Differences in Central and Peripheral Choroidal Thickness among the Subtypes of Age-Related Macular Degeneration in an Asian Population

Age-related macular degeneration (AMD) causes visual impairment in individuals who are >50 years of age. However, no study has investigated AMD when using ultra-wide-field swept-source optical coherence tomography (UWF SS-OCT). We aimed to evaluate central and peripheral choroidal thicknesses using UWF SS-OCT, and to compare these across the AMD subtypes. We included 75 eyes of patients with typical AMD (tAMD), 56 with polypoidal choroidal vasculopathy (PCV), 29 with pachychoroid neovasculopathy (PNV), and 12 with retinal angiomatous proliferation (RAP). To compare choroidal thicknesses in the central and peripheral choroids, we established subfields of <3 mm, <9 mm, and 9-18 mm from the fovea. PNV patients were significantly younger than those with tAMD (p = 0.01). The choroidal thicknesses of PNV were significantly greater than that of tAMD in all subfields (p < 0.01), and choroidal thickness significantly correlated with age and axial length in all subfields (p < 0.05). Even after adjusting for age and axial length, the choroidal thickness in PNV was significantly greater than that in tAMD (p < 0.05). In addition, the ratio of the posterior <9 mm to a peripheral 9-18 mm choroidal thickness in PNV was significantly greater than that in tAMD (p < 0.01). A thickened choroid in PNV was more pronounced in the posterior choroid than in the periphery.