[Visual acuity and endothelial cell density following Descemet membrane endothelial keratoplasty (DMEK)]

Two-year clinical outcome after Descemet membrane endothelial keratoplasty using a standardized protocol

PURPOSE

The purpose of this study is to evaluate 2-year clinical outcome after Descemet membrane endothelial keratoplasty (DMEK) in a variety of endothelial dysfunctions using a standardized protocol.

METHODS

: From a group of 230 eyes which underwent DMEK for Fuchs' endothelial corneal dystrophy (FECD), aphakic and pseudophakic bullous keratopathy, failed full thickness corneal transplants, ICE syndrome, failed DSEK, and TASS the clinical outcomes [best spectacle-corrected visual acuity (BSCVA), central endothelial cell density (ECD)] were evaluated before, and at 6, 12, and 24 months and the success rate, failure rate and postoperative complications were also analyzed.

RESULTS

Out of 230 eyes, 144 eyes (70%) had BSCVA 6/9 or better 2 years postoperatively. Mean donor ECD was 2692.23 (range, 2300-3436) cells/mm2 preoperatively, which was reduced to 1433.64 (range, 619.0-2272.0) cells/mm2 2 years after DMEK surgery, indicating a mean reduction of 1258 cells/mm2 (46%) in ECD.

CONCLUSION

DMEK is a highly successful surgical procedure when following a standard protocol for treating diseases of the corneal endothelium providing a near perfect anatomic restoration and a high degree of visual rehabilitation.

Effect of Unilateral Endothelial Keratoplasty on Vision-Related Quality-of-Life Outcomes in the Descemet Endothelial Thickness Comparison Trial (DETECT): A Secondary Analysis of a Randomized Clinical Trial

Importance

Vision-related quality of life can be a valuable outcome for some interventions in ophthalmology. In the primary Descemet Endothelial Thickness Comparison Trial (DETECT), Descemet membrane endothelial keratoplasty (DMEK) had superior postoperative visual acuity compared with ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK). It is of interest to determine whether this trend extends to quality of life.

Objective

To determine the effect of UT-DSAEK and DMEK on vision-related quality of life.

Design, Setting, and Participants

A prespecified secondary analysis of a 2-surgeon patient- and outcome-masked randomized clinical trial was conducted at the Casey Eye Institute in Portland, Oregon, and Byers Eye Institute in Palo Alto, California. The study was conducted between January 20, 2015, and April 26, 2017. DETECT enrolled 38 individuals and included 50 eyes with isolated endothelial dysfunction; for this analysis, the second eye from a single participant was excluded along with any questionnaires in the first eye after second eye surgery for evaluation of 38 eyes at baseline and 3 months and 26 eyes at 12 months. Mean (SD) baseline visual acuity was 0.35 (0.31) logMAR in the DMEK arm and 0.28 (0.22) logMAR in the UT-DSAEK arm. Each arm consisted of 19 participants: 18 individuals with Fuchs dystrophy and 1 participant with pseudophakic bullous keratopathy.

Interventions

Study eyes were randomized to receive either UT-DSAEK or DMEK.

Main Outcomes and Measures

Responses to the National Eye Institute (NEI) Visual Function Questionnaire-39 (VFQ-39) administered at baseline and 3 and 12 months postoperatively were analyzed using the NEI-defined traditional subscales and composite score on a 100-point scale and with a Rasch-refined analysis.

Results

There were more women in both arms of the study (UT-DSAEK, 12 [63%]; DMEK, 11 [58%]); mean (SD) age was 68 (11) years in the UT-DSAEK arm and 68 (4) years in the DMEK arm. Overall, study participants experienced a 9.1-point improvement in NEI VFQ-39 composite score at 3 months compared with baseline (N = 38; 95% CI, 4.9-13.3; P < .001), and an 11.6-point improvement at 12 months compared with baseline (n = 26; 95% CI, 6.8-16.4; P < .001). Eyes randomized to DMEK had 0.9 points more improvement in NEI VFQ-39 composite score at 3 months compared with UT-DSAEK after controlling for baseline NEI VFQ-39 (95% CI, -6.2 to 8.0; P = .80).

