Blepharoptosis and cognitive performance: a population-based study of 1.4 million adolescents.

The purpose of this study is to examine the association between blepharoptosis and cognitive performance in late adolescence. This population-based, retrospective, cross-sectional study included 1,411,570 Israeli-born adolescents (620,107 women, 43.9%) aged 16-19 years who were medically examined before compulsory military service between 1993 and 2017. The diagnosis of blepharoptosis was verified by an ophthalmologist. Cognitive performance was assessed by a validated intelligence-quotient-equivalent test, comprising four domains (problem-solving, verbal abstraction and categorization, verbal comprehension, and mathematical abilities). Cognitive Z-scores were calculated and categorized as high (≥ 1 standard deviation (SD)), medium (- 1 to < 1 SD), and low (less than - 1 SD). Relationships were analyzed using regression models adjusted for sociodemographic variables including sex, year of birth, residential socioeconomic status, education level, body mass index, and familial country of origin. A total of 577 (41 per 100,000, 32.2% women) adolescents were diagnosed with blepharoptosis. The proportions of unilateral and bilateral visual impairment among adolescents with blepharoptosis were 13.0% and 3.5%, respectively. In a multivariable analysis, blepharoptosis was associated with a 0.18 SD reduction in cognitive Z-score (p < 0.001). The adjusted odds ratios for low and high cognitive Z-scores in adolescents with blepharoptosis were 1.54 (1.25-1.89) and 0.80 (0.62-1.04), respectively. This relationship persisted when adolescents with normal best-corrected visual acuity or unimpaired health status were analyzed separately.  Conclusions: Blepharoptosis is associated with reduced cognitive performance determined in late adolescence. Future prospective studies should investigate the causes of this link and their underlying mechanisms. What is Known: • While earlier investigations have examined the effects of blepharoptosis on vision and quality of life, the association between blepharoptosis and cognitive outcomes in youth has remained unexplored. What is New: • This nationwide study involving 1.4 million Israeli adolescents found a correlation between blepharoptosis and reduced cognitive performance. • Our findings suggest a potential interplay between blepharoptosis and cognitive development in the pediatric population, calling for increased focus on the educational needs of affected individuals.

Visual impairment and cognitive performance: A nationwide study of 1.4 million adolescents.

PURPOSE: Previous research highlights the adverse effects of visual impairment (VI) on academic achievement in children, yet its impact on cognitive performance among adolescents and young adults remains under-studied. Therefore, this investigation aimed to analyse this association in a nationwide sample of Israeli adolescents. METHODS: A retrospective population-based cross-sectional study was conducted among 1,410,616 Israeli-born adolescents aged 16-19 years, who were assessed before mandatory military service between 1993 and 2017. The definition of VI was based on best-corrected visual acuity (BCVA) measurements using a standard Snellen chart. Adolescents with BCVA worse than 6/9 in either or both eyes were classified as having unilateral or bilateral VI, respectively. Cognitive performance was measured using the General Intelligence Score (GIS), based on a validated four-domain test. Relationships were analysed using regression models yielding adjusted odds ratios (ORs) for low (<-1 standard deviation [SD]) and high (≥1 SD) cognitive Z-scores. RESULTS: Of 1,410,616 adolescents (56.1% men), 13,773 (1.0%) had unilateral and 3980 (0.3%) had bilateral VI. Unilateral VI was associated with adjusted ORs for low and high cognitive Z-scores of 1.24 (1.19-1.30) and 0.84 (0.80-0.89), respectively. ORs were accentuated for bilateral VI, reaching 1.62 (1.50-1.75) and 0.81 (0.74-0.90) for low and high cognitive Z-scores, respectively. Cognitive performance subscores mirrored these results, with the visual-spatial functioning subtest demonstrating the greatest effect size. These associations persisted in sub-analyses restricted to adolescents with amblyopia-related VI, mild VI and unimpaired health status. CONCLUSIONS: Visual impairment, including mild and unilateral cases, is associated with reduced cognitive performance scores assessed in late adolescence. Further research is required to gain a comprehensive understanding of the dynamics underlying this relationship.

