Effect of Text Messaging Parents of School-Aged Children on Outdoor Time to Control Myopia: A Randomized Clinical Trial.

Importance: Myopia in school-aged children is a public health issue worldwide; consequently, effective interventions to prevent onset and progression are required. Objective: To investigate whether SMS text messages to parents increase light exposure and time outdoors in school-aged children and provide effective myopia control. Design, Setting, and Participants: This randomized clinical trial was conducted in China from May 2017 to May 2018, with participants observed for 3 years. Of 528 965 primary school-aged children from Anyang, 3113 were randomly selected. Of these, 268 grade 2 schoolchildren were selected and randomly assigned to SMS and control groups. Data were analyzed from June to December 2021. Interventions: Parents of children in the SMS group were sent text messages twice daily for 1 year to take their children outdoors. All children wore portable light meters to record light exposure on 3 randomly selected days (2 weekdays and 1 weekend day) before and after the intervention. Main Outcomes and Measures: The co-primary outcomes were change in axial length (axial elongation) and change in spherical equivalent refraction (myopic shift) from baseline as measured at the end of the intervention and 3 years later. A secondary outcome was myopia prevalence. Results: Of 268 grade 2 schoolchildren, 121 (45.1%) were girls, and the mean (SD) age was 8.4 (0.3) years. Compared with the control group, the SMS intervention group demonstrated greater light exposure and higher time outdoors during weekends, and the intervention had significant effect on axial elongation (coefficient, 0.09; 95% CI, 0.02-0.17; P = .01). Axial elongation was lower in the SMS group than in the control group during the intervention (0.27 mm [95% CI, 0.24-0.30] vs 0.31 mm [95% CI, 0.29-0.34]; P = .03) and at year 2 (0.39 mm [95% CI, 0.35-0.42] vs 0.46 mm [95% CI, 0.42-0.50]; P = .009) and year 3 (0.30 mm [95% CI, 0.27-0.33] vs 0.35 mm [95% CI, 0.33-0.37]; P = .005) after the intervention. Myopic shift was lower in the SMS group than in the control group at year 2 (-0.69 diopters [D] [95% CI, -0.78 to -0.60] vs -0.82 D [95% CI, -0.91 to -0.73]; P = .04) and year 3 (-0.47 D [95% CI, -0.54 to -0.39] vs -0.60 D [95% CI, -0.67 to -0.53]; P = .01) after the intervention, as was myopia prevalence (year 2: 38.3% [51 of 133] vs 51.1% [68 of 133]; year 3: 46.6% [62 of 133] vs 65.4% [87 of 133]). Conclusions and Relevance: In this randomized clinical trial, SMS text messages to parents resulted in lower axial elongation and myopia progression in schoolchildren over 3 years, possibly through increased outdoor time and light exposure, showing promise for reducing myopia prevalence. Trial Registration: Chinese Clinical Trial Registry Identifier: ChiCTR-IOC-17010525.

Effect of Age and Refractive Error on Local and Global Visual Perception in Chinese Children and Adolescents.

PURPOSE: This study investigated the impact of age and myopia on visual form perception among Chinese school-age children. METHODS: This cross-sectional study included 1,074 students with a mean age of 12.1 ± 4.7 (range = 7.3-18.9) years. The mean spherical equivalence refraction (SER) of the participants was -1.45 ± 2.07 D. All participants underwent distance visual acuity (VA), refraction measurement and local and global visual form perception test including orientation, parallelism, collinearity, holes and color discrimination tasks. RESULTS: The reaction times of emmetropes were slower than those of myopic and high myopic groups on both local (orientation, parallelism, and collinearity) and global discrimination tasks (all p < 0.05). A reduction in reaction times was found with increasing age on both local and global discrimination tasks (all p < 0.05). Age was significantly associated with both local and global visual perception performance after adjusting for gender, visual acuity and SER (orientation, ß = -0.54, p < 0.001; parallelism, ß = -0.365, p < 0.001; collinearity, ß = -0.28, p < 0.001; holes, ß = -0.319, p < 0.001; color, ß = -0.346, p < 0.001). CONCLUSIONS: This study revealed that both local and global visual perception improve with age among Chinese children and that myopes seem to have better visual perception than emmetropes.

