Posters

Phototherapeutic keratectomy (PTK) guided topography ablation as treatment for corneal irregular astigmatism

Poster Details

First Author: A.Cano-Ortiz SPAIN

Co Author(s):    A. Villarrubia   L. Leon-Ibanez                 

Abstract Details

Purpose:

To show the functional, refractive and topography results in cases of low corrected distance visual acuity (CDVA) or cases with good CDVA but altered quality of vision, both produced because of irregular astigmatism as a result of a corneal scar (9 cases), numular keratitis (4 cases), corneal haze post-PRK (1 case), penetrating keratoplasty (PK) (1 case) or complicated laser in-situ keratomileusis (LASIK) (1 case).

Setting:

Instituto de Oftalmolog�Ã�­a La Arruzafa. C�Ã�³rdoba. Spain.

Methods:

16 eyes of 16 patients were treated for corneal irregular astigmatism. In all cases, we used WaveLight�Â�® Allegretto-400 Eye-Q Excimer Laser with Gaussian beam profile linked to WaveLight�Â�® Topolyzer�â�„�¢ VARIO Diagnostic Device (Alcon Laboratories, Ft. Worth, TX). 60 microns transepithelial ablation in PTK mode was performed, followed by the PTK guided ablation with the information from Topolyzer that take as references 22,000 elevation points to generate high-resolution corneal images. In 4 cases, we added a third ablation trying to adjust a previous refractive error. Finally, we applied 0,02% mitomycin-C during 12 seconds over the corneal surface.

Results:

We measured preoperatively and postoperatively (1, 3 and 6 months) the uncorrected distance visual acuity (UCDVA), the CDVA, refractive and topography astigmatism as well as refractive spherical equivalent. The mean preoperatively UCDVA and CDVA was 0,36 (0,15-0,9) and 0,49 (0,1-0,95) respectively. Preoperatively, the mean visual acuity with gas permeable contact lens was 0,65 (0,2-1,2) and the deeper limit of a scar was 300 microns measured with corneal tomography. The mean six months postoperatively UCDVA and CDVA was 0,76 (0,4-0,95) and 0,86 (0,4-1,2) respectively. In all cases we could find an improvement in the topography profile.

Conclusions:

PTK guided ablation with WaveLight�Â�® Allegretto-400 Eye-Q Excimer Laser linked to WaveLight�Â�® Topolyzer�â�„�¢ VARIO Diagnostic Device is a safe and effective treatment in cases of irregular astigmatism, even if a deep scar is found preoperatively. Patients should be informed that the best UCDVA and the best CDVA is not achieved until the sixth month after the surgery.

Financial Disclosure:

NONE