Macular thickness and volume of myopic eyes measured using spectral-domain optical coherence tomography

Purpose: The aim was to evaluate macular thickness and volume of young myopic eyes measured using Cirrus HD spectral-domain optical coherence tomography (Cirrus HD-OCT; Carl Zeiss Meditec, Dublin, CA, USA). Methods: Three hundred and thirty-six eyes of 336 healthy young subjects (aged 19 to 25) with various degrees of refractive error and axial length were recruited. Average macular thickness, foveal thickness, inner/outer macular thickness and macular volume were measured using Cirrus HD-OCT. The association between refractive error/axial length and retinal thickness/volume was analysed. Results: The mean average macular thickness, foveal thickness, inner/outer macular thickness and macular volume were 280.7 ± 10.9μm, 258.1 ± 18.4μm, 320.6 ± 12.7/277.3 ± 12.3μm and 10.1 ± 0.4mm³, respectively. Average macular thickness, inner/outer macular thickness and macular volume decreased and foveal thickness increased as the degree of myopia/axial length increased (p-values less than 0.01). The correlation between axial length and macular measurements remained significant when refractive error was controlled (p ≤ 0.017); however, when axial length was controlled, the association between refractive error and macular thickness/volume was no more significant (p ≥ 0.084). Conclusions: In healthy young myopic eyes, thinner macular thickness, lower macular volume and thicker foveal thickness were associated with longer axial length.