Pain is not typically present in<unk> , and aside from vision loss, no symptoms accompany the condition. However, in rare cases,<unk>  may present with sudden onset vision loss and excruciating eye pain, which occurs if the thinning of the cornea leads to perforation. While<unk>  usually affects both eyes, some unilateral cases have been reported.<unk>  is characterized by bilateral thinning (ectasia) in the inferior and peripheral region of the cornea. The distribution of the<unk>  is crescent or arcuate shaped. The cornea just above the region of thinning is of normal thickness, and may protrude anteriorly, which creates an irregular astigmatism. This is described as a "beer belly" appearance since the greatest protrusion occurs below the horizontal midline (unlike keratoconus). Normally,<unk>  does not present with vascularization of the cornea, scarring, or any deposits of lipid.
Pellucid marginal degeneration
Keratoconus
Optic disc drusen
Posterior cortical atrophy
Vitreomacular adhesion
Geographic atrophy
Enlarged vestibular aqueduct
Choroidal neovascularization