Femtosecond assisted intracorneal segments implantation for mild to moderate keratoconus: long term results

Abstract

PurposeTo describe the 2 year results of femtosecond assisted intracorneal segments implantation for the treatment of mild to moderate keratoconus with the use of a femtosecond laser.MethodsProspective case series including 4 eyes of 4 consecutive patients with keratoconus. Patients where implanted with KC Solutions intrastromal segments (IS). Patients’ assessment included visual acuity measurement, manifest refraction, clinical examination and corneal topography and tomography. IS implantation was scheduled in patients with unsatisfying corrected visual acuity (CDVA) and contact lens intolerance. Planning of the operation was done based on the topography and refraction based on nomogram provided by the IS manufacturer. IS were implanted in intracorneal pocket created with the FS200 femtosecond laser. Comparisons were made between pre‐ to postoperative values with the Wilcoxon signed‐rank test.ResultsPreoperative average steep keratometry was 48.45D (range 45.6 to 51.6), whereas at 2 years postoperatively it was 46.73 (44.8 to 48.7), (p<0.05). Preoperatively corneal astigmatism on average was 4.95D (2 to 9.1) and refractive astigmatism was 3.94D (2 to 9), whereas postoperatively average corneal and refractive astigmatism was 2.75 (1.2 to 6) and 1.87 (range 0,5 to 5) (p<0.05 in both comparisons). CDVA improved in all cases by 1 to 2 lines of Snellen visual acuity. Average spherical equivalent refraction was ‐3.22 (‐1.87 to ‐4.5) preoperatively, and postoperatively it was reduced to ‐1,81 (‐0.50 to ‐3,5) (p<0.05). No statistically significant differences were found between the last and 6th month follow up results.ConclusionsAccording to our pilot long term study, Implantation of KC Solutions intrastromal segments with the aid of a femtosecond laser improved all patients’ topographic and refractive astigmatism, visual acuity and refraction.