To determine the relationship between anterior chamber depth (ACD) and percent endothelial cell loss (ECL) after Descemet Stripping Automated Endothelial Keratoplasty (DSAEK).
In 78 eyes receiving ...triple procedure (DSAEK combined with cataract extraction and posterior chamber intraocular lens (PCIOL) implantation), ACD was measured preoperatively with an intraocular lens (IOL) Master and ECL was calculated with specular microscopy at 6 months, 1, 2, 3, and 4 years postoperatively. ACD and ECL from all 78 eyes were compared using correlation analysis and students t test. Eyes were then separated into 2 groups based on ACD, group 1 with ACD < 3mm and group 2 with ACD ≥ 3mm. Students t test was then performed to compare group 1 and group 2 ECL at 6 months, 1, 2, 3, and 4 years postoperative.
Mean ACD for all 78 eyes was 2.93 ± 0.43 mm. Mean ECL was 32.7%, 27.6%, 29.6%, 32.5%, and 37.2% at 6 months, 1, 2, 3, and 4 years. No significant correlation between ACD and ECL was observed at any time point for the combined analysis of 78 eyes (P > .05). At 2 and 4 years postoperative, mean ECL was 32.6% ± 16.1% and 43.0% ± 23.2% in eyes with ACD < 3mm and 25.3% ± 13.0% and 29.6% ± 18.2% in eyes with ACD ≥ 3 mm (P = .041 at 2 years and .008 at 4 years).
ACD and ECL were not directly correlated; however, there may be a threshold ACD in which shallower anterior chambers preoperatively result in greater donor ECL over time.
Purpose To report early complications of Descemet stripping automated endothelial keratoplasty (DSAEK) to treat late endothelial failure after penetrating keratoplasty (PK) using a specific surgical ...strategy. Design Retrospective analysis of a prospectively collected dataset. Methods All 17 eyes with a preoperative diagnosis of failed penetrating keratoplasty graft were identified out of a total pool of 793 eyes that had received DSAEK for endothelial dysfunction in a prospective Institutional Review Board–approved study of endothelial keratoplasty. A standard surgical strategy of careful slit-lamp examination and preoperative optical coherence tomography (OCT) to determine optimal DSAEK graft diameter was combined with undersized Descemet stripping and peripheral bed scraping. Results A total of 17 eyes in 16 patients were identified. The DSAEK graft size ranged from 7.0 to 8.0 mm, with all DSAEK graft diameters less than or equal to the PK diameter. The average follow-up was 16 months (range 2-38 months). All PK grafts cleared and the visual acuity improved in all patients. There were no cases of pupillary block or primary graft failure. There was 1 dislocation (5.9%). The dislocation occurred in an eye with aniridia, prior trabeculectomy, and scleromalacia with postoperative hypotony from a wound leak. Conclusion DSAEK for failed PK using DSAEK grafts with a diameter less than or equal to the PK diameter allowed improved vision with a low complication rate. Preoperative OCT of posterior PK contour can aid in graft diameter selection.
To report endothelial cell loss (ECL) caused by a novel S-stamp preparation technique for Descemet membrane endothelial keratoplasty (DMEK).
Six cadaveric human corneas were prepared for DMEK ...transplantation using a single standardized technique, including the application of a dry ink gentian violet S-stamp to the stromal side of Descemet membrane. Endothelial cell death was evaluated and quantified using computerized analysis of vital dye staining.
ECL caused by the S-stamp was 0.6% (range 0.1%-1.0%), which comprised less than one-tenth of the total ECL caused by our preparation of the DMEK graft from the start to finish, including recovery, prestripping, S-stamping, and trephination (13.7% total ECL, range 9.9%-17.6%).
Our novel S-stamp donor tissue preparation technique is intuitive to learn and holds the promise of preventing iatrogenic primary graft failure due to upside-down grafts without causing unacceptable increases in ECL.
Laboratory studies were performed to evaluate the histologic differences between the recipient bed after deep lamellar endothelial keratoplasty (DLEK) surgery and Descemet's-stripping endothelial ...keratoplasty (DSEK) surgery. Relevant new surgical strategies to prevent dislocation in DSEK surgery were initiated in our first 100 consecutive clinical cases.
