Association study of the serum 25(OH)D concentration and myopia in Chinese children.

ABSTRACT: To analyze the serum 25 hydroxyvitamin D (25[OH]D) concentration in Chinese children with myopia and explore its correlation with myopia.From July to September in 2019, myopic children were collected from the Myopia Influencing Factors Survey Project. The basic information and vision related behaviors of the subjects were collected by questionnaire. The diopter of the children without dilated pupils was measured by the computerized refractometer. Meanwhile, 5 ml fasting venous blood samples were collected for the determination of serum 25(OH)D concentration.A total of 186 children were included in this study, including 90 males and 96 females, with an average age of 8 ±â€Š3.26 years. The detection rate of serum 25(OH)D deficiency in myopic children was 65.59% (122/186). There was statistical significance in the detection rate of serum 25(OH)D deficiency in children with different myopic degrees (χ2 = 6.635, P = .010). The average serum 25(OH)D concentration in myopic children was 14.86 (10.67-18.96) ng/ml, and the difference of serum 25(OH)D concentration in children with different myopia degrees was statistically significant (Z = 20.23, P < .001). Logistic regression analysis showed that after controlling for gender, parental myopia, after-school class, and outdoor activities, the prevalence of developing moderate and high myopia was 2.051 times (95% confidence interval: 1.272-3.724) higher in the serum 25(OH)D deficiency group than in the serum 25(OH)D sufficiency group. There is a positive correlation between serum 25(OH)D concentration and the equivalent spherical degree of myopic children.The study found that serum 25(OH)D concentration is closely related to the prevalence of myopia in Chinese children. The results further support the conclusion that children with a higher level of serum 25(OH)D have a lower prevalence of moderate to high myopia. The results of this study provide a basis for further research into the relationship between vitamin D and visual development in children and its mechanisms.

Myopia, Melatonin and Conjunctival Ultraviolet Autofluorescence: A Comparative Cross-sectional Study in Indian Myopes.

Purpose: To explore the role of outdoor light exposure by estimating ocular sun exposure measured by Conjunctival Ultraviolet Autofluorescence (CUVAF) imaging and serum melatonin levels in myopes and non-myopes.Materials & Methods: Age and sex matched emmetropes and myopes (60 each) aged 10-25 years participated. Those with a history of ocular surgery or any ocular or systemic co-morbidity were excluded. Socio-demographic parameters, sun exposure questionnaires, indoor and outdoor activity profile, morning serum melatonin levels, sleep pattern, degree of myopia, ocular biometry and area of CUVAF on ultraviolet photography were noted and analyzed.Results: Mean age of myopes (18 ± 4.5 years) and emmetropes (18.5 ± 4 years) was similar (P = .523). Serum melatonin levels were significantly higher (P = .001) among myopes (89.45 pg/ml) as compared to emmetropes (52.83 pg/ml). Lifetime sun exposure was significantly lower in myopes than emmetropes (P = .0003). Area of CUVAF was inversely related to degree of myopia (P < .0001). Day time sleepiness was greater in myopes (51.7%) than emmetropes (15%) (P < .0001). There was a positive correlation between serum melatonin levels and axial length among myopes (correlation coefficient = 0.27; P = .03). Age and gender had no association with serum melatonin levels.Conclusion: This study demonstrates an inverse relationship between serum melatonin levels and degree of CUVAF in myopes. A novel link between serum melatonin, axial length and outdoor sun exposure is highlighted in the current study.

Higher HbA1c may reduce axial length elongation in myopic children: a comparison cohort study.

AIMS: To compare the annual axial length (AL) changes in myopic children with type 1 diabetes mellitus (T1DM) and those without diabetes. METHODS: There are two groups of myopic children in this retrospective cohort study. Group 1 consisted of myopic children with T1DM (44 eyes of 22 patients). Group 2 comprised age-matched myopic children without diabetes (44 eyes of 22 children). These two groups were compared with regard to their baseline clinical characteristics. A generalized estimating equations (GEE) model was also used to determine the most likely factor that contributed to the results. RESULTS: The average ages of group 1 and group 2 were 14.8 and 14.6 years, respectively. Children in group 1 had significantly slower annual AL changes (0.051 mm/year vs 0.103 mm/year; 50.5% slower, P = 0.011) and shorter baseline AL (23.97 vs 25.19 mm, P < 0.001) than those in group 2. GEE also showed that serum glycated hemoglobin (HbA1c) level (B = -0.023, P = 0.039) was the most important factor in reducing AL elongation in group 1 myopic children. CONCLUSIONS: Long-term higher HbA1c level may reduce AL elongation. A strict blood sugar control strategy in clinical practice is warranted to axial myopia progression in T1DM children.

