Ethylenediamine tetraacetate: Its Release from Hydrophilic Gel Contact Lenses, Intraocular Penetration and Effect on Calcium in the Cornea after Lime Burns

Abstract

In spite of a standard lime burn technique, the injured rabbit eyes revealed a great variety of corneal damage with totally or partially denuded epithelium and stromal opacities of varying intensity. Irrigation of the eye with water removed more than half of the calcium from the cornea. A further significant decrease of the calcium level was achieved by the action of hydrophilic gel contact lens presoaked with a 1.85% ethylenediamine tetra acetate (EDTA) solution. The lime-burned cornea does not prevent intraocular penetration of EDTA from contact lens fitted on the injured eye. A delay of 1 or 2 h in application of EDTA contact lens after the lime burn and water irrigation of the eye seems to enhance permeation of the chelating agent into the cornea

Final Report on the Safety Assessment of EDTA, Calcium Disodium EDTA, Diammonium EDTA, Dipotassium EDTA, Disodium EDTA, TEA-EDTA, Tetrasodium EDTA, Tripotassium EDTA, Trisodium EDTA, HEDTA, and Trisodium HEDTA

“…Calcium Disodium EDTA is also added to pharmaceuticals to prevent calcium depletion in the body (Budavari 1989). EDTA has been used to treat alkali, particularly lime, burns of the cornea (Praus, Brettschneider, and KrejÏ cṍ 1976). [ 51 Cr]-EDTA has been used since 1966 as a radiotracer for the assessment of glomerular ltration rate (Monteiro et al 1994).…”

Intraocular Penetration of Cysteine from Hydrophilic Gel Contact Lenses through the Intact, Epithelium-Denuded and Lime-Burned Cornea

“…For a successful treatment of some ocular disorders the possibility of drug pene tration from hydrophilic contact lens through the cornea seems to be most important. This fact was studied in our other papers dealing with the applica tion of glucose and sulfate , antibiotics [Brettschneider et al, 1975], and ethylenediaminetetraacetate [Praus et al, 1976], The penetration of a medication is not only a matter of simple diffusion. The epi thelium and endothelium are relatively impermeable to electrolytes, but are readily penetrated by fat-soluble substances.…”

“…The diameter of denuded cornea surface was about 10 mm. The lime burn of the rabbit eye was produced as described elsewhere [Praus et al, 1976]. Contact lenses were put onto the cornea of the rabbit after local anesthesia with a drop of Novesine and left on the eye for various time intervals.…”