Clinical And Functional Results Of Modified Femtolaser Refractive Autokeratoplasty In Patients With Keratoconus

In 2015, a technique of femtolaser refractive autokeratoplasty (FRAK) was developed for patients with 3-4 stages of keratoconus, which is based on remodeling the patient's own cornea without implantation of intrastromal segments or rings (Sitnik G.V. with co-authors, 2015). We modified and personalized the FRAC method, which allowed us to begin performing this operation in the early stages of keratoconus. Purpose is to analyze the clinical and functional results of modified femtolaser refractive autokeratoplasty and evaluate its effectiveness in patients with keratoconus during a follow-up period of 36 months.

The Kaluga branch of the S. Fyodorov Eye Microsurgery Federal State Institution.

24 patients with stage 2 keratoconus aged from 25 to 37 years. The initial spherical and cylindrical components and biometric parameters indicated the deliberate ineffectiveness of intrastromal keratoplasty (ISKP), so all patients were performed FRAK modified technique using a Femto LDV Z8 femtolaser (Ziemer, Switzerland). Two circular corneal incisions were simultaneously performed by femtolaser, resecting a ring-shaped corneal flap with a wedge-shaped profile. The corneal flap width was calculated using a special formula. After the annular flap removal, edges of the wedge-shaped corneal section were stitched using a combined suture fixation. 12 months after the FRAK, the sutures were removed.

Performing personalized FRAK according to indications provides an increase in BCVA already in the early postoperative period with a tendency to further increase an average up to 0,46±0,08 by 36 months after surgery compared to the initial 0,22±0,03, as well as stable state of the ecstatic process throughout the entire follow-up. By the end of the 3-year follow–up period, the spherical refraction component was -1,41±0,47 diopters compared to the initial -8,75±1,15, the cylindrical refraction component was -2.1±0.75 diopters (the initial -4,87±0,40), the average keratometry was 50.79±1.00 diopters (the initial 55,27±0,65). All patients were satisfied with the achieved VA. Keratoconus progression was not noted in any case.

An analysis of the clinical and functional results of the modified FRAK technique for topographically centrally located keratoconus showed that this technology provides a stable refractive effect in patients with stage 2 keratoconus during a follow-up period of 36 months. The modified FRAK technology is effective and can be successfully used in the early stages of keratoconus in cases with initial low visual acuity and axial myopia.