Time spent outdoors through childhood and adolescence - assessed by 25-hydroxyvitamin D concentration - and risk of myopia at 20 years.

PURPOSE: To investigate the relationship between time spent outdoors, at particular ages in childhood and adolescence, and myopia status in young adulthood using serum 25-hydroxyvitamin D [25(OH)D] concentration as a biomarker of time spent outdoors. METHODS: Participants of the Raine Study Generation 2 cohort had 25(OH)D concentrations measured at the 6-, 14-, 17- and 20-year follow-ups. Participants underwent cycloplegic autorefraction at age 20 years, and myopia was defined as a mean spherical equivalent -0.50 dioptres or more myopic. Logistic regression was used to analyse the association between risk of myopia at age 20 years and age-specific 25(OH)D concentrations. Linear mixed-effects models were used to analyse trajectory of 25(OH)D concentrations from 6 to 20 years. RESULTS: After adjusting for sex, race, parental myopia, body mass index and studying status, myopia at 20 years was associated with lower 25(OH)D concentration at 20 years (per 10 nmol/L decrease, odds ratio (aOR)=1.10, 95% CI: 1.02, 1.18) and a low vitamin D status [25(OH)D < 50 nmol/L] at 17 years (aOR = 1.71, 95% CI: 1.06, 2.76) and 20 years (aOR = 1.71, 95% CI: 1.14, 2.56), compared to those without low vitamin D status. There were no associations between 25(OH)D at younger ages and myopia. Individuals who were myopic at 20 years had a 25(OH)D concentration trajectory that declined, relative to non-myopic peers, with increasing age. Differences in 25(OH)D trajectory between individuals with and without myopia were greater among non-Caucasians compared to Caucasians. CONCLUSIONS: Myopia in young adulthood was most strongly associated with recent 25(OH)D concentrations, a marker of time spent outdoors.

Myopia in school-aged children with preterm birth: the roles of time spent outdoors and serum vitamin D.

AIMS: To analyse the factors associated with myopia in school-aged children with preterm birth and with or without retinopathy of prematurity (ROP). METHODS: Children born prematurely between January 2010 and December 2011 were enrolled in this cross-sectional study when they reached school age between April 2017 and June 2018 in a referral centre. The main parameters were cycloplegic refraction, time spent outdoors and serum 25-hydroxyvitamin D (25(OH)D) concentration. RESULTS: A total of 99 eyes from 99 children with a mean age of 6.8 years underwent analysis. The average time spent outdoors was significantly higher in the non-myopic group (0.9 ± 0.5 hours/day) than in the myopic group (0.7 ± 0.3 hours/day) (p = 0.032). After adjustment for age, sex, number of myopic parents, ROP severity, near-work time and serum 25(OH)D concentration, more time spent outdoors was correlated with a lower odds of myopia (OR, 0.13 per additional hour per day; 95% CI, 0.02-0.98; p = 0.048). Mean serum 25(OH)D concentrations were similar between the myopic and non-myopic groups (49.7 ± 13.6 and 48.8 ± 14.0 nmol/mL; p = 0.806) and were not correlated with spherical equivalence power (r = -0.09; p = 0.418). Vitamin D insufficiency was present in 57% of the participants. CONCLUSIONS: Among preterm children with or without ROP, more time spent outdoors was associated with lower odds of myopia. The serum 25(OH)D concentration was not associated with myopia, but a high proportion of the participants had insufficient levels.

No evidence for an association of plasma homocysteine levels and refractive error - Results from the population-based Gutenberg Health Study (GHS).

