Descemet Membrane Endothelial Keratoplasty versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty A Multicenter Randomized Controlled Clinical Trial

Purpose: To compare best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD), refractive astigmatism, and complications after Descemet membrane endothelial keratoplasty (DMEK) and ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK). Design: Prospective, multicenter randomized controlled trial. Participants: Fifty-four pseudophakic eyes of 54 patients with corneal endothelial dysfunction resulting from Fuchs endothelial corneal dystrophy were enrolled in 6 corneal centers in The Netherlands. Methods: Participants were allocated to DMEK (n = 29) or UT-DSAEK (n = 25) using minimization randomization based on preoperative BSCVA, recipient central corneal thickness, gender, age, and institution. Donor corneas were prestripped and precut for DMEK and UT-DSAEK, respectively. Six corneal surgeons participated in this study. Main Outcome Measures: The primary outcome measure was BSCVA at 12 months after surgery. Results: Central graft thickness of UT-DSAEK lamellae measured 101 mu m (95% confidence interval [CI], 90-112 mu m). Best spectacle-corrected visual acuity did not differ significantly between DMEK and UT-DSAEK groups at 3 months (0.15 logarithm of the minimum angle of resolution [logMAR] [95% CI 0.08-0.22 logMAR] vs. 0.22 logMAR [95% CI 0.16-0.27 logMAR]; P = 0.15), 6 months (0.11 logMAR [95% CI 0.05-0.17 logMAR] vs. 0.16 logMAR [95% CI 0.12-0.21 logMAR]; P = 0.20), and 12 months (0.08 logMAR [95% CI 0.03-0.14 logMAR] vs. 0.15 logMAR [95% CI 0.10-0.19 logMAR]; P = 0.06). Twelve months after surgery, the percentage of eyes reaching 20/25 Snellen BSCVA was higher in DMEK compared with UT-DSAEK (66% vs. 33%; P = 0.02). Endothelial cell density did not differ significantly 12 months after DMEK and UT-DSAEK (1870 cells/mm 2 [95% CI 1670-2069 cells/mm(2)] vs. 1612 cells/mm(2) [95% CI 1326-1898 cells/mm(2)]; P = 0.12). Both techniques induced a mild hyperopic shift (12 months: +0.22 diopter [D; 95% CI -0.23 to 0.68 D] for DMEK vs. +0.58 D [95% CI 0.13-1.03 D] for UT-DSAEK; P = 0.34). Conclusions: Descemet membrane endothelial keratoplasty and UT-DSAEK did not differ significantly in mean BSCVA, but the percentage of eyes achieving 20/25 Snellen vision was significantly higher with DMEK. Endothelial cell loss did not differ significantly between the treatment groups, and both techniques induced a minimal hyperopic shift. (C) 2020 by the American Academy of Ophthalmolog

Quality of vision and vision-related quality of life after Descemet membrane endothelial keratoplasty:a randomized clinical trial

PURPOSE: To compare quality of vision and vision‐related quality of life (QOL) in patients undergoing Descemet membrane endothelial keratoplasty (DMEK) or ultrathin Descemet stripping automated endothelial keratoplasty (DSAEK). METHODS: Fifty‐four eyes of 54 patients with Fuchs' dystrophy from six corneal clinics in the Netherlands were randomized to DMEK or ultrathin DSAEK and examined preoperatively, and 3, 6 and 12 months postoperatively. Main outcome measures were corneal higher‐order aberrations (HOAs), contrast sensitivity, straylight and vision‐related QOL. RESULTS: Posterior corneal HOAs decreased after DMEK and increased after ultrathin DSAEK (p ≤ 0.001) 3 months after surgery and correlated positively with best spectacle‐corrected visual acuity (12 months: r = 0.29, p = 0.04). Anterior and total corneal HOAs did not differ significantly between both techniques at any time point. Contrast sensitivity was better (p = 0.01), and straylight was lower (p = 0.01) 3 months after DMEK compared with ultrathin DSAEK; 95% confidence interval [CI] of log(cs) 1.10–1.35 versus 95% CI: 0.84 to 1.12, and 95% CI: log(s) 1.18 to 1.43 versus 95% CI: 1.41 to 1.66, respectively. Both were comparable at later time points. Vision‐related QOL (scale 0–100) did not differ significantly between both groups at any time point and improved significantly at 3 months (β = 12 [95% CI: 7 to 16]; p < 0.001), and subsequently between 3 and 12 months (β = 5 [95% CI: 0 to 9]; p = 0.06). CONCLUSIONS: Descemet membrane endothelial keratoplasty (DMEK) results in lower posterior corneal HOAs compared with ultrathin DSAEK. Contrast sensitivity and straylight recover faster after DMEK but reach similar levels with both techniques at 1 year. Vision‐related QOL improved significantly after surgery, but did not differ between both techniques

