Excimer laser corneal ablation is one of the newest techniques to correct postkeratoplasty ametropia. However, laser in situ keratomileusis (LASIK) and surface photorefractive keratectomy (PRK) are limited because of the irregularity of the corneal surface after transplantation. The major disadvantages of LASIK are related to the creation of the lamellar flap. Complications include free, incomplete, irregular, thin, or buttonholed flaps. The high incidence of corneal haze limits the use of PRK in these eyes. Customized ablation is an effective, safe, and stable option to treat irregular astigmatism from various etiologies. A topography-linked Excimer laser is a potentially excellent approach to treat irregular ametropia after keratoplasty.
However, the transplanted corneal epithelium may have different thickness as well as morphology and different patterns of reepithelialization in different areas of the cornea. This may limit the treatment's efficacy because the topography is performed on epithelium that was removed before laser treatment.
The purpose of this study was to evaluate the efficacy, predictability, safety, and stability of customized transepithelial PRK for irregular postkeratoplasty ametropia using the Corneal Interactive Programmed Topographic Ablation (CIPTA) software program (LIGI).
This study comprised 9 patients who had irregular astigmatism from 2.0 to 8.0 diopters (D) after PKP or deep lamellar keratoplasty. The ametropia was corrected with customized transepithelial PRK and the Corneal Interactive Programmed Topographic Ablation (CIPTA) software program (LIGI). Complete ophthalmic examinations were performed before and after surgery.
Ultimately, it was concluded that the combination of topographic data and the customized flying-spot Excimer laser ablation directly on the epithelium was an effective, predictable, safe, and stable option for correcting irregular ametropia after PKP and deep lamellar keratoplasty.