Relationship of eye burns with calcifications of the cornea?

Abstract

Eye burns followed by calcifications follow two different major patterns: the corrosive substance contained calcium or the continued therapy was applied with phosphate-buffered eye drops. We present case reports of three different types of eye burns and later therapy resulting in corneal calcification. Corneal calcifications are presumably related to longer-lasting phosphate application. One suspicious mechanism is the low content of calcium ion stabilizing proteins such as hyaluronate or fetuin in treatments for severe eye burns. The exceeding of the solubility product of Ca(2+) and PO(4) (-) results in the precipitation of calcium phosphates. In cases of chronic corneal disturbance, we recommend the elimination of phosphate-buffered medications to prevent corneal calcification.

Changing the composition of buffered eye-drops prevents undesired side effects

“…Nevertheless, Bernauer et al 4 described the development of calcification in conjunction with corneal wounds which have been treated with phosphate-buffered artificial tears in conjunction with corneal wounds. The same effects were observed previously5 during the treatment of corneal burns with phosphate-containing drugs6 and in an experimental eye burn model on rabbit corneas treated with phosphate buffer rinsing. Recent reports4 7 from clinical practice concerning calcified human corneas have finally led to considerable changes in the formulation of artificial tears8 by replacing phosphate with citrate in treatment buffers.…”

Rinsing Therapy of Eye Burns

“…We have found this case and earlier reported it on systematic review in these cases [22]. These ex vivo and clinical results were endorsed by an experimental work done by our group on rabbits being rinsed several times with phosphate buffer [23].…”

“…Mostly, the corneal water content and the corneal electrolyte constitution change after eye burns. This is even more the case if rinsing solutions used in the therapy introduce elements or substances that precipitate into the cornea, as shown for phosphate buffer in dry eyes [20] and later on by our group for phosphate buffer application on burnt eyes [21,22]. The same situation occurs with HF with precipitates of CaCl 2 in case of Calcium gluconate application.…”

Phosphate concentration in ophthalmic corticoid preparations

“…Phosphate buffers, however, play a role in the process of inadvertent corneal calcification [1][2][3][4]12]. Calcification occurs when calcium cations and phosphate anions interact within the tissue to form insoluble crystals.…”