PURPOSE: There is a strong association between severe hyperhomocysteinemia and myopia. Thus we studied the hypothesis that even moderately increased levels of homocysteine (Hcy) might be a potentially treatable risk factor for myopia. METHODS: The Gutenberg Health Study (GHS) is a population-based, prospective, observational cohort study in Germany, including 15,010 participants aged between 35 and 74 at recruitment. The baseline examination was conducted from 2007-2012. Refraction was measured using autorefraction (HARK 599, Carl Zeiss AG, Jena, Germany). Hcy was measured by an immunoassay. We included only phakic participants without a history of corneal surgery or corneal laser treatment. We used linear regression models to evaluate the potential association between Hcy and refraction at baseline, and between Hcy and change in refraction between baseline and 5-year-follow-up examination. We used generalized estimating equation models to account for the correlation between fellow eyes. RESULTS: We included 13,749 participants, categorized as having no myopia (spherical equivalent > -0.75 D, 65.2%), low myopia (-0.75 D--2.75 D, 21.5%), moderate myopia (-3.00 D- 5.75 D, 9.8%) and high myopia (≤ -6 D, 3.5%). Median Hcy levels were similar in all groups (µmol/l). We observed no association of Hcy with refraction or 5-year change in refraction in the models adjusted for age, sex and socioeconomic status. CONCLUSION: We found no evidence for an association of Hcy levels and refractive error.

Association between serum 25-hydroxyvitamin D levels and myopia in general Korean adults.

Purpose: We performed this study to determine the association between serum 25-hydroxyvitamin D [25(OH) D] level and myopia in adults. Methods: A total of 25,199 subjects aged ≥20 years were included from the National Health and Nutrition Examination Survey 2008-2012. Blood 25(OH)D levels were evaluated from blood samples. Refractive error was measured without cycloplegia. Myopia and high myopia were defined as ≥-0.50 diopters (D) and ≥-6.0 D, respectively. Other covariates such as education, physical activity, and economic status were obtained from interviews. Results: Linear regression analysis showed that as 25(OH) D level increased by 1 ng/mL, myopic refractive error significantly decreased by 0.01 D (P < 0.001) after adjusting for potential confounders including sex, age, height, education level, economic status, physical activity, and sunlight exposure time. The odds ratios for myopia was 0.75 (95% Confidence interval [CI]; 0.67-0.84, P < 0.001) in the highest 25(OH) D quintile compared to the lowest quintile. The odds ratios for high myopia was 0.63 (95% CI; 0.47-0.85, P < 0.001) in the highest 25(OH)D quintile compared to the lowest quintile. Conclusion: : Serum 25(OH)D level was inversely associated with myopia in Korean adults.

Serum metabolomics profiling and potential biomarkers of myopia using LC-QTOF/MS.

Myopia is the most common form of refractive eye disease, and the prevalence is increasing rapidly worldwide. However, the key metabolic alterations in individuals with high myopia are not understood clearly, and serum biomarkers remain to be determined. The objectives of this study were to identify serum biomarkers and investigate the metabolic alterations of myopia. The serum metabolomics profiling was investigated on 30 high myopia cases and 30 controls (without myopia) using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF/MS), and an independent additional cohort including 20 cases and 19 controls were investigated to validate potential metabolite candidates for biomarkers. According to the metabolic differences, the myopia patients and controls could be divided into different clusters and nine metabolites were found to be closely correlated with myopia. In the cohort of validation, eight metabolites were confirmed. Metabolic pathway analyses of these metabolites of high myopia involved abnormal phospholipid, diacylglycerol, amino acid, and vitamin metabolism, which were closely correlated with oxidative stress and inflammation. Multiple logistic regression analyses showed that γ-glutamyltyrosine and 12-oxo-20-trihydroxy-leukotriene B4 were potential biomarkers of myopia with a combined high sensitivity (97%), specificity (90%), and area under the curve value (0.983). These findings may contribute to an understanding of the pathophysiological changes and pathogenesis of myopia, and provide novel insight into the early prevention and control of high myopia.

Vitamin D and its pathway genes in myopia: systematic review and meta-analysis.

