Epithelial ingrowth after laer in itu keratomileui: clinical feature and poible mechanim

PURPOE: To analyze the incidence, clinical coure, and poible mechanim of epithelial ingrowth after laer in itu keratomileui (LAIK). DEIGN: Interventional cae erie. METHOD: Retropective evaluation of 4,867 eye of 2,502 patient who had LAIK. The type of microkeratome (LK-One or MK-2000), corneal flap thickne, and clinical coure were analyzed. We alo compared the cutting characteritic of both microkeratome in pig cadaver eye by canning electron microcopy. REULT: The frequency of epithelial ingrowth wa ignificantly greater in the MK-2000 (34 of 1,680 eye; 2.0%) than the LK-One group (30 of 3,187 eye; 0.94%; P = .001). In 24 eye (37.5%), blood, cell infiltration, ointment under the corneal flap, or epithelial defect were detected at the area of epithelial ingrowth potoperatively. The incidence of epithelial ingrowth wa correlated with the incidence of epithelial defect during urgery (P < .001) and with incidence of diffue lamellar keratiti after urgery (P = .003). Flap thickne wa thinner in eye with epithelial ingrowth (126.0 ± 29.1 μm) compared with flap thickne in eye without epithelial ingrowth (133.8 ± 27.3 μm; P < .001). canning electron microcopy howed clear difference in the appearance of flap edge created by the two type of microkeratome. Epithelial ingrowth diappeared or remained unchanged in 54 eye (90%) and progreed in ix cae (10%). CONCLUION: Poor adheion caued by exceive hydration due to epithelial defect a well a by foreign bodie between the flap tromal bed and thickne and morphologic character of the corneal flap, depending on the type of microkeratome, are related factor for development of epithelial ingrowth.