Evaluation of the corneal collagen cross-linking demarcation line profile using anterior segment optical coherence...

To evaluate the depth of the stromal demarcation line after corneal collagen cross-linking (CXL) using anterior segment optical coherence tomography.

In this prospective, interventional case series, 23 patients (27 eyes) with progressive keratoconus were enrolled. All patients underwent uneventful CXL treatment. Corneal stromal demarcation line depth was measured centrally, 3 mm temporally, and 3 mm nasally by 2 independent observers using anterior segment optical coherence tomography at 1 month postoperatively in all patients.

Mean depth of the corneal stromal demarcation line measured by the first observer was 310.67 ± 31.04 μm (range, 258-364 μm) centrally, 212.07 ± 24.5 μm (range, 178-279 μm) nasally, and 218.04 ± 21.91 μm (range, 191-261 μm) temporally. Mean depth of the corneal stromal demarcation line measured by the second observer was 308.78 ± 29 μm (range, 262-381 μm) centrally, 211.04 ± 23.93 μm (range, 180-277 μm) nasally, and 217.22 ± 25.51 μm (range, 179-271 μm) temporally. There was a statistically significant difference (P < 0.001) between central and both nasal and temporal depths of the corneal stromal demarcation line (paired samples t test) for both observers. There was no statistically significant difference between nasal and temporal corneal stromal demarcation line depths (paired samples t test, P > 0.05) for each observer.

Mean depth of the corneal stromal demarcation line after CXL treatment is greater centrally in comparison with nasal and temporal depths.