cup:disc ratio

cup:disc ra·ti·o

(kŭp disk rā'shē-ō)
The ratio between the diameter of the cupped or depressed central zone of the optic disc and the diameter of the entire disc; normally lower than 1:3, it is increased in glaucoma.
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
References in periodicals archive ?
DISC, Cup size, Color of the disc, Cup:Disc ratio, Cup disc asymmetry between two eyes, Blurring of the disc margins, Hemorrhage over disc, Tortuosity of vein, Venous pulsation-in normal eye venous pulsation is present, if it is absent and not appear on pressing the globe it is indication of papilledema.
Diagnosis of normal fundus (n = 167), diabetic retinopathy (n = 180), and abnormal cup:disc ratio (n = 104) was made by a senior ophthalmologist, and then, the retinal images were classified by two ophthalmologist who were blinded to each other's findings.
New agreement in assessing vertical cup:disc ratio using 78D lens with slit lamp eyepiece measuring graticule.
* cup:disc ratio: usually up to 0.4 (the C/D ratio indicates the diameter of the cup expressed as a fraction of the diameter of the disc)