Ten pairs of cadaver eyes had a DLEK in 1 eye and a DSEK in the fellow eye, and the posterior stromal surface was analyzed by scanning electron microscopy at x50 magnification. Based on the findings in these cadaver eyes, our DSEK procedure was modified to include surgical roughening in the peripheral recipient bed in 100 consecutive eyes. One hundred percent of these eyes were followed for at least 60 days after surgery to determine the rate of donor dislocation.
In all 10 pairs of cadaver eyes, the DSEK stromal interface showed a smoother surface than DLEK eyes, without the presence of cut stromal fibrils. The DLEK surface was less smooth than the DSEK eyes, but with the presence of uniformly cut fibrils over the entire surface. Subsequent surgical modifications to the DSEK procedure to include scraping and roughening of the recipient peripheral bed in humans resulted in only a 4% (4/100) dislocation rate of the donor tissue into the anterior chamber. One of these 4 dislocated donors was seen on the first postoperative day and was the only primary graft failure in the series. The other 3 cases were fully attached on the first postoperative day with no interface fluid, but they dislocated later on postoperative days 2, 3, and 4.
The high rate of dislocation of the donor disc in DSEK may be caused by the absence of recipient stromal fibrils to initially bind to the donor stromal fibrils. Clinical success with a surgical technique of selectively scraping the peripheral recipient bed to promote donor edge adhesion (while leaving the central bed untouched for vision) may aid in the prevention of donor dislocation in DSEK surgery. Reduction of dislocation in DSEK surgery has also been associated with a reduced rate of iatrogenic primary graft failure (PGF) to 1%.
To identify factors related to graft rejection following Descemet stripping automated endothelial keratoplasty (DSAEK) in the Cornea Preservation Time Study (CPTS).
Cohort study within a multicenter ...randomized clinical trial.
A total of 1330 eyes of 1090 subjects undergoing DSAEK were randomized to receive a donor cornea with preservation time (PT) of 0–7 days (n = 675) or 8–14 days (n = 655) and followed for 3 years. Central endothelial cell density (ECD) was determined by a central image analysis reading center. Multivariable Cox models adjusted for PT, recipient diagnosis, and surgeon effect were used to identify factors associated with rejection.
Cumulative probability of definite graft rejection was 3.6% (99% confidence interval 2.5%–5.3%). Younger recipient age was associated with graft rejection (P < .001; hazard ratio: 0.53 0.33, 0.83 per decade). PT, donor–recipient sex mismatch, recipient diagnosis, recipient race, graft size, discontinuation of topical corticosteroids and immune-modulators, prior immunizations within 3 months, and prior glaucoma surgery were not associated with rejection (P > .01). Among clear grafts with an ECD measurement at baseline and 3 years (n = 913), endothelial cell loss (ECL) was greater in eyes that experienced a rejection episode (n = 27) than in those that did not (n = 886) (48% vs 38%, P = .03). Twelve of 44 eyes (27%) with definite graft rejection subsequently failed, comprising 15% of the 79 failures in the CPTS.
Graft rejection is uncommon after DSAEK and more likely with younger age, in a study cohort mostly > 50 years old. Rejection increases ECL, but it is not a leading cause of DSAEK failure.
•Descemet stripping automated endothelial keratoplasty rejection rates are low (3.6%) after 3 years in the Cornea Preservation Time Study.•Younger recipient age is associated with a higher rejection rate.
The aim of this study was to determine whether loading a Descemet membrane endothelial keratoplasty (DMEK) graft using a drop-in procedure results in more endothelial cell loss (ECL) than the ...standard suction procedure.
Pairs of donor corneas with equivalent preprocessing endothelium were prepared using the standard protocol of our eye bank. One member of each pair was loaded into an injector using the standard suction protocol. The mate graft was loaded using a drop-in protocol, in which the edge of the graft was gently grasped with a forceps, lifted to the edge of the injector, and dropped inside. Grafts were evaluated for ECL and examined for grab marks or other loading-associated damage.
There was no difference in mean ECL of grafts prepared for DMEK using the standard protocol (20.6% ± 4.5%) compared with that of mate grafts prepared using the drop-in loading protocol (19.5% ± 4.8%, P = 0.59). There was no consistent pattern of damage in the drop-in-loaded grafts, as grab marks or other tissue damage associated with the drop-in loading protocol were not consistently identified by a trained corneal surgeon.
