Evaluation of optic disc parameters, circumpapillary retinal nerve fiber layer (cpRNFL) and ganglion cell complex (GCC) in refractive error using SS-OCT: Magnification-corrected analysis

Objective

To observe and analyze the characteristics of optic disc parameters, circumpapillary retinal nerve fiber layer (cpRNFL), and macular ganglion cell complex (GCC) thickness in children and adolescents aged 4–17 years with refractive errors using magnification-corrected swept-source optical coherence tomography (SS-OCT).

Methods

This cross-sectional study included 286 refractive error subjects (286 eyes) aged 4–17 years. The participants were divided into three groups based on spherical equivalent (SE):non-myopia group (-0.5D < SE < +2.0D, 77eyes), low myopia group (-3.0D < SE ≤ -0.5D, 164 eyes), and moderate-to-high myopia group (SE ≤ -3.0D, 45 eyes). SS-OCT was used to evaluate optic disc parameters, cpRNFL and macular GCC thickness, with magnification correction applied to adjust these parameters. Multivariable linear regression was performed to analyze the correlation between optic disc parameters, cpRNFL and macular GCC thickness with age, gender, intraocular pressure (IOP), axial length (AL), keratometry (K), and anterior chamber depth (ACD) before and after magnification correction.

Results

The mean age of the participants was 9.64 ± 2.62 years. After magnification correction, the mean cpRNFL, macular GCC thickness, optic disc area, and rim area were 116.87 ± 11.13 μm, 115.90 ± 6.77 μm, 2.04± 0.58 mm², and 1.32 ± 0.50 mm², respectively. Multivariable linear regression models, adjusted for age, gender, and other ocular parameters, revealed the following findings, before magnification correction, the mean cpRNFL thickness was positively correlated with SE (β = 1.33) and negatively correlated with AL (β = -3.60, both P < 0.05),after magnification correction, no significant correlations were found between cpRNFL thickness and SE or AL (both P > 0.05).For macular GCC thickness, both before and after magnification correction, a positive correlation with SE (β range:0.677 to 1.011) and a negative correlation with AL (β range:2.667to -1.929) were observed (both P < 0.05).For optic disc area and rim area, no significant correlations with SE or AL were observed before magnification correction. However, after magnification correction, both optic disc area and rim area were negatively correlated with SE (β = -0.058 and -0.057, respectively) and positively correlated with AL (β = 0.169and 0.182, both P < 0.05).

Conclusion

In the children and adolescents, after magnification correction, macular GCC thickness demonstrated a negative correlation with increasing myopic degree and AL elongation, while optic disc and rim areas showed positive correlations. However, no significant correlation was observed in cpRNFL thickness. Given that ocular development and remodeling are still ongoing in children and adolescents, interpretation of disc-related parameters and macular GCC thickness requires careful consideration of the effects of magnification correction, AL, and SE.