Keratoconus managed with intacs - One year results

Objectives: To describe the visual outcome of keratoconus managed with Intacs implantation (Addition Technology Inc, Fremont, Calif) and to define criteria that predict good outcome. Methods: This retrospective, nonrandomized, comparative, consecutive case series studied 58 eyes of 43 patients with keratoconus managed by Intacs implantation. The outcome measures were analyzed pre-Intacs and 1 year post-Intacs. Preoperative parameters were correlated with outcome. Main Outcome Measures: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, videokeratography, and patient questionnaires. Results: Intacs were implanted in all eyes with no intraoperative complications. Six eyes underwent additional Intacs surgery. Post-Intacs, the mean +/- SD UCVA improved from less than 20/200 +/- 0.1 line to 20/ 50(-3) +/- 3.1 lines, the mean SD BSCVA was unchanged at 20/32 +/- 2.0 lines, the mean SD spherical equivalent improved from -3.88 +/- 1.64 to -1.04 +/- 1.51 diopters (D), and the mean SD astigmatism improved from 3.34 +/- 2.23 to 1.97 +/- 1.51 D. Twenty-five eyes had a good outcome (UCVA >= 20/40). Multiple regression selected BSCVA, astigmatism, and spherical myopia as the preoperative predictors of outcome. Conclusions: Intacs improve myopia and regular astigmatism in keratoconus. Milder keratoconus (BSCVA > 20/ 32(-2) and astigmatism < 3.50D) and significant spherical myopia (>-1.75) predict better outcome.