To evaluate the effect of a single rebubbling procedure after Descemet membrane endothelial keratoplasty (DMEK) on corneal backscatter and endothelial cell loss (ECL).
Medical records of 130 consecutive DMEK cases (118 patients) were reviewed and 3 groups were formed: group 1 (n = 32), consisting of DMEK cases followed by 1 rebubbling; group 2a (n = 55), including uneventful DMEK cases with complete graft attachment; and group 2b (n = 25), including uneventful DMEK cases with minor peripheral detachment, not requiring rebubbling. Scheimpflug corneal densitometry (CD) of the central (0-2 mm), paracentral (2-6 mm), and mid-peripheral (6-10 mm) zones, endothelial cell density, central corneal thickness, and corneal volume were measured preoperatively and at 3, 6, 12, and 24 months.
Central CD in group 1 decreased from 32.3 ± 8.3 grayscale units preoperatively, to 21.2 ± 3.5 at 24 months. In group 2a, CD decreased from 37.0 ± 11.9 to 19.4 ± 3.0 and in group 2b from 32.5 ± 8.8 to 19.8 ± 3.1. No significant differences were observed among the 3 groups at any examination time point (P ≥ 0.12). At 3 months, paracentral CD of group 2a was significantly lower than that of group 1 (P = 0.047). Endothelial cell density at 3 months was higher in group 2a (1613 ± 503 cells/mm) than in group 1 (1350 ± 557 cells/mm; P = 0.033). ECL at 24 months was 56%, 43%, and 53% in groups 1, 2a, and 2b, respectively. Group 2a showed the lowest ECL, central corneal thickness, and corneal volume throughout the study period.
A single rebubbling procedure does not increase the CD of the central cornea and but results in significantly higher ECL compared with uneventful DMEK with complete graft attachment.