Purpose:
To investigate the optimum timing of Intacs combined with corneal collagen crosslinking (CXL) (simultaneous vs. sequential) for keratoconus and ectasia.
Methods:
In a prospective, controlled clinical trial, 31 eyes were randomized to receive Intacs followed by CXL on the same day (Sim group) (15 eyes) or Intacs followed by CXL at 3 months postoperatively (Seq group) (16 eyes). All eyes received symmetric 350 micron Intacs segments (Addition Technology Inc.) and CXL was performed using the UVX system (Peschke Meditrade GmbH). Clinical outcomes including UCVA, BCVA, MRSE, manifest cylinder, and topographic changes (Kmax) using the Pentacam were assessed pre- and postoperatively.
Results:
Thirteen eyes in the Sim group and 7 eyes in the Seq group have data collected to 3 months postoperatively. For Sim eyes, mean UCVA preoperatively was 20/171 and was 20/162 three months postoperatively. Mean BCVA changed from 20/44 preoperatively to 20/47 at 3 months postoperatively. MRSE improved by 0.94D and manifest cylinder remained the unchanged. Topographically, Kmax flattened by 0.91D. All outcomes failed to reach statistical significance. Similarly, Seq eyes, showed no significant changes in UCVA and BCVA which improved from 20/175 to 20/153 and 20/36 to 20/28 at 3 months postoperatively respectively. MRSE improved by 0.68D, but failed to reach statistical significance. Manifest cylinder remained unchanged as well as topographically measured mean Kmax. No significant differences between Sim and Seq cohorts were observed.
Conclusions:
Early results show no differences in Sim compared to Seq Intacs and CXL. Studies suggest that the beneficial effects of CXL are not achieved until 6 months postoperatively which indicate early healing may be confounding results. The optimal method timing of Intacs combined with CXL remains to be elucidated with further follow-up.
Clinical Trial:
http://www.clinicaltrials.gov NCT01112072
Keywords: keratoconus • refractive surgery: other technologies • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials