Purpose: Changes in tear protein composition of patients who underwent photorefractive keratectomy (PRK) were analyzed.
Methods: Tear samples were obtained from 23 eyes of 23 patients immediately before PRK and on the fourth postoperative day with glass capillaries. Tear proteins were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Digital image analysis and evaluation of the densitometric data of the electrophoretic separations were done with BioDoc-Analyze.
Results: Analysis of discriminance found a significant difference in the protein patterns (p < 0.001). This type of analysis of the electrophoretic densitographs uses all peak information simultaneously. A significant decrease (p < 0.005) in three of the main protein peaks--lactoferrin, immunoglobulin A heavy chain, and lysozyme--was also found after PRK.
Conclusions: Excimer laser ablation of the cornea has an acute effect on lacrimal gland protein secretion. Changes in tear composition may lead to feelings of dryness and to a decrease in tear film stability postoperatively.