Myopia and systemic manifestation of tissue hyperlaxity: A population-based cross-sectional study.

BACKGROUND: Whether non-syndromic connective tissue hyperlaxity is associated with myopia is unknown. The aim of this study was to examine the association between systemic signs of tissue hyperlaxity and myopia among adolescents. METHODS: Included were adolescents assessed before mandatory military service at the age of 16-18 years between 2011 and 2022. Diagnoses of hernias, pes planus, genu varus, genu valgum, and scoliosis, as well as joint injuries were used as surrogate markers for tissue hyperlaxity. The prevalence of these events among adolescents with myopia was evaluated and compared to the non-myopic population. RESULTS: Included were 920 806 adolescents. The mean age was 17.4 ± 1.4 years and 58.6% were men. Myopia was diagnosed in 290 759 adolescents (31.6%) and high myopia in 24 069 adolescents (2.6%). The prevalence of hernias was higher among adolescents with myopia, (2.76%, 95% confidence interval (95% CI): 2.69%-2.82% vs. 2.60%, 95% CI: 2.57%-2.65%), as were pes planus (14.92%, 95% CI: 14.79-15.05 vs. 13.51%, 95% CI: 13.42-13.59) and scoliosis (9.14%, 95% CI: 9.03-9.24 vs. 7.69%, 95%CI: 7.62-7.76). The prevalence of joint injuries was clinically similar between groups (less than 0.1% difference for ankle, shoulder, and knee injuries), as were genu varum and genu valgum (0.66%, 95%CI: 0.64%-0.69% vs. 0.68%, 95% CI: 0.66-0.70, respectively). Adjusted for possible confounders results remained consistent. CONCLUSIONS: Among a large sample of Israeli adolescents, those with myopia had a higher prevalence of hernias, pes planus, and scoliosis. These results could suggest a propensity for systemic conditions related to tissue laxity among myopic adolescents.

Body mass index and astigmatism: A nationwide study.

BACKGROUND: Existing research on the relationship between body mass index (BMI) and astigmatism yields inconsistent results. This study analyses this association in a nationally representative sample of adolescents. METHODS: This retrospective, cross-sectional study included Israeli adolescents who underwent medical assessments before mandatory military service between 2011 and 2022. BMI was categorised based on the US age- and sex-matched percentiles. Astigmatism was categorised by magnitude [low-moderate: 0.75 to <3.00 diopters (D), high: ≥3.00 D], and axis orientation [with-the-rule (WTR), against-the-rule (ATR), or oblique (OBL)]. Sex-stratified regression models adjusted for sociodemographic variables were used. RESULTS: Of 935 989 adolescents evaluated, 887 325 were included [511 465 (57.6%) males, mean age 17.2 years]. Astigmatism was diagnosed in 123 675 (13.9%) adolescents, of whom 117 081 (13.2%) had low-moderate and 6594 (0.7%) had high astigmatism. WTR astigmatism was the most prevalent (8.2%), followed by ATR (4.1%) and OBL (1.6%) types. Compared with low-normal BMI (5th to 50th percentile), the adjusted ORs for total astigmatism increased with increasing BMI, peaking at 1.65 (1.57-1.74) in males and 1.74 (1.64-1.86) in females with severe obesity. ORs were accentuated for high astigmatism, reaching 3.51 (3.01-4.09) in males, and 3.45 (2.83-4.22) in females with severe obesity. WTR astigmatism demonstrated the strongest association with BMI, with ORs reaching 2.26 (2.13-2.40) in males and 2.04 (1.90-2.20) in females with severe obesity. The results persisted in a series of subgroup analyses. CONCLUSIONS: Obesity is associated with higher odds of astigmatism in adolescence. Further investigation into the role of weight management in astigmatism development is warranted.

