Posters

Comparative evaluation of laser correction results in induced postkeratoplastic ametropia by LASIK and PRK

Poster Details

First Author: A.Karimova RUSSIA

Co Author(s):    G. Kachalina   I. Mushkova   Y. Kishkin        

Abstract Details

Purpose:

to compare the results of LASIK and PRK methods in an induced refractive error correction after penetrating keratoplasty (PKP)

Setting:

The S. Fyodorov Eye Microsurgery State Institution, Russia

Methods:

we observed 76 eyes (76 patients) with residual ametropy after the PKP in pre- and post-keratorefractive surgery, out of which 46 eyes were operated by the standart LASIK technology - group I, 30 eyes by the transepithelial PRK technology - group II. Examination of the patients included, besides the standard refractive eye examinations, confocal microscopy, keratotopography and optical coherence tomography of anterior segment in the High Resolution Cornea mode.

Results:

after the keratorefractive surgery the spherical component decreased in the group I from -2.67±3.06 D to -0.25±0.61 D, in the group II from -2.66±2.38 D to -1.47±1.43 D. The average value of the cylindrical component also significantly decreased from 4.48±2.72 D to 1.23±1.64 D after the LASIK and from 3.31±1.96 D to 2.56±1.78 D after the PRK (р<0.05). Uncorrected visual acuity compared with preoperative values significantly increased in the group I from 0.12±0.1 to 0.49±0.25, in the group II from 0.1±0.06 to 0.3±0.16. Loss of lines of corrected visual acuity was in no cases. In the group I epithelial defects were appeared during the formation of corneal flap with microkeratome and the removal of the vacuum ring in 8 eyes with changed epithelial cytoarchitectonic and degeneration of Bowman's membrane. There were not complications during the surgery in the group II. The formation of subepithelial fibroplasia was appeared after PRK technology on 6 eyes. The identification of disorders of transparency of the extracellular matrix was determined before surgery in these patients.

Conclusions:

The functional effect of refractive correction after PKP was significantly higher after LASIK surgery as compared to PRK. The change of epithelial cytoarchitectonic and degeneration of Bowman's membrane is contraindication for induced refractive error correction after the PKP by the LASIK. The identification of disorders of transparency of the extracellular matrix is contraindication for the PRK. FINANCIAL INTEREST: NONE