1.) Make sure you read the C/D ratio card completely.

2.) The so-called C/D ratio is the fractional or decimal part of the disc or optic nerve head (ONH) the physiological cup occupies.

The the cup to disc C/D ratio of figure (3) would be judged as (.25) horizontal and (.40) in the vertical dimension or simply recorded as .25/.40 which stands for 25% horizontally and 40% vertically.

3.) Recording: since the cup is not always symmetrical, as indicated above, the horizontal and the vertical dimensions must be recorded.

Example:

The example shows the O.D. And O.S., however, these are understood and do not have to be labeled. The upper is always the right eye and the inferior is always the left eye. Likewise, the upper component of the C/D ratio is understood to be the horizontal and the inferior the vertical.

Example # 2

The cup is not always symmetrical as is illustrated in example # 2 the vertical part of the physiological cup seems to be weaker than the horizontal component and in glaucoma is the part of the cup that changes the most, at least, in the early stages of the disease. There is also another vertical aspect that you should watch for "inferior temporal notching". This is when the physiological cup extends to the disc rim or very near to the rim. The best way to evaluate the C/D ratio is with the slit lamp and a 60D, 90D, 78D or Super Field lenses. This gives you a good stereoscopic and magnified view of the cup and allows you to see if the vessel deflection within the nerve head are indeed part of the cupping. You should indicate in the record that the SLx or SLE: (slit lamp examination) with 90D ©Volk lens is based on vessel deflection.

4.) Location:

The position of a lesion or other findings on the fundus should be indicated by the, clock position, how many disc diameters from the optic disc it is located, and its approximate size in disc diameters.

5.) Venous Pulsation: The presents or lack of venous pulsation should always be documented in the patients record. Venous pulsation may be either spontaneous (SVP), weak, or has to be elicited. If there is no venous pulsation and it cannot be elicited this is a diagnostic finding that needs further investigation. There are at least three conditions that can prevent venous pulsation from being seen or elicited.

A.) Papilledema

B.) High IOP's

C.) Very low blood pressure

6.) Artery vein (A/V) Ration: The A/V ratio is the ratio of the arteries width to the veins and a normal finding would be 2/3 or 4/5. The A/V estimation should be made before the third bifurcation. There are a number of conditions that can alter the normal A/V ratio, but one must pay attention to which of the two have changed. Are the arteries abnormally narrow or are the veins abnormally wide?

A.) Diabetes: the veins are abnormally wide.
B.) Papilledema: the veins are abnormally wide too, but there are usually other signs (i.e., Lack of venous pulsation, elevated nerve head margins, hemorrhages, congested nerve head and lack of physiological cup).

C.) Optic atrophy: depending on the extent; all the vessels may be attenuated or the arteries alone may be abnormally narrow.

7.) Arteriolar Light Reflex: The (ALR) is the ratio of the width of light being reflected off the surface of the artery to the over all width of that artery. As the walls of the artery thickens less light is allowed to pass through the artery, more is reflected back and the arteriolar light reflex becomes larger or variable as is in cases of arteriosclerosis and atherosclerosis.

The Normal ALR is 1/3 or 1/4

8.) Foveal Reflex: The foveal reflex is a very important opthalmoscopic finding and should always be recorded either positively or negatively which ever the case. The reflex is actually located in the vitreous as a result of the shape of the fovea. The fovea acts like a concave mirror which gathers the light from the ophthalmoscope and focuses it slightly in front of the retina as a point of light. Since the retina acts as the area of reference this point of light will move in the opposite direction to the direction you move your ophthalmoscope.

The presents of the foveal light reflex (FLR) must be recorded as either positive or negative and should note the quality of the reflex. If it is easily seen then just (+) FLR is fine, however, if it is dim and hard to see you should record (+) FLR but dim and/or small. If the FLR is not seen it should be recorded as (-) FLR and some comment regarding the appearance of the macula area should be noted. A (-) FLR might be the result of the following: drusens, retinal pigment epithelium (RPE) migration, edema, age related macular degeneration (ARMD) sometime referred to as age related maculopathy (ARM) which might include all the aforementioned conditions.

9.) Hemorrhages:

A.) Blot And Dot: Are the result of bleeding that occurs in the deeper layers of the retina and are spherical in shape. Their size may vary from very small, hardly seen, to rather obvious splash like appearing hemorrhages both being deeper red in color than the retina.

B.) Flame Shaped: These the result of bleeding that occurs very near the surface of the retina in the nerve fiber layer and follows the nerve fibers which gives them their flame like appearance.

C.) Subhyaloidal, Preretinal: these are the result of bleeding that occurs on the surface of the retina and are located between the retina and the hyaloid membrane of the vitreous. The hemorrhage appears as a red pool with a flat top when viewed from the front which is the result of gravity and the blood migrating to the lowest point. (It is not called a boat type hemorrhage.)

Types Of Hemorrhages: