Outcomes of Collagen Crosslinking in Patients with Keratoconus and Co-Existent Limbal Stem Cell Deficiency.

PURPOSE: To analyse the outcomes of collagen crosslinking (CXL) in eyes with progressive keratoconus (KC) and secondary limbal stem cell deficiency (LSCD) caused by vernal keratoconjunctivitis (VKC).

METHODS

Patients with progressive KC and VKC having co-existent LSCD who underwent CXL from May 2016 to October 2023 were included. Demographic details, clinical and corneal topography data were collected preoperatively, at 1-months, 3-months, 6-months and 1-year. Details of the CXL procedure and early postoperative complications were noted. Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA) and topographic indices including flattest keratometry (K1), steepest keratometry (K2), mean keratometry (Km), maximum keratometry (Kmax) and thinnest corneal thickness (TCT) were noted at 1-year and compared with the preoperative data.

RESULTS

Fifteen eyes of 11 patients were included in the study. Partial LSCD was present in 14 eyes and underwent epithelium-off CXL and 1 eye with total LSCD underwent transepithelial CXL. The mean logarithm of the minimum angle of resolution (logMAR) UCVA pre-CXL was 0.67±0.38 which improved to 0.54±0.32 at 6-months (p=0.05) and 0.65±0.35 logMAR at 1-year post-CXL (p = 0.005). Pre-CXL Km was 53.5±4.77 (median-51.95D) which decreased to post-cxl value of 51.72±3.65 at 6-months (p=0.014) and 52.34±3.83 (median-51.3D) at 1-year (p=0.09). Kmax reduced from 63.41±7.11 (median-63.7D) pre-CXL to 60.65±5.31 (median-59.6) (p=0.05) at 6-months and 61.4±6.01 (median-61.9D) at 1-year post-CXL (p=0.115). Of the 14 eyes that underwent epi-off CXL, 2 eyes (14.28%) had persistent epithelial defects (PEDs), one of which needed amniotic membrane graft (AMG).

CONCLUSION

In our series, most eyes with keratoconus having co-existent LSCD had uncomplicated ocular surface healing post-CXL and remained stable at 1-year with significant improvement in visual acuity. Our study shows that CXL can be successfully performed in cases of Keratoconus with co-existing LSCD without any serious complications.