To assess the visual impact of ocular wavefront aberrations, corneal thickness, and corneal light scatter prospectively after Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK) in humans.
Data were obtained prospectively from 20 eyes pre-operatively and at 1, 3, 6, and 12 months post- DSAEK. At each visit, best spectacle corrected visual acuity (BSCVA) and visual acuity with glare (Brightness Acuity Testing - BAT) were recorded and ocular wavefront measurements and corneal Optical Coherence Tomography (OCT) performed. Magnitude and sign of individual Zernike terms (higher order aberrations HOA) were determined. Epithelial, host stromal, donor stromal, and total corneal thickness were quantified. Brightness, intensity profiles of OCT images were generated to quantify light scatter in the whole cornea, subepithelial region, anterior and posterior host stroma, interface, and donor stroma.
Mean BSCVA and glare disability at low light levels improved from 1 to 12 months post-DSAEK. All corneal thicknesses and ocular lower- and HOAs were stable from 1 through 12 months, whereas total corneal, host stromal, and interface brightness intensities decreased significantly over the same period. A repeated measures ANOVA across the follow up period found that the change in scatter, but not the change in higher order aberrations, could account for the variability occurring in acuity from 1 to 12 months post-DSAEK.
While ocular HOAs and scatter are both elevated over normal post-DSAEK, our results demonstrate that improvements in visual performance occurring over the first year post-DSAEK are associated with decreasing light scatter. In contrast, there were no significant changes in ocular HOAs during this time. Because corneal light scatter decreased between 1 and 12 months despite stable corneal thicknesses over the same period, we conclude that factors that induced light scatter, other than tissue thickness or swelling (corneal edema), significantly impacted the visual improvements that occurred over time post-DSAEK. A better understanding of the cellular and extracellular matrix changes of the subepithelial region and interface, incurred by the surgical creation of a lamellar host -graft interface, and the subsequent healing of these tissues, is warranted.
This study describes the in vivo confocal microscopy findings in two patients who had deep anterior lamellar keratoplasty (DALK) following Descemet’s stripping automated endothelial keratoplasty (DSAEK).
The study reviewed the cases of two patients who first underwent DSAEK followed by DALK when their vision failed to improve due to residual stromal scarring. In the first case, a DSAEK was performed for a patient with pseudophakic bullous keratopathy. After surgery, the patient’s vision failed to improve satisfactorily due to residual anterior stromal opacity and irregularity. Subsequently, the patient underwent a DALK. The same two consecutive operations were performed for a second patient with keratoconus whose previous penetrating keratoplasty had failed and had secondary graft ectasia. In vivo confocal microscopy was performed 2 months after the DALK surgery in both cases.
At 3 months after DALK, the best-corrected visual acuity was 6/30 in case 1 and 6/24 in case 2. In vivo confocal microscopy in both cases revealed the presence of quiescent keratocytes in the stroma layers of the DSAEK and DALK grafts, which was similar in the central and peripheral cornea. There was no activated keratocytes or haze noted in the interface between the grafts.
Our short-term results show that performing a DALK after a DSAEK is an effective way of restoring cornea clarity in patients with residual anterior stromal opacity. In vivo confocal microscopy showed that there were no activated keratocytes seen in the interface of the grafts, which suggests that optimal visual acuity may be obtained with minimal interface haze.
cornea; transplant; keratocytes; histology
To perform a comparative cost-effectiveness analysis of Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK) for corneal endothelial disease.
Retrospective cost-effectiveness analysis
This cost-effectiveness analysis was performed from a third-party payer perspective with a 5-year time horizon. Probabilities of outcomes and complications of each of the procedures were calculated based on review of the published literature. A model was constructed to compare the costs and utilities associated with DSAEK and PK. Costs of donor tissue preparation, surgery, follow-up, post-operative complications and procedures were considered. Utility values were based on quality adjusted life years (QALYs) associated with visual acuity outcomes. Both costs and utilities were discounted at 3% per year. Sensitivity analyses were performed on key model inputs.
