[Limbal and perilimbal changes in wearers of HEMA lenses]

Incompatibility of HEMA contact lenses leads to changes in the conjunctiva and cornea which frequently appear in the region of the corneal limbus. From the limbus toward the sclera one can differentiate four stages according to the clinical picture: (1) enlargement of the pericorneal capillary network; (2) pronounced pericorneal injection right to the rim of the contact lens; (3) border-like edema in the area actually in contact with the lens; (4) additional haemorrhage in this area. From the limbus toward the cornea three typical changes occur: (1) peripheral edema of the cornea; (2) neovascularization of the cornea; (3) pannus formation.