Conclusions and Relevance

Improvement in vision-related quality of life was not shown to be greater with DMEK compared with UT-DSAEK.

Trial Registration

ClinicalTrials.gov identifier: NCT02373137.

Descemet Endothelial Thickness Comparison Trial: A Randomized Trial Comparing Ultrathin Descemet Stripping Automated Endothelial Keratoplasty with Descemet Membrane Endothelial Keratoplasty

PURPOSE

To compare clinical outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) in the treatment of corneal endothelial dysfunction.

DESIGN

Patient and outcome-masked, randomized controlled clinical trial.

PARTICIPANTS

Patients with damaged or diseased endothelium from Fuchs endothelial dystrophy or pseudophakic bullous keratopathy who were considered good candidates for DMEK or UT-DSAEK.

METHODS

Study eyes were randomized by the eye bank to UT-DSAEK or DMEK 1 to 2 days before surgery.

MAIN OUTCOME MEASURES

The primary outcome of the trial was best spectacle-corrected visual acuity (BSCVA) at 6 months. Secondary outcomes included 3- and 12-month BSCVA; 3-, 6-, and 12-month endothelial cell counts; intraoperative and postoperative complications; and change in pachymetry.

RESULTS

A total of 216 patients with endothelial dysfunction were screened, and 50 eyes of 38 patients were enrolled by 2 surgeons at Casey Eye Institute at Oregon Health & Science University in Portland, Oregon, and at Byers Eye Institute at Stanford University in Palo Alto, California. Overall, we found DMEK to have better visual acuity outcomes compared with UT-DSAEK after correcting for baseline visual acuity: compared with UT-DSAEK, those randomized to DMEK had 1.5 lines better BSCVA at 3 months (95% confidence interval [CI], 2.5-0.6 lines better; P = 0.002), 1.8 lines better BSCVA at 6 months (95% CI, 2.8-1.0 lines better; P < 0.001), and 1.4 lines better BSCVA at 12 months (95% CI, 2.2-0.7 lines better; P < 0.001). Average endothelial cell counts were 1963 cells/mm² in DMEK and 2113 cells/mm² in UT-DSAEK at 6 months (P = 0.17) and 1855 cells/mm² in DMEK and 2070 cells/mm² in UT-DSAEK at 12 months (P = 0.051). Intraoperative and postoperative complication rates were similar between groups.

CONCLUSIONS

Descemet membrane endothelial keratoplasty had superior visual acuity results compared with UT-DSAEK at 3, 6, and 12 months in patients with isolated endothelial dysfunction with similar complication rates.

Survey of Experts on Current Endothelial Keratoplasty Techniques

OBJECTIVE

To survey cornea specialists' opinions on different endothelial keratoplasty techniques and to gauge the perceived need for and utility of a randomized controlled trial (RCT) comparing them.

METHODS

A short survey was distributed to a group of cornea specialists at the Endothelial Keratoplasty Group meeting at the American Academy of Ophthalmology meeting in November 2015.

RESULTS

Thirty-three of 80 practicing surgeons present at the EKG meeting participated in the survey, yielding a response rate of 41%. Ninety-seven percent (n=32) of our respondents reported performing Descemet's Stripping Endothelial Keratoplasty (DSEK) regularly, and 70% reported having performed Descemet's Membrane Endothelial Keratoplasty (DMEK) at least once (n=23). While most respondents (n=26, 79%) thought there was at least some evidence that DMEK is superior to DSEK in terms of visual acuity, there was less certainty about comparing ultrathin-DSEK (UT-DSEK) to DMEK with 48% (n=16) thinking there was at least some evidence of DMEK's superiority, 6% (n=2) thinking there was at least some evidence of UT-DSEK's superiority, and 30% (n=10) unsure. Seventy-two percent (n=23) of respondents thought an RCT comparing visual acuity outcomes in UT-DSEK versus DMEK would be at least moderately beneficial, and 82% (n=27) reported they were at least moderately likely to change their EK technique based on the results of said RCT.

