Refractive errors and visual impairment among children and adolescents in southernmost China

Anterior chamber and angle characteristics in Chinese children (6-11 years old) with different refractive status using swept-source optical coherence tomography

BACKGROUND

The anatomic structure of the anterior chamber (AC) helps to explain differences in refractive status in school-aged children and is closely associated with primary angle closure (PAC). The aim of this study was to quantify and analyze the anterior chamber and angle (ACA) characteristics in Chinese children with different refractive status by swept-source optical coherence tomography (SS-OCT).

METHODS

In a cross-sectional observational study, 383 children from two primary schools in Shandong Province, China, underwent a complete ophthalmic examination. First, the anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) were evaluated automatically using a CASIA2 imaging device. AOD and TISA were measured at 500, 750 μm nasal (N1 and N2, respectively), and temporal (T1 and T2, respectively) to the scleral spur (SS). Cycloplegic refraction and axial length (AL) were then measured. According to spherical equivalent refraction (SER), the children were assigned to hyperopic (SER > 0.50D), emmetropic (-0.50D < SER ≤ 0.50D), and myopic groups (SER ≤ -0.50D).

RESULTS

Out of the 383 children, 349 healthy children (160 girls) with a mean age of 8.23 ± 1.06 years (range: 6-11 years) were included. The mean SER and AL were - 0.10 ± 1.57D and 23.44 ± 0.95 mm, respectively. The mean ACD and ACW were 3.17 ± 0.24 mm and 11.69 ± 0.43 mm. The mean AOD were 0.72 ± 0.25, 0.63 ± 0.22 mm at N1, T1, and 0.98 ± 0.30, 0.84 ± 0.27 mm at N2, T2. The mean TISA were 0.24 ± 0.09, 0.22 ± 0.09mm2 at N1, T1, and 0.46 ± 0.16, 0.40 ± 0.14mm2 at N2, T2. The myopic group had the deepest AC and the widest angle. Compared with boys, girls had shorter AL, shallower ACD, narrower ACW, and ACA (all p < 0.05). By Pearson's correlation analysis, SER was negatively associated with ACD, AOD, and TISA. AL was positively associated with ACD, ACW, AOD, and TISA. In the multiple regression analysis, AOD and TISA were associated with deeper ACD, narrower ACW, and longer AL.

CONCLUSION

In primary school students, the myopic eyes have deeper AC and wider angle. ACD, ACW, AOD, and TISA all increase with axial elongation. ACA is highly correlated with deeper ACD.

Status of Visual Impairment among Children with Special Needs in Rural China

INTRODUCTION

Previous studies have reported a high prevalence of visual defects in children with special needs. However, routine ocular examinations for these children in rural areas of China are lacking. This study aimed to evaluate the status of visual impairment (VI) in children at special education schools in rural China.

METHODS

A total of 316 students from two special schools in Zunyi city, Guizhou province, were enrolled. Full ophthalmic examinations were performed, and gene-sequencing services were offered to potential patients.

RESULTS

The mean age of the 316 participants was 12.27 ± 3.49 years and 75 showed abnormal ophthalmic manifestations on slit-lamp examination. Visual acuity (VA) was assessed in 232 eyes, and the mean VA (logarithm of the minimum angle of resolution, logMAR) was 0.27 ± 0.34. Whole-exome sequencing identified 19 mutations in these children, which might explain their visual complaints. Children with Down syndrome had a significantly higher prevalence of ocular disorders than those without.

CONCLUSION

VI is common among children at special education schools in rural areas; however, routine screening and effective interventions have not been consistently implemented. Efforts should be made to address this issue in these already disadvantaged children.