BACKGROUND: To investigate the prevalence and correction of anisometropia among primary school children in northwestern China.
METHODS: A cross-sectional school-based study was conducted in Shaanxi Province. Visual acuity (VA) and autorefraction without cycloplegia were assessed in all participants, and some received axial length (AL) measurements. Anisometropia was categorised based on spherical equivalent (SE), cylindrical (CYL), and AL. The prevalence of anisometropia and refractive correction across different ages and sexes, and correlations between ocular parameters, were analysed.
RESULTS: The study included 29 153 children aged 6-12 (mean age 9.52 ± 1.73 years) for VA and autorefraction measurements, and 1176 children for AL measurements. The prevalence of myopia (SE ≤ -0.50 D), hyperopia (SE ≥ +0.50 D), and anisometropia (interocular SE difference ≥1.00 D) was 65.26%, 15.09%, and 16.50%, respectively. Anisometropia severity, based on SE (χ2 = 443.758, p < 0.001), CYL (χ2 = 41.669, p < 0.001), and AL (χ2 = 95.505, p < 0.001), increased with age, with no significant differences between sexes. Interocular SE difference correlated with interocular spherical power (r = 0.806, p < 0.001), CYL (r = 0.21, p < 0.001), and AL (r = 0.365, p < 0.001). Additionally, interocular CYL difference was positively correlated with interocular AL difference (r = 0.16, p < 0.001). Despite the high prevalence of anisometropia, less than 30% of affected children received refractive correction.
CONCLUSIONS: Anisometropia of SE, CYL, and AL increased progressively with age. Despite the elevated prevalence of anisometropia, the utilisation of refractive correction remained strikingly low.

OBJECTIVE: To investigate the incidence rate and risk factors for anisometropia among young schoolchildren.
METHODS: A population-based cohort study, the Myopia Investigation Study in Taipei, was conducted in primary schools in Taipei City. Children were recruited for biannual comprehensive eye examinations over 2 years. Cycloplegic autorefraction and slit lamp examinations were performed biannually. Data on demographic information, parental history, lifestyle and near-work activities were collected using parent-administered questionnaires at the first and final visits. Anisometropia was defined as ≥1 D difference in the spherical equivalent (SE) refractive error.
RESULTS: A total of 7035 8-year-old children completed the 2-year follow-up evaluations. The average annual incidence of anisometropia was 3.8%. Multivariable logistic regression analysis revealed that baseline SE (odds ratio [OR]: 0.87 95% CI: 0.80-0.95) and female sex (OR: 1.24, 95% confidence interval [CI]: 1.02-1.50) were significantly associated with incident anisometropia. Among lifestyle risk factors, spending <1 h per day in after-school outdoor activities on weekdays (OR: 1.38, 95% CI: 1.08-1.76) and performing near work at a distance <30 cm (OR: 1.33, 95% CI: 1.08-1.64) were significantly associated with an increased risk of incident anisometropia. In the multiple linear regression analysis, the inter-eye difference in SE increased significantly in children performing near work at distances <30 cm (adjusted β = 0.03; p = 0.02).
CONCLUSIONS: This study indicated the annual incidence of anisometropia in Taiwanese schoolchildren. Less time spent outdoors and shorter eye-to-object distances during near work increased the risk of incident anisometropia.

To investigate the prevalence of anisometropia and associated parameters among school-aged children in Nantong, China.
This school-based, cross-sectional study examined students from primary schools, junior high schools, and senior high schools in an urban area of Nantong, China. Univariate and multivariate logistic regression analyses were used to investigate the specific correlations between anisometropia and related parameters. Non-cycloplegic autorefraction was assessed for each student. Anisometropia was defined as the spherical equivalent refraction (SE) difference ≥ 1.0 D between eyes.
A total of 9,501 participants were validated for analyses, of which 53.2% (n = 5,054) were male, and 46.8% (n = 4,447) were female. The mean of age was 13.32 ± 3.49 years, ranging from 7-19 years. The overall prevalence of anisometropia was 25.6%. Factors such as myopia, scoliosis screening positive, hyperopia, female sex, older age, and higher weight had a significantly higher risk of anisometropia (p < 0.05).
There was a high prevalence of anisometropia in school-age children. Some physical examination parameters are closely related to children\'s anisometropia, especially myopia and scoliosis. Preventing myopia and controlling its progression may be the most important ways to reduce the prevalence of anisometropia. Correcting scoliosis may be an important factor in controlling the prevalence of anisometropia, and maintaining good reading and writing posture may be helpful in controlling the prevalence of anisometropia.

