CAX is an acronym for the Central AXis of the plaque.

Distances on the CAX can be referenced to the surface of the plaque or to 1 mm from the face of the plaque. When the plaque face is touching the external surface of the sclera, 1 mm in front of the plaque corresponds, approximately, to the location of the retina on the inner surface of the sclera.

In this example the tumor apex is NOT centered over its base in order to clarify the differences between the tumor and plaque axes. The Rx point (yellow) is at the apex of the tumor.

TAX is an acronym for the Tumor AXis. The tumor axis is a line projected from the geometric center of the tumor base through the tumor apex.

Distances on the TAX can be referenced to the external sclera or to 1 mm inset from the external sclera which corresponds, approximately, to the location of the retina.

In this example the tumor apex is NOT centered over its base in order to clarify the differences between the tumor and plaque axes. The Rx point (yellow) is at the apex of the tumor.