo for one year and then crossed over to atropine 0.01% eyedrops for half a year. The control group had used 0.01% atropine for one year and then crossed over to placebo eyedrops for half a year. Central and horizontal peripheral refractions (15° and 30° at the temporal and nasal retina) were measured under non-cycloplegia and cycloplegia. RESULTS: No significant differences in age, gender, and central refraction were identified between the two groups (P > 0.05). Under non-cycloplegia, the control group showed significant relative hyperopia in the temporal 30° retina and the nasal retina (P = 0.031; P < 0.001; P < 0.001). In the study group, the relative hyperopia in the temporal 30° retina disappeared (P = 0.983). After cycloplegia, the control group had less myopia in central refractions and less hyperopia in temporal RPR (P < 0.001; P = 0.039; P < 0.001). The study group did not present significant changes in central refractions and temporal RPR (P = 0.122; P = 0.222; P = 0.475). CONCLUSIONS: For myopic children, atropine 0.01% eyedrops can alleviate relative hyperopia in the temporal retina and the hyperopic shift before cycloplegia. The effect might participate in myopia control.

Myopia progression after cessation of low-dose atropine eyedrops treatment: A two-year randomized, double-masked, placebo-controlled, cross-over trial.

PURPOSE: The purpose of the study was to evaluate myopia progression and axial elongation after stopping 0.01% atropine eye drops through a 2-year cross-over study. METHODS: This study was a randomized, double-masked, placebo-controlled, cross-over trial in mainland China. 220 children aged 6-12 years with spherical equivalent range of -1.00 D to -6.00 D in both eyes were enrolled in Phase 1 for 1 year. Children who had completed the first year's follow-up continued in the second phase. In Phase 2, the placebo group was crossed over to the 0.01% atropine group (referred to as the 'placebo-atropine group'), and the 0.01% atropine group was crossed over to the placebo group (referred to as the 'atropine-placebo group'). All children underwent the examination of cycloplegic refraction and axial length at a 6-month interval. Only data from right eyes were included in analysis. RESULTS: One hundred thirty-three subjects completed 2 years of follow-up. In the first year, the mean myopia progression in atropine-placebo group was 0.21 ± 0.08 D slower than that in placebo-atropine group. After cross-over treatment, the mean myopia progression in atropine-placebo group was 0.22 ± 0.07D faster than that in placebo-atropine group in the second year. Over 2 years, the mean myopia progression was -1.26 ± 0.66D and -1.25 ± 0.70D in the atropine-placebo and placebo-atropine groups (p = 0.954). CONCLUSIONS: The difference in myopia progression between atropine-placebo group and placebo-atropine group in Phase 1 was similar to Phase 2 during the cross-over treatment. Through our cross-over trial, the results suggest that there is no rebound effect after using 0.01% atropine eye drops to prevent progression of myopia.

Ocular Perfusion Pressure in 7- and 12-Year-Old Chinese Children: The Anyang Childhood Eye Study.

Purpose: The purpose of this study was to report the distribution of mean ocular perfusion pressure (MOPP) and its associated factors in Chinese children. Methods: We enrolled 3048 grade 1 students and 2258 grade 7 students of the Anyang Childhood Eye Study in central China. Systolic and diastolic blood pressure (SBP and DBP) were recorded with a digital automatic sphygmomanometer. Intraocular pressure (IOP) was assessed by a non-contact tonometer. MOPP was calculated as 2/3 × (DBP + 1/3[SBP - DBP]) - IOP. Risk factors for myopia were obtained through a questionnaire survey. Results: The MOPP was 33.83 ± 6.37 mm Hg (mean ± SD) in grade 1, which was lower than 36.99 ± 6.80 mm Hg in grade 7 (P < 0.001). Compared with myopic eyes, non-myopic eyes had higher MOPP in grade 7 (37.72 ± 6.72 mm Hg versus 36.58 ± 6.57 mm Hg, P < 0.001) and in grade 1 (33.88 ± 6.29 mm Hg versus 33.12 ± 7.03 mm Hg, P = 0.12). Multivariable analysis showed that higher MOPP was associated with less myopia (P < 0.001), higher body mass index (BMI; P < 0.001), thinner central corneal thickness (P < 0.001), less time on near work (P < 0.001), and more time on sleeping (P = 0.04). Conclusions: MOPP was higher in children of older age, with higher BMI, less time on near work, and more time on sleeping, and was higher in eyes with less myopia. Translational Relevance: We found that MOPP might be an indicator for the detection of myopia development.

Effect of 0.01% atropine eyedrops on intraocular pressure in schoolchildren: a randomized clinical trial.

