Transepithelial PTK With Intrastromal Corneal Ring Segment and Accelerated Corneal CXL for Treatment of Keratoconus
Accelerated corneal collagen crosslinking (a-CXL) using increased optical intensity to shorten treatment time and new intrastromal corneal ring segments (ICRS’s) having larger cross sectional diameter and smaller inner optical zone (Intacs-SK0.5mm) were recently added to our armamentarium. The aim of this study was to evaluate the outcomes of the combined same day transepithelial phototherapeutic keratectomy (t-PTK) with Intacs-SK0.5mm insertion and a-CXL treatment in keratoconic patients.
This study included patients with keratoconus undergoing combined same day treatment including t-PTK followed by one ICRS implantation followed by a-CXL. Patients were evaluated for preoperative and postoperative uncorrected distance visual acuity (UDVA), spectacle-corrected distance visual acuity (CDVA), manifest refraction, corneal topography and total higher-order aberrations (HOA). Postoperatively, patients were followed at 1 and 4 days (bandage contact lens removal), 1, 3, 6 months, and then yearly. The primary outcomes for this study were measured at 6 months.
Nineteen eyes of twelve patients aged 30.3±11.7 years (range 19-52) were included. There was an improvement in visual acuity with both UDVA and CDVA showing statistically significant change and improving respectively (logMAR) from 0.71±0.4 preoperatively to 0.45±0.3 (p=0.007) postoperatively and from 0.28±0.2 to 0.16±0.1 (p=0.016). Postoperative values of refractive cylinder along with spherical equivalent (SE) were statistically significantly lower than preoperative values (p=0.046). Postoperative corneal flattening was noted with statistically significant change in maximal simK, minimal simK and mean simK (p≤0.001) and significant reduction of steepest K (p=0.014). The total HOA was statistically significantly reduced from 5.7±1.7µm preoperatively to 3.8±1.7µm postoperatively (p<0.001). There were no intraoperative or postoperative complications in study group.
Our study shows that t-PTK combined with one ICRS and a-CXL performed sequentially on the same day in keratoconic patients improves visual acuity, decreases keratometry readings and reduces total HOAs.