To the Editor.
—The article by Krupin et al, which appeared in the October issue of the Archives (92:312, 1974), presents data purporting to demonstrate that substantial quantities of dexamethasone sodium phosphate penetrate into the cornea and anterior chamber following its topical administration to the eye. The authors point out that their results differ from the data obtained in our laboratories. Krupin et al attribute these differences in experimental results to the presumed greater sensitivity of their system. We feel that the differences cannot be explained so lightly and that the discrepancies merit further discussion.Krupin et al question the sensitivity of our method and its ability to detect radioactive corticosteroid of the specific activity used in our experiments. They imply that radioactive steroids with a specific activity of less than 10 microcuries/mg cannot produce measurable drug levels in the eye. However, these authors appear to have ignored the difference
Leibowitz HM, Kupferman A. Ocular Penetration in Rabbits of Topically Applied Dexamethasone. Arch Ophthalmol. 1975;93(4):315-317. doi:10.1001/archopht.1975.01010020325011