Annual Incidences and Progressions of Myopia and High Myopia in Chinese Schoolchildren Based on a 5-Year Cohort Study.

Purpose: To determine the annual incidences and rates of progression of myopia and high myopia in Chinese schoolchildren from grade 1 to grade 6 and explore the possible cause-specific risk factors for myopia. Methods: From 11 randomly selected primary schools in Anyang city, central China, 2835 grade 1 students were examined with annual follow ups for 5 years. Students were invited to undergo a comprehensive examination, including cycloplegic autorefraction, ocular biometry, and standardized questionnaires. Results: The mean spherical equivalent refraction decreased substantially from +0.94 ± 1.03 diopter (D) in grade 1 to -1.37 ± 2.08 D in grade 6, with rapid annual myopic shifts, especially for students in grades 3 through 6 (-0.51 to -0.59 D). The prevalence of myopia increased substantially, with the yearly incidence of myopia increasing from 7.8% in grade 1 and 2 to 25.3% in grades 5 and 6, and the incidence of high myopia increased from 0.1% to 1.0%. The 5-year incidence of myopia was lowest among children who has a baseline spherical equivalent refraction of greater than +2.00 D (4.4%), and increased to nearly 92.0% among children whose baseline spherical equivalent refraction was 0.00 to -0.50 D. The incidence of myopia was higher in children who had less hyperopic baseline refraction, two myopic parents, longer axial length, deeper anterior chamber, higher axial length-corneal radius of curvature ratio, and thinner lenses. Conclusions: Both the annual incidence and progression rates of myopia and high myopia were high in Chinese schoolchildren, especially after grade 3. Hyperopic refraction of children should be monitored before primary school as hyperopia reserve to prevent the onset of myopia and high myopia.

The performance of an integrated model including retinal information in predicting childhood hypertension.

BACKGROUND: The objective of this study was to examine the association of an integrated model (composed of retinal arteriolar caliber, height, and sex) with blood pressure (BP) among a group of Chinese children, and assess the predictive value of the integrated model for childhood hypertension. METHODS: This study included 1460 candidates aged 12.634 ± 0.420 years. Height, weight, waist circumference, and BP were obtained and ophthalmological measurements were taken. The computer-imaging program (IVAN, University of Wisconsin, Madison, WI) was used to measure calibers of retinal vessels. Receiver-operating characteristic curve (ROC) analyses were performed to assess the accuracy of the integrated model as a diagnostic test of elevated BP in children. RESULTS: The accuracy of the integrated model (assessed by area under the curve) for identifying elevated BP was 0.777 (95% confidence interval: 0.742-0.812). The optimal threshold of the integrated model for defining hypertension was 0.153, and the calculation formula for the specific predictive risk was: Logit (p/1 - p) = -5.666 - 0.261 × retinal arteriolar caliber + 0.945 × sex + 0.438 × height. In identifying elevated BP, the sensitivity and specificity were 0.711 and 0.736, respectively. CONCLUSIONS: The model containing eye message is a comprehensive and relatively effective index to identify elevated BP in 12-year-old children, which can offer assistance to further understand childhood microcirculation disease. IMPACT: We firstly incorporated retinal vascular diameter, sex, and height into one integrated model to identify hypertension in 12-year-old children. The current discrimination of hypertension in children is difficult. There have been some studies to simplify the diagnosis of children's hypertension, but they were limited to anthropometric measurements. We proposed a composed model containing microcirculation information to predict childhood hypertension. Based on the knowledge that microcirculation is not only a means to study the manifestations but also early pathogenic correlates of hypertension, the combined model containing microcirculation message as a method may provide new insights into the diagnosis of childhood hypertension.

An analysis of macular ganglion cell complex in 7-year-old children in China: the Anyang Childhood Eye Study.