CONCLUSION

There is substantial interest in an RCT comparing visual acuity outcomes in UT-DSEK versus DMEK.

Intraoperative OCT-Assisted DMEK: 14 Consecutive Cases

PURPOSE

To describe the utility of a new intraoperative optical coherence tomographer (OCT) to evaluate endothelio-Descemet graft orientation during Descemet membrane endothelial keratoplasty (DMEK) procedures.

METHODS

Prospective, observational, and single-center pilot case series including 14 eyes of 14 patients consecutively scheduled for DMEK surgery. After injecting the graft into the anterior chamber, the graft orientation was assessed with the help of anterior segment OCT. The surgical time and unfolding time were measured. The postoperative measurements included best-corrected visual acuity, central pachymetry, and specular microscopy at 1 month.

RESULTS

Using the OCT images, it was possible to evaluate the graft orientation in all cases. The mean unfolding time was 6.1 ± 3.0 minutes, the mean best-corrected visual acuity was 0.3 ± 0.3 logarithm of the minimum angle of resolution, the mean decrease in central pachymetry was 213 ± 177 μm, and the mean central endothelial cell count was 1906 ± 319 cells per square millimeter.

CONCLUSIONS

Live intraoperative OCT is useful to visualize and assess graft orientation in DMEK surgery. It enables faster graft positioning with less graft manipulation in the presence of severe corneal edema.

The First 100 Eyes of Standardized Descemet Stripping Automated Endothelial Keratoplasty versus Standardized Descemet Membrane Endothelial Keratoplasty

PURPOSE

To compare results of the first 100 eyes of Descemet stripping automated endothelial keratoplasty (DSAEK) and Descemet membrane endothelial keratoplasty (DMEK) that were performed with a standardized technique at a single institution.

DESIGN

Single-center, retrospective case series.

PARTICIPANTS

The first 100 eyes of standardized DSAEK and DMEK that underwent surgery for Fuchs corneal dystrophy at our center. We excluded patients with prior ocular surgery other than cataract surgery to limit confounding variables.

METHODS

Best spectacle-corrected visual acuity (BSCVA; in logarithm of the minimal angle of resolution [logMAR] units) was obtained and specular microscopy of donor corneal tissue was performed before surgery. Postoperative complications, BSCVA, and the percent of endothelial cell loss (ECL) recorded at 6 months were compared with the Student t test. Patients with pre-existing ocular comorbidity that impacted visual potential such as macular degeneration, amblyopia, advanced glaucoma, and other optic neuropathies were excluded from the analysis of visual acuity, but were included for the outcomes of complications and ECL.

MAIN OUTCOME MEASURES

Visual acuity improvement, ECL 6 months after surgery, postoperative complications, iatrogenic primary graft failure (IPGF), and rebubbling.

RESULTS

Of the 200 eyes, 62 DSAEK eyes and 70 DMEK eyes had 6-month BSCVA available and no vision-limiting comorbidities. Mean BSCVA increased from 0.41±0.19 logMAR and 0.27±0.11 logMAR before surgery to 0.20±0.13 logMAR and 0.11±0.13 logMAR 6 months after DSAEK and DMEK, respectively (P<0.001). Seventy-one DSAEK eyes and 70 DMEK eyes had 6-month ECL data available: ECL was 25.9±14.0% after DSAEK and 27.9±16.0% after DMEK (P=0.38). There were no IPGFs in the DSAEK cohort and there were 4 of 100 IPGFs after DMEK (P=0.12). Rebubbling was performed in 2 of 100 eyes after DSAEK and in 6 of 100 eyes after DMEK (P=0.28).

CONCLUSIONS

Compared with DSAEK, DMEK provided better visual recovery and comparable 6-month ECL. The DMEK group had a higher, although not statistically significant, percentage of rebubbling procedures and IPGFs.

