Eye doctors use optic disc cupping and retinal nerve fiber layer changes to analyze progression of glaucoma. Usually increased optic disc cupping and decreased RNFL thickness are changes that occur slowly over time in uncontrolled glaucoma patients. However, some patients have acute attacks of glaucoma where the internal drainage of the eye becomes suddenly stopped up. This causes an acute and significant rise in eye pressure that can cause permanent damage.
This study determined that these acute "angle-closure" attacks does decrease the nerve fiber layer thickness but does not significantly increase optic nerve cupping.