Table 1

Anterior segment parameters measured by anterior segment optical coherence tomography and their definitions

ParameterDefinition
Angle opening distance at 500 and 750 µm (AOD500, AOD750)The distance between the posterior corneal surface and the anterior iris surface on a line perpendicular to the trabecular meshwork, 500 and 750 µm from the scleral spur, respectively.
Trabecular iris space area at 500 and 750 µm (TISA500, TISA750)The surface area of a trapezoid with the following boundaries: anteriorly, the angle opening distance at 500 or 750 µm from the scleral spur; posteriorly, a line drawn from the scleral spur perpendicular to the plane of the inner scleral wall to the iris; superiorly, the inner corneoscleral wall and inferiorly, the iris surface.
Anterior chamber depthThe axial distance from the corneal endothelium to the anterior lens surface.
Anterior chamber widthThe distance between the two scleral spurs.
Anterior chamber areaThe cross-sectional area of the anterior chamber bordered by the posterior surface of the cornea, the anterior surface of the iris and the anterior surface of the lens within the pupil.
Iris areaRegion defined as the cross-sectional area of the iris from the scleral spur to the pupil.
Iris curvatureThe perpendicular distance from a line between the most central to the most peripheral points of the iris pigment epithelium to the posterior iris surface at the point of greatest convexity.
Iris thicknessIris thickness at 750 µm from the scleral spur (IT750).
Lens vaultThe perpendicular distance from the anterior pole of the lens to the horizontal line between the scleral spurs.
Pupil diameterThe distance between the pupil edges of the iris.