Corneal stromal demarcation line determined with anterior segment optical coherence tomography following a very high intensity corneal collagen cross-linking protocol.

PURPOSE: To evaluate corneal stromal demarcation line depth after very high intensity (18 mW/cm) ultraviolet-A irradiation for a 5-minute corneal collagen cross-linking (CXL) protocol with the use of anterior segment optical coherence tomography.

METHODS

This prospective interventional study enrolled 14 patients (18 eyes) with progressive keratoconus who underwent CXL with an ultraviolet-A irradiation intensity of 18 mW/cm for 5 minutes. One month postoperatively, corneal stromal demarcation line depth was measured with the use of anterior segment optical coherence tomography by 2 independent observers. The rate of reepithelialization and endothelial cell density at a 3-month follow-up period were also evaluated.

RESULTS

No intraoperative or postoperative complications were observed in any of the patients. No statistically significant difference between the 2 observers' measurements was observed (P = 0.989). Mean corneal stromal demarcation line depth was 223 ± 32 μm (range, 159-265 μm). The mean endothelial cell density decreased from 2714 ± 174 preoperatively to 2671 ± 192 at 3 months postoperatively; however, this decrease was not statistically significant (P = 0.221).

CONCLUSIONS

Corneal stromal demarcation line depth after a very high intensity 5-minute CXL protocol seems to be shallower than the standard Dresden protocol.