The Planar Dosimetry window displays isodose maps, plaque(s), points of interest, dose profile lines and anatomy on planar cross sections of the eye. The default display is a single pane illustrating a meridian plane bisecting the eye through the center of the active plaque. The meridian planne can be rotated about the AP axis of the eye. A coronal plane that, by default, bisects the eye at the equator may be also be displayed instead of, or in addition to the meridian plane. Controls to rotate the meridian and translate the coronal plane are provided. The planar cross sections may optionally be superimposed over calibrated CT or MR images.
The status line just below the window title bar lists the currently active dose matrix set, surface, matrix size and surface orientation or offset from the equator.
Points of interest (POI) and a user defined prescription (Rx) point may be digitized by enabling the appropriate cursor mode and clicking on the diagram. A ruler tool allows measurement between points. In the example on the right, a chord distance of 4.18 mm between the limbus and the projection onto the outer scleral surface of a suture eyelet is illustrated.
Additional control over 2D isodose plotting is provided in the Plot menu.
The toolbar buttons near the top of the window select the dose matrix set, cursor function, and window layout.
Click the Profiles button to display the dose profiles toolbar. The buttons in the profiles toolbar activate the display of dose profile lines. Dose profile lines and their endpoints can be dragged in a manner analogous to points of interest using the profile (PROF) mouse cursor function.
The nerve-coronal plane location is expressed as an x-offset in mm from the geometric posterior pole. The geometric posterior pole is modeled as being at the inner scleral surface near the fovea. The default scleral thickness is 1.0 mm and the default x-axis offset of the nerve coronal plane is -0.5 mm, centering the nerve-coronal plane in the sclera just posterior to the pole and intersecting the posterior sclera and about 2/3 of the optic nerve.
This is an example of a multiplanar CT reconstruction of the nerve-coronal plane from a 3D axial series with slice thickness of about 0.6 mm. The crosshairs are centered on Plaque simulator's x-axis which passes through the poles. Visible are the rectus muscles and the nerve where it connects to the sclera.
The pane on the left above illustrates the optic disc & nerve azimuth angle on the axial bisecting (aka 9 o'clock) meridian plane. The pane on the right illustrates the optic nerve & disc elevation with respect to the axial bisecting plane in the coronal "nerve plane" located 0.5 mm posterior to the posterior pole as illustrated in the meridian plane pane.