• We examined the effects of topically applied pivalylphenylephrine (PPE) and pivalic acid (PA) on the corneal endothelium of rabbits and the direct effects of PPE and PA on monolayer cultures of bovine corneal endothelium. The PPE-treated corneas without epithelium significantly increased in thickness, whereas no change in thickness was observed in corneas with epithelium intact. The PA did not alter the thickness of corneas with or without epithelium. Although 0.001% PE had no noticeable effect in two hours, 0.01% PPE caused breakdown of intercellular junctions in cultured cells in five minutes. Higher concentrations of PPE caused the cells to detach from the culture dishes within 30 minutes of treatment. Only 1% PA caused cell elongation and loss of intercellular contact after 60 to 90 minutes of exposure; lower concentrations did not effect cultured cells.
Staatz WD, Edelhauser HF, Lehner R, Van Horn DL. Cytotoxicity of Pivalylphenylephrine and Pivalic Acid to Corneal Endothelium. Arch Ophthalmol. 1980;98(7):1279-1282. doi:10.1001/archopht.1980.01020040131021