Macular Sublayer Thickness in Healthy Iranian Children: An Optical Coherence Tomography Study from the...

To establish normative values for macular sublayer thickness in healthy Iranian children using optical coherence tomography (OCT) and to assess the effects of age and gender.

This study was part of the population-based Shiraz pediatric eye study. Of 2400 children aged 6-12 years invited, 480 were randomly selected for optical biometry and macular spectral-domain OCT (SD-OCT) imaging. Finally, 431 OCT scans from children with medium axial length (AL; 21.5-26.5 mm) were analyzed. The OCT device automatically segmented seven retinal sublayers, and their thickness was measured across Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. Thickness in the central 1-mm subfield was assessed by gender and age groups (6-9 vs. 10-12 years), adjusted for AL. Regression analysis examined the impact of age, sex, and AL on retinal sublayer thickness. Only data from the right eye were used.

The mean age of participants was 9.12 ± 1.59 years (range, 6-12), with 254 (58.9%) being girls. The mean AL was 22.91 ± 0.71 mm, and the mean foveal thickness was 258 ± 8 µm. A normative database was created for the total retinal thickness and the seven retinal sublayers across the nine ETDRS subfields. Boys had longer globes (by approximately 0.4 mm; P < 0.001) and thicker foveae (by about 5 µm; P = 0.001) compared to girls. Among the seven sublayers studied, boys had a thicker ganglion cell complex layer (P = 0.014) and outer nuclear layer (ONL; P = 0.012), while girls had a thicker retinal pigment epithelium (RPE; P = 0.029). The inner nuclear layer and outer plexiform layer showed no significant differences (P = 0.075 and P = 0.810, respectively). The mean AL was 22.78 ± 0.68 mm in the 6-9 age group and 23.10 ± 0.72 mm in the 10-12 age group (P < 0.001). The older age group (10-12 years) exhibited thicker ONL (P = 0.009) and RPE (P = 0.002) layers compared to the younger group.

This study provides normative data for macular sublayer thickness in Iranian children aged 6-12 years using Heidelberg SD-OCT. Boys had longer ALs and thicker maculae, while girls had a thicker RPE layer. Older children had longer globes and thicker retinas, mainly due to increased ONL and RPE thickness.