Prevalence, Characteristics, and Risk Factors of Moderate or High Hyperopia among Multiethnic Children 6 to 72 Months of Age: A Pooled Analysis of Individual Participant Data.

PURPOSE: To describe the prevalence, ocular characteristics, and associated risk factors of moderate to high hyperopia in early childhood. DESIGN: Pooled analysis of individual participant data from population-based studies. PARTICIPANTS: Six- to 72-month-old multiethnic children who participated in 4 population-based studies of pediatric eye diseases. METHODS: The pooled studies conducted comparable parental interviews and ocular examinations including cycloplegic autorefraction. Presence of hyperopia was defined based on cycloplegic refractive error in the worse eye. Multivariate analyses were performed to evaluate the association of potential risk factors with hyperopia risk. MAIN OUTCOME MEASURES: Prevalence and odds ratios of moderate to high hyperopia (≥4.0 diopters [D]). RESULTS: Cycloplegic refraction was completed in 15 051 children 6 to 72 months of age. Among these children, the overall prevalence of moderate to high hyperopia (≥4.0 D) in the worse eye was 3.2% (95% confidence interval, 2.9%-3.5%), accounting for 15.6% of all hyperopia (≥2.0 D). Among children with moderate to high hyperopia, both eyes were affected in 64.4%, 28.9% showed spherical anisometropia of 1.0 D or more, and 19.5% showed astigmatism of 1.5 D or more. Among 36- to 72-month-old children with moderate to high hyperopia, 17.6% wore glasses. Prevalence of moderate to high hyperopia was slightly less in 12- to 23-month-old children and was relatively stable in children 24 months of age and older. Non-Hispanic and Hispanic white race and ethnicity, family history of strabismus, maternal smoking during pregnancy, and being a participant in the United States studies were associated with a higher risk of moderate to high hyperopia (P < 0.05). CONCLUSIONS: By assembling similarly designed studies, our consortium provided robust estimates of the prevalence of moderate to high hyperopia in the general population and showed that in 6- to 72-month-old children, moderate to high hyperopia is not uncommon and its prevalence does not decrease with age. Risk factors for moderate to high hyperopia differ from those for low to moderate hyperopia (2.0-<4.0 D) in preschool children, with family history of strabismus and maternal smoking during pregnancy more strongly associated with moderate to high hyperopia than low to moderate hyperopia.

An Update of Eye Shape and Myopia.

Myopia is one of the most prevalent eye diseases, and its advanced form, high myopia, is a leading cause of subsequent pathologic myopia, which in turn results in an increased risk of retinal diseases. The prevalence of myopia and high myopia is 28.3% and 4.0% of the global population, respectively, and these numbers are estimated to increase to 49.8% for myopia 9.8% for high myopia by 2050, thus making myopia a severe global socioeconomic problem. The eye shape has been receiving increasing attention as a possible biomarker for myopia. Among several modalities, magnetic resonance imaging (MRI) is currently considered to be the best to measure the 3-dimensional eye shape, and one study using MRI revealed that myopic eyes became much larger in all 3 dimensions, but more so in length (0.35 mm/D) than in height (0.19 mm/D) or in width (0.10 mm/D), which fitted in global and axial elongation models. Another recent study reported that emmetropic retinas were oblate but oblateness decreased with myopia progression. According to a study to evaluate eye shapes in high myopia, although all emmetropic eyes had a blunt shape, almost half of the high myopic eyes had a pointed shape. Multiple lines of evidence suggest that abnormal eye shape changes can cause not only simple myopia but also various ocular complications through biomechanical stretching. In this review, we highlight recent findings on eye shape changes in myopic eyes and abnormal eye shapes in pathologic myopia.

Ocular blood flow evaluation by laser speckle flowgraphy in pediatric patients with anisometropia.

Purpose: To determine the differences and reproducibility of blood flow among hyperopic anisometropic, fellow, and control eyes. Methods: We retrospectively studied 38 eyes of 19 patients with hyperopic anisometropia (8.2 ± 3.0 years of age) and 13 eyes of eight control patients (6.8 ± 1.9 years). We measured the optic nerve head (ONH) and choroidal circulation using laser speckle flowgraphy (LSFG) and analyzed the choroidal mean blur rate (MBR-choroid), MBR-A (mean of all values in ONH), MBR-V (vessel mean), MBR-T (tissue mean), and sample size (sample), which are thought to reflect the ONH area ratio, area ratio of the blood stream (ARBS). We then assessed the coefficient of variation (COV) and intraclass correlation coefficient (ICC) and compared the differences among amblyopic, fellow, and control eyes in MBR, sample, and ARBS. Results: The ONH, MBR-A, MBR-T, and ARBS of amblyopic eyes were significantly higher than those of fellow eyes (P < 0.01, P < 0.05, and P < 0.05, respectively), and control eyes (MBR-A and ARBS, P < 0.05, for both comparisons). The sample-T (size of tissue component) in amblyopic eyes was significantly smaller than that in fellow and control eyes (P < 0.05). Blood flow in the choroid did not differ significantly between the eyes. The COVs of the MBR, sample, and ARBS were all ≤10%. All ICCs were ≥0.7. The COVs of pulse waveform parameter fluctuation, blowout score (BOS), blowout time (BOT), and resistivity index (RI) in the ONH and choroid were ≤10%. Conclusion: The MBR value of the LSFG in children exhibited reproducibility. Thus, this method can be used in clinical studies. The MBR values of the ONH in amblyopic eyes were significantly high. It has been suggested that measuring ONH blood flow using LSFG could detect the anisometropic amblyopic eyes.

Risk factors for early-onset high myopia after treatment for retinopathy of prematurity.

PURPOSE: To investigate the prevalence of myopia and high myopia and the risk factors for high myopia in infants at 3 years of age with retinopathy of prematurity (ROP). STUDY DESIGN: Retrospective, observational. METHODS: We retrospectively analyzed all 89 preterm infants (178 eyes) with medical records of ROP between October 2008 and March 2018 at Toho University Medical Center Omori Hospital; these infants had a birth weight of less than 1,500 g and were followed up at least until 3 years of age. Cycloplegic autorefraction was performed to measure refractive outcomes. Multivariate analysis was performed to determine the risk factors for early-onset high myopia at 3 years of age. RESULTS: The prevalence of myopia and high myopia was significantly higher in the treated group (59.7% and 17.9%, respectively) than in the untreated group (19.7% and 0%, respectively) (p<0.001). Spherical equivalent (SE) at age 3 was more myopic in the treatment group (-1.72 ± 3.53 D) than in the untreated group (0.54 ± 1.08 D) (p<0.001). In the sub-analysis of the treatment group, there was a significant correlation between SE at age 3 and the number of laser shots (R2 = 0.36, p<0.001). Multivariate logistic analysis showed that the number of laser shots was an independent risk factor for early onset high myopia (p<0.05). CONCLUSION: The number of laser shots is an independent risk factor for early onset high myopia, and preterm infants who have undergone laser treatment for severe ROP should be considered for early optical correction with cycloplegic refractive examination.

Prevalence of Myopia and Its Associated Factors Among Japanese Preschool Children.

