How to get segmented OPTIC DISC from retinal image?

1. How do you calculate the size of an optic disc?
2. How do you examine an optic disc?
3. What is CD ratio in eye test?

How do you calculate the size of an optic disc?

To do this, I use the 78- or 90-D lens to measure the vertical and horizontal diameters of the optic disc with the slit beam. I then multiply the diameters by correction factors (1.1 for the Volk 78 D and 1.3 for the Volk 90 D) to get an estimated disc size.

How do you examine an optic disc?

The optic nerve is examined at the slit lamp by using special lenses, usually with NO contact with the eye. The optic nerve or optic disc may also be evaluated by using an instrument known as the Direct Ophthalmoscope. The examiner views inside the eye by coming close to the patient with a portable device.

What is CD ratio in eye test?

The cup-to-disc ratio (often notated CDR) is a measurement used in ophthalmology and optometry to assess the progression of glaucoma. The optic disc is the anatomical location of the eye's "blind spot", the area where the optic nerve leave and blood vessels enter the retina.