A Randomized Controlled Trial Comparing Femtosecond-Enabled Deep Anterior Lamellar Keratoplasty And Standard Deep Anterior Lamellar Keratoplasty (Feds Study)

Published 2022 - 40th Congress of the ESCRS

Reference: FPM02.05 | Type: Free paper | DOI: 10.82333/ddyf-hz26

Authors: Nir Sorkin* ¹ , Wendy Hatch ² , Michael Mimouni ² , Kevin Thorpe ³ , Vera Stiuso ² , Neera Singal ²

¹Department of Ophthalmology,Tel Aviv Medical Center and the Tel Aviv University,Tel Aviv,Israel;Department of Ophthalmology and Vision Sciences,University of Toronto,Toronto,Canada, ²Department of Ophthalmology and Vision Sciences,University of Toronto,Toronto,Canada, ³Applied Health Research Centre (AHRC),Toronto,Canada

Purpose

To compare outcomes of femtosecond-enabled deep anterior lamellar keratoplasty (FE-DALK) and standard deep anterior lamellar keratoplasty (S-DALK).

Setting

A single-center, open label, randomized control trial.

Methods

Ninety-seven eyes of 97 participants with either keratoconus or corneal scarring were randomized to undergo either FE-DALK (n=48) or S-DALK (n=49). Assessments were performed pre-operatively and 6, 12 and 15 months postoperatively.

Main Outcome Measures: Primary outcomes: postoperative astigmatism and post-hoc surgically induced corneal astigmatism (SIA), both at 15 months. Secondary outcomes: postoperative astigmatism and SIA at 6 and 12 months; 6-, 12- and 15-month postoperative uncorrected- and best spectacle-corrected visual acuity, steep and flat keratometry, manifest sphere and astigmatism, rate of conversion to penetrating keratoplasty (PK), big-bubble success, central corneal thickness, endothelial cell count and complications.

Results

In intention-to-treat (ITT) analysis, mean postoperative astigmatism in the FE-DALK (n=29) and S-DALK (n=26) groups at 15 months was 7.6±4.4 and 6.4±5.2D, respectively (p=0.469). Mean SIA was 9.4±7.9 and 8.9±5.7D, respectively (p=0.764). In an analysis of successful DALK cases only, mean postoperative astigmatism in the FE-DALK (n=24) and S-DALK (n=20) groups at 15 months was 7.3±4.4 and 6.2±4.9D, respectively (p=0.531). Mean SIA was 9.1±7.8 D and 7.9±4.6 D, respectively (p=0.547).

PK conversion rate was 15/48 eyes (31%) and 18/49 eyes (37%), respectively (p=0.722). Big-bubble success rate was 22/33 eyes (67%) and 16/31 eyes (52%), respectively (p=0.262). Comparison of the remaining secondary outcomes showed only weak statistical evidence.

Conclusions

In this randomized controlled trial, FE-DALK and S-DALK showed comparable functional and anatomical outcomes. A possible difference in big-bubble success rates should be further investigated in larger trials as well as in trials incorporating emerging modifications of the femtosecond DALK technique.