Base case analysis found DSAEK to be less costly compared to PK ($9,362 vs.$10,239), with greater utility (3.15 QALY vs. 2.47 QALY). Sensitivity analyses revealed that even at graft failure rates for DSAEK approaching the rates for PK, DSAEK would still be cost saving. Varying the dislocation rate in our model shows that even at dislocation rates approaching 50%, DSAEK remains less costly. Further, with DSAEK rejection rates as high as 28%, DSAEK would remain a dominant procedure over PK.
Comparative cost-effectiveness analysis of DSAEK vs. PK indicates favorable cost and utility outcomes associated with DSAEK for treatment of corneal endothelial disease. Longer follow-up of DSAEK outcomes will provide more accurate information regarding long-term cost-effectiveness of the procedure.
To investigate a correlation between the severity of histologic changes of Descemet’s membrane in patients with Fuchs’ endothelial dystrophy and the postoperative best-corrected visual acuity following Descemet’s membrane stripping endothelial keratoplasty (DSAEK).
In a retrospective study design, a histologic grading system was created based on common characteristics observed histologically among 92 DSAEK specimens sent to the UW Eye Pathology Laboratory with a clinical diagnosis of Fuchs’ dystrophy from three separate corneal surgeons. Cases were graded as mild, moderate, or severe based on four characteristics including guttae dispersion, presence of a laminated Descemet’s membrane, presence of embedded guttae, and density of guttae. Regression models were built to study the relationship between preoperative visual acuity, histological findings and best corrected visual acuity six months, 1 year, and 2 years after DSAEK surgery.
No correlation was found between the severity of histologic changes of Descemet’s membrane and preoperative visual acuity. A correlation exists, however, between the preoperative visual acuity and final visual acuity. Cases with a laminated Descemet’s membrane but no embedded guttae (n=8) appear less responsive to DSAEK surgery. Otherwise, the severity of histologic changes of Descemet’s membrane observed in patients with Fuchs’ corneal dystrophy following DSAEK did not show a statistically significant correlation with final visual acuity.
Our analysis fails to show an inverse relationship between the severity of histologic changes of Descemet’s membrane and the best-corrected visual acuity of ≥ 20/40 following DSAEK for Fuchs’ endothelial dystrophy. However, in a subset of Fuchs’ dystrophy patients, those who develop a laminated Descemet’s membrane without embedded guttae, the visual recovery following DSAEK is less than expected. The laminated architecture of Descemet’s membrane without embedded guttae may facilitate the separation between the layers of Descemet’s and, thus, incomplete removal of the recipient’s Descemet’s membrane during DSAEK, which may then limit the postoperative visual outcome.
The purpose of this paper is to report our experience of Descemet’s stripping and non-Descemet’s stripping automated endothelial keratoplasty (DSAEK/nDSAEK) for microcorneas using 6.0 mm donor grafts.
Three eyes of two patients (a 56-year-old woman and a 59-year-old woman) with microcornea and suffering from bullous keratopathy were treated with either DSAEK or nDSAEK. A small donor graft (6.0 mm) was inserted into the anterior chamber using a double glide (Busin glide and intraocular lens sheet glide) donor insertion technique. Both patients were followed for at least 12 months. Clinical outcomes, including intraoperative and postoperative complications, visual acuity, and endothelial cell density were evaluated.
In all three cases (100%), no intraoperative complications were noted. In one case with a flat keratometry value (32.13 D), a partial donor detachment was noted one day postoperatively, but it was reattached by rebubbling. In another case, rejection was noted 8 months postoperatively, but treatment with systemic corticosteroids was successful. A clear cornea remained in all three cases (100%), with best-corrected visual acuity greater than 20/100 (mean 20/50) at 12 months. Mean postoperative endothelial cell counts were 2,603 ± 18 cells/mm2 at 6 months (7.4% decrease from preoperative donor cell counts) and 1,799 ± 556 cells/mm2 at 12 months (36.5% decrease).