OBJECTIVE: To describe the prevalence of refractive error (RE) and its association with other environmental and health factors among population aged ≥50 years who lived in Gilan, Iran in 2014.
METHODS: In this population-based cross-sectional study, 3281 individuals aged ≥50 years living in Gilan for at least 6 months were enrolled. The prevalence of different types of REs including myopia (spherical equivalent (SE)≤-0.50D), high myopia (SE ≤ -6.00D), hyperopia (SE≥ + 0.50D), high hyperopia (SE≥ + 3.00D), astigmatism (cylinder < -0.50D) and high astigmatism (cylinder < -2.25D) were determined. Anisometropia was defined as the SE difference of ≥1.00D between the two eyes. Associated factors including age, body mass index (BMI) and education were also studied.
RESULTS: 2587 eligible individuals (58% female subjects) with the mean age of 62.6 ± 8.8 years participated (87.6% response rate). The prevalence of myopia, hyperopia and astigmatism was 19.2%, 48.6% and 57.4%, respectively. 3.6% high hyperopia, 0.5% high myopia and 4.5% high astigmatism were identified. The positive simultaneous effects3 of older age (Odds Ratio (OR) = 3.14), nuclear (OR = 1.71) and posterior subcapsular (OR = 1.61) cataracts as well as the negative effects of higher levels of education (OR = 0.28) were obtained on myopia. Higher BMI was found as a risk factor for hyperopia (OR = 1.67), while older patients were less likely to be hyperopic (OR = 0.31).
CONCLUSIONS: Higher incidence of myopia and astigmatism was found in patients aged over 70 years. It was also found that patients at older ages who suffered with cataracts were at a higher risk of myopia, while elderly people with greater BMI were at a higher risk of hyperopia.

To identify gene variants associated with anisometropia development in children.
This is a population-based, cross-sectional, and longitudinal genetic association study involving 1057 children aged 6 to 10 years with both baseline and 3-year follow-up data. Six single nucleotide polymorphisms (SNPs), ZC3H11B rs4373767, ZFHX1B rs13382811, KCNQ5 rs7744813, SNTB1 rs7839488, PAX6 rs644242, and GJD2 rs524952 were analyzed in all children. Anisometropia was defined by an interocular difference in SE of ≥1 diopter (D) (Aniso-SE) and an interocular difference in axial length (AL) of ≥0.3 mm (Aniso-AL), respectively. Genetic associations of individual SNPs and joint SNP effects were analyzed.
ZFHX1B rs13382811 was associated nominally with Aniso-AL (odds ratio [OR], 1.66; P = 0.003) at baseline. At 3 years, rs13382811 was significantly associated with Aniso-AL (OR, 1.49; P = 0.001) and became nominally associated with Aniso-SE (OR, 1.40; P = 0.01). In addition, PAX6 rs644242 was significantly associated with Aniso-AL at 3 years (OR, 1.45; P = 0.002). At the 3-year follow-up, PAX6 rs644242 was associated significantly with Aniso-AL development (OR, 1.61; P = 0.0003) and nominally with Aniso-SE development (P = 0.03) in children who were not anisometropic at baseline, whereas ZFHX1B rs13382811 was associated nominally with Aniso-AL development (P = 0.02). An additive SNP analysis indicated children carrying the risk allele T of ZFHX1B rs13382811 and allele A of PAX6 rs644242 might have a 4.33- and 6.90-fold of increased risk of Aniso-SE and Aniso-AL development by 3 years, respectively.
This study identified two susceptible gene variants, ZFHX1B rs13382811 and PAX6 rs644242, for anisometropia development in Hong Kong Chinese children, implicating their role in imbalanced refractive change and axial elongation between both eyes.