OBJECTIVE: To conduct a systematic review and meta-analysis of the association of blood vitamin D (25-hydroxyvitamin D, 25(OH)D) concentration and vitamin D pathway genes with myopia. METHODS: We searched the MEDLINE and EMBASE databases for studies published up to 29 January 2018. Cross-sectional or cohort studies which evaluated the blood 25(OH)D concentration, blood 25(OH)D3 concentration or vitamin D pathway genes, in relation to risk of myopia or refractive errors were included. Standard mean difference (SMD) of blood 25(OH)D concentrations between the myopia and non-myopia groups was calculated. The associations of blood 25(OH)D concentrations and polymorphisms in vitamin D pathway genes with myopia using summary ORs were evaluated. RESULTS: We summarised seven studies involving 25 008 individuals in the meta-analysis. The myopia group had lower 25(OH)D concentration than the non-myopia group (SMD=-0.27 nmol/L, p=0.001). In the full analysis, the risk of myopia was inversely associated with blood 25(OH)D concentration after adjusting for sunlight exposure or time spent outdoors (adjusted odds ratio (AOR)=0.92 per 10 nmol/L, p<0.0001). However, the association was not statistically significant for the <18 years subgroup (AOR=0.91 per 10 nmol/L, p=0.13) and was significant only for 25(OH)D3 (likely to be mainly sunlight derived), but not total 25(OH)D (AOR=0.93 per 10 nmol/L, p=0.00007; AOR=0.91 per 10 nmol/L, p=0.15). We analysed four single nucleotide polymorphisms in the VDR gene from two studies; there was no significant association with myopia. CONCLUSIONS: Lower 25(OH)D is associated with increased risk of myopia; the lack of a genetic association suggests that 25(OH)D level may be acting as a proxy for time outdoors.

Conjunctival ultraviolet autofluorescence area, but not intensity, is associated with myopia.

BACKGROUND: Conjunctival ultraviolet autofluorescence (CUVAF) has been used as a biomarker of time spent outdoors. Smaller CUVAF area is associated with myopia in southern hemisphere cohorts. Further research is required to determine if this association is replicated in northern latitudes and whether average CUVAF intensity is a valuable metric. This prospective study explored the association between myopia, CUVAF (area and intensity) and additional indicators of sun exposure (vitamin D3 and self-reported sun exposure preferences) across seasons at a location of 55° north. METHODS: Young adults (age 18-20) provided blood samples biannually (March/April and September/October) over an 18-month period (four phases) for the assessment of 25-hydroxyvitamin D (25(OH)D3 ) concentrations (liquid chromatography-tandem mass spectrometry). CUVAF (total area, average intensity) and self-reported sun exposure preferences were recorded at each phase. Axial length and corneal radius were measured. Refractive error was measured by autorefractor and spherical equivalent refraction used to classify participants into refractive groups: myopic (spherical equivalent refraction ≤ -0.50 DS) or non-myopic. RESULTS: Fifty-four participants (24 myopes, 30 non-myopes) participated. CUVAF area was negatively associated with the presence of myopia (odds ratio = 0.94, 95 per cent confidence interval = 0.90-0.98, p = 0.002). Myopes = 4.5 mm2 (interquartile range [IQR] 0.95-6.4 mm2 ), non-myopes = 7.0 mm2 (IQR = 2.0-10.7 mm2 ). No significant association was found between CUVAF intensity and refractive group (p = 0.17). There was no significant association between sun exposure preferences or serum concentration of 25(OH)D3 and refractive status (all p ≥ 0.21). CUVAF measures were not associated with ocular biometry measures (all p ≥ 0.084). CUVAF area was unaffected by season (all p ≥ 0.45) and variations in CUVAF area over the study period did not exceed the repeatability of the measurement technique. CONCLUSION: Myopia was associated with smaller areas of CUVAF indicative of less cumulative ultraviolet-B exposure. These findings suggest that CUVAF measures are a useful, non-invasive biomarker of the time spent outdoors in adults in northern hemisphere populations.

Independent association of whole blood miR-328 expression and polymorphism at 3'UTR of the PAX6 gene with myopia.

