Assessment of epithelial integrity and cell viability in epithelial flaps prepared with the epi-LASIK procedure

Abstract

Most basal cells in epithelial flaps prepared with different epikeratome devices were dead.

Effect of Flap Removal in Myopic Epi-LASIK Surgery on Visual Rehabilitation and Postoperative Pain: A Prospective Intraindividual Study

“…Second, Tanioka et al [18] found that most basal cells in epithelial flaps were dead, which conflicts with the histological findings reported by Pallikaris et al [13]. Tanioka et al [18] postulated that most basal cells in epithelial flaps are not viable, and that this dead basal cell layer collapses during the immediate postoperative period (POD 1–2) to be replaced by migration and proliferation of adjoining healthy basal cells.…”

“…It has recently been concluded that most of the epithelial cells were morphologically normal, with minor degeneration of cells after formation of an epithelial flap [20]. Some reports noted that although the corneal epithelium appeared to be normal immediately after surgery, on POD 1 it showed fewer basal cells and did not firmly adhere to the underlying stromal bed [17,18]. …”

“…Tanioka et al [18] postulated that most basal cells in epithelial flaps are not viable, and that this dead basal cell layer collapses during the immediate postoperative period (POD 1–2) to be replaced by migration and proliferation of adjoining healthy basal cells. Partial apoptosis or necrosis of the epithelial flap may therefore interfere with rapid and smooth re-epithelialization during the early postoperative period.…”

“…Theoretically, epithelial flaps should be associated with less postoperative pain, faster visual recovery, and less corneal haze [15,16] and should control corneal wound healing, by acting as a mechanical barrier between the tear film and ablated stroma [11]. The opposite results have recently been reported: postoperative epithelial damage such as reduction of the basal cells leads to a delay in visual recovery and increase in pain [17,18]. …”

Comparative evaluation of ‘flap on’ and ‘flap off’ techniques of Epi-LASIK in low-to-moderate myopia

“…[7][8][9][10] It has been proposed that the presence of the flap reduces postoperative pain and development of corneal haze, though this has not been confirmed in clinical studies. 11,12 It has also been debated that the presence of epithelial cells in the flap may actually hinder the migratory phase of epithelial regeneration and delay the visual recovery.…”