Corneal ectasia 6.5 months after small-incision lenticule extraction

Our case involves a 19-year-old patient with forme fruste keratoconus. Small-incision lenticule extraction was performed, and 6.5 months after surgery, corneal ectasia was diagnosed. Preoperatively, the minimum central corneal thickness was 546 μm in the right eye and 542 μm in the left eye; the refractive correction was -6.75 -1.00 × 45 and -6.75 -0.75 × 140, respectively; the lenticular thickness was 137 μm and 135 μm, respectively. At 6.5 months, ectasia was diagnosed based on anterior and posterior surface keratometry of 38.4/39.5 diopters (D) and -6.3/-6.8 D, respectively, in the right eye and 38.6/40.8 D and -7.1/-6.6 D, respectively, in the left eye. The keratometry increased gradually and the corneal thickness decreased after surgery, and these trends continued during the 13-month follow-up. This report documents corneal ectasia as a complication of small-incision lenticule extraction and highlights the importance of preoperative evaluation and the need for long-term follow-up.