BACKGROUND: This study used spectral-domain optical coherence tomography (SD-OCT) imaging to describe the distribution of macular ganglion cell complex (GCC) thickness and its association with ocular and systemic parameters in 7-year-old children in China. METHODS: The study involved a school-based, cross-sectional analysis of the Anyang Childhood Eye Study (ACES) and included 2,505 first-grade students from urban areas in Anyang, Henan Province, Central China. All participants underwent systemic and ocular examinations. Both GCC and retinal nerve fiber layer (RNFL) thickness were measured using the iVue-100 OCT (Optovue, Fremont, CA, USA). Intraocular pressure (IOP) was recorded with noncontact tonometer (Huvitz, HNT-7000). Axial length (AL) was measured using optical biometry (Lenstar LS 900, Haag-Streit Diagnostics, Koniz, Switzerland). RESULTS: The mean GCC thickness was 95.31±7.67 µm. GCC thickness had negative associations with AL (r=-0.124, P<0.001), cup-to-disc (C-D) area ratio (r=-0.068, P=0.0033), horizontal C-D (H C-D) ratio (r=-0.048, P=0.0384), and vertical C-D (V C-D) ratio (r=-0.074, P=0.0013). Positive correlations were found with spherical equivalent (SE) (r=0.080, P=0.0001), RNFL thickness (r=0.363, P<0.001), height (r=0.059, P=0.0036), fovea parameters, disc area (r=0.078, P=0.0007), rim area (r=0.115, P<0.001), rim volume (r=0.119, P<0.001), and optic nerve head volume (r=0.097, P<0.001). GCC thickness had no significant association with IOP, age, sex, or weight, waist, or head circumference. CONCLUSIONS: This study provides normative GCC data for 7-year-old healthy children in China. The findings support an association between GCC and AL, SE, RNFL, height, and C-D ratio in children.

Prevalence and risk factors of pseudomyopia in a Chinese children population: the Anyang Childhood Eye Study.

AIMS: To investigate the prevalence and predictors of pseudomyopia in Chinese children and its association with myopia progression. METHODS: A prospective, school-based, cohort study of 6- and 13-year-old children was conducted in Anyang, China. Pre-cycloplegic and post-cycloplegic autorefraction were performed at baseline and 1 year later. Pseudomyopia was defined as spherical equivalent refractive (SER) error in the better-seeing eye ≤-0.50 D before cycloplegia and >-0.50 D after cycloplegia. Among pseudomyopic children, pseudomyopic power was defined as non-cycloplegic SER subtracted from cycloplegic SER. Market survey was collected in all optometry stores in Anyang city to investigate how cycloplegia is used for refracting children. RESULTS: A total of 2612 children aged 6 years and 1984 children aged 13 years were included. Of the two cohorts, median cycloplegic SER (IQR) was 1.00 D (0.50, 1.38) and -1.13 D (-2.63, 0.13) respectively, myopia prevalence was 5.2% and 61.0%, pseudomyopia prevalence was 24.1% and 18.9%, and median pseudomyopic power was 1.13 D (0.63, 1.63) and 0.38 D (0.13, 0.88). In both cohorts, greater baseline hyperopia was the strongest predictor of pseudomyopia (p<0.001), whereas time spent on near work was not associated with pseudomyopic power (p>0.05). After 1 year, 15.6% (98/629) of 6-year-olds and 10.7% (40/374) of 13-year-olds with pseudomyopia developed myopia. Compared with myopes, pseudomyopic children with the same pre-cycloplegic SER had slower myopic progression (p<0.001). Among all 127 optometry stores in Anyang, only 4 (3.15%) used cycloplegia for refracting children. CONCLUSION: Pseudomyopia is more prevalent in younger, more hyperopic children. Pseudomyopia is not an independent risk factor for myopic progression in this setting.

Sleep Duration, Bedtime, and Myopia Progression in a 4-Year Follow-up of Chinese Children: The Anyang Childhood Eye Study.

