The Graft Thickness in Descemet Stripping Automated Endothelial Keratoplasty: What Is the Importance to the Final Visual Outcome?

Introduction: Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) is currently considered the procedure of choice for the treatment of endothelial dysfunctions. Despite DSAEK being a promising procedure to improve visual acuity (VA), the ideal graft thickness donor still remains under discussion. Purpose: To analyze the influence of graft thickness on postoperative VA and complications in DSAEK surgery. Methods: Retrospective study of 112 eyes that underwent DSAEK surgery. Donor grafts were obtained by dissection with automatic microkeratome, using different head sizes. Central corneal thickness (CCT) of donor corneas before dissection was measured by ultrasound pachymetry. The choice of the cutting depth was based on CCT measurements and the final desired residual corneal thickness, corresponding to the estimated donor graft thickness (EDGT). The eyes were divided into 3 groups, depending on the EDGT: <180 μm (Group 1), 180 - 200 μm (Group 2) and >200 μm (Group 3). Intraoperative, postoperative complications and the best corrected visual acuity (BCVA) at 6 months postoperatively were evaluated, comparing these 3 groups. Results: The average EDGT was 164 ± 10 μm in Group 1188 ± 7 μm in Group 2 and 234 ± 30 μm in Group 3. At 6 months postoperative the average BCVA was significantly better in Group 1 (BCVA: 0.74 ± 0.20), compared to Group 2 (BCVA: 0.54 ± 0.20) and Group 3 (BCVA: 0.39 ± 0.18). Intraoperative and postoperative complications included: graft perforation during cutting (0.9% of cases), graft rejection (3.6%), primary graft failure (4.5%), and graft detachment (3.6%). Its distribution was uniform between the 3 groups. Conclusion: The study proves that DSAEK is an effective surgical technique for the treatment of endothelial dysfunction, demonstrating that the use of thinner grafts (EDGT < 180 μm) can improve the final visual outcome, with a significant improvement on BCVA, without increasing the risk of complications.