Corneal collagen crosslinking using riboflavin and ultraviolet-A light for keratoconus: one-year analysis using Scheimpflug imaging.

ABSTRACT

PURPOSE: To evaluate changes in corneal curvature, corneal elevation, corneal thickness, lens density, and foveal thickness after corneal collagen crosslinking with riboflavin and ultraviolet-A (UVA) light in eyes with progressive keratoconus. SETTING: Grewal Eye Institute, Chandigarh, India. METHODS: Subjective refraction, best corrected visual acuity (BCVA), Scheimpflug imaging, and optical coherence tomography were performed preoperatively and 1 week, 1, 3, and 6 months, and 1 year after crosslinking. RESULTS: There were no significant differences (P > 0.05) in mean values between preoperatively and 1 year postoperatively, respectively, in BCVA (0.22 +/- 0.10 and 0.20 +/- 0.10), spherical equivalent (-6.30 +/- 4.50 diopters (D) and -4.90 +/- 3.50 D), or cylinder vector (1.58 x 7( degrees ) +/- 3.8 D and 1.41 x 24( degrees ) +/- 3.5 D). There was no significant difference in mean measurements between preoperatively and 1 year postoperatively, respectively, for central corneal thickness (458.9 +/- 40 microm and 455.2 +/- 48.6 microm), anterior corneal curvature (50.6 +/- 7.4 D and 51.5 +/- 3.6 D), posterior corneal curvature (-7.7 +/- 1.2 D and -7.4 +/- 1.1 D), apex anterior (P = .9), posterior corneal elevation (P = .7), lens density (P = .33), or foveal thickness (175.7 +/- 35.6 microm and 146.4 +/- 8.5 microm; P = .1). CONCLUSIONS: Stable BCVA, spherical equivalent, anterior and posterior corneal curvatures, and corneal elevation 1 year after crosslinking indicate that keratoconus did not progress. Unchanged lens density and foveal thickness suggest that the lens and macula were not affected after UVA exposure during crosslinking.