Introduction to GCC Map
The GCC map for a normal eye shows a bright circular band surrounding the macula representing a thick GCC from
healthy ganglion cells (figure A). The center of the macula is thinner because there are no ganglion cells in this area, as
demonstrated on page 13. In glaucoma, as the ganglion cells are lost, the GCC complex becomes thinner (figure B).
The GCC thickness values are analyzed and compared to an extensive normative database. This normative database
contains over 300 healthy eyes from various ethnicities with an age range from 18-80. The results are presented in two
maps and a parameter table. The Deviation Map shows the percent loss from normal as determined by the normative
database. The map is color coded where blue and black represent GCC thinning. A 50% loss in this map means that this
patient has a GCC layer that is 50% thinner than normal. All Deviation and Significance Maps have a circular mask in
the center of the macula where the analysis is not possible due to an
absence of ganglion cells in this region.