We report for the first time the successful use of a small donor graft (6.0 mm) for DSAEK/nDSAEK in cases of microcornea. Additional stud ies using a large number of patients are required to evaluate fully the potential advantages and drawbacks of small diameter donor grafts for microcornea.
microcornea; Descemet’s stripping; non-Descemet’s stripping; automated endothelial keratoplasty; small donor grafts
To evaluate myofibroblast differentiation as an etiology of haze at the graft-host interface in a cat model of Descemet’s Stripping Automated Endothelial Keratoplasty (DSAEK).
DSAEK was performed on 10 eyes of 5 adult domestic short-hair cats. In vivo corneal imaging with slit lamp, confocal, and optical coherence tomography (OCT) were performed twice weekly. Cats were sacrificed and corneas harvested 4 hours, and 2, 4, 6, and 9 days post-DSAEK. Corneal sections were stained with the TUNEL method and immunohistochemistry was performed for α-smooth muscle actin (α-SMA) and fibronectin with DAPI counterstain.
At all in vivo imaging time-points, corneal OCT revealed an increase in backscatter of light and confocal imaging revealed an acellular zone at the graft-host interface. At all post-mortem time-points, immunohistochemistry revealed a complete absence of α-SMA staining at the graft-host interface. At 4 hours, extracellular fibronectin staining was identified along the graft-host interface and both fibronectin and TUNEL assay were positive within adjacent cells extending into the host stroma. By day 2, fibronectin and TUNEL staining diminished and a distinct acellular zone was present in the region of previously TUNEL-positive cells.
OCT imaging consistently showed increased reflectivity at the graft-host interface in cat corneas in the days post-DSAEK. This was not associated with myofibroblast differentiation at the graft-host interface, but rather with apoptosis and the development of a subsequent acellular zone. The roles of extracellular matrix changes and keratocyte cell death and repopulation should be investigated further as potential contributors to the interface optical changes.
The purpose of this study was to compare endothelial cell counts after Descemet’s stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty in Asian eyes.
This was a retrospective study of patients from our prospective Singapore Corneal Transplant Study cohort who received corneal transplantation in 2006–2008. We compared eyes that underwent DSAEK or penetrating keratoplasty for Fuchs’ endothelial dystrophy or pseudophakic and aphakic bullous keratopathy. Clinical data, and donor and recipient characteristics were recorded. Of 241 patients who met our inclusion criteria, 68 underwent DSAEK and 173 underwent penetrating keratoplasty. The main outcome measure was endothelial cell loss at 1 year. Secondary outcome measures were graft survival and visual outcomes at 1-year follow-up.
There were no significant differences in baseline characteristics of patients between the treatment groups. Percent endothelial cell loss at 1-year follow-up was greater in penetrating keratoplasty eyes (40.9% ± 2.9%) compared with DSAEK eyes (22.4% ± 2.3%; P < 0.001). DSAEK-treated eyes had significantly superior uncorrected visual acuity (mean difference = 0.42 ± 0.0059; P < 0.001) and best spectacle-corrected visual acuity (mean difference = 0.14 ± 0.032; P < 0.001) as compared with penetrating keratoplasty-treated eyes. Penetrating keratoplasty-treated eyes had worse astigmatism as compared with DSAEK-treated eyes (−3.0 ± 2.1 versus −1.7 ± 0.8; P < 0.001). Graft survival at 1 year was comparable in both groups, ie, 66/68 (97.0%) DSAEK-treated eyes versus 158/173 (92.0%) of penetrating keratoplasty-treated eyes had clear grafts (P = 0.479).
We report lower percent endothelial cell loss comparing DSAEK and penetrating keratoplasty at 1-year follow-up in Asian eyes, with comparable graft survival rates in both groups.
Descemet’s stripping automated endothelial keratoplasty; endothelial cell count; penetrating keratoplasty
To use excimer laser smoothing passes to reshape DSAEK endothelial grafts, and to evaluate the effect on the donor endothelium.