PURPOSE: This study aimed to find associations between miR-328 expression in whole blood, polymorphism at 3'UTR of the PAX6 gene (paired box homeotic gene 6) and myopia. METHODS: We evaluated 451 individuals (142 individuals with low, 49 with moderate and 13 with high-degree myopia, and 247 healthy individuals). DNA and RNA were extracted from peripheral blood samples. Expression of miR-328 was assessed and genotyping of single-nucleotide polymorphisms (SNPs) of the PAX6 (rs662702) performed using the Applied Biosystems 7900HT Real-Time Polymerase Chain Reaction System. RESULTS: Moderate and high degree myopia showed significant differences between TT and CT genotypes of the PAX6 gene (p < 0.001). In the myopia group, 71.4% of the subjects had the TT genotype and 28.6% had the CT genotype; meanwhile in the control group, 97.1% had the TT genotype and 2.9% had the CT genotype. The odds ratio of having moderate and/or high degree myopia for individuals with the CT genotype was 13.6 (2.865-64.55) 95% CI versus TT genotype (p = 0.001). MiR-328 results showed that ∆Ct values differed statistically significantly between the myopia and control groups. Patients with myopia in the peripheral blood cells had a higher expression of miR-328 than controls (p < 0.05). CONCLUSIONS: Significant differences were detected between the PAX6 gene (rs662702) TT and CT genotypes in moderate and high degree myopia; the risk C allele increased the risk for myopia. The expression level of miR-328 in peripheral blood cells was higher in patients with myopia than controls. We did not find the association between expression of mir-328 in the peripheral blood cells and PAX6 gene (rs662702) polymorphism comparing myopia and control groups.

Myopes have significantly higher serum melatonin concentrations than non-myopes.

PURPOSE: Experimental animal models of myopia demonstrate that higher melatonin (Mel) and lower dopamine (DA) concentrations actively promote axial elongation. This study explored the association between myopia and serum concentrations of DA and Mel in humans. METHODS: Morning serum concentrations of DA and Mel were measured by solid phase extraction-liquid chromatography-tandem mass spectrometry from 54 participants (age 19.1 ± 0.81 years) in September/October 2014 (phase 1) and March/April 2016 (phase 2). Axial length (AL), corneal radii (CR) and spherical equivalent refraction (SER) were also recorded. Participants were defined as myopic if non-cycloplegic spherical equivalent refractive error ≤-0.50 DS at phase 1. RESULTS: Nine participants were lost to follow up. Mel concentrations were measurable for all myopes (phase 1 n = 25, phase 2 n = 22) and non-myopes (phase 1 n = 29, phase 2 n = 23). SER did not change significantly between phases (p = 0.51). DA concentrations were measurable for fewer myopes (phase 1 n = 13, phase 2 n = 12) and non-myopes (phase 1 n = 23, phase 2 n = 16). Myopes exhibited significantly higher Mel concentrations than non-myopes at phase 1 (Median difference: 10 pg mL-1 , p < 0.001) and at phase 2 (Median difference: 7.3 pg mL-1 , p < 0.001) and lower DA concentrations at phase 2 (Median difference: 4.7 pg mL-1 , p = 0.006). Mel concentrations were positively associated with more negative SER (all r ≥ -0.53, all p < 0.001), longer AL (all r ≥ 0.37, all p ≤ 0.008) and higher AL/CR ratio (all r ≥ 0.51, all p < 0.001). CONCLUSION: This study reports for the first time in humans that myopes exhibit higher serum Mel concentrations than non-myopes. This may indicate a role for light exposure and circadian rhythm in the human myopic growth mechanism. Further research should focus on younger cohorts exhibiting more dynamic myopic progression and explore the profile of these neurochemicals alongside evaluation of sleep patterns in myopic and non-myopic groups.

Genetically low vitamin D concentrations and myopic refractive error: a Mendelian randomization study.

Background: Myopia prevalence has increased in the past 20 years, with many studies linking the increase to reduced time spent outdoors. A number of recent observational studies have shown an inverse association between vitamin D [25(OH)D] serum levels and myopia. However, in such studies it is difficult to separate the effects of time outdoors and vitamin D levels. In this work we use Mendelian randomization (MR) to assess if genetically determined 25(OH)D levels contribute to the degree of myopia. Methods: We performed MR using results from a meta-analysis of refractive error (RE) genome-wide association study (GWAS) that included 37 382 and 8 376 adult participants of European and Asian ancestry, respectively, published by the Consortium for Refractive Error And Myopia (CREAM). We used single nucleotide polymorphisms (SNPs) in the DHCR7, CYP2R1, GC and CYP24A1 genes with known effects on 25(OH)D concentration as instrumental variables (IV). We estimated the effect of 25(OH)D on myopia level using a Wald-type ratio estimator based on the effect estimates from the CREAM GWAS. Results: Using the combined effect attributed to the four SNPs, the estimate for the effect of 25(OH)D on refractive error was -0.02 [95% confidence interval (CI) -0.09, 0.04] dioptres (D) per 10 nmol/l increase in 25(OH)D concentration in Caucasians and 0.01 (95% CI -0.17, 0.19) D per 10 nmol/l increase in Asians. Conclusions: The tight confidence intervals on our estimates suggest the true contribution of vitamin D levels to degree of myopia is very small and indistinguishable from zero. Previous findings from observational studies linking vitamin D levels to myopia were likely attributable to the effects of confounding by time spent outdoors.