AIM: To assess the effect of 0.01% atropine eye drops on intraocular pressure (IOP) in myopic children. METHODS: A placebo-controlled, double-masked, randomized study. Totally 220 children aged 6 to 12y with myopia ranging from -1.00 to -6.00 D in both eyes were enrolled. Children were randomized in a 1:1 ratio to either 0.01% atropine eye drops or a placebo group using generated random numbers. All participants underwent the examination of IOP and cycloplegic refraction at baseline, 6 and 12mo. The change of IOP and the proportion of subjects with increased IOP in atropine and placebo groups were compared. RESULTS: Of 220 children, 117 were boys (53.2%). A total of 159 (72.3%) participants completed the follow-up at the 1-year study. At baseline, the mean IOP was 15.74 mm Hg (95%CI, 15.13 to 16.34 mm Hg) for the 0.01% atropine group and 15.59 mm Hg (95%CI, 15.00 to 16.19 mm Hg) for placebo group (mean difference, 0.14 mm Hg; P=0.743) after adjusting for central corneal thickness at baseline. At one year follow-up, the mean change of IOP was 0.16 mm Hg (95%CI, -0.43 to 0.76 mm Hg) for the 0.01% atropine group and -0.11 mm Hg (95%CI, -0.71 to 0.50 mm Hg) for placebo group (mean difference, 0.27 mm Hg; P=0.525) after adjusting for central corneal thickness. The 51.4% of children have increased IOP in the 0.01% atropine group, compared with 45.9% in the placebo group (P=0.511). CONCLUSION: The 0.01% atropine eye drops do not significantly affect the risk of elevated IOP. It is relatively safer to use in the studies that try to minimize myopia progression. However, a further long-duration study is required to be validated.

Cost-effectiveness and cost-utility of traditional and telemedicine combined population-based age-related macular degeneration and diabetic retinopathy screening in rural and urban China.

Background: To assess the cost-effectiveness and cost-utility of a population-level traditional and telemedicine combined age-related macular degeneration (AMD) and diabetic retinopathy (DR) screening program in rural and urban China. Methods: Decision-analytic Markov models were conducted to evaluate the costs and benefits of traditional and telemedicine combined AMD and DR screening from a societal perspective. A cohort of all participants aged 50 years old and above was followed through a total of 30 1-year Markov cycles. Separate analyses were performed for rural and urban settings. Relevant parameters such as the prevalence of AMD and DR, transition probability, compliance with screening and treatment, screening sensitivity, specificity, utility, and mortality were collected from published studies specific to China, other Asian counties' studies, or unpublished data sources such as the National Committee for the Prevention of Blindness. Costs of screening, full examination, and treatment come from the real medical environments and unified pricing of Beijing Municipal Medical Insurance Bureau. Primary outcomes were incremental cost-utility ratios (ICURs) using quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) using years of blindness avoided. One-way deterministic and simulated probabilistic sensitivity analyses were conducted to reflect uncertainty. Findings: Under the status quo, the total expected medical costs for a 50-year-old patient with AMD or DR were $869·59 and $1,514·18 in rural and urban settings, respectively. Both traditional and telemedicine screening were highly cost-effective. In rural settings, ICURs were $191 (95% confidence interval [CI]: $66 to $239) and $199 (95% CI: $-12 to $217), and ICERs were $2,436 (95% CI: $1,089 to $3,254) and $2,441 (95% CI: $1,452 to $3,900) for traditional and telemedicine screening separately. Even more surprising, both screening strategies dominated no screening in urban settings. Our results were insensitive and robust to extensive sensitivity analyses. Among all acceptable screening intervals (from 1 to 5 years), annual screening could not only produce biggest benefits but also keep ICERs less than three times and one time the per capita gross domestic product (GDP) in rural and urban settings separately. When compared with traditional screening, ICERs of telescreening were less than three times the per capita GDP in rural settings ($2,559 to $8,809) and less than one time the per capita GDP in urban settings (less than $5,564), annual telescreening produced the biggest benefits, it could avert 119 and 270 years of blindness in rural and urban areas separately when 100,000 people were screened. Interpretation: We performed decision-analytic Markov models for combined AMD and DR screening in rural and urban China, and the results showed that population-level combined screening for AMD and DR is likely to be highly cost-effective in both rural and urban China for people over 50 years old. Optimal screening may have an interval of every year based on teleophthalmology platforms. In the future, China should pay more attention to chronic eye diseases and the government should establish a sound chronic disease management system and make every patient enjoy equal medical services. Funding: National Natural Science Foundation of China, NSFC (82171051); the Major Innovation Platform of Public Health & Disease Control and Prevention, Renmin University of China and Beijing Nova program (Z191100001119072).

Association Between Color Vision Deficiency and Myopia in Chinese Children Over a Five-Year Period.

Purpose: To explore the relationship of color vision deficiency with myopia progression and axial elongation in Chinese primary school children during a five-year cohort study. Methods: A total of 2849 grade 1 students (aged 7.1 ± 0.4 years) from 11 primary schools were enrolled and followed up for five years. Cycloplegic autorefraction and axial length were measured annually. Color vision testing was performed using Ishihara's test and the City University color vision test. Results: The prevalence of color vision deficiency was 1.68%, with 2.81% in boys and 0.16% in girls. Color-deficient cases consisted of 91.6% deutan and 8.3% protan. Over the five years, the cumulative incidence of myopia was 35.4% (17/48) in the color-vision deficiency group, which was lower than the 56.7% (1017/1794) in the color normal group (P = 0.004). Over the five-year study period, the change in spherical equivalent refraction in the color vision-deficiency group (-1.81 D) was also significantly lower than that in the color normal group (-2.41 D) (P = 0.002). Conclusions: The lower incidence and slower progression of myopia in children with color-vision deficiency over the five-year follow-up period suggest that color-deficient individuals are less susceptible to myopia onset and development.

