ESCRS - PO0718 - New Incision Pattern In Femtosecond Penetrating Keratoplasty + Polymer Device - Prevention Of Postkeratoplastic Ametropia?

New Incision Pattern In Femtosecond Penetrating Keratoplasty + Polymer Device - Prevention Of Postkeratoplastic Ametropia?

Published 2023 - 41st Congress of the ESCRS

Reference: PO0718 | Type: Free paper | DOI: 10.82333/8rmr-j998

Authors: Svetlana Izmailova 1 , Valeriia Suchkova 1 , Mariam Taevere 2 , Artem Ciganov 1 , Lana Arutyunyan* 1

1Anterior Segment Transplant and Optical Reconstructive Surgery,S. Fyodorov Eye Microsurgery Federal State Institution,Moscow,Russian Federation, 2Clinical and functional diagnostics,S. Fyodorov Eye Microsurgery Federal State Institution,Moscow,Russian Federation

Purpose

To develop a new algorithm of a femtosecond laser work for penetrating keratoplasty, which would allow reliable placement of a polymer device and reduce the likelihood of developing postkeratoplastic ametropia.

Setting

The study was carried out on the basis of S. Fyodorov Eye Microsurgery Federal State Institution using a femtosecond laser. We used a polymer device (intrastromal ring) manufactured at our Institution. 21 patients (22 eyes) were operated. The maximum follow-up period is 5 years. Surgery is performed under the control of intraoperative OCT.

Methods

We have developed a technique according to which the femtosecond laser create pattern "mushroom" with the formation of 90 degrees "step". The diameter(D) of the upper cut is 1 mm larger than the D of the lower cut. At the same time with trepanation of the stepped bed, a lamellar cut is formed, which is a continuation of the "step" to the limbus, the inner D is equal to the D of the upper cut, and the outer one exceeds it by 1 mm. The D of the recipient's cornea bed is 0.2 mm larger than the corneal transplantat. The D of the intrastromal ring is 0.5 mm less than the D of the lamellar pocket. The ring is placed in the formed lamellar pocket, then the corneal transplantat is fixed to the recipient's cornea with a uninterrupted blanket suture.

Results

The femtosecond laser program developed by us makes it possible to vary the size of the pattern depending on size of patient’s cornea. We obtained a higher correctable visual acuity in patients already on 7th day after operation in the comparisson with patiens who were operated by using standard penetrating keratoplasty technology. In the late postoperative period after the removal of sutures, the patients had a shift towards hypermetropic refraction, pentacam showed a better condition of anterior and posterior corneal surface.

Conclusions

With the help of femtosecond technologies, the intrastromal polymer ring places the correct position around the entire circumference and remains fixed by the surrounding tissues in its lamellar pocket, which eliminates the need for extra suturing. Even after removal of sutures, we did not face ring’s dislocation. Careful observation in the late postoperative period showed a decrease in the development of ametropia. This technique needs further study.