Abstract
Purpose :
Although the relationship between axial myopia and decreased choroidal thickness (ChT) is well-established in adults, there have been varying reports regarding this relationship in children. Most studies report choroidal thinning in children with axial myopia, although one study has reported increased ChT in Indian children, and none quantify the decrease in ChT with degree of axial length (AXL) elongation. Similarly, studies of the relationship between retinal thinning and increased AXL in children have varying reports of no association, decreased retinal thickness, and delayed retinal thinning which only occurs after choroidal thinning. We report the association of subfoveal ChT and central macular thickness (CMT) with AXL in a cohort of myopic children in Singapore.
Methods :
The PROM-Kids cohort included children aged 7-16 years presenting to a myopia clinic in Singapore. Children were reviewed at baseline with measurements of cycloplegic refraction, AXL, and height. Data including age, gender, race, parental myopia, and myopia treatment at baseline were obtained through the medical record and questionnaire. Optical coherence tomography (OCT) was performed and auto-segmentation of CMT and ChT completed with the manufacturer algorithm. The right eye was chosen for analysis. Stepwise multivariate regression was performed to find associations between CMT and ChT with risk factors of age, gender, race, parental myopia, AXL, spherical equivalent, height, and myopia treatment at baseline.
Results :
695 patients were included. Subfoveal ChT had a significant negative relationship with AXL when controlled for the variables listed above (β=-9.75, 95% CI -17.15 to -2.34, p=0.01). CMT had a statistically significant positive relationship with male gender (β=6.06, 95% CI 3.10-9.02, p<0.001), axial length (β=1.99, 95% CI 0.47 to 3.51, p=0.01), and baseline myopia treatment with glasses (β=19.15, 95% CI 3.85-34.46, p=0.01).
Conclusions :
In our cohort, we were able to replicate and quantify the relationship between increased AXL and thinner subfoveal ChT, with ~10 μm decrease in ChT per mm of axial elongation after controlling for confounding variables. We also demonstrate a small positive relationship between CMT and AXL, perhaps lending credence to the previously suggested hypothesis that ChT decreases before any macular thinning during myopic progression in children.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.