Diffuse Lamellar Keratitis Following Epithelial Defect by In vivo Confocal Microscopy

Abstract

Abstract: : Purpose: To examine the inflammatory reaction in postLASIK eyes with acute or late onset DLK due to per- or postoperative epithelial defect. Methods: Six consecutive patients developed a stage 1-3 DLK after a LASIK operation. Six corneas of five patients were examined by in vivo confocal microscope (IVCM). IVCM on conjunctival venules was performed on 2/6 DLK patients and 4 controls to quantitate leukocyte rolling and extravasation. Three patients had peroperative epithelial erosion. Idiopathic epithelial detachment occurred in one patient 9 days postLASIK and in one patient twice: 7 and 19 months after the procedure. The sixth patient developed DLK 11 months postLASIK after a traumatic epithelial erosion. All cases led to DLK within 1 to 4 days. IVCM was performed 1 to 8 days after the onset of the epithelial defect. Five patients, who underwent uneventful LASIK operation served as controls for the corneal IVCM. Results: Neither LASIK operation nor DLK induced inflammatory reaction in the conjunctival vessels. Two of the four patients that were examined 0-1 days after the onset of DLK expressed with small objects, possible inflammatory cells (diameter 6-10 µm) in the interface. One patient showed bright, approx. 13µm objects in the interface one day after the onset of DLK, whereas the other three cases (examined 1-7 days after the onset of DLK) presented only with keratocyte activation and increased extracellular matrix light reflection. Control patients showed only mild keratocyte activation on day 5. Conclusions: LASIK operation, neither with nor without DLK induced inflammatory reaction to conjunctival vessels. Consequently, DLK related to an epithelial defect does not always lead to leukocyte infiltration in the LASIK interface. We postulate that the clinical findings originate from epithelial-stromal or inflammatory cell-stromal cell interaction leading to keratocyte activation. Thus lifting and cleaning of the flap may not always be needed.

Keywords: refractive surgery: complications • refractive surgery: LASIK • microscopy: confocal/tunneling