Histopathology of epi-LASIK in eyes with virgin corneas and eyes with previously altered corneas

Histopathology of epi-LASIK in eyes with virgin corneas and eyes with previously altered corneas
2007 Nov
Ali€ JL, Rodriguez AE, Mendez MC, Kanellopoulos J.
Vissum-Instituto Oftalmol€gico Alicante, Alicante, Spain. jlalio@vissum.com
J Cataract Refract Surg.

PURPOSE: To perform a histological analysis of free epithelial flaps that were intentionally created with an Epi-K epikeratome (Moria S.A.) during epi-LASIK in eyes with virgin corneas and eyes with previous corneal surgery or keratoconus. SETTING: Vissum-Instituto Oftalmol€gico de Alicante, Alicante, Spain. METHODS: This prospective and consecutive case series comprised 18 free flaps obtained from 18 patients. Twelve patients had virgin corneas, and 6 had altered corneas from previous surgery, trauma, or keratoconus. The flaps were fixed in 4% buffered formaldehyde (pH 7) for posterior histopathological analysis. Serial cuts of each flap were performed, and the sheets were stained with hematoxylin-eosin and periodic acid-Schiff. The main outcome measure was the histopathology of the corneal flaps. RESULTS: All flaps from virgin corneas consisted entirely of epithelium without residual stromal tissue or Bowman's layer. Histopathological analysis of the flaps after epi-LASIK in patients with previously altered corneas showed varying levels of stroma in all cases. CONCLUSION: Epi-LASIK with the Epi-K epikeratome effectively cleaved the epithelium from Bowman's layer in healthy corneas; however, when the integrity of Bowman's layer is compromised, epi-LASIK should be avoided as stromal invasion will likely occur.

PMID: 17964391 [PubMed - indexed for MEDLINE]