UNASSIGNED: To investigate the prevalence, associated factors, and inter-eye differences of myopia and astigmatism in an adult Japanese population-based cohort.
UNASSIGNED: A total of 4282 participants from the Tohoku Medical Megabank Organization Eye Study (ToMMo Eye Study) underwent comprehensive ocular examinations as well as extensive physiological tests and a lifestyle questionnaire. The spherical equivalent (SE) and cylinder power were obtained as refractive parameters. The age- and gender-stratified prevalences of high myopia (SE < -5D), myopia (SE < -0.5D), hyperopia (SE > 0.5D), astigmatism (cylinder power < -0.5D), and anisometropia (SE difference >1D) were calculated. Multivariable analyses were performed to identify associated factors for refractive error (RE). Distribution and associated factors of the inter-eye difference in RE were also investigated.
UNASSIGNED: The age-adjusted prevalence of high myopia, myopia, hyperopia, astigmatism, and anisometropia was 15.9%, 63.5%, 14.7%, 51.1%, and 14.7%, respectively. Both myopia and high myopia were more prevalent in the younger age group, while astigmatism was more prevalent in the older age group. Age, education, blood pressure, intraocular pressure, and corneal thickness are significantly associated with myopic refraction. Age, gender, intraocular pressure, and corneal thickness are correlated with astigmatism. Older age was associated with against-the-rule astigmatism. Older age, myopia, and longer education showed a significant correlation with large inter-eye differences in SERE.
UNASSIGNED: This study demonstrated the high prevalence of myopia in young Japanese, which may be caused by a generational shift. This study also confirmed the influence of age and education on both the prevalence and inter-eye differences of RE.

There are some uncertainties about the effect of low-power red laser treatment on myopia control for anisometropic myopia in children. To evaluate the effect and safety of low-power red laser treatment on refractive development for anisometropic myopia in children, a contralateral comparison study was conducted.
The more myopic eye of child with anisometropic myopia was treated with low-power red laser treatment (LRL group), the other eye received no treatment other than the wearing of single-focus spectacles (SFS) (SFS Group). The LRL treatment was given at home under parental guidance for 3 minutes each time, twice daily with a minimal interval of 4 hours, 7 days per week, using an equipment that produces red laser of 650 nm wavelength at an illuminance range of roughly 1200-1800 lux and an energy of 0.60 mw for a 4-mm pupil (class I classification).
Among 51 included children, 44 (86.27%) completed the 3-months study, consisting of 15 girls (34.1%) and 29 boys (65.9%). After 3-months axial length (AL) and spherical equivalent refraction (SER) progression were -0.08 mm [95% CI (confidence interval), 0.11 to 0.06 mm] and +0.23 diopter (D) (95% CI, 0.13-0.33 D) for LRL group and +0.08 mm (95% CI, 0.05-0.11 mm) and -0.07 D (95% CI, -0.16-0.03 D) for SFS group. AL and SER progression between the groups varied by 0.17 mm (95% CI, 0.13-0.20 mm) and -0.30 D (95% CI, -0.42 to -0.18 D). There was no visible structural damage on optical coherence tomography (OCT) scans.
AL growth, myopia progression, and anisometropia of the binoculars can all be slowed down by LRL treatment. Compared to SER progression, axial elongation is more accurate and simpler to monitor. LRL treatment unrecorded functional and structural damage of binoculus.

To analyze the demographics and clinical outcomes of posterior chamber phakic intraocular (IOL) implantation for refractive amblyopia in children and adolescents.
A prospective interventional study was performed on children and adolescents with amblyopia at a tertiary eye care center from January 2021 to August 2022. Twenty-three eyes of 21 anisomyopic and isomyopic amblyopia patients operated for posterior chamber phakic IOL (Eyecryl phakic IOL) as a treatment for amblyopia were included in the study. Patient demographics, pre- and postoperative visual acuity, cycloplegic refraction, anterior and posterior segment examination, intraocular pressure, pachymetry, contrast sensitivity, endothelial count, and patient satisfaction scores were evaluated. Patients were followed up at day 1, 6 weeks, 3 months, and 1 year after surgery, and visual outcomes and complications were documented.
The mean age of patients was 14.16 ± 3.49 years (range: 10-19 years). The mean intraocular lens power was - 12.20 diopter spherical (DS) in 23 eyes and - 2.25 diopter cylindrical (DC) in four patients. The mean unaided distant visual acuity (UDVA) and best-corrected visual acuity (BCVA) were 1.39 ± 0.25 and 0.40 ± 0.21 preoperatively on the log of minimum angle of resolution (logMAR) chart. Postoperatively, the visual acuity improved by 2.6 lines in 3 months period and maintained till 1 year. Postsurgery, contrast sensitivity in the amblyopic eyes significantly improved, and the average endothelial loss recorded was 5.78% at 1 year, which was statistically insignificant. Patient satisfaction score was statistically significant, with 4.736/5 recorded on the Likert scale.
Posterior chamber phakic IOL is a safe, effective, and alternative method for treating amblyopia patients who are noncompliant with glasses, contact lenses, and keratorefractive procedures.

