OPTIC DISC

     John Grigg
     Senior Lecturer
     Department of Ophthalmology, University of Sydney
     johng@eye.usyd.edu.au
 
Understanding optic nerves and the relation of the optic disc cup to glaucoma
 
  • In these exercises (see bottom of page) you will use the drawing tools to outline the optic disc, define the optic disc cup and then calculate the cup to disc ratio.

    You will need the shockwave plugin which is freely downloadable from
    http://sdc.shockwave.com/shockwave/download/

    1. Outline the border of the optic nerve

    2. Outline the optic disc cup

    3. Measure the vertical optic disc diameter and the vertical cup diameter.

    You can draw over the picture as shown below. The changes can be saved by a 'screen dump' to your hard drive (print screen key on Windows, or Control-Shift-3 keys on Macintosh).  

     

    The images below feature examples to illustrate the use of the drawing tools to outline disc features.  


    The blue shading represents the optic disc cup in cross section  

     


    Note peripapillary atrophy around disc  

     


    Disc margin outline in blue

 
DRAWING EXERCISES