Results at 7years after cross-linking procedure in keratoconic patients.

PURPOSE: Long-term evaluation of functional results based on visual acuity, keratometry, spherical equivalent and refractive cylinder in patients with progressive keratoconus treated with corneal collagen cross-linking (CXL). MATERIALS AND METHODS: We studied a group of 114 eyes of 91 consecutive patients treated from 2006 to 2009 by "Epi-off type" CXL. In the preoperative period, all patients had a complete ophthalmologic examination. The inclusion criteria were: patients aged 15 to 54years, with various stages of keratoconus, with a corneal thickness of at least 400µm at the thinnest point. The exclusion criteria were: patients with a corneal thickness of less than 400µm at the thinnest point, with Vogt's striae or herpetic keratitis, dry eye syndrome or aphakia. The patients were then followed at 1, 3 and 6months, and then every year between 1 and 7years postoperatively. RESULTS: There was a decrease in the minimum K and maximum K, respectively 1.6 and 2.0, at 7years postop. (P<0.05). The cylinder decreased from -4.45 D to -3.50 D at 7 years postop (P<0.05). The spherical equivalent decreased by 1.66 D at 7 years (P<0.05). Uncorrected visual acuity increased from an average of 0.78 to 0.679 log MAR (P<0.05) at 7 years postop. The best-corrected visual acuity increased from a mean of 0.64 to 0.52 log Mar (P<0.05) at 7 years postop. CONCLUSIONS: The results of CXL were stable at 7 years in all patients, consisting of reduction of keratometric values and refraction, and improvement in visual acuity.