Time outdoors, blood vitamin D status and myopia: a review.

BACKGROUND: Myopia is a major public health concern throughout the world and the prevalence has been increasing rapidly in recent years, especially in urban Asia. The "vitamin D hypothesis" has been raised recently because vitamin D may be a link between less time outdoors and increased risk of myopia. METHODS: We reviewed all studies published in English which examined the association of time outdoors and blood vitamin D status with myopia. RESULTS: The protective effect of time spent outdoors on the risk of myopia onset has been well-established with numerous observational studies and three trials published. Five studies reporting the association between the blood vitamin D status and the risk of myopia and two studies examining the variations in the vitamin D receptor as potential risk factors for myopia development were identified. Most of the current evidence was cross-sectional in nature and had not properly controlled important confounders in its analyses. The evidence supporting that vitamin D played a role in myopia development is weak and the mechanisms are unclear. CONCLUSIONS: At the current stage, it is still unclear whether blood vitamin D status regulates the onset or progression of myopia. Blood vitamin D status may only serve as a biomarker of outdoor exposure, which is the real protective factor for myopia.

Association Between Myopia, Ultraviolet B Radiation Exposure, Serum Vitamin D Concentrations, and Genetic Polymorphisms in Vitamin D Metabolic Pathways in a Multicountry European Study.

IMPORTANCE: Myopia is becoming increasingly common globally and is associated with potentially sight-threatening complications. Spending time outdoors is protective, but the mechanism underlying this association is poorly understood. OBJECTIVE: To examine the association of myopia with ultraviolet B radiation (UVB; directly associated with time outdoors and sunlight exposure), serum vitamin D concentrations, and vitamin D pathway genetic variants, adjusting for years in education. DESIGN, SETTING, AND PARTICIPANTS: A cross-sectional, population-based random sample of participants 65 years and older was chosen from 6 study centers from the European Eye Study between November 6, 2000, to November 15, 2002. Of 4187 participants, 4166 attended an eye examination including refraction, gave a blood sample, and were interviewed by trained fieldworkers using a structured questionnaire. Myopia was defined as a mean spherical equivalent of -0.75 diopters or less. Exclusion criteria included aphakia, pseudophakia, late age-related macular degeneration, and vision impairment due to cataract, resulting in 371 participants with myopia and 2797 without. EXPOSURES: Exposure to UVB estimated by combining meteorological and questionnaire data at different ages, single-nucleotide polymorphisms in vitamin D metabolic pathway genes, serum vitamin D3 concentrations, and years of education. MAIN OUTCOMES AND MEASURES: Odds ratios (ORs) of UVB, serum vitamin D3 concentrations, vitamin D single-nucleotide polymorphisms, and myopia estimated from logistic regression. RESULT: Of the included 3168 participants, the mean (SD) age was 72.4 (5) years, and 1456 (46.0%) were male. An SD increase in UVB exposure at age 14 to 19 years (OR, 0.81; 95% CI, 0.71-0.92) and 20 to 39 years (OR, 0.7; 95% CI, 0.62-0.93) was associated with a reduced adjusted OR of myopia; those in the highest tertile of years of education had twice the OR of myopia (OR, 2.08; 95% CI, 1.41-3.06). No independent associations between myopia and serum vitamin D3 concentrations nor variants in genes associated with vitamin D metabolism were found. An unexpected finding was that the highest quintile of plasma lutein concentrations was associated with a reduced OR of myopia (OR, 0.57; 95% CI, 0.46-0.72). CONCLUSIONS AND RELEVANCE: Increased UVB exposure was associated with reduced myopia, particularly in adolescence and young adulthood. The association was not altered by adjusting for education. We found no convincing evidence for a direct role of vitamin D in myopia risk. The relationship between high plasma lutein concentrations and a lower risk of myopia requires replication.

