Elschnig Opic Nerve Head Classifications

 TYPE I

FUNNEL

Type (I) optic nerve heads are relatively flat in nature. The cup to disc ratio is usually only zero (0) to (.15 ) in size. The amount of physiological cupping is less than or equal to one (1) diopter in depth.

TYPE II

CYLINDER

Type (II) optic nerve heads are vertical in nature and have a sharp temporal rim. Feeder vessels flow over the cup's rim and down the vertical cup's edge. Bifurcation of the central vessels are visible. The cup to disc ratio can vary greatly from relatively small (.15 ) to large (.6 ) to (.7 ). The amount of physiological cupping is from (1) to (5) diopters in depth.

TYPE III

BOWL

Type (III) optic nerve heads have very little to no sharp temporal cup rim. Feeder vessels follow the gradual slop of the cup. Bifurcation of the central vessels are visible. The cup to disc ratio is again variable from (.1 ) to (.6 ) in size. The amount of physiological cupping is from (1) to (3) diopters in depth.

TYPE IV

NASAL HOOK

Type (IV) optic nerve heads have very little to no sharp temporal cup rim. Feeder vessels follow the gradual slope into the nasal hook. Bifurcation of the central vessels may or may not be seen for they are displace nasally into the nasal hook. Nasal hooks are commonly seen in moderate to high myopic patients. The cup to disc ratio is variable from (.2 ) to (.7 ). The amount of physiological cupping is from (1) to (5) diopters in depth.

TYPE V

BEAN POT

Type (V) optic nerve heads are usually reserved for glaucomatous cupping. Bifurcation of the central vessels may or may not be seen in the base of the cup. All vessels plunge over the rolled rim. The lamina cribrosa is commonly visible with grey dots know as "lamellar dots" are often seen. Lamellar dots, however, are not always diagnostic of glaucoma.