Purpose: To investigate the prevalence of myopia and factors associated with spherical equivalent (SE), axial length (AL), and axial length to corneal radius of curvature (AL/CR) ratio among Japanese preschool children. Study Design: Prospective observational study. Methods: This cross-sectional study evaluated subjects aged 4-6 years from a preschool. Non-cycloplegic autorefraction was measured using the Spot Vision Screener, while AL and corneal radius (CR) were measured using the Myopia Master. Parental myopia and environmental factors were investigated using the myopia-related factor questionnaire. The worse eye with higher myopic SE was chosen for analysis, and multiple linear regression models was performed using AL, SE, and AL/CR ratio as dependent variables. Results: A total of 457 out of 514 participants (239 males, 52.3%) aged 4-6 years (mean 4.77 ± 0.65 years) were included. The mean SE was 0.13 ± 0.63 D, AL was 22.35 ± 0.67 mm, CR was 7.76 ± 0.25 mm, and AL/CR ratio was 2.88 ± 0.72. The overall prevalence of myopia and high myopia were 2.9 and 0.2%, respectively. Multiple regression analysis showed that myopic SE was significantly associated with male sex (ß = -0.14, p = 0.02) and parental myopia (ß = -0.15, p = 0.04). Meanwhile, longer AL was significantly associated with older age (ß = 0.13, p = 0.02), male sex (ß = 0.44, p < 0.001), parental myopia (ß = 0.24, p = 0.01), and screen time (including smartphones, tablets, and computers) (>1 h, ß = 0.14, p = 0.04). A higher AL/CR was significantly associated with older age (ß = 0.02, p < 0.001), male sex (ß = 0.03, p < 0.001), ratio and parental myopia (ß = 0.03, p = 0.02). Conclusion: The prevalence of myopia and high myopia were 2.9 and 0.2%, respectively, among Japanese preschool children in 2021. Longer AL was associated with older age, male sex, parental myopia, and screen time in children aged 4-6 years. Children with a high risk of myopia can be identified early based on parental myopia information for early prevention.

Characteristics of myopic traction maculopathy in myopic Singaporean adults.

PURPOSE: To investigate the characteristics, risk factors and visual impact of myopic traction maculopathy (MTM) among adults with myopia in Singapore. METHODS: We analysed 3316 myopic eyes of adults aged over 40 years who participated in the Singapore Epidemiology of Eye Diseases-2 study. Detailed questionnaires and ophthalmic examinations were conducted. A total of 2913 myopic eyes of 1639 subjects were graded for MTM by spectral-domain optical coherence tomography. MTM is defined as the presence of retinoschisis, lamellar or full-thickness macula hole and foveal retinal detachment. Fundus photographs were graded for myopic macular degeneration (MMD). RESULTS: Of these 2913 myopic eyes, the mean and SD of age was 60.1±8.0 years; the spherical equivalent (SE) was -2.5±2.3 D; and the axial length (AL) was 24.6±1.3 mm. MTM was found in 0.9% of myopic eyes and 7.3% of highly myopic eyes. In the multivariate analysis, myopic SE (p<0.001), longer AL (p<0.001), MMD (p=0.01) and epiretinal traction (p<0.001) were independent risk factors for MTM. MTM was not associated with age (p=0.38). MTM was significantly associated with poorer best-corrected visual acuity (BCVA) (p<0.01). CONCLUSIONS: Our population-based study revealed that MTM was present in 0.9% of myopic eyes and 7.3% of highly myopic eyes. While greater myopic SE, longer AL, MMD and epiretinal traction are risk factors of MTM, age was not related to MTM. MTM has a negative effect on BCVA.

Assessment of the Macular Microvasculature in High Myopes With Swept Source Optical Coherence Tomographic Angiography.

