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> or =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<3.50 D) and significant spherical myopia (>-1.75) predict better outcome.