Corneal Cross-Linking in Keratoconus Using the Standard and Rapid Treatment Protocol: Differences in Demarcation Line and 12-Month Outcomes

摘要

Purpose.: To compare the occurrence rate and depth of the demarcation line and topographical outcome after corneal cross-linking (CXL) for keratoconus using two different treatment protocols. Methods.: A retrospective analysis of 131 eyes with progressive keratoconus treated with CXL using riboflavin and UV-A was performed. Eyes were treated either with the standard Dresden protocol (30 minutes irradiation, 3 mW/cm2, UV-XTM 1000) or a rapid protocol (10 minutes irradiation, 9 mW/cm2, UV-XTM 2000). The presence and depth of the corneal demarcation line was assessed with an anterior segment optical coherence tomography device 1 month after CXL by a masked observer. Corneal topography and tomography was performed at baseline and at 12-month follow-up with Pentacam and the TMS (Topographic Modeling System) device. Results.: In the standard protocol group, 76.5% (62/81) of treated corneas revealed a demarcation line 1 month after CXL, whereas such a demarcation line was observed in only 22% (11/50) of eyes treated with the rapid protocol (P 0.0001). The demarcation line was significantly more superficial in the rapid protocol group (P = 0.004). Corneal topography values between baseline and 12 months after CXL showed a mean change of a??0.76 diopters (D) in Kmax (SD ?± 2.7) in the standard protocol group versus a mean change of +0.72 D in Kmax (SD ?± 1.5) in the rapid protocol (P = 0.007). Conclusions.: The rapid CXL protocol negatively influences the occurrence and depth of the demarcation line 1 month after CXL. Our results show a negative effect on the topographical outcome 1 year after CXL.