Computer analysis of the optic cup in glaucoma

This paper describes two complementary methods for computer analysis of the optic disc in glaucoma. The objective of both techniques is to detect and monitor changes in the optic disc through the use of digital image processing techniques that allow user intervention. In the first method, optic disc photographs from successive years are digitized, scaled and registered (aligned) with each other, and are then displayed in rapid sequence on a television monitor. Changes in the optic cup thus appear as localized movement on the display, while stable regions of the optic cup appear stationary. Both monocular and stereo photographs can be processed by this technique. In the second method, stereo optic disc photographs are digitized and processed by a new, robust, photogrammetric computer algorithm that quantifies optic cup depth information. Together, these two techniques may be valuable for both clinical and research purposes in the detection and monitoring of glaucomatous optic cupping.