[1] Tufts Univ, Sch Med, New England Eye Ctr, Boston, MA 02111 USA
[2] MIT, Dept Elect Engn, Cambridge, MA 02139 USA
[3] MIT, Dept Comp Sci, 77 Massachusetts Ave, Cambridge, MA 02139 USA
[4] MIT, Elect Res Lab, Cambridge, MA 02139 USA
[5] Fed Univ Brazil, Dept Ophthalmol, Sao Paulo, Brazil
[6] Univ Erlangen Nurnberg, Pattern Recognit Lab, D-91054 Erlangen, Germany
[7] Univ Erlangen Nurnberg, SAOT, D-91054 Erlangen, Germany