Preliminary results of a multicenter randomized clinical trial comparing Descemet Membrane Endothelial Keratoplasty (DMEK) with ultrathin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK)

Purpose : To compare best corrected visual acuity, endothelial cell density, and complications after Descemet Membrane Endothelial Keratoplasty (DMEK) and ultrathin Descemet Stripping Automated Endothelial Keratoplasty (UT-DSAEK). Methods : Multicenter prospective randomized clinical trial (RCT). 55 eyes of 55 patients suffering from irreversible corneal endothelial dysfunction due to Fuchs' endothelial corneal dystrophy were randozmized to receive DMEK or UT-DSAEK in six tertiary and secondary eye clinics in the Netherlands. Donor grafts were centrally prepared by the Beverwijk Euro Cornea bank. Patients underwent ophthalmic examinations preoperatively and 3 months postoperatively. Results : Preoperative BCVA did not differ between both groups (DMEK:0.38±0.18 logMAR vs. UT-DSAEK:0.33±0.21 logMAR, P=0.32). Three months after the operation, BCVA improved significantly (P<0.001). However, there was no statistically significant difference in BCVA between both groups (DMEK: 0.16±0.16 vs. UT-DSAEK: 0.19±0.11 logMAR, P=0.59). One graft in each group was damaged during preparation. Donor endothelial cell density (ECD) did not differ between both groups (DMEK:2668±168 vs. UT-DSAEK:2638±193 cells/mm^2). Three months after the operation, ECD was significantly higher after DMEK (1868±478 vs. 1295±673 cells/mm^2, P= 0.01). Rebubbling was required in 17% of cases after DMEK, and was not reuquired after UT-DSAEK. Primary graft failure requiring repeated transplantation occurred in 7% of cases after DMEK, but not after UT-DSAEK. Conclusions : The preliminary results of this multicenter RCT indicate that DMEK and UT-DSAEK achieve a similar improvement in BCVA three months after the operation. However, DMEK was associated with a significantly higher complication rate. To the best of our knowlegde, this is the first report from a RCT comparing both transplantation techniques. This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018

Does Facebook Use Predict College Students’ Social Capital? A Replication of Ellison, Steinfield, and Lampe’s (2007) Study Using the Original and More Recent Measures of Facebook Use and Social Capital

In 2007 Ellison, Steinfield, and Lampe published an article on the positive association between Facebook use and social capital that started a decade of research on the social outcomes of social network site use. Although cited almost 9,000 times, it received critique on the conceptualization and operationalization of Facebook use and social capital. In this study we replicate Ellison et al.’s study with original and alternative measures of social capital and Facebook use, thereby shedding light on the robustness, stability, and ecological validity of the original findings. We found that Facebook intensity positively predicts the original social capital measures, lending support to the validity of the original findings. Its relationship with structural measures, however, was weak for bridging and absent for bonding social capital

Does Facebook Use Predict College Students’ Social Capital? A Replication of Ellison, Steinfield, and Lampe’s (2007) Study Using the Original and More Recent Measures of Facebook Use and Social Capital

In 2007 Ellison, Steinfield, and Lampe published an article on the positive association between Facebook use and social capital that started a decade of research on the social outcomes of social network site use. Although cited almost 9,000 times, it received critique on the conceptualization and operationalization of Facebook use and social capital. In this study we replicate Ellison et al.’s study with original and alternative measures of social capital and Facebook use, thereby shedding light on the robustness, stability, and ecological validity of the original findings. We found that Facebook intensity positively predicts the original social capital measures, lending support to the validity of the original findings. Its relationship with structural measures, however, was weak for bridging and absent for bonding social capital

A machine learning approach to explore predictors of graft detachment following posterior lamellar keratoplasty: a nationwide registry study

Machine learning can be used to explore the complex multifactorial patterns underlying postsurgical graft detachment after endothelial corneal transplantation surgery and to evaluate the marginal effect of various practice pattern modulations. We included all posterior lamellar keratoplasty procedures recorded in the Dutch Cornea Transplant Registry from 2015 through 2018 and collected the center-specific practice patterns using a questionnaire. All available data regarding the donor, recipient, surgery, and practice pattern, were coded into 91 factors that might be associated with the occurrence of a graft detachment. In this research, we used three machine learning methods; a regularized logistic regression (lasso), classification tree analysis (CTA), and random forest classification (RFC), to select the most predictive subset of variables for graft detachment. A total of 3647 transplants were included in our analysis and the overall prevalence of graft detachment was 9.9%. In an independent test set the area under the curve for the lasso, CTA, and RFC was 0.70, 0.65, and 0.72, respectively. Identified risk factors included: a Descemet membrane endothelial keratoplasty procedure, prior graft failure, and the use of sulfur hexafluoride gas. Factors with a reduced risk included: performing combined procedures, using pre-cut donor tissue, and a pre-operative laser iridotomy. These results can help surgeons to review their practice patterns and generate hypotheses for empirical research regarding the origins of graft detachments