Five-year follow-up of corneal morphology and corneal refractive power changes after uneventful DMEK.

PURPOSE: To investigate changes of corneal thickness spatial profile (CTSP), corneal volume (CV) distribution, and total corneal refractive power (TCRP) over a course of 60 months after uneventful Descemet membrane endothelial keratoplasty (DMEK). METHODS: In our prospective, comparative study, sixty DMEK cases without intraoperative and postoperative complications and with complete 60-month follow-up were included (group 1). CTSP at corneal apex (CCT) and at 2 mm, 4 mm, 6 mm, and 8 mm rings, CV in 3 mm, 5 mm, 7 mm, and 10 mm zones, and TCRF in 2 mm, 4 mm 6 mm, and 8 mm zones were evaluated preoperatively and at 3, 6, 12, 24, and 60 months postoperatively. The 60-month results were compared to an age-matched group of uncomplicated pseudophakic eyes (group 2; n = 20). RESULTS: The CCT and CTSP at 2, 4, and 6 mm increased significantly at 60 months compared to 3-month outcomes (P < 0.001). Similarly, CV increased significantly in 3 mm, 5 mm, and 7 mm zones at 60 months compared to 3 months outcomes (P < 0.001). The TCRP showed in all zones a significant decrease at 3 months (P < 0.001) followed by a continuous and significant increase at 60 months (P < 0.001). The 60-month CCT and CTSP at 2 mm were similar to group 2 (P ≥ 0.094). CONCLUSION: Sixty months after uneventful DMEK, CT within the central 2 mm zone and CV at 3 mm zone were similar to uncomplicated pseudophakic eyes. A continuous and statistically significant increase of TCRP was observed in all measured zones after the 3-month examination.

Corneal Remodeling After Myopic SMILE Versus FS-LASIK: A Spatial Analysis of Short- and Mid-Term Corneal Thickness, Volume, and Shape Changes.

PURPOSE: 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 ± 0.27; 3-yr Q = 0.45 ± 0.27; P = 0.711) but decreased significantly after FS-LASIK (2-mo Q = 0.52 ± 0.47; 3-yr Q = 0.47 ± 0.44; P = 0.028). Similarly, the posterior corneal asphericity remained stable after SMILE (2-mo Q = -0.11 ± 0.15; 3-yr Q = -0.11 ± 0.13; P = 0.902) but decreased significantly after FS-LASIK (2-mo Q = -0.13 ± 0.14; 3-yr Q = -0.16 ± 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.

Spatial Analysis of Corneal Densitometry, Thickness Profile, and Volume Distribution After Uneventful Descemet Membrane Endothelial Keratoplasty.

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.