Serum Concentration of Zinc, Copper, Selenium, Manganese, and Cu/Zn Ratio in Children and Adolescents with Myopia.

The purpose of the present study was the assessment of the serum concentration of antioxidant microelements-zinc, copper, selenium, manganese, and Cu/Zn ratio in children and adolescents with myopia. Eighty-three children were examined (mean age 14.36 ± 2.49 years) with myopia. The control group was 38 persons (mean age 12.89 ± 3.84 years). Each patient had complete eye examination. The serum concentration of zinc, copper, manganese, and selenium was determined by atomic absorption spectrometry. Cu/Zn ratio, which is the indicator of the oxidative stress, was also calculated. The average serum concentration of zinc in myopic patients was significantly lower (0.865 ± 0.221 mg L-1) in comparison to the control group (1.054 ± 0.174 mg L-1). There was significantly higher Cu/Zn ratio in myopic patients (1.196 ± 0.452) in comparison to that in the control group (0.992 ± 0.203). The average serum concentration of selenium in the study group was significantly lower (40.23 ± 12.07 µg L-1) compared with that in the control group (46.00 ± 12.25 µg L-1). There were no essential differences between serum concentration of copper and manganese in the study group and the control group. Low serum concentration of zinc and selenium in myopic children may imply an association between insufficiency of these antioxidant microelements and the development of the myopia and could be the indication for zinc and selenium supplementation in the prevention of myopia. Significantly, higher Cu/Zn ratio in the study group can suggest the relationship between myopia and oxidative stress.

Serum 25-hydroxyvitamin D level is associated with myopia in the Korea national health and nutrition examination survey.

The aim of this article was to assess the associations of serum 25-hydroxyvitamin D [25(OH)D] and daily sun exposure time with myopia in Korean adults.This study is based on the Korea National Health and Nutrition Examination Survey (KNHANES) of Korean adults in 2010-2012; multiple logistic regression analyses were performed to examine the associations of serum 25(OH)D levels and daily sun exposure time with myopia, defined as spherical equivalent ≤-0.5D, after adjustment for age, sex, household income, body mass index (BMI), exercise, intraocular pressure (IOP), and education level. Also, multiple linear regression analyses were performed to examine the relationship between serum 25(OH)D levels with spherical equivalent after adjustment for daily sun exposure time in addition to the confounding factors above.Between the nonmyopic and myopic groups, spherical equivalent, age, IOP, BMI, waist circumference, education level, household income, and area of residence differed significantly (all P < 0.05). Compared with subjects with daily sun exposure time <2 hour, subjects with sun exposure time ≥2 to <5 hour, and those with sun exposure time ≥5 hour had significantly less myopia (P < 0.001). In addition, compared with subjects were categorized into quartiles of serum 25(OH)D, the higher quartiles had gradually lower prevalences of myopia after adjustment for confounding factors (P < 0.001). In multiple linear regression analyses, spherical equivalent was significantly associated with serum 25(OH)D concentration after adjustment for confounding factors (P = 0.002).Low serum 25(OH)D levels and shorter daily sun exposure time may be independently associated with a high prevalence of myopia in Korean adults. These data suggest a direct role for vitamin D in the development of myopia.

Rheumatic Disease Autoantibodies in Autoimmune Liver Diseases.