ECL was not significantly different in grafts prepared using a drop-in loading procedure compared with grafts prepared using the standard suction protocol. The drop-in loading protocol may be particularly useful to surgeons who load their own grafts and eye bank processing technicians who encounter a "flat" DMEK graft that does not scroll or a loosely scrolled DMEK graft.
To report 6-month results in a large, prospective study of Descemet-stripping automated endothelial keratoplasty (DSAEK).
A 5-mm scleral-limbal tunnel approach was created for placement of an ...automated microkeratome-prepared 8.0-mm endothelial graft after DSAEK in 150 consecutive cases between September 2005 and October 2006. Six-month follow-up data were available on 100 eyes. Intraoperative peripheral scraping was performed to promote adherence of the donor. Preoperative and postoperative visual acuity with and without spectacle correction (BSCVA and UCVA), refractive astigmatism, average topographic keratometry, surface asymmetry index, surface regularity index, and pachymetry were measured prospectively.
After DSAEK surgery, average BSCVA improved from 20/86 to 20/38, and average UCVA improved from 20/155 to 20/73, which were both statistically significant (P < 0.05). Excluding 26 eyes with known retinal pathology: 97% of the 74 eyes had a vision of 20/40 or better at 6 months and 14% obtained 20/20 or better. Refractive astigmatism changed an average 0.06 D, and average topographic keratometry changed an average -0.13 D, which were not statistically significant. Surface regularity index and surface asymmetry index improved to normal levels of 0.67 and 1.03, respectively (P < 0.001 and P = 0.002). Pachymetry decreased significantly from 0.70 to 0.66 mm (P = .001).
This large prospective study of DSAEK shows that this surgery provides a significant improvement in vision, corneal thickness, and surface regularity. It does not change refractive astigmatism or average topographic keratometry significantly. This newer technique of endothelial keratoplasty yields many of the benefits of its predecessors, deep lamellar endothelial keratoplasty and posterior lamellar keratoplasty, while improving the visual results.
To report the immediate postoperative complications and the 6- and 12-month clinical results in a large series of cases undergoing the new triple-procedure Descemet's stripping automated endothelial ...keratoplasty (DSAEK) and concurrent cataract surgery.
Prospective, noncomparative, interventional case series.
Three hundred fifteen eyes of 233 patients with Fuchs' corneal dystrophy were evaluated for the complications of dislocation and iatrogenic primary graft failure (IPGF). Two hundred three eyes of 149 patients had 6-month postoperative data available for other outcome analysis.
A standardized technique of DSAEK with extensive use of cohesive viscoelastic was performed in all 315 eyes with Fuchs' dystrophy, and 225 of those eyes had cataract surgery concurrently. Of the 203 eyes with 6-month data, concurrent phacoemulsification with intraocular lens placement (triple procedure) was performed in 149 of those eyes.
The complications of graft dislocation and IPGF were recorded for all eyes. Six- and 12-month postoperative best spectacle-corrected visual acuity (BSCVA), refractive spherical equivalent (SE), and central donor endothelial cell density (ECD) were measured prospectively and then compared with preoperative values for the triple-procedure eyes.
There were 4 dislocations (4%) among the 90 straight DSAEK cases and 4 dislocations (1.8%) among the 225 triple-procedure cases (P = 0.327). There was not a single case of IPGF in any of the 315 DSAEK cases. After the triple procedure, the BSCVA in eyes without comorbidity (n = 122) improved with 93% at 20/40 or better at 6 months and 97% at 20/40 or better at 12 months. Refractive SE at 6 months averaged 0.11+/-1.08 diopters (D), with 73% of eyes within 1 D of emmetropia and 95% within 2 D of emmetropia. The postoperative mean ECD was 1955 cells/mm(2) at 6 months (n = 125) and 1979 cells/mm(2) at 12 months (n = 89) and represented a 32% cell loss from that before surgery (P<0.001) for both postoperative time points.
The new triple-procedure DSAEK combined with cataract surgery provides rapid visual recovery and allows selection of an appropriate intraocular lens. Dislocations are rare (1.8%) and primary graft failure did not occur.