Purpose: To investigate the relationship between sleep duration and bedtime with myopia progression and axial elongation during a 4-year follow-up in primary school children. Methods: This study included 1887 children (aged 7.09 ± 0.41 years) who had cycloplegic refractions data at baseline and a fourth visit and 2209 children (aged 7.10 ± 0.41 years) for axial length. All children underwent comprehensive ophthalmologic examinations, including cycloplegic refraction and ocular biometry, and standardized questionnaires, including average night-time sleep duration (h/d) and bedtime (time to bed). Myopia was defined as spherical equivalent < -0.5 diopters. Results: At the last follow-up, the mean myopia progression and axial elongation for all children were -1.89 ± 1.28 diopters and 1.22 ± 0.57 mm. After stratifying the sleep duration into tertile groups, myopia progression and axial elongation were slower in children with highest sleep duration tertile (P = 0.04 and P =0.014) in girls but not in boys, compared with the middle sleep duration tertile. However, after adjusting for potential confounders, no significant association was found for sleep duration with myopia progression and axial elongation for the children (P = 0.255 and P = 0.068), and the association with axial elongation was only of borderline significance in girls (P = 0.045). The bedtime was not associated with myopia progression and axial elongation in the regression analyses (P = 0.538; P = 0.801). Conclusions: These results show that there was no significant association between sleep duration and bedtime with myopia progression and axial elongation among children. The findings in girls might be related to the earlier onset of puberty.

Association of visual acuity with educational outcomes: a prospective cohort study.

BACKGROUND/AIM: To quantify the impact of baseline presenting visual acuity (VA), refractive error and spectacles wear on subsequent academic performance among Chinese middle school children. METHODS: A prospective, longitudinal, school-based study on grade 7 Chinese children (age, mean±SD, 12.7±0.5 years, range=11.1-15.9) at four randomly selected middle schools in Anyang, China. Comprehensive eye examinations including cycloplegic autorefraction were performed at baseline, and information on demographic characteristics, known risk factors for myopia and spectacle wear was collected. Academic test scores for all subjects in the curriculum were obtained from the local Bureau of Education. Main outcome measure was total test scores for five subjects at the end of grade 9, adjusted for total scored at the beginning of grade 7. RESULTS: Among 2363 eligible children, 73.1% (1728/2363) had seventh grade test scores available. 93.9% (1623/1728) completed eye examinations, and 98.5% (1599/1623) of these had ninth grade test scores. Adjusting only for baseline test score, the following were significantly associated with higher ninth grade scores: younger age, male sex, less time outdoors, better baseline presenting VA, higher parental education and income and parental myopia, but refractive error and spectacle wear were not. In the full multivariate model, baseline test score (p<0.001), presenting VA (p<0.01), age (p<0.001), quality of life (p<0.05) and parental education (p<0.001) and myopia (either: p<0.05; both: p<0.05) remained significantly associated with better ninth grade scores. CONCLUSIONS: In this longitudinal study, better presenting VA, but not cycloplegic refractive error or spectacle wear, was significantly associated with subsequent academic performance.

Astigmatism and its components in 12-year-old Chinese children: the Anyang Childhood Eye Study.

PURPOSE: To determine prevalence of refractive (RA), corneal (CA) and internal astigmatism (IA), including variation with gender and spherical equivalent refraction (SE), in a population of 12-year-old Chinese children. METHODS: A total of 1783 students with a mean age of 12.7 years (range 10.0-15.6 years) completed comprehensive eye examinations in the Anyang Childhood Eye Study. Data of cycloplegic refraction and corneal curvature were analysed. RESULTS: Prevalences of RA, CA and IA ≥1.0 D were 17.4% (95%CI 15.6% to 19.2%), 52.8% (50.5% to 55.1%)%) and 20.9% (19.0% to 22.8%), respectively. With different limits of astigmatism axes classification, including ±15°, ±20° and ±30°, RA and CA axes were mainly 'with-the-rule' (WTR) (ie, correcting axis of negative cylinders at or near 180°), while those for IA axes were mainly 'against-the-rule' (ATR) (ie, correcting axis of negative cylinders at or near 90°). RA was not different between the genders, but girls had higher prevalence and greater means of CA and IA. RA and CA increased in students with higher ametropia (more myopia and more hyperopia) and were the highest in a high myopic group (SE≤-6 D), while IA was stable across refraction groups. Children with RA higher than 0.50 D were more likely to have lens corrections (51%, 57%, 61% and 69% for magnitudes of ≥0.50 D, ≥0.75 D, ≥1.0 D and ≥1.5 D, respectively). CONCLUSIONS: Prevalence of RA in the Chinese 12-year-old children was relatively high compared with other studies. RA and CA had mainly 'WTR' astigmatism, while IA was mainly ATR and partially compensated for CA. Girls had greater means and prevalences of CA and IA than did boys. Both RA and CA, but not IA, increased with refractive errors away from emmetropia.