Background: The risk of pathologic myopia (PM) increases with worsening myopia and may be related to retinal microvasculature alterations. To evaluate this, we analyzed the macular microvasculature of myopes with swept source-optical coherence tomographic angiography (SS-OCTA) in adolescent and young adult Singaporeans. Methods: This is a prevalent case-control study including 93 young Chinese from the Strabismus, Amblyopia and Refractive error in Singaporean children (STARS, N = 45) study and the Singapore Cohort Study of Risk Factors for Myopia (SCORM, N = 48) studies. Macular vessel density (VD) measurements were obtained from 3 × 3 mm SS-OCTA scans and independently assessed using ImageJ. These measurements were compared between individuals with non-high myopia [non-HM, N = 40; SE >-5.0 diopter (D)] and HM (SE ≤-5.0D, N = 53). Results: The mean macular VD was 40.9 ± 0.6% and 38.2 ± 0.5% in the non-HM and HM, groups, respectively (p = 0.01 adjusted for age and gender). Mean FAZ area in the superficial layer was 0.22 ± 0.02 mm2 in the HM group, which was smaller compared to non-HM group (0.32 ± 0.03 mm2, p = 0.04). Mean deep FAZ area was similar between the two groups (0.45 ± 0.03 mm2 and 0.48 ± 0.04 mm2 in the HM and non-HM groups, respectively, p = 0.70). Conclusions: VD was lower and superficial FAZ area was smaller, in adolescents and young adults with HM compared to non-HM. These findings require validation in prospective studies to assess their impact on the subsequent development of PM.

Prevalence, risk factors and impact of posterior staphyloma diagnosed from wide-field optical coherence tomography in Singapore adults with high myopia.

PURPOSE: To investigate the prevalence and risk factors of posterior staphyloma using wide-field optical coherence tomography (WF-OCT) in adults with high myopia in Singapore. DESIGN: Population-based cross-sectional study. METHODS: Adults with spherical equivalent (SE) ≤ -5D in either eye at the first visit of Singapore Epidemiology of Eye Diseases study and Singapore Prospective Study Program study were recruited. Posterior staphyloma was diagnosed using WF-OCT (PLEX® Elite9000, Carl Zeiss Meditec). Myopic macular degeneration (MMD), myopic traction maculopathy (MTM) and vision-related quality of life (VRQoL) were assessed using fundus photographs, DRI-Triton OCT (Topcon) and the Impact of Vision Impairment (IVI) questionnaire, respectively. Factors associated with posterior staphyloma were identified with multilevel, multivariable logistic regression. Impact of posterior staphyloma on MMD, MTM and visual function was analysed with multilevel, multivariable logistic regression and linear mixed model, respectively. RESULTS: Among the 225 eyes [mean SE = -6.5 ± 2.2 D, mean axial length (AL) = 26.2 ± 1.5 mm] of 117 participants (mean age = 60.3 ± 7.1 years), posterior staphyloma was detected in 47 (20.9%) eyes of 38 (32.5%) participants. Older age [odds ratio (OR), 1.18; 95% confidence interval (CI), 1.10-1.26], more myopic SE (0.63; 0.51-0.77) and increased AL (2.51; 1.69-3.73) were associated with higher prevalence of posterior staphyloma (all p < 0.001). Adults with posterior staphyloma had higher odds of MMD (2.67; 1.23-5.82; p = 0.013), MTM (3.79; 1.13-12.68; p = 0.031) and worse IVI Reading (ß = -1.44; -2.31 to 0.58; p = 0.001) scores. CONCLUSIONS: About one in three adults with high myopia had posterior staphyloma, which was associated with increased odds of having myopic maculopathy and a detrimental impact on VRQoL.

Optical coherence tomography angiography for the assessment of choroidal vasculature in high myopia.

