open-angle glaucoma vs glaucoma

open-angle glaucoma and glaucoma both are nouns.

Word	Noun	Adjective	Verb	Adverb
open-angle glaucoma	Yes	No	No	No
glaucoma	Yes	No	No	No

As nouns, glaucoma is a hypernym of open-angle glaucoma; that is, glaucoma is a word with a broader meaning than open-angle glaucoma:

open-angle glaucoma: glaucoma caused by blockage of the canal of Schlemm; produces gradual loss of peripheral vision
glaucoma: an eye disease that damages the optic nerve and impairs vision (sometimes progressing to blindness)

open-angle glaucoma (noun)	glaucoma (noun)
glaucoma caused by blockage of the canal of Schlemm; produces gradual loss of peripheral vision	an eye disease that damages the optic nerve and impairs vision (sometimes progressing to blindness)