Acceptance of Seasonal Influenza Vaccine Following COVID-19 Vaccination: A Survey among Israel Defense Forces Soldiers.

Data regarding the contribution of COVID-19 vaccine rollouts to real-world uptake of influenza vaccination remains unclear. This cross-sectional survey-based study among Israel Defense Forces (IDF) soldiers aimed to assess the impact of the COVID-19 pandemic and specifically, previous COVID-19 vaccines uptake, on the intention to vaccinate for influenza during 2021-2022 season. Participants engaged in an online survey addressing vaccination history and current vaccine-related preferences. The survey was delivered prior to the initiation of the IDF's annual influenza immunization campaign. A multinomial logistic regression model was applied to analyze factors correlated with unwillingness to receive influenza vaccine. Overall, 825 invitations to participate in the survey were distributed and the overall response rate was 78.5%. Among the 648 participants who replied (61.6% males, median age of 20 years), 51.9% were willing to receive the upcoming influenza vaccine. Factors associated with vaccine reluctance included being female, not receiving the previous season's influenza vaccine, not having a previous diagnosis of COVID-19, and having decreased uptake of COVID-19 vaccines. Among participants not intending to receive an influenza vaccine, 50.3% stated that they are healthy and have no need for the vaccine and 36.2% stated they received too many vaccines over the previous year. The results of this study may suggest that influenza vaccination rates in the post-COVID-19 vaccine era may be reduced due to a perceived "vaccine saturation" phenomenon, owing to the density of COVID-19 vaccine administration. Future interventions such as campaigns related to maximizing influenza vaccination coverage should address repeated doses of COVID-19 vaccine administration.

Socio-demographic disparities in amblyopia prevalence among 1.5 million adolescents.

BACKGROUND: Amblyopia, when not diagnosed at appropriate age, leads to uncorrectable visual impairment with considerable social and financial implications. The aim of this study was to assess socio-demographic disparities in amblyopia prevalence among Israeli adolescents, in order to identify susceptible groups in the population. METHODS: A nationwide, population-based, cross-sectional study of Israeli adolescents examined between 1993 and 2017. All study participants underwent visual acuity examination with socio-demographic data and previous medical history documented. Associations were analyzed using univariable and multivariable logistic regression models. RESULTS: Among 1 334 650 Israeli-born candidates aged 17.15±0.26 years, amblyopia was diagnosed in 1.07%. The overall prevalence of amblyopia has declined from 1.59% in 1993 to 0.87% in 2017. Being in the lowest socioeconomic status and below average cognitive function scores increased the odds of amblyopia in both males [odds ratio (OR) 1.64, 95% confidence interval (CI) 1.45-1.87; OR 1.27, 95% CI 1.19-1.35, respectively] and females (OR 1.61, 95% CI 1.30-1.98; OR 1.27, 95% CI 1.18-1.36, respectively). Among males, Orthodox and ultra-Orthodox educational systems were associated with increased odds of amblyopia (OR 1.16, 95% CI 1.09-1.25; OR 1.90, 95% CI 1.73-2.09). A significantly higher prevalence of amblyopia was recorded among 219 983 immigrants (1.51%, P<0.001). CONCLUSIONS: Although the overall prevalence of amblyopia has decreased during the observed years, we found substantial evidence of socio-demographic disparities in amblyopia prevalence among adolescents, suggesting disparities in the prevention of the disease and its treatment. Demonstration of inequities at a national level could aid future guidance of health policy and augment current vision screening programs.

Primary Care Interventions to Address COVID-19 Vaccine Hesitancy Among Israel Defense Forces Soldiers.