AIMS: To assess specific layers of the choroid in highly myopic young adults and to examine their associations with levels of myopia. METHODS: We recruited 51 young myopes (n=91 eyes) from the Singapore Cohort of Risk Factors for Myopia cohort. We performed standardised optical coherence tomography (OCT) and OCT angiography imaging and developed a novel segmentation technique assessing choroidal layers' thickness (overall choroidal thickness (CT), medium-vessel choroidal layer (MVCL) thickness, large-vessel choroidal layer (LVCL)) and vasculature (choroidal vessel density (%), choroidal branch area (CBA, %) and mean choroidal vessel width (MCVW, mm)). RESULTS: We found that eyes with extreme myopia (EM) had thinner vascular layers compared with high myopia (HM), that is, LVCL (36.0±1.5 vs 39.2±1.2 µm, p=0.002) and MVCL (185.5±5.7 vs 198.2±4.6 µm, p=0.014). Overall CT was thinnest in the nasal and inferior quadrants in EM (nasal: 157.1±9.6 vs 187.2±8.3 µm, p<0.001; superior: 236.6±11.1 vs 257.0±9.5 µm, p=0.02; temporal: 228.0±10.6 vs 254.3±8.8 µm, p=0.012; and inferior quadrant: 198.7±10.0 vs 239.8±8.3 µm, p=<0.001) when compared with HM. We also observed significantly more vessel branching in eyes with EM as compared with eyes with HM (CBA, 10.2%±0.7% vs 9.95%±0.8%, p=0.018). CONCLUSIONS: The novel segmentation technique and introduced choroidal parameters may serve as new biomarkers to study disease conditions in myopia.

Annual Myopia Progression and Subsequent 2-Year Myopia Progression in Singaporean Children.

Purpose: To investigate the association between 1-year myopia progression and subsequent 2-year myopia progression among myopic children in the Singapore Cohort Study of the Risk Factors for Myopia. Methods: This retrospective analysis included 618 myopic children (329 male), 7 to 9 years of age (mean age, 8.0 ± 0.8) at baseline with at least two annual follow-up visits. Cycloplegic autorefraction was performed at every visit. Receiver operating characteristic (ROC) curves from multiple logistic regressions were derived for future fast 2-year myopia progression. Results: Children with slow progression during the first year (slower than -0.50 diopter [D]/y) had the slowest mean subsequent 2-year myopia progression (-0.41 ± 0.33 D/y), whereas children with fast progression (faster than -1.25 D/y) in year 1 had the fastest mean subsequent 2-year myopia progression (-0.82 ± 0.30 D/y) (P for trend < 0.001). Year 1 myopia progression had the highest area under the curve (AUC) for predicting fast subsequent 2-year myopia progression (AUC = 0.77; 95% confidence interval [CI], 0.73-0.80) compared to baseline spherical equivalent (AUC = 0.70; 95% CI, 0.66-0.74) or age of myopia onset (AUC = 0.66; 95% CI, 0.61-0.70) after adjusting for confounders. Age at baseline alone had an AUC of 0.65 (95% CI, 0.61-0.69). Conclusions: One-year myopia progression and age at baseline were associated with subsequent 2-year myopia progression in children 7 to 9 years of age. Translational Relevance: Myopia progression and age at baseline may be considered by eye care practitioners as two of several factors that may be associated with future myopia progression in children.

Association of Parental Myopia With Higher Risk of Myopia Among Multiethnic Children Before School Age.

