Results Of Intracorneal Ring Implantation In Patients With Corneal Ectasia After Laser In Situ Keratomileusis

Department of Ophthalmology of the Faculty of Professional Education of the Russian State Medical University named after N.I. Pirogov, Moscow

From 2016 to 2023 ICR implantation was performed on 42 eye with ectasia after keratomileusis. The corneal tunnel with the specified parameters was formed by a femtosecond laser according to the protocol. On 22 cases 1 segment was implanted in the eye, on 20 cases - 2 segments (Ferrara, Intacs) were implanted. The minimum of pachymetry was 375 micron. In 3 cases the interface under the corneal cap was opened, which did not affect the further course of the surgery. The following parameters were evaluated: the degree of ectasia, the presence of the risk of keratoconus on corneal maps, changes in value of sphere and cyl, changes in UNVA and BCVA, the degree of thinning after keratomileusis in %, the need for spectacle or CL correction.

Stabilization of the ectatic process was achieved in 95% of cases. On 3 eyes crosslinking of corneal collagen was performed in terms of 6-36 months after surgery. The refraction value has changed by sphere to 1,75 – 4,0 D, by the cyl  - 1,5 – 6,75 D. The UNVA changed by an average of 0,3; BCVA by 0,5. In 2 cases, the epithelium grew into the tunnel in the early postoperative period. In 1 case the second segment was placed after 6 months, in 1 eye after 3 years the 140-degree segment was replaced with a ring segment (320 degrees).

ICR implantation is effective in stabilizing the ectatic process, improving refractive indices and visual functions. Changes in all indicators occur within 12-24 months. The best results were achieved in patients who underwent the intervention as early as possible.