Amniotic membrane transplantation in cases of corneal calcification – follow up with ultrasound biomicroscopy

Ultrasound biomicroscopy as a diagnostic method of corneal degeneration and inflammation

“…Intact epithelium and absence of Bowman layer in the presence of high level of phosphate ions plus an inflammatory response seem to provide the necessary environment for the formation of calcium salts deep within the stroma of the cornea (37,45). Reports have implicated the role of sodium hyaluronate artificial tears, preservatives of eyedrops with phosphate buffers, timolol, retinoic acid and dexamethasone in calcium salt depositions (36,41,42).…”

“…Reports have implicated the role of sodium hyaluronate artificial tears, preservatives of eyedrops with phosphate buffers, timolol, retinoic acid and dexamethasone in calcium salt depositions (36,41,42). Calcium salt deposition can also occur in cases of older patients, decreased tear production, and history with previous herpes virus infection (37,45). The high phosphate concentration leads to a critical increase of the calcium phosphate which together with the breakdown of the tissue barrier, results in the formation of hydroxyapatite deposits (36).…”