Importance: Parental myopia is an important risk factor for preschool myopia in Asian children. Further investigation of the association between parental myopia and early-onset myopia risk in other racial/ethnic groups, such as African American and Hispanic white children, could improve understanding of the etiology and treatment of this condition. Objective: To investigate the association of parental myopia with refractive error and ocular biometry in multiethnic children aged 6 to 72 months. Design, Setting, and Participants: This cohort study pooled data from children in 3 population-based studies with comparable design from the US, Singapore, and Australia. Parental myopia was defined as the use of glasses or contact lenses for distance viewing by the child's biological parent(s). Multivariable regressions were conducted to assess the association of parental myopia. Data were collected from 2003 to 2011 and analyzed from 2017 to 2019. Main Outcomes and Measures: Cycloplegic refraction and prevalence of myopia (spherical equivalent refractive error of≤-0.5 diopters [D]) in the more myopic eye. Results: The analysis cohort included 9793 children, including 4003 Asian, 2201 African American, 1998 Hispanic white, and 1591 non-Hispanic white participants (5106 boys [52.1%]; mean [SD] age, 40.0 [18.9] months). Compared with children without parental myopia, the odds ratios for early-onset myopia were 1.42 (95% CI, 1.20-1.68) for children with 1 parent with myopia, 2.70 (95% CI, 2.19-3.33) for children with 2 parents with myopia, and 3.39 (95% CI, 1.99-5.78) for children with 2 parents with childhood-onset myopia. Even among children without myopia, parental myopia was associated with a greater ratio of axial length to corneal curvature radius (regression coefficient for myopia in both parents, 0.023; P < .001) and more myopic refractive error (regression coefficient for myopia in both parents, -0.20 D; P < .001). Effects of parental myopia were observed in all 4 racial/ethnic groups and across age groups except those younger than 1 year. However, parental myopia was not associated with the age-related trends of refractive error (regression coefficient for children without parental myopeia, 0.08; for children with 2 parents with myopia, 0.04; P = .31 for interaction) and ratio of axial length to corneal curvature radius (regression coefficient for children without parental myopeia, 0.031; for children with 2 parents with myopia, 0.032; P = .89 for interaction) beyond infancy. Conclusions and Relevance: Parental myopia, especially childhood-onset parental myopia, was associated with a greater risk of early-onset myopia in Asian, Hispanic, non-Hispanic white, and African American children. The observed associations of parental myopia in children as early as 1 year of age and in children without myopia suggests that genetic susceptibility may play a more important role in early-onset myopia and that parental myopia may contribute to myopia in children by setting up a more myopic baseline before school age.

MRI of posterior eye shape and its associations with myopia and ethnicity.

PURPOSE: To evaluate posterior eye shape variations across a wide refractive error range using brain MRI in a multiethnic cohort. METHODS: Adult subjects in the multiethnic Singapore Epidemiology of Eye Disease study were included. Spherical equivalent (SE) was measured using subjective refraction, and axial length (AL) was measured using optical biometry. MRI was performed using a 3-Tesla whole body scanner with a 32-channel head coil. The radii and asphericity based on fitting of the posterior two-thirds of the eye (240°) were calculated. The refractive error status was categorised as myopic (SE<-0.5 D) or non-myopic (SE≥-0.5 D). RESULTS: A total of 450 adult participants (mean age 64.2±6.5 years old) were included. Less oblate asphericity was associated with more myopic SE, longer AL and with a refractive error categorisation of myopia (p<0.001 for all). Asphericity values were less oblate in myopic compared with non-myopic eyes (p<0.001). Multivariate analysis showed that Chinese subjects had less oblate eyes than Malay and Indian subjects, especially in non-myopic eyes. CONCLUSIONS: A less oblate posterior eye shape was associated with myopic eyes. Chinese eyes have less oblate shapes than Malay and Indian eyes, especially in non-myopic eyes.

Prevention and Management of Myopia and Myopic Pathology.

Myopia is fast becoming a global public health burden with its increasing prevalence, particularly in developed countries. Globally, the prevalence of myopia and high myopia (HM) is 28.3% and 4.0%, respectively, and these numbers are estimated to increase to 49.8% for myopia and 9.8% for HM by 2050 (myopia defined as -0.50 diopter [D] or less, and HM defined as -5.00 D or less). The burden of myopia is tremendous, as adults with HM are more likely to develop pathologic myopia (PM) changes that can lead to blindness. Accordingly, preventive measures are necessary for each step of myopia progression toward vision loss. Approaches to prevent myopia-related blindness should therefore attempt to prevent or delay the onset of myopia among children by increased outdoor time; retard progression from low/mild myopia to HM, through optical (e.g., defocus incorporated soft contact lens, orthokeratology, and progressive-additional lenses) and pharmacological (e.g., low dose of atropine) interventions; and/or retard progression from HM to PM through medical/surgical treatments (e.g., anti-VEGF therapies, macula buckling, and scleral crosslinking). Recent clinical trials aiming for retarding myopia progression have shown encouraging results. In this article, we highlight recent findings on preventive and early interventional measures to retard myopia, and current and novel treatments for PM.