<unk>  is an idiopathic, non-inflammatory condition. The thinning of the corneas may approach 20% of normal thickness. There may be an increase in the number of mucopolysaccharides in the corneal stroma. The Bowman's layer of the cornea may be absent, irregular, or have ruptured areas.
Pellucid marginal degeneration
Keratoconus
Optic disc drusen
Posterior cortical atrophy
Vitreomacular adhesion
Geographic atrophy
Enlarged vestibular aqueduct
Choroidal neovascularization