Effects of specialized laser keratomileusis on the concentration of potassium ions in the lacrimal fluid

: The content of potassium ions in the lacrimal fluid was evaluated before and in various periods after laser specialized keratomileusis (LASIK) in order to determine the scope and terms of therapeutic measures. Seventeen patients with myopia were examined before and after LASIK. Lacrimal production before the operation was evaluated by Schirmer's and Norn's tests. The concentration of K+ ions in the lacrimal fluid was measured on a Reflotron IV biochemical analyzer. Before operation the concentrations of potassium ions were 1.5 times higher than normally in the patients complaining of discomfort. Lacrimal concentration of K+ ions and results of Norn's and Schirmer's tests were in high correlation. After LASIK potassium ion concentrations were increased in all patients and returned to the initial level almost completely within 1 week postoperation. Treatment with artificial tear preparations containing no potassium ions during the early postoperative period is physiological.