Fig 1.
Technique used to measure the peripapillary choroidal thickness (ppCT).
Optical coherence tomographic image (left) and fundus photograph (right) showing the eight circumpapillary sites where the ppCT was measured. To determine the zero coordinate of the circumpapillary circle, a line was drawn from the fovea to the center of the optic disc. The intersection of this line with the circumpapillary circle was designated as the zero coordinate and the temporal site. The other 7 sites were set at 45° intervals from the zero coordinate. The papillo-macular position (PMP) angle was determined in the fundus photographs as the angle form by a horizontal line and the foveal-optic disc line (yellow double arrows). N, nasal; SN, superonasal; S, superior; ST, superotemporal; T, temporal; IT, inferotemporal; I, inferior; IN, inferonasal.
Table 1.
Demographic information of the participants.
Fig 2.
Means ± standard deviations of the ppCT in eight locations.
N, nasal; SN, superonasal; S, superior; ST, superotemporal; T, temporal; IT, inferotemporal; I, inferior; IN, inferonasal.
Fig 3.
Spearman’s coefficients of correlation and standardized coefficients of multiple regression for the PMP, axial length, optic disc tilt, and the ppCT.
Sectors that are significantly correlated are shown in gray. ppCT, peripapillary choroidal thickness; PMP, papillo-macular-position; N, nasal; SN, superonasal; S, superior; ST, superotemporal; T, temporal; IT, inferotemporal; I, inferior; IN, inferonasal sectors.
Fig 4.
Relationship between ppCT and optic disc tilt.
A proportional enlargement of the eyeball does not affect the optic disc tilt, but an excessive enlargement and subclinical posterior staphyloma will increase the optic disc tilt and stretch the temporal side of the optic disc like a conus.