Search

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).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).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).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.

PURPOSE The purpose of this study is to analyze the course of corneal densitometry (CD), endothelial cell density (ECD), best-corrected visual acuity (BCVA), and central corneal thickness (CCT) 5 years after uneventful Descemet membrane endothelial keratoplasty (DMEK). METHODS Sixty uneventful cases (51 patients) with a minimum follow-up of 5 years were included. CD of various corneal layers (anterior, central, posterior, and total layer) and zones (0-2 mm, 2-6 mm, and 6-10 mm) were measured with Scheimpflug tomography. ECD, BCVA, and CCT were also evaluated. RESULTS Total CD at 0 to 2 mm and 2 to 6 mm zones significantly decreased from 33 ± 10 and 27.8 ± 8 grayscale units (GSU) preoperatively to 21.8 ± 3.1 and 22.2 ± 4.2 GSU at 5 years, respectively (P < 0.001). On the contrary, total CD at the 6 to 10 mm zone significantly increased from 30 ± 8.3 GSU preoperatively to 34.6 ± 7.8 GSU at 5 years (P < 0.001). ECD significantly decreased from 2496 ± 267 cells/mm2 preoperatively to 1063 ± 470 cells/mm2 at 5 years (P < 0.001). Similarly, CCT significantly decreased from 686 ± 109 μm preoperatively to 557 ± 37 μm at 5 years (P < 0.001). Postoperative BCVA was significantly better after DMEK for every examination time point. CONCLUSIONS Despite a slight CD increase at all layers of all corneal zones from the second to the fifth postoperative year, the excellent visual outcome was maintained throughout 5-year follow-up. Thus, DMEK seems to effectively treat corneal endothelial disease in the long term.

PURPOSE To evaluate the effect of ultraviolet A radiation on retinal function and structure after the corneal collagen crosslinking procedure. METHODS In the present prospective, single-center cohort study 17 eyes of 17 patients who underwent collagen crosslinking (Dresden protocol) for the treatment of corneal ectasia were examined preoperatively and at 2 and 6 weeks postoperatively with multifocal electroretinogram and optical coherence tomography. The P1 amplitude density (P1-AD) of the central retinal response was documented in 5 concentric rings, with ring 1 (R1) representing the foveal response and rings 2 to 5 (R2-R5) corresponding to successive annuli of stimulation. Visual acuity, corneal densitometry at the 0 to 2 mm zone and at the 2 to 6 mm annulus, and macular thickness (MT; central, 1 mm, 3 mm, and 5 mm zones) were recorded. RESULTS The preoperative values of P1-AD were R1 = 109.96 ± 28.96, R2 = 49.8 ± 14.46, R3 = 29.85 ± 8.9, R4 = 19.33 ± 6.3, and R5 = 16.39 ± 5.48 nV/deg. At 2 weeks, these values were R1 = 77.54 ± 24.47, R2 = 36.55 ± 12.53, R3 = 21.53 ± 7.71, R4 = 15.3 ± 6.13, and R5 = 13.32 ± 5.48, showing a significant reduction for R1-R4 (P ≤ 0.026). The 6-week P1-AD was R1 = 99.8 ± 31.23, R2 = 40.67 ± 16.39, R3 = 24.98 ± 7.13, R4 = 16.35 ± 4.84, and R5 = 13.76 ± 3.98, showing no significant differences compared with preoperative values (P ≥ 0.054). Corneal densitometry increased significantly at 2 weeks (P < 0.001) and remained increased at 6 weeks (P < 0.001), showing statistically insignificant correlations with 2-week P1-AD (P ≥ 0.553). The central MT increased (P = 0.787), whereas MT at 1 mm (P = 0.444), 3 mm (P = 0.039), and 5 mm (P < 0.001) zones decreased. CONCLUSIONS The return of P1-AD to preoperative (physiologic) values at 6 weeks confirms the safety standards of the duration and intensity of ultraviolet A radiation, as proposed by the Dresden protocol. However, temporary postoperative retinal dysfunction cannot be excluded.

To present normative corneal densitometry (CD), thickness (CT), and volume (CV) after uneventful Descemet membrane endothelial keratoplasty (DMEK).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).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 (P0.001), 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 (P0.001), 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 (P0.001), showing no significant differences compared with both control groups (P ≥ 0.122).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.

PURPOSE To compare the rebubbling rate and clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) with 5% sulfur hexafluoride (SF6) gas versus 100% air as a tamponade for graft attachment. METHODS Retrospective, comparative, interventional case series including 368 consecutive pseudophakic eyes with Fuchs endothelial dystrophy or pseudophakic bullous keratopathy that underwent DMEK in a tertiary referral center between October 2010 and August 2015 using either air (group 1, 191 eyes) or 5% SF6 (group 2, 177 eyes) as a tamponade. The rebubbling rate, complications, best-corrected distance visual acuity (BCVA), manifest refraction, and endothelial cell density were analyzed before and at 1 week, 1, 3, 6, 12, 24, and 36 months after surgery. RESULTS The rebubbling rate was 20.4% (39/191, group 1) versus 6.8% (12/177, group 2; P < 0.001). Complications included cystoid macular edema (n = 5, group 1, and n = 10, group 2; P = 0.14) and 1 case of presumed allograft rejection (n = 1, group 2). The follow-up period was 12 ± 8 months for group 1 and 6 ± 4 months for group 2. BCVA (logarithm of the minimum angle of resolution) had improved after 12 months from 1.43 ± 0.63 to 0.18 ± 0.26 (group 1, P < 0.001) and from 1.8 ± 0.63 to 0.18 ± 0.17 (group 2, P < 0.001). The percentage of eyes with BCVA ≥0.2 logarithm of the minimum angle of resolution at 12 months was 70.9% (90/127, group 1) and 78.4% (40/51, group 2; P = 0.3). Endothelial cell loss at 12 months after DMEK was 44 ± 18% (group 1) versus 33 ± 15% (group 2, P = 0.07). CONCLUSIONS The use of a tamponade with 5% SF6 yielded a significantly lower incidence of graft detachment requiring surgical reintervention with no detrimental effect on graft endothelial cells. Thus, routine use of 5% SF6 for a graft tamponade in DMEK is recommended.

A 74-year-old man underwent Descemet membrane endothelial keratoplasty (DMEK) for endothelial decompensation due to Fuchs endothelial dystrophy. After descemetorhexis, the DMEK graft was inserted into the anterior chamber. However, unfolding of the graft was not possible as the graft was very tightly rolled together and the anterior chamber deep. After placing a 30G-cannula connected to an air-filled syringe inside the roll’s lumen, a small air bubble was injected, which allowed the roll to open up, until it assumed a “taco” configuration around the bubble. Then, the graft was centered by pressing the posterior part of the roll against, and sweeping it over the iris. In the present case a “tight” DMEK roll was successfully unfolded by injection of a single air bubble into the roll’s lumen and centered by a “sweeping” the partialy unfolded graft over the iris. This technique allowed a controlled unfolding and centering of the DMEK graft with limited trauma to the donor endothelium and may be applied in cases where other less traumatic maneuvers are not successful.