Ocular biometrics and uncorrected visual acuity for detecting myopia in Chinese school students

Abstract

The study is to evaluate the performance of ocular biometric measures and uncorrected visual acuity (UCVA) for detecting myopia among Chinese students. Among 5- to 18-year-old Chinese students from two cities of China, trained eye-care professionals performed assessment of ocular biometrics (axial length (AL), corneal curvature radius (CR), anterior chamber depth) under noncycloplegic conditions using NIDEK Optical Biometer AL-Scan, distance visual acuity using retro-illuminated logMAR chart with tumbling-E optotypes, and cycloplegic refractive error using NIDEK autorefractor with administration of 0.5% tropicamide. Spherical equivalent (SER) in diopters (D) was calculated as sphere plus half cylinder, and myopia was defined as SER ≤ − 0.5 D. Performances of ocular biometrics and UCVA (individually and in combination) for detecting myopia were evaluated using sensitivity and specificity, predictive values, and area under ROC curve (AUC) in both development dataset and validation dataset. Among 3436 students (mean age 9.7 years, 51% female), the mean (SD) cycloplegic SER was − 0.20 (2.18) D, and 1269 (36.9%) had myopia. Cycloplegic SER was significantly correlated with AL (Pearson Correlation coefficient r = − 0.82), AL/CR ratio (r = − 0.90), and UCVA (r = 0.79), but was not correlated with CR (r = 0.02, p = 0.15). The AL/CR ratio detected myopia with AUC 0.963 (95% CI 0.957–0.969) and combination with UCVA improved the AUC to 0.976 (95% CI 0.971–0.981). Using age-specific AL/CR cutoff (> 3.00 for age < 10 years, > 3.06 for 10–14 years, > 3.08 for ≥ 15 years) as myopia positive, the sensitivity and specificity were 87.0% (95% CI 84.4–89.6%) and 87.8% (86.0–89.6%), respectively, in the development dataset and 86.4% (95% CI 83.7–89.1%) and 89.4% (95% CI 87.3–91.4%), respectively, in the validation dataset. Combining AL/CR and UCVA (worse than 20/32 for age < 10 years, and 20/25 for ≥ 10 years) provided 91.9% (95% CI 90.4–93.4%) sensitivity and 87.0% (95% CI 85.6–88.4%) specificity, positive value of 80.6% (95% CI 78.5–82.6%) and negative value of 94.8% (95% CI 93.8–95.8%). These results suggest that AL/CR ratio is highly correlated with cycloplegic refractive error and detects myopia with high sensitivity and specificity, AL/CR ratio alone or in combination with UCVA can be used as a tool for myopia screening or for estimating myopia prevalence in large epidemiological studies with limited resources for cycloplegic refraction.

Prevalence of myopia among senior students in Fenghua, Eastern China, before and during the COVID-19 pandemic

“…The refractive data collected for this study were from noncycloplegic autorefraction, because there are difficulties of using cycloplegic in large population health screening, and it is challenging to implement in practice. However, it has been confirmed that there is a high agreement between cycloplegic refraction and noncycloplegic optometry results ( 51 ), the latter of which is adequate and has been recommended for screening in populations such as schools ( 52 , 53 ). Another limitation is the lack of detailed information about reading study time, outdoor activity time, time for extracurricular practical activities and time spent on online courses and digital devices among students in different type of schools before and during the COVID-19 pandemic.…”

Distribution and correlation of refractive parameters in children with different corneal curvatures in southeast China

“…The prevalence rate of high myopia among children in China climbed year by year between 2014 to 2018 [34] , and children with low CC and long AL were much more likely to develop pathological retina changes and thus jeopardize their visual acuity if they were not effectively prevented and controlled [39] . The ocular biometric measures were not affected by accommodation, so it could be obtained from modern biometers objective and reliable results under noncycloplegic conditions [1] . The measurement process of AL was simple, easy to perform, and highly acceptable to patients.…”

“…Li et al [34] observed that the prevalence rate of high myopia defined by AL was higher than that defined by SE, which was evidence that lower CC could mask to some extent the decrease in SE and increase in AL. According to the study [1] , the prevalence rate of myopia in preschool children was low in China as well as in Europe, but increased with age as they entered the school years. Slowing the rate of myopia progression was a central goal of myopiarelated research, but preventing the onset of myopia was even more valuable [35] .…”

“…W orldwide, the incidence of myopia is high and increasing, especially in East Asian countries [1] . According to the survey data of the National Health Commission of the People's Republic of China, the prevalence of myopia in China remained at a high level, with a rising trend [2] .…”

Associations between corneal curvature and other anterior segment biometrics in young myopic adults

“…Myopia is a common ocular health issue with an estimated global prevalence of 28.3%, especially affecting children and young adults in east and south-east Asian countries 1 , 2 . During the development of myopia, ocular biometrics are believed to play crucial roles 3 , 4 . Although the key mechanism of myopia mainly involves elongation of the eyeball and vitreous cavity 5 , changes of anterior segment structures are also suggested to play roles in myopia 6 , 7 .…”