to report refractive, topographic and tomographic outcomes 2 years after corneal collagen crosslinking(CCL) in patients with progressive keratoconus

in this prospective study, 76 eyes of 40 patients with progressive keratoconus and a corneal thickness at least 400 microns were enrolled . After baseline examination, crosslinking was done using riboflavin 0.1% and ultraviolet A irradiation (370 nm, 3 mW/cm2) for 30 minutes. Uncorrected visual acuity (UCVA), and best spectacle-corrected visual acuity (BSCVA), manifest refraction spherical equivalent (MRSE) and cylinder, keratometric readings (K) and corneal thickness (CCT) were evaluated at baseline, at 6, 12 and 24 months follow up after CCl.

mean logarithm of the minimum angle of resolution baseline BSCVA and UCVA were 0.16 ±0.14 and 0.47 ±0.01 respectively. At 24 months, mean BSCVA and UCVA were 0.12 ±0.10(P=0.035) and 0.41 ±0.01(P==0.001); the improvements were significant. Changes in MRSE and cylinder were not significant during the two years follow up. At 2 years, mean minmum K, maximum K and Avrage K decreased significantly by 0.75 (P=0.000), 0.97 (P=0.049) and 0.52 D(P=0.000), respectively, compared with baseline. Anterior Best Fit Sphere (BFS) was 7.65 ±0.32 mm, preoperatively; the difference between baseline and 24 months was statistically significant (0.04 mm)(P=0.006). But the mean baseline post BFS did not show significant changes(P=0.459)when compared with 2 years after CCL, which not statistically significant .The CCT decreased significantly by 38 microns after 2 years(P=0.000).

: CCL is an effective treatment for stop the progression of KCN as shown by reduced keratometry and improved vision.