Purpose
To evaluate the visual, topographic, and aberrometric outcomes 12 months after combined transepithelial phototherapotic keratectomy (t-PTK) and corneal collagen crosslinking (CXL) in eyes with progressive keratoconus.
Methods
This is a retrospective case series involving 18 eyes of 15 patients with progressive keratoconus treated with combined t-PTK and CXL. The main outcomes measured at baseline and 12 months after treatment were; uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), spherical equivalent, cylinderical refraction, corneal topographic parameters including Simulated (Sim) K1, Sim-K2, average K, Kmax, steepest point of the anterior surface (AKf), corneal aberrations including secondary astigmatism, trefoil, coma, and spherical aberration.
Results
The mean age of the patients was 26.7±7.5 (13-43) years. The mean baseline UDVA was 0.7±0.4 logMar, while it was improved to 0.5±0.4 logMar after 12 months (p=0.007). The mean CDVA was improved from 0.2±0.2 to 0.1±0.1 logMar (p=0.05). The mean cylinderical refraction and spheric equivalent were decreased from -3.3±1.2 D ,-2.6±1.5 D to 2.4±1.6 D, -2.0±1.6 D respectively (p=0.03, p>0.05 respectively). The mean Sim-K1, K2, average K, apical K, Kmax, and AKf were 46.52±2.25 D, 49.91±1.89 D, 48.14±1.89 D, 55.72±3.65 D, 55.80±3.90 D, and 54.87±2.99 D respectively. They were decreased to 45.64±2.04 D, 49.18±1.99 D, 47.33±1.82 D, 54.60±3.82 D, 53.89±3.39 D, and 53.74±2.27 D respectively (all p<0.05). The mean baseline coma was significantly decreased from -1.2±0.4 µm to -1.0±0.4 µm 12 months after treatment (p=0.004). The mean secondary astigmatism, trefoil, and spherical aberration did not show any significant difference after treatment (all p>0.05). No complications were seen intra and post operatively.
Conclusions
This study found that combined t-PTK and CXL is effective and safe in the treatment of progressive keratoconus through one year of follow up. Combined t-PTK and CXL not only improves the topographic and refractive parameters but also improves the optical quality of the eye in progressive keratoconus.