Vaccine hesitancy is an obstacle to achieving high vaccination rates for COVID-19. Current knowledge on vaccine uptake is mostly based on hypothetical intention to vaccinate surveys. We compared intention to vaccinate and real-world vaccine uptake among 511 soldiers in a military unit during an unrestricted, on-site COVID-19 vaccine rollout. Soldiers were offered group lectures, on-site consultations and primary care office visits, discussing concerns on vaccination with a primary care physician. Overall, 359 (70.3%) soldiers participated in the group lectures, 33 (6.5%) in on-site consultations and 19 (3.7%) attended primary care visits. Overall, 459 (89.8%) of 511 soldiers vaccinated for COVID-19. Of the 90 soldiers initially refusing, 38 (42.2%) had agreed to receive a vaccine. On-site COVID-19 vaccine rollout joined with primary care communication interventions may maximize vaccine uptake within a young-adult community. Future studies should evaluate the effectiveness of these efforts across different populations in a controlled and comparative manner.

Correlation of Refractive Error with Anisometropia Development in Early Childhood.

PURPOSE: This study aims to investigate the relationship between the type and severity of refractive error and anisometropia development in preschool children. DESIGN: Retrospective cohort study. METHODS: Data from Maccabi Healthcare Services, Israel's second-largest Health Maintenance Organization (HMO), were analyzed. The study included all isometropic children aged 1 to 6 years, re-examined for refraction at least 2 years following their initial examination between 2012 and 2022. Anisometropia was defined as a ≥1 diopter interocular difference in spherical equivalent. Relationships were assessed using logistic regression models adjusted for key sociodemographic factors. RESULTS: Among 33,496 isometropic children (51.2% male, mean age 3.2 ± 1.5 years), the prevalences of emmetropia, myopia, and hyperopia were 26.7% (n = 8944), 4.2% (n = 1397), and 69.1% (n = 23,155), respectively. Over a mean follow-up period of 5.1 ± 2.4 years, 2593 children (7.7%) were diagnosed with anisometropia. Adjusted odds ratios (ORs) for anisometropia gradually increased with baseline refractive error severity, reaching 13.90 (5.32-36.34) in severe myopia and 4.19 (3.42-5.15) in severe hyperopia. This pattern was also evident in cylindrical anisometropia, where ORs increased with greater baseline astigmatism, peaking at 12.10 (9.19-15.92) in children with high astigmatism (≥3 D). Associations remained consistent in sensitivity and subgroup analyses including across both sexes and when using a stricter anisometropia criterion. CONCLUSIONS: Children aged 1 to 6 years, initially without anisometropia but showing increasing severity of myopia, hyperopia, or astigmatism, are more likely to develop anisometropia. This underscores the importance of follow-up refractive measurements within this population to promptly diagnose and treat anisometropia and prevent potential visual complications.

Body mass index and visual impairment in Israeli adolescents: A nationwide study.

BACKGROUND: Previous research on the association between body mass index (BMI) and visual impairment (VI) in youth has reported inconsistent findings. We aimed to investigate this association in a national cohort of Israeli adolescents. METHODS: This retrospective, population-based, cross-sectional study included 1 697 060 adolescents (56.4% men; mean age 17 years) who underwent mandatory pre-military service assessments from 1993 to 2017. BMI was classified based on the US age- and sex-matched percentiles. Unilateral or bilateral VI was classified as best-corrected visual acuity (BCVA) worse than 6/9 in either or both eyes, respectively. Sex-stratified regression models adjusted for sociodemographic variables were used to analyse the BMI-VI relationship. RESULTS: Overall, 17 871 (1.05%) and 5148 (0.30%) adolescents had unilateral and bilateral VI, respectively. Compared with high-normal BMI (50th to 85th percentile), adjusted odds ratios (ORs) for unilateral and bilateral VI gradually increased with higher BMI, reaching 1.33 (1.13-1.55) and 1.80 (1.37-2.35) in men with severe obesity, and 1.51 (1.24-1.84) and 1.52 (1.08-2.14) in women with severe obesity, respectively. Men with underweight also had increased ORs for unilateral and bilateral VI (1.23; 1.14-1.33 and 1.59; 1.37-1.84, respectively), a pattern not observed in women (0.96; 0.86-1.07 and 1.02; 0.83-1.25, respectively). Results were maintained when the outcome was restricted to mild VI, as well as in subgroups of adolescents with unimpaired health and those without moderate-to-severe myopia. CONCLUSIONS: Abnormal BMI, and particularly obesity, is associated with increased OR for VI in late adolescence.

