Clinical outcomes of Bowman-Stromal inlay and corneal collagen crosslinking in contralateral eyes in patients with progressive keratoconus.

PURPOSE: This study aims to report the outcomes of Bowman-Stromal Inlay (BSI) versus corneal collagen crosslinking (CXL) in patients with progressive keratoconus.

METHODS

A retrospective, nonrandomized, interventional, comparative study included 16 patients (n = 32 eyes) with bilateral keratoconus. We analyzed the medical records of patients who had undergone CXL in one eye and BSI in the other, with a minimum follow-up period of 12 months. The medical records were reviewed for outcomes in the form of refractive and tomographic parameters.

RESULTS

A total of 16 patients (32 eyes; 16 CXL, 16 BSI) were included in the study. The mean follow-up period was 30.64 ± 6.14 months in the CXL group and 29.5 ± 5.9 months in the BSI group (range: 6 - 61 months). The visual improvement after surgery was better in the BSI group compared to the CXL group, although the changes were not statistically significant (P (UCVA) = 0.25, P (BCVA) = 0.56). No change was observed in the post-operative Kmax and Kmean values throughout the follow-up period in both groups. The postoperative corneal thickness increased significantly in the BSI group (P < 0.001), while it remained unchanged in the CXL group (P = 0.14). After these initial postoperative changes, the pachymetry remained stable throughout the follow-up period. The BSI group showed a significant improvement in asphericity (P = 0.02) postoperatively, whereas asphericity remained unchanged after CXL (P = 0.89). Topographic astigmatism did not show significant changes in either group after surgery compared to the preoperative values. Neither group had any eyes showing the progression of tomographic parameters.

CONCLUSION

Both CXL and BSI demonstrated efficacy in preventing the progression of ectasia in keratoconus. BSI showed additional benefits of improved asphericity and increased pachymetry compared to CXL.