Prevalence of cataract and cataract surgery in urban and rural Chinese populations over 50 years old: a systematic review and Meta-analysis.

AIM: To summarize the data of epidemiological studies on cataract prevalence over 50 years old in urban and rural areas of China from 2000 to 2020, and to analyze the prevalence of cataract and operation rate in China. METHODS: By searching PubMed, EMBASE, Web of Science, Wanfang Data and CNKI, Chinese and English literatures on the prevalence of cataract in China were retrieved, and the relevant characteristic data were extracted. Then, Stata v15SE software was used for Meta-analysis and heterogeneity test. According to the results of heterogeneity, the corresponding effect models were selected to combine the extracted data. RESULTS: A total of 20 studies were included in this study, with a total of 111 434 cases. Meta-analysis showed heterogeneity. According to the random effect model, the overall prevalence of cataract in Chinese people over 50 years old was 27.45%, that in rural was 28.79%, and that in urban was 26.66%. The overall coverage rate of cataract surgery was 9.19%. CONCLUSION: The prevalence of cataract is high in China, and there is still room for improvement in surgical coverage, so it is very important to promote cataract screening and prevention.

Cost-Utility Analysis of Screening for Diabetic Retinopathy in China.

Background. Diabetic retinopathy (DR) has been primarily indicated to cause vision impairment and blindness, while no studies have focused on the cost-utility of telemedicine-based and community screening programs for DR in China, especially in rural and urban areas, respectively.Methods. We developed a Markov model to calculate the cost-utility of screening programs for DR in DM patients in rural and urban settings from the societal perspective. The incremental cost-utility ratio (ICUR) was calculated for the assessment.Results. In the rural setting, the community screening program obtained 1 QALY with a cost of $4179 (95% CI 3859 to 5343), and the telemedicine screening program had an ICUR of $2323 (95% CI 1023 to 3903) compared with no screening, both of which satisfied the criterion of a significantly cost-effective health intervention. Likewise, community screening programs in urban areas generated an ICUR of $3812 (95% CI 2906 to 4167) per QALY gained, with telemedicine screening at an ICUR of $2437 (95% CI 1242 to 3520) compared with no screening, and both were also cost-effective. By further comparison, compared to community screening programs, telemedicine screening yielded an ICUR of 1212 (95% CI 896 to 1590) per incremental QALY gained in rural setting and 1141 (95% CI 859 to 1403) in urban setting, which both meet the criterion for a significantly cost-effective health intervention.Conclusions. Both telemedicine and community screening for DR in rural and urban settings were cost-effective in China, and telemedicine screening programs were more cost-effective.

Varying Dose of Atropine in Slowing Myopia Progression in Children Over Different Follow-Up Periods by Meta-Analysis.

Purpose: To evaluate the efficacy and safety of atropine for slowing myopia progression and to investigate whether the treatment effect remains constant with continuing treatment. Method: Studies were retrieved from MEDLINE, EMBASE, and the Cochrane Library from their inception to May 2021, and the language was limited to English. Randomized controlled trials (RCTs) and cohort studies involving atropine in at least one intervention and placebo/non-atropine treatment in another as the control were included and subgroup analysis based on low dose (0.01%), moderate dose (0.01%-<0.5%), and high dose (0.5-1.0%) were conducted. The Cochrane Collaboration and Newcastle-Ottawa Scale were used to evaluate the quality of RCTs and cohort studies, respectively. Results: Twelve RCTs and fifteen cohort studies involving 5,069 children aged 5 to 15 years were included. The weighted mean differences in myopia progression between the atropine and control groups were 0.73 diopters (D), 0.67 D, and 0.35 D per year for high-dose, moderate-dose, and low-dose atropine, respectively (χ2 = 13.76; P = 0.001, I 2 = 85.5%). After removing studies that provided extreme findings, atropine demonstrated a significant dose-dependent effect on both refractive change and axial elongation, with higher dosages of atropine resulting in less myopia progression (r = 0.85; P = 0.004) and less axial elongation (r = -0.94; P = 0.005). Low-dose atropine showed less myopia progression (-0.23 D; P = 0.005) and less axial elongation (0.09 mm, P < 0.001) in the second year than in the first year, whereas in high-dose atropine more axial elongation (-0.15 mm, P = 0.003) was observed. The higher dose of atropine was associated with a higher incidence of adverse effects, such as photophobia with an odds ratio (OR) of 163.57, compared with an OR of 6.04 for low-dose atropine and 8.63 for moderate-dose atropine (P = 0.03). Conclusion: Both the efficacy and adverse effects of atropine are dose-dependent in slowing myopia progression in children. The efficacy of high-dose atropine was reduced after the first year of treatment, whereas low-dose atropine had better efficacy in a longer follow-up period.