Long-Term Effect Of Corneal Cross-Linking In A Keratoconus Patients: Does Cone Location Make A Difference?

To enable better comprehension of the long-term effects of accelerated CXL in keratoconus in Saudi Arabian populations, owing to the divergence in keratoconus parameters based on ethnic backgrounds. The other objective of the study entailed the investigation of whether cone location was an important predictor of the outcomes.

The methodology entailed the use of a retrospective single-center study, the various preoperative measurements of visual acuity, corneal astigmatism, keratometry reading, and corneal thickness were collected, the cone location was determined, and the measurements were evaluated and compared at 6 months, 1year, and 2 years interval post CXL. Every step of the present study was founded on the Declaration of Helsinki principles, Institutional Review Board approval was obtained.

A retrospective single-center study, 600 eyes of Saudi Arabia patients treated with accelerated CXL over 2 years were reviewed for the inclusion criteria, out of which 108 had been treated with accelerated CXL. The 108 eyes had been diagnosed with progressive Keratoconus and had undergone CXL. Preoperative measurements of visual acuity, corneal astigmatism, keratometric reading including K1, K2, and Kmax, and corneal thickness were collected in addition to cone location whether central or paracentral. these measurements were evaluated and compared to 6 months,1, and 2  years intervals post-CXL. Further, the central and paracentral cones have been defined by the Pentacam coordinates of maximum keratometry (Kmax).

The findings indicated significant progress with regard to astigmatism measurements and corneal thickness. A comparison of keratometry parameters pre-treatment and post-treatment measurement also disclosed a significant reduction in K1, K2, K max, and pachymetry at the 1-year interval, and at the 2-year interval, with a significant reduction in astigmatism at the 1-year interval only. Nevertheless, there was no significant difference between the central and para-central cones, concerning the diverse parameters at the 1-year interval and the 2-year interval, and the cone location did not have a significant association with either pre-op staging of keratoconus or 2-year progression status.

We found that there were no appreciable differences in CXL results between cone sites. Thus, we have advocated for the use of CXL in individuals with early keratoconus. In a long-term postoperative follow-up period, the study's findings demonstrate that CXL is an effective and safer technology and approach to treating keratoconus. There is a glaring lack of large validation studies and multivariable sub-analysis to establish independent predicting markers, so our study didn't show enough evidence to support the claim that the cone location would have an effect on the efficacy of cross-linking, even though the cone location may or may not have an effect on cxl efficacy.