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Background: In recent decades, myopia has turned into a public health issue across the world. Between 1993 and 2016, the percentage of myopes increased from 10.4% to 34.2%. This study aims to analyze the myopia prevalence in Spanish children from five to seven years old over the last five years and to predict the rate of myopia in Spain by 2030. Methods: The sample consisted of children aged between 5 and 7, who underwent an optometric examination consisting of the measurement of visual acuity (VA) and determination of objective and subjective refraction. The cut-off points to define refractive error are established by the spherical equivalent (SE) value: hyperopia for an SE over or equal to +0.50 D; myopia for an SE under or equal to −0.50 D; and emmetropia when the SE is between −0.50 D and +0.50 D. Results: The myopia rate in Spanish children aged between five and seven was 19%. Myopia prevalence progressively increased as children grew up (p ≤ 0.001). It is estimated that, in the year 2030, the rate of myopia will be 30.2% [CI: 25.3–35.0], of which 81.9% [CI: 78.3–85.3] will have low myopia, 10.0% [CI: 7.2–12.8] moderate myopia, and 7.3% [CI: 4.9–9.7] high myopia. Conclusions: Nineteen percent of Spanish children between five and seven are myopes. In 2030, is expected that 30.2% of Spanish children between 5 and 7 years of age will be myopes. These estimations will support eye care professionals in recommending that children spend more time outdoors to prevent the onset of myopia and the use of methods to control myopia to avoid reaching these figures of high myopia. [ABSTRACT FROM AUTHOR]

Background: Different designs of ophthalmic lenses have been studied to control the progression of myopia in children. This study aims to evaluate the short-term efficacy of a new design of ophthalmic lens with asymmetric myopic peripheral defocus (MPDL) on myopia progression in children compared to a control group wearing a single-vision lens (SVL). Methods: Children aged 5 to 12 with myopia up to −0.50 D, astigmatism and anisometropia under 1.50 D, and corrected visual acuity over 20/20 were randomized to either the study group (MPDL) or control group (SVL). The myopia progression was evaluated by measuring axial length (AL) growth (IOL Master; Zeiss) over a period of one year. Results: Ninety-two subjects were recruited. Forty-six children were randomly assigned to the control group, and 46 to the study group. In total, 83 children completed the clinical trial, with a mean age of 10.81 [9.53–11.92] years, among which 59.04% were female. After one year of treatment, there was less AL elongation in the study group compared to the control group (0.16 ± 0.16 mm vs. 0.24 ± 0.16 mm, p = 0.034). Conclusions: The MPDL significantly reduced the absolute growth of AL by 39% (p = 0.014) and relative growth of AL by 37.3% (p = 0.012) after 12 months in comparison to the control group in a Spanish population. [ABSTRACT FROM AUTHOR]

Background: The objective of this study is to determine the relationship between publications and authors. In turn, the different areas of research on the ocular complications of myopia are also identified, and the most cited publication by citation networks is determined. Methods: The search for publications is carried out in the Web of Science database using the term "myopia OR nearsightedness AND retin* OR degenerat* OR detachment OR patholog* OR glaucoma OR cataract OR machulopathy OR "choroidal neovascularization" for the period between 1978 and December 2022. Publication analysis was performed using the Citation Network Explorer, VOSviewer and CiteSpace software. Results: A total of 9357 publications and 78,400 citation networks were found across the network, with 2021 being the year with the highest number of publications, 712. The most cited publication was "Myopia", published in The Lancet journal in 2012 by Morgan et al. with a citation index of 1006. By using the clustering function, seven groups covering the different research areas in this field were found: axial growth of the eye; myopic maculopathy; ocular complications in patients with myopia after a surgery; glaucoma; retinal detachment; cataracts and retinopathy of prematurity. Conclusions: The citation network offers a quantitative and qualitative analysis of the main papers on ocular complications of myopia. The research on this field is multidisciplinary; however, the main topic studied is the axial growth of the eye. [ABSTRACT FROM AUTHOR]

Background: Due to the importance of choroidal thickness in the development of myopia, this study examined the effect of MiSight contact lenses (CLs) on the choroidal thickness of myopic children and the differences between responders and non-responders to the treatment with these CLs. Methods: A total of 41 myopic children were fitted with MiSight CLs and 33 with single-vision spectacles. They were followed up for two years. Subfoveal choroidal thickness and choroidal thickness 1 and 3 mm temporal and nasal to the fovea were measured by OCT at baseline and one and two years after the treatment. Differences in all the choroidal thickness parameters were assessed in each group over time. Patients from the MiSight group were classified based on a specific range of changes in axial length at the end of the second year of treatment as "responders" (AL change < 0.22 mm/per year) and "non-responders", and the choroidal thickness of both groups was analyzed. Results: The subfoveal choroidal thickness of the MiSight and single-vision spectacle groups did not show any changes over time. Wearing MiSight CLs induced relative choroidal thickening in the responder group in the first year of treatment. Conclusion: Choroidal thickness might work as a predictor of the effectiveness of MiSight in myopia treatment. [ABSTRACT FROM AUTHOR]

