Table 2 Ocular parameter definitions

Central corneal thickness (CCT)

Distance between the two parallel hyperechoic / hyperintense lines representing the corneal epithelium and basement membrane on the outside and Descemet’s membrane and the corneal endothelium on the inside, in the mid-sagittal plane, along the axis of the globe [26].

Anterior chamber depth (ACD)

Distance between the central anterior corneal epithelium to the anterior lens capsule, along the axis of the globe [27].

Aqueous depth (AQD)

Distance between the corneal endothelium and the anterior surface of the lens, along the axis of the globe [27].

Anteroposterior Lens Diameter (APLD)

Distance between the anterior and posterior capsule of the lens, at the widest point, in the sagittal plane.

Mediolateral Lens Diameter (MLLD)

Distance between the equators of the lens, at the widest point, in the dorsal plane.

Dorsoventral Lens Diameter (DVLD)

Distance between the equators of the lens, at the widest point, in the sagittal plane.

Vitreous chamber depth (VCD)

Distance between the posterior lens capsule and the innermost surface of the retina, along the axis of the globe, in the sagittal plane.

Anteroposterior depth of the eye globe including the scleroretinal rim (APDSRR)

Distance between the central anterior corneal epithelium to the outermost surface of the sclera, along the axis of the globe, in the sagittal plane [3].

Anteroposterior depth of the eye globe excluding the scleroretinal rim (APD)

Distance between the central anterior corneal epithelium to the innermost surface of the retina, along the axis of the globe, in the sagittal plane [3].

Optic Nerve Sheath Diameter (ONSD)

Width of the optic nerve sheath, measured approx. 3mm caudal to the optic disc (dorsal plane) [28].

Optic Nerve Diameter (OND)

Width of the optic nerve, measured approx. 3mm caudal to the optic disc (dorsal plane, T2-SPAIR images)