Changes in the Higher Order Ocular Aberrations and Central Corneal Thickness After T-PRK and Fs-LASIK

Abstract

Introduction: Refractive surgery procedures, transepithelial photorefractive keratectomy (T-PRK), and femtosecond laser in situ keratomileusis (Fs-LASIK) are regarded as safe and efficacious methods for correcting myopia and myopic astigmatism. These two methods do not have many differences in results when treating spherical myopia while differences exist in the treatment of astigmatism correction. Vector analysis presents a powerful tool to show the real differences between these two methods regarding high ocular aberrations and central corneal thickness of treated eyes. Aim: The aim of the study is to investigate changes in higher order ocular aberrations (HOAs) and central corneal thickness (CCT) following treatment of myopia and myopic astigmatism above -5.00DS and up to -2.00DC after either T-PRK or Fs-LASIK. Methods: Patients (30 eyes per group) underwent T-PRK (group I) or Fs-LASIK (group II) procedure using the Schwind Amaris 750S laser. HOAs (3mm&5mm pupil) and CCT were measured objectively at pre-, 1,3 & 6 months postop in each case. Results: Key results at 6 months were: i) mean values of trefoil (5mm pupil) were 0.092μm (sd,0.055,95% CI 0.072 to 0.112) & 0.126μm (sd,0.078,95% CI 0.098 to 0.154) in group I, and 0.088μm (sd,0.058,95% CI 0.067 to 0.109) & 0.064μm (sd,0.034,95% CI 0.052 to 0.076) in group II (P=0.001 at 6 months); ii) Changes in CTT (ΔCTT) and best spherical equivalent correction (ΔBSE) was significant in group II (ΔCCT=-26.55[ΔBSE]-14.06,R=0.486,P=0.006) but not in group I (p=0.034). Conclusions: After T-PRK trefoil is worse than Fs-LASIK. The predictability of corneal changes is better following Fs-LASIK.

Comparative Analysis of Corneal Higher-Order Aberrations after Laser-Assisted In Situ Keratomileusis, Photorefractive Keratectomy, and Small Incision Lenticule Extraction with Correlations to Change in Myopic Q-Value and Spherical Equivalent with and without Astigmatism

“…However, despite the statistical significance of PRK's larger impact on oblique trefoil, the clinical implications are potentially limited due to the minor influence of oblique trefoil on overall retinal image quality [16]. Biscevic et al [21] also found that PRK induced greater trefoil changes compared to LASIK. Nonetheless, the unique impact of PRK on vertical coma and oblique trefoil may highlight a specific interaction between the technique and the aberrations.…”

Refractive Management of Surgical-Induced Presbyopia in a Young Patient with Vision-Related Quality of Life Complaints: A Case Report

“…PRK was chosen as the corneal procedure given that the patient had occupational risk for trauma. Furthermore, some studies suggest that PRK induces fewer aberrations than laser in situ keratomileusis (LASIK), which is an important consideration in a patient who already has two IOLs [ 9 , 10 ].…”

Quality of Vision After LASIK, PRK and FemtoLASIK: An Analysis Using the Double Pass Imaging System HD AnalyzerTM®

“…Symptoms related to HOA such as night vision impairment, glare, halos or diplopia are the main responsible for patient dissatisfaction, even when the UDVA is 20/20 or better. [1][2][3][4] Nowadays, with the newly ablation profiles wave-front optimized and wave-front guided, those HOA are much less frequent.…”