Clinical Outcomes of Two Symmetrical Kera-rings Implantation in Grade Three Keratoconus; A Retrospective Non-Randomized Study

a retrospective non- randomized controlled clinical study. The study included twenty-three grade 3 keratoconic eyes of twenty-three patients, the keratoconus staging was based on Amsler-Krumeich classification The ICRS surgery was performed with the patient under topical anesthesia. A tunnel channel was created by femtosecond laser using a 60-kHz infrared neodymium glass femtosecond laser at a wavelength of 1053 nm (Abbott Laboratories Inc., Abbott Park, Illinois, USA). Two symmetrical kerarings (Mediphacos Inc., Belo Horizonte, Brazil), were implanted in all cases with 160° arc and 0.25, 0.30 mm according to corneal thickness in implantation site. After surgery, the patients had a full ocular evaluation on days 1, 7, and 14, and again after a month. For a period of 1-year, corneal topography readings were taken quarterly.