OBJECTIVE To present a case of a complicated intracorneal ring segment (ICRS) implantation procedure in a patient with keratoconus, who experienced significant visual improvement, although the ICRS implantation had to be aborted. METHODS A 25-year-old female patient with keratoconus underwent femtosecond laser-assisted ICRS implantation in her right eye (OD) for improving visual acuity. RESULTS The procedure had to be aborted, because ICRS implantation was not possible. Anterior segment imaging 1 month after the procedure showed full-thickness corneal incision with corneal microperforation. However, patient's visual acuity improved significantly due to amelioration of the keratometric findings. Keratometric and visual improvement was preserved at 6 months postoperatively. CONCLUSIONS Our case report shows that femtosecond laser-assisted full-thickness corneal incision on the astigmatic axis combined with the intracorneal tunnel creation resulted unexpectedly in keratometric and visual improvement in this keratoconus patient, even without the implantation of the ICRS.