Background: To investigate whether macular structure could be affected by axial elongation and to determine the association between macular intraretinal thickness and the microstructure of β-zone parapapillary atrophy (PPA) in myopic eyes.
Methods: The study recruited 113 healthy myopic subjects (113 eyes). Images of the macula, subfoveal choroid, and optic nerve head were acquired using spectral-domain optical coherence tomography (SD-OCT). An automatic segmentation algorithm was used to segment the macular images into 7 intraretinal layers. PPA widths with and without Bruch's membrane (PPA+BM and PPA-BM, respectively) were evaluated. Linear regression analysis was performed to evaluate the association between macular intraretinal thickness and axial length and the microstructure of PPA.
Results: An increase in axial length was associated with a decrease in whole macular thickness of the peripheral region and an increase in whole macular thickness of the central region. Thickness alterations of the macular intraretinal layers were most apparent in the peripheral region. A significant correlation was found between PPA-BM width and macular intraretinal layer thickness, whereas no significant correlation was found between PPA+BM width and macular intraretinal layer thickness. Moreover, both PPA+BM and PPA-BM widths significantly correlated with subfoveal choroidal thickness.
Conclusions: Macular intraretinal layer thickness may be affected by PPA-BM width. These findings indicate that the microstructure of PPA should be considered when evaluating the macula in patient with myopia and glaucoma.
Keywords: Axial length; Macular thickness; Myopia; β-Parapapillary atrophy with Bruch’s membrane; β-Parapapillary atrophy without Bruch’s membrane.