Intraocular pressure and myopia progression in Chinese children: the Anyang Childhood Eye Study.

PURPOSE: To explore the relationship between intraocular pressure (IOP) at baseline and myopia progression in Chinese children from the Anyang Childhood Eye Study. DESIGN: Prospective school-based cohort study. METHODS: A total of 1558 grade 7 students completed the entire 2-year study. Ocular biometry, cycloplegic refractions and pneumotonometry were performed. Three years of follow-up have been completed for the children aged 12 years. The refractive groups and the tertiles of IOP were assessed by analysis of variance, to look for differences in mean values of spherical equivalent and IOP, respectively. RESULTS: The children's mean baseline IOP was 15.87±3.42 mm Hg. Mean IOP was significantly higher in girls by 0.57 mm Hg (p=0.024). In the whole sample, there was a mean change in spherical equivalent of -1.05 D over 2 years. The baseline IOP was 15.69 mm Hg in those progressing 1 D or more vs 16.09 mm Hg for those progressing <1 D (p=0.022). In the myopic group, myopes progressing >1 D had mean IOP of 15.94 vs 16.42 mm Hg for those myopes progressing 1 D or less (p=0.024). CONCLUSIONS: In this sample of Chinese children, myopia progression over 2 years was inversely related to IOP, suggesting that IOP had essentially no relationship with myopia progression in school children. The lower IOP in progressing myopic eyes may indicate more compliant sclerae.

Cycloplegic refraction by 1% cyclopentolate in young adults: is it the gold standard? The Anyang University Students Eye Study (AUSES).

AIMS: To document the difference between non-cycloplegic and cycloplegic refraction and explore its associated factors in Chinese young adults. METHODS: A school-based study including 7971 undergraduates was conducted in Anyang, Henan Province, China. Cycloplegia was achieved with two drops of 1% cyclopentolate and 1 drop of Mydrin P (Tropicamide 0.5%, phenylephrine HCl 0.5%) with a 5 min interval. Non-cycloplegic and cycloplegic refractions were measured by an autorefractor. A paired-sample t-test and Spearman correlation analysis were used for analysis with data from only the right eyes included.  RESULTS: Of the 7971 students examined, 7793 (97.8%) with complete data were included, aging 20.2±1.5 years. Male students accounted for 36.8%. Overall, there was a significant difference between non-cycloplegic and cycloplegic SE (spherical equivalent) of 0.83±0.81D (p<0.01). The difference was 1.80±1.11D, 1.26±0.93D and 0.69±0.69D for those with cycloplegic hyperopia, emmetropia and myopia, respectively (p<0.01 for all). Those with a hyperopic shift less than 0.25D and 0.5D accounted for 11.1% and 34.1%, respectively. A significant relationship was found between difference in SE and cycloplegic refraction (r=0.33, b=0.11, p<0.01). Without cycloplegia, prevalence of hyperopia and emmetropia would be underestimated by 6.2% (1.0% vs 7.2%) and 5.7% (3.8% vs 9.5%), respectively, with prevalence of myopia and high myopia overestimated by 12.1% (95.3% vs 83.2%) and 6.1% (17.2% vs 11.1%).  CONCLUSION: Lack of cycloplegia will lead to significant misclassification of myopia, emmetropia and hyperopia in Chinese young adults. Cycloplegia is therefore essential for this age-group in epidemiological studies.

Association between blood pressure and retinal arteriolar and venular diameters in Chinese early adolescent children, and whether the association has gender difference: a cross-sectional study.

