Abstract
Purpose::
To evaluate the behavior and morphology of the corneal epithelial structure in the early postoperative period after laser sub-epithelal keratectomy (LASEK) and Epi LASIK procedures by confocal microscopy.
Methods::
Prospective, longitudinal, comparative, non randomized case series at the cornea department of the Fundacion Hospital Nuestra Señora de la Luz; between April 2005 and October 2006. We included patients with an age between 21 to 50 years and with a refractive error less than 6 D of spherical equivalent . Patients were divided in two groups depending on the refractive technique done: Group 1 : Epi LASIK with the Moria Epi-K ; and Group 2 LASEK. Both groups were evaluated with confocal microscopy ( Confoscan 3, Nidek) at 1,4,7,15 and 30 days postoperative. The images obtained were analyzed with the Navis 4.3.1 software. The following variables were noted: Cell density, layer organization, epithelium- stroma interphase. Cell density was calculated in a 0.0192mm2 area . Statistical analysis was carried with t test and chi square.
Results::
By confocal microscopy we observed in the 1st postoperative day, that both groups preserve viable basal cells in the epithelial flap with slightly loss in their morphology, the Epi-LASIK group had a epithelial flap preserving better cell morphology and organization in a single layer. Both groups showed a diminished average cell count that began to recover at the 7th day. Preoperative cell density Group 1: 89.4, Group 2: 93.9. 1st day postoperative cell density Group1:50.6, Group2: 53.8, by 7 day postoperative Group1: 63.9, Group 2: 68.1, by 15 day Group 1: 72.2, Group 2: 73.98, at 30 day postoperative Group 1: 91.3, Group 2: 93.4 , 1 month after surgery both groups reached cell counts at a preoperative value. The layer organization was 62.5% for Group1, 20% Group 2 at the 1st postoperative day, by day 7 Group 1:68%, Group 2: 75%, by day 15 Group 1:100% , Group 2: 85%, by day 30 had 100% of cell layer organization.
Conclusions::
We observed viable cells in the 1st postoperative day in eyes treated with both Epi-LASIK and LASEK. There are no differences in cell count, morphology and cell organization at 1 month after surgery.
Keywords: cornea: epithelium • refractive surgery: comparative studies • microscopy: confocal/tunneling