UNASSIGNED: Amblyopia is defined as a reduction in visual acuity unilaterally or bilaterally without any detectable cause. It is a major public health issue in developing and underdeveloped countries. Its prevalence is usually underestimated because of proper study and lack of awareness. The aim of the study was to find out the prevalence of amblyopia among patients attending the Outpatient Department of Ophthalmology of a tertiary care centre.
UNASSIGNED: This descriptive cross-sectional study was conducted among outpatients visiting a tertiary care centre in the Outpatient Department of Ophthalmology between 1 January 2017 to 31 December 2019. Ethical approval was obtained from the Institutional Review Board (Registration number: 407/2020 P). All patients had gone through a comprehensive eye examination. Convenience sampling was used. Point estimate and 99% Confidence Interval were calculated.
UNASSIGNED: Among 82972 patients, prevalence of amblyopia was 344 (0.41%) (0.37-0.46, 99% Confidence Interval). Amblyopia was more common in anisometropia 263 (63.50%). A total of 117 (34%) patients had no history of eye examination and were newly diagnosed with amblyopia. Astigmatism was the most common type of refractive error among 224 (56.70%) amblyopic patients.
UNASSIGNED: The prevalence of amblyopia was found to be lower than in previous studies conducted in similar settings. Early detection and diagnosis of amblyopia can help to design more effective plans and treatments to reduce amblyopia through optical correction and amblyopia therapy.
UNASSIGNED: amblyopia; anisometropia; astigmatism; refractive errors.

The study aims to assess two refractive instrument-based methods of vision screening (SureSight and PlusoptiX) to detect refractive amblyopia risk factors (ARFs) and significant refractive errors in Chinese preschool children and to develop referral criteria according to the 2021 AAPOS guidelines.
Eye examinations were conducted in children aged 61 to 72 months (n = 1,173) using a PlusoptiX photoscreener, SureSight autorefractor, and cycloplegic retinoscopy (CR). The Vision Screening Committee of AAPOS\'s preschool vision screening guidelines from 2021 were adopted for comparison. Paired t-test analysis and Bland-Altman plots were used to assess the differences and agreement between the PlusoptiX photoscreener, SureSight autorefractor, and CR. In addition, the validity of the cut-off values of the several ARFs measured with the SureSight and PlusoptiX was estimated using receiver operating characteristic (ROC) curves and compared to the age-based 2021 AAPOS examination failure levels.
A total of 1,173 children were tested with comprehensive eye examinations. When the referral numbers based on the 2013 (43/3.67%) and 2021 (42/3.58%) AAPOS guidelines were compared, significant differences between the values of astigmatism (72.09 vs. 52.38%) and anisometropia (11.63 vs. 38.10%) were found. The 95% limits of agreement (LOA) of the spherical value and the cylindrical value between PlusoptiX and CR were 95.08 and 96.29%. It was 93.87 and 98.10% between SureSight and CR. Considering refractive failure levels, the ROC curves obtained the optimal cut-off points. However, the PlusoptiX and the SureSight showed lower efficiency in hyperopia (Youden index, 0.60 vs. 0.83) and myopia (Youden index, 078 vs. 0.93), respectively. After adjusting the above cut-off points, the optimized NES (Nanjing Eye Study) referral criteria for myopia, hyperopia, astigmatism, and anisometropia were -0.75, 1.25, -1.0, and 0.5 with PlusoptiX and -1.25, 2.75, -1.5, and 0.75 with SureSight.
SureSight and PlusoptiX showed a good correlation with CR and could effectively detect refractive ARFs and visually significant refractive errors. There were obvious advantages in detecting hyperopia using SureSight and myopia using PlusoptiX. We proposed instrumental referral criteria for age-based preschool children based on AAPOS 2021 guidelines.