Objective. To analyse the prevalence of myopia among a sample of more than 6000 children in Spain as well as to determine the impact of risk factors in its progression. Methodology. A total of 6,152 children aged from 5 to 7 were examined. The participants underwent an eye examination that included visual acuity, refraction without cycloplegia, and tests of accommodative and binocular function. In addition, a questionnaire regarding their lifestyle, family history, and geographical data was carried out. Finally, data were analysed using the SPSS version 25 program. Results. The prevalence of myopia in the sample of children studied has increased from 17% in 2016 to 20% in 2017. Likewise, the number of children with high myopia has also increased, from 1.7% in 2016 to 3.6% in 2017. 43.3% of the participants spent more than 3 hours a day doing near activities, and 48.9% of this group spent more than 50% of this time using electronic devices. In addition, only 9.7% spent more than 2.5 hours outdoors each day. Conclusion. Myopia prevalence appears to be increasing in Spain. Lifestyle factors appear to be increasing the risk of myopia. [ABSTRACT FROM AUTHOR]

Purpose. Quantifying adaptation to light distortion of subjects undergoing orthokeratology (OK) for myopia during the first month of treatment. Methods. Twenty-nine healthy volunteers (age: 22.34 ± 8.08 years) with mean spherical equivalent refractive error −2.10 ± 0.93D were evaluated at baseline and days 1, 7, 15, and 30 of OK treatment. Light distortion was determined using an experimental prototype. Corneal aberrations were derived from corneal topography for different pupil sizes. Contrast sensitivity function (CSF) was analyzed for frequencies of 1.50, 2.12, 3.00, 4.24, 6.00, 8.49, 12.00, 16.97, and 24.00 cpd under photopic conditions. Results. Average monocular values of all light distortion parameters measured increased significantly on day 1, returning to baseline after 1 week (P<0.05 in all cases). Spherical-like aberration stabilized on day 7 for all pupil diameters, while coma-like for smaller pupils only. CSF was significantly reduced on day 1 for all spatial frequencies except for 1.5 cpd, returning to baseline afterwards. Significant correlation was found between light distortion and contrast sensitivity for middle and high frequencies (P<0.05) after 15 days. Conclusion. Despite consistently increased levels of corneal aberrations, light distortion tends to return to baseline after one week of treatment, suggesting that neural adaptation is capable of overcoming optical quality degradation. [ABSTRACT FROM AUTHOR]

Background: To aim of the study was describe the growth of publications on genetic myopia and understand the current research landscape through the analysis of citation networks, as well as determining the different research areas and the most cited publications. Methods: The Web of Science database was used to perform the publication search, looking for the terms "genetic*" AND "myopia" within the period between 2009 and October 2020. The CitNetExplorer and CiteSpace software were then used to conduct the publication analysis. To obtain the graphics, the VOSviewer software was used. Results: A total of 721 publications were found with 2999 citations generated within the network. The year 2019 was singled out as a "key year", taking into account the number of publications that emerged in that year and given that in 2019, 200 loci associated with refractive errors and myopia were found, which is considered to be great progress. The most widely cited publication was "Genome-wide meta-analyses of multiancestry cohorts identify multiple new susceptibility loci for refractive error and myopia", an article by Verhoeven et al., which was published in 2013. By using the clustering function, we were able to establish three groups that encompassed the different research areas within this field: heritability rate of myopia and its possible association with environmental factors, retinal syndromes associated with myopia and the genetic factors that control and influence axial growth of the eye. Conclusions: The citation network offers a comprehensive and objective analysis of the main papers that address genetic myopia. [ABSTRACT FROM AUTHOR]

Background: Many epidemiological and experimental studies have established that myopia is caused by a complex interaction between common genetic and environmental factors. The objective of this study was to describe and compare the allelic and genotypic frequencies of the rs524952 (GJD2), rs8000973 (ZIC2), rs1881492 (CHRNG), rs1656404 (PRSS56), rs235770 (BMP2), and rs7744813 (KCNQ5) SNPs (single-nucleotide polymorphism) between responder and nonresponder patients who had undergone a two-year treatment with lenses for myopia control. Method: Twenty-eight participants from the MiSight Assessment Study Spain (MASS), who had received treatment for myopia control for two years with MiSight contact lenses, were examined. The criteria for better/worse treatment response was the change in the axial length (< / ≥ 0.22 mm two years after the treatment). The clinical procedure consisted of the extraction of a saliva sample, and the participants also underwent an optometric examination. Genetic data were analyzed using SNPStats software (Catalan Institute of Oncology, Barcelona, Spain), and statistical analysis was performed using SPSS v.25 (SPSS Inc., Chicago, IL, USA). Demographic variables were analyzed using the Student's t-test. Results: The T allele, the one with the lowest frequency, of the "rs235770" SNP was associated with a better treatment response [AL/CR (axial length/corneal radius): OR = 3.37; CI = 1.079–10.886; SE (spherical equivalent): OR = 1.26; CI: = 0.519–57.169; p = 0.019). By performing haplotype analysis, significant differences were found between the rs235770...rs1881492 and rs235770–rs1656404 polymorphisms. The latter presented a strong linkage disequilibrium with each other (r2 ≥ 0.54). Conclusion: The result of lens therapies for myopia control could vary depending on genetic variants. Studies with a larger sample are needed to confirm the results presented in this pilot study. [ABSTRACT FROM AUTHOR]