Long-Term Disability After Traumatic Spinal Injuries: A Military Retrospective Study.

BACKGROUND: Traumatic spinal injuries (TSI) pose a significant life-long burden, impacting both military and civilian populations. Assessing long-term outcomes is crucial for comprehending the enduring consequences of the initial insult and informing effective prevention and management strategies. Most existing studies have narrowly focused on subsets of traumatic cord injuries, leaving a gap in understanding the broader impact of severe spinal trauma. This study aims to examine severe TSIs in military personnel, who may face unique risk factors and injury patterns, and its association with long-term disability. METHODS: A retrospective cohort study was conducted on all military personnel who suffered traumatic injuries (Injury Severity Score ≥ 9) from 1997 to 2020. Severe spinal injuries were defined using the spinal Abbreviated Injury Scale ≥ 3 (n = 95), and compared to all other injuries as a reference group (n = 1,394). Data were extracted and cross-referenced from three distinct nationwide registries-pre-hospital, admission, and rehabilitation. Logistic regression analysis was used to evaluate the impact of spinal injuries on long-term disabilities (defined as the highest possible disability tier). The study received approval from the institutional review board of the Israel Defense Forces Medical Corps. RESULTS: Motor vehicle accidents and falls were the primary causes of spinal injuries (50.5% and 15.8%, respectively). The median age at injury was 20 years (interquartile range 19-22). Personnel with spinal trauma had a significantly higher prevalence of Injury Severity Score ≥ 25 (46.3% vs. 19.9%, P < .001), longer median hospital stays (11 vs. 8 days, P = .036), and increased intensive care unit admissions (55% vs. 40%, P = .05). The median follow-up duration was 10.9 years (interquartile range 6.7-14.3). Spinal injuries were associated with a more than 10-fold increase in the adjusted odds ratio for severe permanent disability (11.92, 95% CI, 5.95-23.72). CONCLUSION: Upon long-term follow-up, military personnel with severe TSI exhibit a significantly higher prevalence of debilitating disability compared to those with significant non-spinal traumatic injuries. These findings highlight the critical need for targeted prevention strategies and improved management of spinal injuries to reduce long-term disability. Strengths of this study include its extensive follow-up period and the use of multiple nationwide registries. However, the study may be limited by potential discrepancies in identity matching across databases and the reliance on disability claims, which may underrepresent the true prevalence of long-term disability. Future research should explore the efficacy of early interventions and rehabilitation strategies in mitigating long-term disability following spinal injuries. This study underscores the importance of developing evidence-based policies to enhance care for individuals with TSIs.

Rapid Rollout and Initial Uptake of a Booster COVID-19 Vaccine Among Israel Defense Forces Soldiers.

