Purpose: To present normative corneal densitometry (CD), thickness (CT), and volume (CV) after uneventful Descemet membrane endothelial keratoplasty (DMEK). Methods: Medical records of 212 consecutive surgeries were reviewed. One hundred cases without intraoperative and postoperative complications were included (group 1). Scheimpflug CD of the optically relevant 0- to 2-mm zone and 2- to 6-mm annulus, CT at the 2-, 4-, and 6-mm rings, and CV at the 3-, 5-, and 7-mm zones were evaluated preoperatively and at 3, 6, 12, and 24 months postoperatively. The 24-month results were compared with an age-matched group of uncomplicated pseudophakic eyes (group 2; n = 20) and a group of healthy, young subjects (group 3; n = 30). Results: Total CD at 0 to 2 mm was 33.9 ± 10.7 grayscale units preoperatively and decreased to 20.3 ± 4.7 at 24 months (P < 0.001), being significantly higher compared with both control groups (P ≤ 0.026). Total CD at 2 to 6 mm was 27.9 ± 8.1 preoperatively and decreased to 20.2 ± 4.6 at 24 months (P < 0.001), showing no statistically significant difference compared with group 2 (P = 0.061). At 24 months, group 1 showed a similar central CT, CT at the 2-mm and 4-mm rings compared with group 2 (P ≥ 0.440); however, CT at 6 mm increased significantly (P = 0.008). CV at 3, 5, and 7 m decreased significantly at 24 months (P < 0.001), showing no significant differences compared with both control groups (P ≥ 0.122). Conclusions: Twenty four months after uneventful DMEK, CT within the central 4-mm zone and CV at the 3-, 5-, and 7-mm zones were similar to uncomplicated pseudophakic eyes. The total CD at the 0- to 2-mm zone and midperipheral CT at the 6-mm ring were higher compared with the pseudophakic controls.

To evaluate the short-and mid-term changes of corneal thickness spatial profile (CTSP), corneal volume distribution (CVD), and corneal asphericity after small-incision lenticule extraction (SMILE) for correction of myopia and astigmatism and compare the results with femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK).Method: Thirty eyes of 18 patients who underwent SMILE were compared with a group of 30 eyes of 16 patients who underwent FS-LASIK. The groups were matched for preoperative central corneal thickness and lenticule thickness/ablation depth. Scheimpflug corneal tomography was performed preoperatively and postoperatively at 2 months and 3 years. The CTSP was evaluated on 4 concentric rings (2, 4, 6, and 8 mm). The CVD was evaluated at 3 concentric zones (3, 5, and 7 mm). Changes in the anterior and posterior asphericity at a 6-mm zone were also evaluated.Results: Between the 2-month and 3-year examination, the CTSP showed a similar increase for both groups at all measured points and rings (P $ 0.168). The CVD also showed a similar increase for both groups at all measured zones (P $ 0.278). The anterior corneal asphericity remained stable after SMILE (2-mo Q = 0.46 6 0.27; 3-yr Q = 0.45 6 0.27; P = 0.711) but decreased significantly after FS-LASIK (2-mo Q = 0.52 6 0.47; 3-yr Q = 0.47 6 0.44; P = 0.028). Similarly, the posterior corneal asphericity remained stable after SMILE (2-mo Q = 20.11 6 0.15; 3-yr Q = 20.11 6 0.13; P = 0.902) but decreased significantly after FS-LASIK (2-mo Q = 20.13 6 0.14; 3-yr Q = 20.16 6 0.15; P = 0.034).Conclusions: CTSP and CVD between the 2-month and 3-year examination showed a similar increase after SMILE and FS-LASIK. During the postoperative course, the anterior and posterior corneal asphericity remained more stable after SMILE compared with FS-LASIK.

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