Abstract
Purpose :
We conducted a prospective, longitudinal study to evaluate the refractive, keractometric and biomechical outcomes of the newly developed topography guided crosslinking.
Methods :
17 keratoconic eyes underwent topography guided crosslinking (Avedro Inc., USA). The topography was used to design a patient specific UV beam, which was centered and had peak intensity at the location of the cone. The delivered energy varied from 10 at the center to 3 J/cm2 at the periphery of the UV beam. The maximum treated diameter was 8 mm. Topography was measured with Pentacam (OCULUS Optikgeräte Gmbh, Germany). Corneal deformation was measured with Corvis-ST (OCULUS Optikgeräte Gmbh, Germany). Refractive, keratometric and deformation was measured pre and post (6 months) surgery.
Results :
Mean MRSE reduced by 0.53 ± 0.35D (p = 0.15). Flat and steep axis keratometry, mean keratometry and maximum keratometry also reduced without statistical significance [-0.39 ± 0.21D (p = 0.08), -0.11 ± 0.26D (p = 0.69), -0.25 ± 0.23D (p = 0.30), -0.59 ± 0.59 (p = 0.34), respectively]. Root mean square (RMS) of anterior lower order aberration, higher order aberration and total aberration was -0.67 ± 0.32 (p = 0.06), -0.09 ± 0.07 (p = 0.22), -0.67 ± 0.33 (p = 0.06) was relatively unchanged at 6 months. Similar results were obtained with the RMS of posterior corneal surface. However, mean deformation amplitude reduced significantly by -0.04 ± 0.02 (p = 0.025).
Conclusions :
Clinical outcomes of topography guided crosslinking were similar to published short term outcomes of conventional crosslinking, which is not centered on the cone location. Further study with larger sample size and longer follow-up is needed.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.