Intrastromal corneal ring segments implantation with the aid of a femtosecond laser in cases of mild to moderate keratoconus: A 3‐year study

Abstract

AbstractPurpose: To evaluate the 3‐year results of femtosecond assisted intrastromal corneal ring segments (ICRS) implantation for the treatment of mild to moderate keratoconus.Methods: Prospective case series including 4 eyes of 4 consecutive patients with keratoconus.Each patient was implanted with ICRSs according to the preoperative topography and refraction. The segments were implanted in intracorneal pocket created with the FS200 femtosecond laser. Planning of the operation was done based on the nomograms provided by the manufacturer. Patients' follow‐up involved visual acuity measurement, refraction control, clinical examination, corneal topography (Pentacam and Orbscan) and anterior segment OCT. The operation was performed due to patients' unsatisfying spectacle corrected visual acuity and contact lens intolerance.Results: Preoperative average steep keratometry was reduced from 53,3D (range 50.7–55.7D) to 48.6D (range 46.9‐50D) 3 years postoperatively. Preoperative average topographic astigmatism was 5.35D (range 4.2–7.9D) while postoperative was 2.7D (range 0.7–4.3D). Refraction assessment showed reduction of the refractive astigmatism from 3.5D (range 2.0–5.0D) to 2,5D (range 0.5–3.75D) and improvement of spherical equivalent from −5.0D (range − 4.0 to −7.25D) preoperatively to −2.5D (range −1.25 to −3.25D) 3 years postoperatively. Average pre‐op spectacle corrected visual acuity was 4/10, when post‐op visual acuity assessment on Snellen scale showed average improvement by 2 lines (range from 0 to 5 lines).Conclusions: The femtosecond assisted ICRS implantation based on the results of our study, improved all patients' visual acuity, topographic and refractive parameters 3 years postoperatively.