Purpose
The aim was to evaluate the efficacy of intrastromal corneal rings using femtosecond laser depending on the patient’s topography for the correction of keratoconus.
Patients and methods
This was a prospective interventional study. A total of 33 eyes of thirty-one patients with keratoconus, with mean age 26.85±6.59 years, were included in the study. Fourteen cases were male and 19 were female. Intrastromal corneal ring segments, Kerarings, were implanted for keratoconus correction after corneal tunnel creation with the aid of femtosecond laser (Fs200).
Results
The mean age of the studied patients was 26.85±6.59 years. The mean uncorrected visual acuity before and after the procedure was 0.78±0.38 and 0.24±0.19, respectively. The mean BCVA before and after the procedure was 0.19±0.12 and 0.12±0.10, respectively. There was statistically significant difference between preoperative and postoperative mean sphere, cylinder, and spherical equivalent (<0.001). There was significant decrease in the maximum value and an increase in the center value leading to a decrease in the mean maximum –center value from −6.05±3.42 preoperatively to −2.23±2.38 postoperatively. There was also significant decrease in the aberration coefficient value.
Conclusion
Kerarings in eyes with keratoconus improved postoperative topographic characteristics and visual acuity. Nomograms for intrastromal corneal ring segment insertion based on preoperative topography in addition to refraction are suggested, rather than relying primarily on refraction.