April 2011
Volume 52, Issue 14
ARVO Annual Meeting Abstract  |   April 2011
Simultaneous versus Sequential Intacs and Cornea Collagen Crosslinking for Keratoconus and Ectasia
Author Affiliations & Notes
  • Peter S. Hersh
    Ophthalmology, Cornea and Laser Eye Institute, Teaneck, New Jersey
  • Kristen L. Fry
    Cornea & Laser Eye Institute, UMDNJ New Jersey Med School, Teaneck, New Jersey
  • Steven A. Greenstein
    Cornea and Laser Eye Institute, Albert Einstein College of Medicine, Teaneck, New Jersey
  • Footnotes
    Commercial Relationships  Peter S. Hersh, None; Kristen L. Fry, None; Steven A. Greenstein, None
  • Footnotes
    Support  Research to Prevent Blindness
Investigative Ophthalmology & Visual Science April 2011, Vol.52, 5197. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      Peter S. Hersh, Kristen L. Fry, Steven A. Greenstein; Simultaneous versus Sequential Intacs and Cornea Collagen Crosslinking for Keratoconus and Ectasia. Invest. Ophthalmol. Vis. Sci. 2011;52(14):5197.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

To investigate the optimum timing of Intacs combined with corneal collagen crosslinking (CXL) (simultaneous vs. sequential) for keratoconus and ectasia.


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.


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.


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 

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.