Anterior chamber and angle characteristics in Chinese children (6-11 years old) with different refractive status
Li Li Zhao1, Xiu Zhen Lu2,3, Guo Dong Tang2,3
1Shandong University of Traditional Chinese Medicine, Jinan, 250014, PR China.
Insights
Myopic children have deeper anterior chambers (AC) and wider angles, with measurements like anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) increasing with axial length. These findings are crucial for understanding refractive status in children.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Optometry
Background:
- Anterior chamber (AC) anatomy influences refractive status and is linked to primary angle closure (PAC).
- Understanding AC and angle (ACA) characteristics in children is vital for refractive error assessment.
Purpose of the Study:
- To quantify and analyze anterior chamber and angle (ACA) characteristics in Chinese children with varying refractive statuses.
- To investigate the relationship between refractive status, axial length, and ACA parameters using swept-source optical coherence tomography (SS-OCT).
Main Methods:
- A cross-sectional study involving 349 healthy Chinese primary school students (ages 6-11).
- Utilized CASIA2 imaging device for automated measurement of anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA).
- Categorized children into hyperopic, emmetropic, and myopic groups based on spherical equivalent refraction (SER) and analyzed correlations with axial length (AL).
Main Results:
- Myopic children exhibited deeper AC and wider angles compared to hyperopic and emmetropic children.
- Anterior chamber depth (ACD), anterior chamber width (ACW), angle-opening distance (AOD), and trabecular-iris space area (TISA) all showed positive correlations with axial length (AL).
- Girls presented with shorter AL, shallower ACD, narrower ACW, and narrower ACA compared to boys.
Conclusions:
- Myopic eyes in primary school students are characterized by deeper anterior chambers and wider angles.
- Axial elongation is associated with increased ACD, ACW, AOD, and TISA.
- Anterior chamber angle (ACA) is strongly correlated with deeper anterior chamber depth (ACD).
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.