BACKGROUND: To establish the independent association between blood pressure (BP) and retinal vascular caliber, especially the retinal venular caliber, in a population of 12-year-old Chinese children. METHODS: We have examined 1501 students in the 7th grade with mean age of 12.7 years. A non-mydriatic fundus camera (Canon CR-2, Tokyo, Japan) was used to capture 450 fundus images of the right eyes. Retinal vascular caliber was measured using a computer-based program (IVAN). BP was measured using an automated sphygmomanometer (HEM-907, Omron, Kyoto, Japan). RESULTS: The mean retinal arteriolar caliber was 145.3 µm (95% confidence interval [CI], 110.6-189.6 µm) and the mean venular caliber was 212.7 µm (95% CI, 170.6-271.3 µm). After controlling for age, sex, axial length, BMI, waist, spherical equivalent, birth weight, gestational age and fellow retinal vessel caliber, children in the highest quartile of BP had significantly narrower retinal arteriolar caliber than those with lower quartiles (P for trend< 0.05). Each 10-mmHg increase in BP was associated with narrowing of the retinal arterioles by 3.00 µm (multivariable-adjusted P < 0.001), and the results were consist in three BP measurements. The association between BP measures and retinal venular caliber did not persist after adjusting for fellow arteriolar caliber. And there was no significant interaction between BP and sex, age, BMI, and birth status. CONCLUSIONS: In a large population of adolescent Chinese children, higher BP was found to be associated with narrower retinal arterioles, but not with retinal venules. Sex and other confounding factors had no effect on the relationship of BP and retinal vessel diameter.

Ocular residual and corneal astigmatism in a clinical population of high school students.

PURPOSE: Total refractive astigmatism is usually the first consideration that guides the selection of contact lens type (e.g., spherical or toric), while the ocular source of the astigmatism is a second, but more important consideration, for the final clinical decision. This study was conducted to provide detailed data on this topic by evaluating astigmatic components in Chinese adolescents. METHODS: Participants were recruited from healthy high school students undergoing an annual ocular examination at a local hospital. Total astigmatism (TA), corneal astigmatism (CA), and ocular residual astigmatism (ORA) were determined by a Hartmann-Shack wavefront analyzer system (KR-1W, Topcon) with the natural pupil. The axis relationship between CA and ORA was placed into three categories: on-axis, defined as an axis with a difference of 0 ± 10°; opposite-axis, a difference of 90 ± 10°; and the rest defined as oblique-axis. RESULTS: The study consisted of 1,466 students (57.84% girls, age: 16.49 ± 1.05 years). ORA was present in 83.97%, 66.64%, and 45.23% of participants, according to the various criteria for astigmatism (≥ 0.50 D, ≥ 0.75 D, and ≥ 1.00 D, respectively). While with-the-rule was the most common axis orientation for both TA (76.28%) and CA (89.94%), against-the-rule predominated in ORA (93.82%; χ2 = 1688.544, p < 0.001). Opposite-axis was the major type of axis difference (90.96%) of clinical significance (i.e., ≥ 1.00 D) between CA and ORA, which also prevailed in all levels of TA (range: 56.25-82.26%). CONCLUSIONS: ORA is common in high school students and usually demonstrates a compensation relationship with CA, which should be taken into consideration when determining the design of contact lenses to correct refractive error.

Distribution and associations of intraocular pressure in 7- and 12-year-old Chinese children: The Anyang Childhood Eye Study.

PURPOSE: To report the intraocular pressure (IOP) and its association with myopia and other factors in 7 and 12-year-old Chinese children. METHODS: All children participating in the Anyang Childhood Eye Study underwent non-contact tonometry as well as measurement of central corneal thickness (CCT), axial length, cycloplegic auto-refraction, blood pressure, height and weight. A questionnaire was used to collect other relevant information. Univariable and multivariable analysis were performed to determine the associations of IOP. RESULTS: A total of 2760 7-year-old children (95.4%) and 2198 12-year-old children (97.0%) were included. The mean IOP was 13.5±3.1 mmHg in the younger cohort and 15.8±3.5 mmHg in older children (P<0.0001). On multivariable analysis, higher IOP in the younger cohort was associated with female gender (standardized regression coefficient [SRC], 0.11, P<0.0001), increasing central corneal thickness (SRC, 0.39, P<0.0001), myopia (SRC, 0.05, P = 0.03), deep anterior chamber (SRC, 0.07, P<0.01), smaller waist (SRC, 0.07, P<0.01) and increasing mean arterial pressure (SRC, 0.13, P<0.0001). In the older cohort, higher IOP was again associated with female gender (SRC, 0.16, P<0.0001), increasing central corneal thickness (SRC, 0.43, P<0.0001), deep anterior chamber (SRC, 0.09, P<0.01), higher body mass index (SRC, 0.07, P = 0.04) and with increasing mean arterial pressure (SRC, 0.09, P = 0.01), age at which reading commenced (SRC, 0.10, P<0.01) and birth method (SRC, 0.09, P = 0.01), but not with myopia (SRC, 0.09, P = 0.20). CONCLUSION: In Chinese children, higher IOP was associated with female gender, older age, thicker central cornea, deeper anterior chamber and higher mean arterial pressure. Higher body mass index, younger age at commencement of reading and being born of a caesarean section was also associated with higher IOP in adolescence.