The surge of breakthrough COVID-19 among fully vaccinated individuals has raised the prospects of booster dose administration. In Israel, concerns of waning immunity and dominance of the B.1.617.2 (delta) variant resulted in approval of a third-dose (booster) vaccination for the entire eligible population starting on August 29, 2021. This study aims to evaluate vaccine uptake for booster doses among a population of previously vaccinated individuals during a rapid rollout and to analyze socio-demographic characteristics associated with vaccine uptake. A cross-sectional study among Israel Defense Forces soldiers with high access to booster doses of BNT162b2. Subjects eligible for booster doses were voluntarily vaccinated at three vaccine sites constructed within soldiers' bases. We analyzed associations between subjects' socio-demographic characteristics and booster vaccine uptake at the culmination of vaccine rollout using logistic regression models. 1157 soldiers from an IDF brigade were eligible for third dose vaccination (received second dose > 5-months before rollout), with 978 (84.5%) receiving a third, booster dose during the study's timeframe. Subjects' median age was 20.5 (IQR 19.7-21.5) and 791 (68.4%) were male. Notable socio-demographic characteristics associated with increased vaccine uptake in a multivariable model included increased age (OR 1.16, 95% CI 1.02-1.31), high socio-economic status (OR 2.12, 95% CI 1.25-3.59) and female sex (OR 1.87, 95% CI 1.26-2.74). Below-average cognitive function score was associated with decreased vaccine uptake (OR 0.61, 95% CI 0.39-0.95). This study demonstrates that real-world vaccine hesitancy remains a major obstacle, even among a population previously acceptant to COVID-19 vaccines. Decreased uptake for vaccines may be associated with socio-demographic variables in-spite of high-access vaccine rollouts. Reasons for vaccine hesitancy among previously vaccinated individuals, along with the benefits of population-wide booster administration should be further investigated.

The Definition-Dependent Nature of Myopia Prevalence: A Nationwide Study of 1.5 Million Adolescents.

PURPOSE: The application of myopia definition varies considerably within the literature. The purpose of this study was to examine the relationship between different myopia and high myopia definitions and resultant prevalence estimates. METHODS: A population-based cross-sectional study of 1,588,508 Israeli adolescents assessed for medical fitness before mandatory military service at the age of 17 years between 1993 through 2015. Participants underwent non-cycloplegic autorefraction. Nine definitions of myopia and seven definitions of high myopia were examined. Prevalence estimates for each definition were calculated and compared with the reference definition (right eye spherical equivalent (SE)≤-0.50D and ≤-6.00D for myopia and high myopia, respectively), to yield a rate ratio (RR) across definitions. RESULTS: Applying the right eye SE≤-0.50D reference definition yielded 31.0% myopia prevalence. While some definitions resulted in similar prevalence estimates, using the right eye SE of ≤-0.75D; ≤-1.00D or least minus meridian of ≤-0.75D definitions yielded 28.8%, 26.3%, and 26.9% myopia prevalence, respectively, which corresponded to a 7.1%, 15.1% and 13.4% reduction in myopia RR, respectively. The prevalence of high myopia demonstrated considerable alternations, with a 1.7-fold increase in prevalence for the narrower threshold of SE≤-5.00D compared with SE≤-6.00D reference definition (4.2% and 2.4%, respectively). CONCLUSIONS: The prevalence of myopia and especially high myopia varies between frequently applied definitions, considering diverse thresholds, eye lateralization, and spherical vs. astigmatic refractive components. This variability highlights the pressing need for standardization of myopia definition in ophthalmic research. The results of this study provide crude estimates of a "conversion rate" across data, allowing comparisons between studies that utilize different myopia definitions.

Central Serous Chorioretinopathy Development following Cessation of Terbinafine Treatment.

This report describes a case of central serous chorioretinopathy (CSCR) occurring following cessation of terbinafine treatment. A 51-year-old man presented for a routine ophthalmic examination. He was treated with oral terbinafine for onychomycosis up to 3 months before the presentation. Spectral-domain optical coherence tomography (OCT) showed extrafoveal subretinal fluid in both eyes with small underlying pigment epithelial detachments. There were no additional relevant findings in the patient history or ocular examination. A diagnosis of CSCR was made. After 10 weeks without treatment, OCT demonstrated almost complete resolution of subretinal fluid in both eyes. The exact key ingredients of the perfect storm leading to CSCR in young, healthy individuals are still unknown. Here, we describe, to our knowledge, the first documented case, where the appearance of CSCR was apparently triggered by cessation of antifungal treatment. This unusual case may provoke further research that will bring us closer to understanding the mechanism behind the appearance of CSCR. It may also widen the scope of the routine anamnesis when dealing with patients newly diagnosed with this enigmatic condition.

