Presence and distribution of hyaluronan in human corneas after phototherapeutic keratectomy

Purpose: To evaluate the reactive hyaluronan (HA) formation in the human cornea following excimer laser surgery. Methods: Fourteen patients underwent phototherapeutic keratectomy in order to remove corneal opacifications caused by a range of diseases. A penetrating corneal transplantation was performed between 6 and 44 months later because of unsatisfactory visual outcome. The corneal buttons were fixed in 4% formaldehyde containing 1% cetylpyridine chloride. The histological sections were stained for the presence of hyaluronan. Results: Hyaluronan was found in the subepithelial region of the ablated area in thirteen out of fourteen human corneal specimens. It was present as long as 44 months after surgery and it is found despite of topical steroid treatment postoperatively. Conclusion: The human cornea commonly reacts to excimer laser surgery by the formation of hyaluronan.