Correlation between corneal stromal demarcation line depth and topographic outcomes after two pulsed-light-accelerated crosslinking protocols

摘要

Purpose: To report the visual and topographic outcomes of two pulsed-light-accelerated CXL (A-CXL) protocols at a 12-month follow-up and their correlation with the corneal stromal demarcation line (DL) depth. Patients and methods: Retrospective comparative cohort of patients with documented progressive keratoconus were included. Two epi-off pulsed-light [1s on–1s off] A-CXL protocols were compared: irradiance 30*8 and 45*5:20 (fluence 7.2 J/cmsup2,/sup). UDVA, CDVA, spherical equivalent (SE), topographic astigmatism, Ksubmin/sub, Ksubmax/sub, Ksubm/sub, central corneal thickness (CCT), thinnest pachymetry (TCT) and endothelial cell density (ECD) were measured preoperatively and months 1, 3, 6 and 12 postoperative. Corneal DL was measured 1 month postoperatively using anterior segment optical coherence tomography. Results: Fifty eyes (27 patients): 22 eyes in group A-CXL (30*8), 28 eyes in group A-CXL (45*5:20). Mean age (years) was 19.04±4.71 and 20.32±4.57. DL depth (μm) at month 1 was 200.63±10.01 μm and 184.53±19.68 μm for group A-CXL (30*8) and group A-CXL (45*5:20), respectively ( p 0.001). Significant improvement in CDVA, topographic astigmatism, Ksubmin/sub, Ksubmax/sub and Ksubm/sub was observed in both groups (no significant difference between groups) and no significant changes were observed in CCT, TCT and ECD with regard to baseline. Over 85% of the eyes in both protocols achieved stabilization or improvement in maximum K at the end of the follow-up. No significant correlations between DL and any visual or topographic outcomes were observed at 12 months. Conclusion: No correlation between DL depth and visual or topographic outcomes was observed on either protocol. Although significant improvement on CDVA, topographic astigmatism, Ksubmin/sub, Ksubmax/sub and Ksubm/sub was observed in both groups at 12 months, further research is needed to assure safety and effectiveness at stabilizing keratoconus progression.