Effect of uncorrection versus full correction on myopia progression in 12-year-old children.

PURPOSE: To investigate the effects of no correction versus full correction on myopia progression in Chinese children over a period of 2 years. METHODS: Myopia was defined as cycloplegic spherical equivalent (SE) of ≤ -0.50 D. Uncorrection was defined as no spectacles worn, and full correction was defined as when the value of SE subtracted from the dioptric power of the child's current spectacles was less than 0.5 D. Ocular examinations included visual acuity, cycloplegic autorefraction, axial length and vertometer measurements. Questionnaires were completed by parents on behalf of the children. RESULTS: A total of 121 myopic children, with a median age of 12.7 years, were screened from the Anyang Childhood Eye Study, with 65 in the uncorrected group and 56 in the full correction group. At 2-year follow-up, children with no correction had slower myopia progression (-0.75 ± 0.49 D vs. -1.04 ± 0.49 D, P < 0.01) and less axial elongation (0.45 ± 0.18 mm vs. 0.53 ± 0.17 mm, P = 0.02) than children with full correction. In multivariate modeling, adjusting for baseline SE or axial length, age, gender, height, number of myopic parents, age at myopia onset, and time spent in near work and outdoors, children with no correction still had slower myopia progression (-0.76 ± 0.07 vs. -1.03 ± 0.08 D, P < 0.01) and less axial elongation (0.47 ± 0.03 mm vs. 0.51 ± 0.03 mm, P < 0.01). Myopia progression decreased significantly with an increasing amount of undercorrection in all children (r = 0.22, b = 0.16, P = 0.01). CONCLUSION: Our findings suggest that myopic defocus slows the progression of myopia in already myopic children, supporting previous findings from animal studies.

Studies using concentric ring bifocal and peripheral add multifocal contact lenses to slow myopia progression in school-aged children: a meta-analysis.

PURPOSE: To evaluate the effect of soft contact lens with concentric ring bifocal and peripheral add multifocal designs on controlling myopia progression in school-aged children. METHODS: We systematically searched MEDLINE, EMBASE, Cochrane Library and reference lists of included trials. Methodological quality of included trials was assessed using Jadad Scale and Newcastle-Ottawa Quality Assessment Scale items. RESULTS: We identified five randomised controlled trials (RCTs) and three cohort studies with a total of 587 myopic children. Compared with the control group, concentric ring bifocal soft contact lenses showed less myopia progression with a weighted mean difference (WMD) of 0.31 D (95% CI, 0.05~0.57 D, p = 0.02) and less axial elongation with a WMD of -0.12 mm (95% CI, approximately -0.18 to -0.07 mm, p < 0.0001) at 12 months. Relative to the control group, peripheral add multifocal soft contact lenses showed less myopia progression with a WMD of 0.22 D (95% CI 0.14~0.31 D, p < 0.0001) and less axial elongation of -0.10 mm (95% CI -0.13~0.07 mm, p < 0.0001) at 12 months, respectively. The soft contact lenses with concentric ring bifocal and peripheral add multifocal designs produced additional myopia control rates of 30~38% for slowing myopia progression and 31~51% for lessening axial elongation within 24 months. CONCLUSIONS: Both concentric ring bifocal and peripheral add multifocal soft contact lenses are clinically effective for controlling myopia in school-aged children, with an overall myopia control rates of 30~50% over 2 years. Concentric ring bifocal soft contact lenses seem to have greater effect than peripheral add multifocal soft contact lenses.

Chinese Eye Exercises and Myopia Development in School Age Children: A Nested Case-control Study.