Determining factors associated with endothelial cell loss after Descemet stripping automated endothelial keratoplasty (DSAEK) could improve long-term graft survival.
To evaluate the associations of ...donor, recipient, and operative factors with endothelial cell density (ECD) 3 years after DSAEK in the Cornea Preservation Time Study.
This cohort study was a secondary analysis of data collected in a multicenter, double-masked, randomized clinical trial. Forty US clinical sites with 70 surgeons participated, with donor corneas provided by 23 US eye banks. Individuals undergoing DSAEK for Fuchs dystrophy or pseudophakic/aphakic corneal edema were included.
The DSAEK procedure, with random assignment of a donor cornea with a preservation time of 0 to 7 days or 8 to 14 days.
Endothelial cell density at 3 years as determined by a reading center from eye bank and clinical specular or confocal central endothelial images.
The study included 1090 participants (median age, 70 years) with 1330 affected eyes (240 bilateral cases 22.0%), who underwent DSAEK for Fuchs dystrophy (1255 eyes 94.4%) or pseudophakic/aphakic corneal edema (PACE) (75 eyes 5.6%). Of these, 801 eyes (60.2%) belonged to women and 1207 (90.8%) to white individuals. A total of 749 participants (913 eyes; 164 21.9% bilateral cases) had functioning grafts with acceptable endothelial images preoperatively and at 3 years postoperatively and were included in this analysis. Factors associated with a lower ECD at 3 years (estimated effect with 99% CI) in the final multivariable model included donors with diabetes (-103 -196 to -9 cells/mm2), lower screening ECD (-234 -331 to -137 per 500 cells/mm2), recipient diagnosis of PACE (-257 -483 to -31 in cells/mm2), and operative complications (-324 -516 to -133 in cells/mm2). Endothelial cell loss (ECL) from a preoperative measurement to a 3-year postoperative measurement was 47% (99% CI, 42%-52%) for participants receiving tissue from donors with diabetes vs 43% (99% CI, 39%-48%) without diabetes; it was 53% (99% CI, 44%-62%) for participants diagnosed with PACE vs 44% (99% CI, 39%-49%) for those diagnosed with Fuchs dystrophy, and 55% (99% CI, 48%-63%) in participants who experienced operative complications vs 44% (99% CI, 39%-48%) in those who did not. No other donor, recipient, or operative factors were significantly associated with 3-year ECD.
Donor diabetes, lower screening ECD, a PACE diagnosis in the recipient, and operative complications were associated with lower ECD at 3 years after DSAEK surgery and may be associated with long-term graft success. While causation cannot be inferred, further studies on the association of donor diabetes and PACE in recipients with lower 3-year ECD warrant further study.
To assess the relationship between intraoperative unscrolling time of the donor Descemet membrane endothelial keratoplasty (DMEK) tissue and 6-month postoperative endothelial cell loss (ECL), and to ...determine whether donor age, scroll tightness, and the presence of an S stamp are related to unscrolling time.
Ninety-three consecutive uncomplicated DMEK surgeries performed on eyes with Fuchs endothelial dystrophy using our standardized technique (ie, prestripped tissue with or without a premarked S stamp from our eye bank, overstripping the recipient, Straiko glass injector, no-touch tap technique, and bubble of 20% SF6 gas) were evaluated. Intraoperative unscrolling times and 6-month endothelial cell densities were measured and analyzed.
Sixty-nine cases comprised the study cohort. The median unscrolling time was 4 minutes (range: 0.8-17.5 minutes), and the median ECL was 26.9% (range: -4.3% to 80.0%). There was no relationship between unscrolling time and ECL at 6 months by the Pearson correlation coefficient (r = -0.02, P = 0.89). Younger donor age, tighter scrolls, and absence of an S stamp had no correlation with longer unscrolling times (all P > 0.05). Only 2 of 4 cases of iatrogenic primary graft failure had unscrolling times available for analysis; in this limited sample, there was no association between iatrogenic primary graft failure and unscrolling time.
Once the DMEK tissue is safely in the anterior chamber, surgeons need not rush the "DMEK dance" because longer unscrolling times may not endanger the endothelium.
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