Inverted Posterior Femto-Keratoplasty: Quality of the Surface of the Corneal Section and Preliminary Clinical Outcomes

Purpose. To evaluate the quality of the surface of an ultra-thin donor transplant prepared from the endothelial surface of the cornea using a femtosecond laser and to demonstrate the preliminary clinical results.
Patients and Methods. 4 eyes were operated: 3 with Fuch`s endothelial dystrophy and 1 with pseudophakic bullous keratopathy. All patients were treated with DSEK with an ultrathin graft prepared by Alcon Wavelight FS 200 femtosecond laser (Germany). Before and after surgery UCVA, BSCVA, astigmatism, ECD were measured. EC death, graft thickness and CCT were evaluated at 12 months` observation. Atomic force microscopy was used for examination of 10 samples. Control group was 5 corneal flaps obtained by mechanical microkeratome (Moria SLK-2, France). Main group — 5 corneal flaps, obtained by femtosecond laser. Nonparametric Mann-Whitney test was used for statistical analysis. Coefficient of reliability p < 0.05 was considered to be significant.
Results. RMS value of femto-laser group samples was 18.6 ± 7.8 um. RMS of microkeratome group samples was 22.3 ± 18.3 um. Statistical analysis did not reveal significant differences between the values of the studied parameter in these groups (p > 0.05). Transparent engraftment was observed in all cases, no corneal edema was identified. BSCVA ranged from 0.2 to 0.6, which was associated with the presence of concomitant pathology. Astigmatism was 1.35 ± 1.0 D. ECD = 1526 ± 434 cells/mm2. EC loss = 48.0 ± 12.8 %. Graft thickness in the central zone was 78.0 ± 18.1 µm. Center-Edge Index — 0.84 ± 0.12. CCT = 600 ± 31 um. No postoperative complications were found.
Conclusion. The developed settings allowed to obtain high-quality ultra-thin graft with a sufficiently uniform surface without a risk of perforation. Preliminary clinical results showed the method potential for restoration of corneal transparency. ECD loss corresponded to the one achievable by DSAEK.

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