Corneal Cross-Linking in Young Patients with Documented Progressive Keratoconus
In the following prospective, interventional case series, researchers reported refractive, topographic, aberrometric and tomographic outcomes 24 months after corneal cross-linking (CXL) in patients up to 18 years of age with progressive keratoconus.
A total of 40 eyes underwent riboflavin-ultraviolet A-induced CXL. Researchers evaluated uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), sphere and cylinder, topography, aberrometry, tomography, and endothelial cell counts at baseline and at 1, 3, 6, 12 and 24 months.
Mean logarithm of the minimum angle of resolution (logMAR) baseline UCVA and BSCVA were 0.79 ± 0.21 and 0.39 ± 0.10, respectively. According to the researchers, mean UCVA and BSCVA at 2 years were 0.58 ± 0.18 and 0.20 ± 0.09, respectively. They noted that the improvement in UCVA and BSCVA was significant throughout the postoperative follow-up (p < .05) and that mean spherical equivalent refraction showed a significant decrease of 1.57 D at 24 months (p = .02). They also determined that mean baseline simulated keratometry was 46.32 D in the flattest meridian and 51.48 D in the steepest meridian; at 2 years, the values were 45.30 D (p = .04) and 50.21 D (p = .07), respectively. For a 3-mm pupil, researchers found that there was a significant reduction (p < .05) in whole eye (total), corneal, higher-order, and astigmatic wavefront aberrations at 24 months. They observed a significant difference (p < .05) in total coma and total spherical aberration 2 years after CXL. Moreover, mean baseline pupil center pachymetry decreased significantly (p = .04) at 6 months, but recovered by 12 months and remained stable thereafter through the 2-year follow-up. Endothelial cell counts did not change significantly (p = .32).
In conclusion, CXL improved UCVA and BSCVA in the study patients, most likely by significantly reducing corneal asymmetry and corneal as well as total wavefront aberrations.