Abstract
Purpose:
To analyse the visual and refractive outcomes of topography-guided photorefractive keratectomy (PRK) to treat irregular astigmatism following penetrating keratoplasty (PK).
Methods:
Retrospective case-series study. After accessing our database, eyes submitted to topography-guided PRK (Allegretto WaveTM Eye-Q, WavelightTM, Erlangen, Germany) with Topography-guided Customized Ablation Treatment software (T-CAT) after PK, were identified and medical records reviewed. Patients with follow-up less than 3 months and history of other ocular comorbidities or interventions were excluded. Pre and postoperative clinical data were collected, namely uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest refraction, topography parameters obtained with Orbscan IIz® system (Bausch & Lomb, Rochester) and endothelial cell density.
Results:
Thirty-one eyes of 30 patients, mean aged 45.03 ± 13.39 years, with mean follow-up of 9.18 ± 8.24 months, were included. There was a significant improvement of UCVA (0.95±0.27 logMAR preoperatively versus 0.38±0.30 logMAR postoperatively, p<0.001) and BCVA (0.25±0.16 and 0.15±0.19 logMAR respectively, p=0.004). At last follow-up, 66.6% of the eyes had gained UCVA lines and 14.8% had lost. Refractive parameters also presented a significant improvement, with the refractive cylinder decreasing from 6.35±2.21 preoperatively to 1.96±1.14 postoperatively (p<0.001) and the spherical equivalent (SE) improving from -3.36±3.68 to -1.11±1.63 diopters, (p=0.002). In the last visit, 53.8% of the eyes presented SE among ± 1diopter. There was no significant decrease in endothelial cell density.
Conclusions:
Topography-guided ablation is an efficient and safe treatment for irregular astigmatism and high ametropia after penetrating keratoplasty. Most patients improved visual acuity and refractive parameters.