SARS-CoV-2 Omicron Variant: Clinical Presentation and Occupational Implications in Young and Healthy IDF Soldiers.

INTRODUCTION: To this date, there is little known about the symptoms, their duration, and occupational implications of Coronavirus disease (COVID-19) in the military population. Decisions regarding implementing precaution measures are based on data deriving from the general population. Moreover, the Omicron variant seems to cause a disease with lesser severity than previous variants. We aimed to describe the clinical presentation and estimate the loss of workdays due to mild COVID-19 during an Omicron predominant wave among a young, healthy, and mostly vaccinated military population. MATERIALS AND METHODS: A cross-sectional, survey-based study among IDF soldiers who replied to an online questionnaire following recovery from COVID-19. Data included self-reported vaccination status, symptoms presentation and duration, and service-related sick days. Student's t-test and chi-square test of independence were used to compare differences in continuous and categorical variables, respectively. A binary logistic regression analysis was performed to estimate the odds ratio and 95% CIs for prolonged symptom duration (4 days and above) by participants' characteristics. The IDF medical corps institutional review board approved this study. RESULTS: A total of 199 soldiers, with a mean age of 21.9 years, were included in the study. Upper respiratory tract symptoms, headache, and constitutional symptoms were found to be the most common among symptomatic soldiers. The median reported time for inability to continue the daily routine, including work, was 5 days [Interquartile range (IQR), 0-10]. Median duration of symptoms was 4 days (IQR, 0-10). In addition, women were found to have longer symptomatic disease (odds ratio = 2.34; 95% CI, 1.20-4.52). CONCLUSIONS: Our findings demonstrate that even among a young and fully vaccinated population, COVID-19 caused by the Omicron variant may result in substantial medical leave from military service, compared to common cold or influenza virus infection. Our study sample was relatively small; however, the response rate was high and our results shed light on the yet-to-be fully characterized Omicron variant-related COVID-19. Despite the current common perception of COVID-19 as a self-limiting mild disease with low burden of symptoms, our findings show the potential occupational burden of infection with COVID-19 on military units and their readiness and could be considered when discussing public health restrictions and further steps taken to minimize outbreaks ramifications.

Myopia and BMI: a nationwide study of 1.3 million adolescents.

OBJECTIVE: This study analyzed the association between adolescent BMI and myopia severity. METHODS: This cross-sectional study comprised 1,359,153 adolescents who were medically examined before mandatory military service. Mild-to-moderate and high myopia were defined based on right-eye refractive data. BMI was categorized based on the US age- and sex-matched percentiles. Logistic regression models were applied separately for women and men to estimate odds ratios (ORs) for myopia per BMI category. RESULTS: A total of 318,712 adolescents had mild-to-moderate myopia and 23,569 had high myopia. Compared with low-normal BMI (reference group), adjusted ORs for mild-to-moderate and high myopia increased with increasing BMI status, reaching 1.39 (95% CI: 1.23-1.57) and 1.73 (95% CI: 1.19-2.51) for men with severe obesity, respectively, and 1.19 (95% CI: 1.12-1.27) and 1.38 (95% CI: 1.14-1.65) for women with mild obesity, respectively. ORs for mild-to-moderate and high myopia were also higher in men with underweight (OR = 1.20; 95% CI: 1.18-1.23 and OR = 1.39; 95% CI: 1.30-1.47) and women with underweight (OR = 1.06; 95% CI: 1.03-1.09 and OR = 1.12; 95% CI: 1.04-1.22). The overall size effect was greater for men than women (pinteraction < 0.001), in whom the group with severe obesity did not reach statistical significance. CONCLUSIONS: BMI was associated with myopia in a J-shaped pattern, with the size effect being greater for adolescent men than women. This study indicates that both low BMI and high BMI are associated with mild-to-moderate and severe myopia.