what‘s the mean of ungradable image?

what‘s the mean of ungradable image?  

  By: qjiewang on Jan. 10, 2022, 3:09 a.m.

Dear Organizer: I'm not a experts in glaucoma, so I have a question about "ungradable image". Is it means hard to distinguish or just normal health people?

Re: what‘s the mean of ungradable image?  

  By: kawal211 on Jan. 10, 2022, 10:14 a.m.

ungradable image are poor quality images. so we can't draw any conclusions from those images