Clinical outcomes of Descemet membrane endothelial keratoplasty using eye bank-prepared tissues

PURPOSE

To investigate the outcomes of Descemet membrane endothelial keratoplasty (DMEK) using prestripped donor tissue prepared by an eye bank.

DESIGN

Retrospective, noncomparative case series.

METHODS

This retrospective, noncomparative, observational study investigated the outcomes of the first 40 consecutive DMEK procedures performed by a single surgeon using prestripped tissues prepared by a single eye bank during the period September 17, 2013 to July 1, 2014. A new technique to unfold the Descemet membrane grafts using a single cannula was described. Medical records were reviewed to obtain the prestripped and poststripped endothelial cell counts (ECC), postoperative ECC, visual acuity measurements, and complications.

RESULTS

Of the 43 prestripped tissues received, 40 were transplanted. The leading indications for DMEK were Fuchs endothelial corneal dystrophy (n = 28) and bullous keratopathy (n = 11). Nine DMEK procedures were performed in combination with phacoemulsification and posterior chamber intraocular lens implantation. Six patients had undergone prior glaucoma surgeries. The mean follow-up duration was 5.3 months (range, 1 week to 11 months). Preoperative spectacle-corrected visual acuity was ≤20/200 in 8 patients (20%) and ≤20/40 in 37 patients (92.5%). Primary graft failure occurred in the first case. Thirty-eight patients had improved vision postoperatively. Among the 39 patients who had successful DMEK, postoperative BCVA was ≥20/20 in 20 patients (51.2%), ≥20/25 in 30 patients (76.9%), and ≥20/40 in 34 patients (87.2%) by the last follow-up. There was no secondary graft failure. Rejection occurred in 2 patients because of self-discontinuation of topical corticosteroid. The most common complication was partial detachment requiring air injection (11 of 40 patients; 27.5%). Mean ECC loss after stripping of Descemet membrane was 3.9% (range, 6.5% gain to 14.5% loss). During the first 6 months after transplantation, the average ECC loss was 30.5% (range, 3.8%-67.4% loss).

CONCLUSIONS

DMEK using eye bank-prepared tissue achieved outcomes comparable to those reported for DMEK using surgeon-prepared tissue.

Corneal donor tissue preparation for Descemet's membrane endothelial keratoplasty

Descemet's Membrane Endothelial Keratoplasty (DMEK) is a form of corneal transplantation in which only a single cell layer, the corneal endothelium, along with its basement membrane (Descemet's membrane) is introduced onto the recipient's posterior stroma(3). Unlike Descemet's Stripping Automated Endothelial Keratoplasty (DSAEK), where additional donor stroma is introduced, no unnatural stroma-to-stroma interface is created. As a result, the natural anatomy of the cornea is preserved as much as possible allowing for improved recovery time and visual acuity(4). Endothelial Keratoplasty (EK) is the procedure of choice for treatment of endothelial dysfunction. The advantages of EK include rapid recovery of vision, preservation of ocular integrity and minimal refractive change due to use of a small, peripheral incision(1). DSAEK utilizes donor tissue prepared with partial thickness stroma and endothelium. The rapid success and utilization of this procedure can be attributed to availability of eye-bank prepared precut tissue. The benefits of eye-bank preparation of donor tissue include elimination of need for specialized equipment in the operating room and availability of back up donor tissue in case of tissue perforation during preparation. In addition, high volume preparation of donor tissue by eye-bank technicians may provide improved quality of donor tissue. DSAEK may have limited best corrected visual acuity due to creation of a stromal interface between the donor and recipient cornea. Elimination of this interface with transplantation of only donor Descemet's membrane and endothelium in DMEK may improve visual outcomes and reduce complications after EK(5). Similar to DSAEK, long term success and acceptance of DMEK is dependent on ease of availability of precut, eye-bank prepared donor tissue. Here we present a stepwise approach to donor tissue preparation which may reduce some barriers eye-banks face in providing DMEK grafts.