Corneal cross-linking for keratoconus: Evaluation of the retina and choroid

Purpose: To investigate the possible structural changes of the central choroid and retina after collagen cross-linking (CXL) in patients with progressive keratoconus (KCN). Methods: Twenty-five eyes of 25 patients were included in this study. Patients underwent enhanced depth imaging optical coherence tomography (EDI-OCT) before and 1 month after CXL. The values for central macular thickness (CMT), subfoveal choroidal thickness (CHT), and choroidal volume (CHV) were evaluated. Results: CMT before and after CXL was 263.24 +/- 16.25 mu m and 263.20 +/- 16.51 mu m, respectively (p = 0.98). CHT was 362.08 +/- 36.80 mu m and 367.84 +/- 33.67 mu m before and after CXL, respectively (p = 0.26). CHV was 8.74 +/- 0.33 mm3 and 8.68 +/- 0.36 mm3 before and after CXL, respectively (p = 0.11). There was no significant difference in the corrected distance visual acuity before and after CXL (0.06 +/- 0.05 and 0.05 +/- 0.05 logMAR, respectively, p = 0.65). Conclusion: Central retinal and choroidal thicknesses are not changed after corneal cross- linking.