Purpose: To evaluate the depth of the stromal demarcation line after corneal collagen cross-linking (CXL) using anterior segment optical coherence tomography.
Methods: 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.
Results: 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.
Conclusions: Mean depth of the corneal stromal demarcation line after CXL treatment is greater centrally in comparison with nasal and temporal depths.