Abstract
Purpose :
Pulsed-light accelerated corneal cross-linking (pa-CXL) theoretically achieves an additional oxygen concentration which allows more singlet oxygen release for crosslinking of collagen molecules rendering it more effective than continuous-light CXL.To evaluate the effectiveness and safety of pa-CXL in patients with progressive keratoconus (KC). Tomographic and refractive changes were analyzed at baseline, 1, 3 and 6 months after treatment.
Methods :
Prospective, comparative, non-randomized, interventional study. Refraction, UDVA, CDVA, and corneal tomography (Pentacam, Occulus, Germany) at baseline, 1, 3, 6 and 12 months were measured. CXL technique: Corneal soaking with riboflavin solution. UV-A radiation: 1 second on, 1 second off (30 mW/cm2 ) x 8 minutes=7.2J/cm2 total energy dose for both techniques.
Results :
A total 60 eyes of which 16 (26.6%) had severe KC (>54D), 23 (38.3%) moderate KC (48-54 D) and 21 (35%) mild KC (<48 D) The preoperative mean UDVA was 0.87±0.49 logMAR, after pa-CXL the mean UDVA was 0.85±0.39 at 6.94±2.28 months follow up (2.6-10.67 months). Preoperative CDVA was 0.36±0.35 logMAR, after pa-CXL the mean CDVA was 0.35±0.28 logMAR. Before treatment the maximum keratometry (Kmax) was 54.19±5.77 D (44.6-69.2 D), after pa-CXL the Kmax was 54.43±6.80 D (45.3-68.8 D). Paquimetry at baseline was 440.86 ±46.90 microns to 435.80±43.46 microns at last follow-up. When comparing transepithelial vs stromal pa-CXL, no statiscally significant differences were found in UDVA (p=0.67), KMax (P=0.39), Km (p=0.27). Statistically significant differences were found in CDVA (p=0.01) and Central corneal thickness (p=0.001).
Conclusions :
Results of pulsed-light accelerated CXL at 6 months were encouraging, although a total of 8 eyes (13.33%) of the treated eyes showed progression (3 eyes (5.0%) stromal pa-CXL, 5 eyes (8.33%) transepithelial pa-CXL). Of the 8 eyes, 6 eyes (75.0 %) had severe KC, 2 eyes (25.0 %) had moderate KC and no eyes (0%) with mild KC progressed; 86.67% of treated eyes remained stable or showed early signs of regression; mild (100%), moderate (91.3%) and severe (62.5%) KC. Transepithelial and stromal pulsed-light accelerated CXL techniques were both safe and effective although CDVA was significantly better (p=0.01) in stromal vs transepithelial pa-CXL.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.