Chinese eye exercises have been implemented in China as an intervention for controlling children's myopia for over 50 years. This nested case-control study investigated Chinese eye exercises and their association with myopia development in junior middle school children. Outcome measures were the onset and progression of myopia over a two-year period. Cases were defined as 1. Myopia onset (cycloplegic spherical equivalent ≤ -0.5 diopter in non-myopic children). 2. Myopia progression (myopia shift of ≥1.0 diopter in those who were myopic at baseline). Two independent investigators assessed the quality of Chinese eye exercises performance at the end of the follow-up period. Of 260 children at baseline (mean age was 12.7 ± 0.5 years), 201 were eligible for this study. There was no association between eye exercises and the risk of myopia-onset (OR = 0.73, 95%CI: 0.24-2.21), nor myopia progression (OR = 0.79, 95%CI: 0.41-1.53). The group who performed high quality exercises had a slightly lower myopia progression of 0.15 D than the children who did not perform the exercise over a period of 2 years. However, the limited sample size, low dosage and performance quality of Chinese eye exercises in children did not result in statistical significance and require further studies.

Peripapillary retinal nerve fibre layer thickness and its association with refractive error in Chinese children: the Anyang Childhood Eye Study.

BACKGROUND: To report the thickness of the peripapillary retinal nerve fibre layer (pRNFL) in Chinese children and examine its association with refractive error, axial length (AL) and optic disc parameters. DESIGN: Population-based cross-sectional study. PARTICIPANTS: A total of 2893 seven-year-old children from 11 randomly selected primary schools in Anyang, central China. METHODS: Participants underwent ophthalmic examinations including optical biometry, cycloplegic autorefraction and spectral-domain ocular coherence tomography. MAIN OUTCOME MEASURES: Retinal nerve fibre layer thickness in 16 radial sections, cycloplegic spherical equivalent, AL. RESULTS: The mean (SD) average RNFL thickness was 102.01(8.02) µm. The average RNFL thickness decreased with smaller disc area (r = 0.18, R2 = 0.03, P < 0.0001), bigger cup area (r = -0.11, R2 = 0.01, P < 0.0001), smaller rim area (r = 0.28, R2 = 0.08, P < 0.0001), smaller nerve head volume (r = 0.27, R2 = 0.07, P < 0.0001), longer AL (r = -0.15, R2 = 0.02, P < 0.0001) and a negative spherical equivalent (r = 0.11, R2 = 0.01, P < 0.0001). Hyperopic children had a thicker RNFL than emmetropic children [102.45(8.13) µm vs. 100.81 (7.18) µm, P < 0.001]. Myopic children had thinner RNFL than emmetropic children [99.17 (7.69) µm vs. 100.81 (7.18) µm, P < 0.05]. CONCLUSION: Retinal nerve fibre layer thickness decreased with increasing AL, higher myopia, bigger cup area, smaller disc and rim area, and a smaller nerve head volume, but the coefficient of determination for all these associations was small. The RNFL in myopes was significantly thinner than emmetropes or hyperopes, but with small absolute differences. The study provides RNFL values for healthy 7-year-old Chinese children. Follow up of this cohort to observe the change of RNFL thickness with myopia and possible change in detected associations with age is planned.

Corneal Power, Anterior Segment Length and Lens Power in 14-year-old Chinese Children: the Anyang Childhood Eye Study.

To analyze the components of young Chinese eyes with special attention to differences in corneal power, anterior segment length and lens power. Cycloplegic refractions and ocular biometry with LENSTAR were used to calculate lens power with Bennett's method. Mean refraction and mean values for the ocular components of five different refractive groups were studied with ANOVA and post-hoc Scheffé tests. There were 1889 subjects included with full data of refraction and ocular components. As expected, mean axial length was significantly longer in myopic eyes compared to emmetropes. Girls had steeper corneas, more powerful lenses and shorter eyes than boys. Lens power was lower in boys and also lower in myopic eyes. Lens thickness was the same for both genders but was lower in myopic eyes. Although cornea was steeper in myopic eyes in the whole sample, this was a gender effect (more girls in the myopic group) as this difference disappeared when the analysis was split by gender. Anterior segment length was longer in myopic eyes. In conclusion, myopic eyes have lower lens power and longer anterior segment length, that partially compensate their longer axial length. When analyzed by gender, the corneal power is not greater in low and moderate myopic eyes.