Early Changes in Visual Quality and Corneal Structure after DMEK: Does DMEK Approach Optical Quality of a Healthy Cornea?

Abstract

Purpose To evaluate early changes in visual function and visual quality parameters after Descemet membrane endothelial keratoplasty (DMEK) and to compare the outcomes with healthy controls. Methods Thirteen patients who underwent DMEK and 14 controls were evaluated. All subjects underwent visual function evaluation, including visual acuity under photopic and mesopic lighting conditions and contrast sensitivity (CSV) tests CSV 1000 and Pelli-Robson. Corneal parameters were assessed with Oculus Pentacam. Corneal mean keratometry (Km), corneal densitometry values, and low and high order aberrations (LOA and HOA) were recorded. In DMEK patients, all tests were performed before surgery and 1 and 6 months after surgery. Results In patients who underwent DMEK, photopic visual acuity improved from 0.59 to 0.31 at 1 month (p=0.013) and 0.13 at 6 months (p=0.008); mesopic visual acuity and all contrast sensitivity values (both CSV and Pelli-Robson test) improved significantly in the first month (p < 0.005). A significant decrease was observed in corneal density in the 0–2 mm ring (from 43.83 to 35.60, p=0.043) and mean posterior Km (from −5.84 to −6.80, p=0.005) in the first month. Corneal HOAs and all corneal densities improved at 6 months after DMEK (p < 0.05). All visual function parameters and corneal aberrations remained lower and higher, respectively, compared with healthy controls (p < 0.05). Corneal densities were comparable with controls at 6 months after DMEK (p > 0.05). Conclusions Patients undergoing DMEK present visual function improvement and a decrease in corneal density at 1 month after surgery. Decrease in corneal posterior HOAs can be observed at 6 months. However, visual function outcomes and corneal aberrations remained worse compared with healthy controls.

Effects of Combined Cataract Surgery on Outcomes of Descemet's Membrane Endothelial Keratoplasty: A Systematic Review and Meta-Analysis

“…A total of seven DMEK studies ( n = 692 eyes) ( 49 , 54 , 56 , 60 , 62 , 68 ), and three “triple DMEK” studies ( n = 275 eyes) reported BCVA at 1–6 months postoperative ( 64 , 65 , 67 ). The mean BCVA following DMEK was 0.50 logMAR (reported by one study), 0.14 (95% CI: 0.10–0.20) logMAR, and 0.07 (95% CI: 0.09–0.22) logMAR at 1-, 3-, and 6-month postoperative, respectively ( Figures 5C,D ), whereas the mean BCVA following “triple DMEK” was 0.19 (95% CI: 0.12–0.29) logMAR, 0.15 (95% CI: 0.11–0.19) logMAR, and 0.19 logMAR (reported by one study) at 1, 3, and 6 months postoperative, respectively ( Figures 5E,F ).…”

Region of Interest Densitometry Analysis of Descemet Membrane Endothelial Keratoplasty Dehiscence on Anterior Segment Optical Coherence Tomography

“…Previous studies with Scheimpflug imaging demonstrated increased CD in edematous states following DMEK surgery which decreased as the eyes were followed longitudinally. 21 , 23 , 25 – 27 To explain the decreased CD in our dehisced DMEK areas, the darker images (decreased CD) on AS-OCT may represent aqueous fluid percolating through the stroma and creating small pockets of fluid (because fluid is seen as dark on AS-OCT, e.g., epithelial bullae). The edematous lamellar separations lead to decreased CD.…”

“… 19 CD has previously been studied in DMEK, but these studies were all done with Scheimpflug imaging (i.e., Oculus Pentacam; Oculus, Wetzlar, Germany). 2 , 20 – 27 Limitations in the Pentacam software do not allow for selection of specific regions of interest for CD measurement. Rather, studied areas are typically confined to four annular zones (0–2 mm, 2–6 mm, 6–10 mm, and 10–12 mm) and four corneal layers (anterior, posterior, central, and total).…”

Assessment of Corneal Densitometry in Big-Bubble Dissection Versus Manual Dissection Deep Anterior Lamellar Keratoplasty

“…In addition, the software calculates corneal densitometry (backscattered light) using an add-on tool to the standard software of the Pentacam. 9 The program first identifies the corneal apex, captures 25 images over different meridians, and then analyzes an area with a diameter of 12 mm. Densitometric measurements are presented in grayscale units ranging from 0 (a minimum light scatter and maximum transparency) to 100 (a maximum light scatter and minimum transparency).…”