BACKGROUND: Autoimmune liver diseases (ALDs) are known to be associated with systemic autoimmune rheumatic diseases (SARDs) and their autoantibodies. We aimed to study the prevalence of SARDs and related autoantibodies, as well as their prognostic implications in a group of patients with ALDs. METHODS: This was a cross-sectional study. Sixty patients with ALDs (38.3% with autoimmune hepatitis; 11.7% with primary biliary cirrhosis; 25% with primary sclerosing cholangitis and 25% with overlap syndrome) were studied for the presence of SARDs and their autoantibodies. RESULTS: There was autoimmune rheumatic disease in 20% of the studied sample. Systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) were the commonest (11.6% and 5%, respectively). Antinuclear antibodies (ANAs) were present in 35% of the patients, followed by anti-Ro (20.0%); anti-nucleosome (18.3%); rheumatoid factor (10%) anti-CCP (8.3%); anti-RNP (8.3%); anti-ds-DNA (6.6%); anti-La (3.3%); anti-Sm (3.3%), anti-ribosomal P (3.3%). Anti-Ro (p = 0.0004), anti-La (p = 0.03), anti-RNP (p = 0.04) and anti-Sm (p = 0.03) were commonly found in patients with SARD, but not anti-DNA, anti-nucleosome and anti-ribosomal P. No differences were found in liver function tests regarding to the presence of autoantibodies. CONCLUSIONS: There was a high prevalence of SARD and their autoantibodies in ALD patients. Anti-Ro, anti-La, anti-RNP and anti-Sm positivity points to an association with systemic autoimmune rheumatic diseases. The presence of autoantibodies was not related to liver function tests.

Low serum vitamin D is associated with axial length and risk of myopia in young children.

The aim of the study was to investigate the relationship between serum 25(OH)D levels and axial length (AL) and myopia in 6-year-old children. A total of 2666 children aged 6 years participating in the birth-cohort study Generation R underwent a stepwise eye examination. First, presenting visual acuity (VA) and AL were performed. Second, automated cycloplegic refraction was measured if LogMAR VA > 0.1. Serum 25-hydroxyvitamin D [25(OH)D] was determined from blood using liquid chromatography/tandem mass spectrometry. Vitamin D related SNPs were determined with a SNP array; outdoor exposure was assessed by questionnaire. The relationships between 25(OH)D and AL or myopia were investigated using linear and logistic regression analysis. Average 25(OH)D concentration was 68.8 nmol/L (SD ± 27.5; range 4-211); average AL 22.35 mm (SD ± 0.7; range 19.2-25.3); and prevalence of myopia 2.3 % (n = 62). After adjustment for covariates, 25(OH)D concentration (per 25 nmol/L) was inversely associated with AL (ß -0.043; P < 0.01), and after additional adjusting for time spent outdoors (ß -0.038; P < 0.01). Associations were not different between European and non-European children (ß -0.037 and ß -0.039 respectively). Risk of myopia (per 25 nmol/L) was OR 0.65 (95 % CI 0.46-0.92). None of the 25(OH)D related SNPs showed an association with AL or myopia. Lower 25(OH)D concentration in serum was associated with longer AL and a higher risk of myopia in these young children. This effect appeared independent of outdoor exposure and may suggest a more direct role for 25(OH)D in myopia pathogenesis.

Relevant factors of estrogen changes of myopia in adolescent females.

BACKGROUND: Gender is one of the risk factors accounting for the high prevalence of adolescent myopia. Considerable research results have shown that myopia incidence of female is higher than that of male. This study aimed to analyze the correlation between ocular parameters and serum estrogen level and to investigate the vision changes along with estrogen change in menstrual cycle of adolescent females. METHODS: A total of 120 young females aged between 15 and 16 years, diagnosed with myopia were recruited. Spherical lens, cylindrical lens, axis, interpupillary distance (IPD), and vision in each tested eye of the same subject were measured by automatic optometry and comprehensive optometry, with repetition of all measurements in the menstrual cycle of the 2 nd or 3 rd days, 14 th days, and 28 th days, respectively. Serum estradiol (E 2 ) levels were assayed by chemiluminescence immunoassay at the same three times points of the menstrual cycle mentioned above. RESULTS: In young females with myopia, the spherical lens showed a statistically significant difference among all different time in menstrual cycle (all P < 0.0001). The cylindrical lens, axis, and IPD were changed significantly during the menstrual cycle (P < 0.05). The vision of the three different time points in menstrual cycle had a significant difference (χ2 = 6.35, P = 0.042). The vision during the 14 th and 28 th day was higher compared to that on the 2 nd or 3 rd days (P = 0.021). Serum E 2 levels were significantly different at different time points in menstrual cycle (P < 0.05). E 2 levels reached its maximum value on the 14 th day and the minimum value on the 2 nd or 3 rd day. CONCLUSIONS: In adolescent females, the spherical lens and other related ocular parameters vary sensitively with different levels of E 2 in menstrual cycle. Vision in late menstrual stage is significantly higher than that in premenstrual stage.