Abstract
Purpose :
Corneal cross-linking has been established as an effective therapy to prevent progression of keratoconus. Accelerated trans-epithelial cross-linking (ATE-CXL) has been developed with the merit that it is a shorter time procedure without corneal epithelial removal and thinner cornea (≧380μm) can be the indication. In the present study, we compared efficacy and safety of ATE-CXL for keratoconus between thinner and thicker than 380μm.
Methods :
Thirty-four eyes of 27 patients, who underwent ATE-CXL (30mW/cm2, 3min) with completion of 24 months follow-up, were enrolled. The eyes were divided into two groups: Group1,10 eyes of 8 patients with thinnest cornea thickness (TCT) <380um; Group 2, 24eyes of 19 patients with TCT≧380um. Hypotonic solution was administrated to Group1 until corneal thickness increased more than 380um at the intraoperative measurements before UV-A irradiation.
We measured uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), maximum and average keratometric values (K-max, Ave-K), central corneal thickness (CCT), TCT by anterior segment OCT and corneal endothelial cell density (ECD) by specular microscopy. The changes from baseline to 24 months after surgery between the two groups were compared. Linear mixed model was used for statistic. P<0.05 was set as statistical significance.
Results :
K-max at baseline and 24 months in Group 1 was 68.9±8.1 D, 61.1±6.1 D. That in Group 2 was 54.5±6.5, 54.8±7.5. The changes of K-max and Ave-K from baseline to 24 months in Group1 (ΔK-max: -7.8±7.7 D, ΔAve-K: -4.3±6.1 D) were significantly smaller than those in Group 2 (ΔK-max: 0.2±3.0 D, ΔAve-K: 0.6±2.7 D) (p<0.001 and p=0.01, respectively), whereas the changes from baseline and 24 months after surgery in UCVA, BCVA, CCT, TCT and ECD did not show statistical differences between the groups.
Conclusions :
ATE-CXL is not only an effective and safe treatment for keratoconus patients with corneal thickness more than 380µm but also for corneas thinner than 380µm. The effect of reducing keratometric values was stronger for the group of thinner corneas.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.