The stromal surface of microkeratome-cut DSAEK grafts was smoothed using excimer laser smoothing passes with masking fluid. Excimer laser hyperopic ablation was used to improve the uniformity of graft thickness within the optical zone. Fourier-domain optical coherence tomography (OCT) was used to measure endothelial graft pachymetry, plan ablations, and evaluate donor contour. Vital dye staining was performed to assess endothelial cell damage. Scanning electron microscopy (SEM) images of stromal surfaces were graded on a 5-point scale by masked observers to evaluate surface roughness.
Four grafts underwent excimer laser smoothing. Vital dye staining showed no endothelial damage. Microkeratome-cut surfaces treated with laser smoothing (mean grade=2.04) were smoother than non-smoothed microkeratome-cut surfaces (mean grade=4.07, p<0.01), surfaces which underwent dry laser ablation (mean grade=3.63, p<0.01), and manually dissected interfaces (mean grade=4.75, p<0.0001). No difference was observed between stromal beds created by peeling Descemet’s membrane (mean grade=1.64) compared to surfaces produced by microkeratome cutting followed by laser smoothing (mean grade=2.04, p=0.14). One graft underwent combined excimer smoothing and peripheral hyperopic ablation. The centre-periphery thickness difference was 15μm prior to ablation and 4μm afterward.
Laser smoothing passes can be used to improve the contour and smoothness of DSAEK grafts without damaging donor endothelial cells. Clinical trials are needed to determine whether reshaping donors using excimer laser can deliver improved visual outcomes following DSAEK.
endothelial graft; DSAEK; excimer laser; smoothing; endothelium
Fuchs endothelial dystrophy (FED) is a condition in which there is
premature degeneration of corneal endothelial cells. When the number of
endothelial cells is reduced to a significant degree, fluid begins to
accumulate within the cornea. As a result, the cornea loses its transparency
and the individual suffers a reduction in vision. The only successful
surgical treatment for this condition is replacement of part or all of the
cornea with healthy tissue from a donor. The established procedure,
penetrating keratoplasty (PKP), has been used for many years and its safety
and efficacy are well known. Endothelial keratoplasty (EK) techniques are
relatively new surgical procedures and their safety and efficacy relative to
PKP are uncertain.
The objective of this review was to compare the benefits and
complications related to two surgical methods (EK and PKP) of replacing the
diseased endothelial layer of the cornea with a healthy layer in people with
We searched CENTRAL (which contains the Cochrane Eyes and Vision
Group Trials Register) (The Cochrane Library 2014, Issue
1), MEDLINE (January 1950 to January 2014), EMBASE (January 1980 to January
2014), Latin American and Caribbean Health Sciences Literature Database
(LILACS) (January 1982 to January 2014), the metaRegister
of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov
(www.clinicaltrials.gov). There were no date or language
restrictions in the electronic searches for trials. The electronic databases
were last searched on 27 January 2014.
We included all randomised controlled trials (RCTs) comparing EK
versus PKP for people (of any age and gender) who had been clinically
diagnosed with FED.
Data collection and analysis
Two authors independently screened the search results, assessed trial
quality and extracted data using the standard methodological procedures
expected by The Cochrane Collaboration.
We included three RCTs that enrolled a total of 139 eyes of 136
participants and analysed 123 (88%) eyes. Two RCTs randomised eyes into
either the endothelial keratoplasty (EK) group or penetrating keratoplasty
(PKP) group and one RCT randomised eyes into either the femtosecond
laser-assisted endothelial keratoplasty (FLEK) group or PKP group. The RCTs
comparing EK with PKP did not show any significant differences between
procedures with respect to best corrected visual acuity (BCVA) at two years
(mean difference (MD) 0.14 logMAR; 95% confidence interval (CI) −0.08
to 0.36; P = 0.23) or at one year (MD 0.09 logMAR; 95% CI −0.05 to
0.23; P = 0.22), whereas the trial comparing FLEK with PKP showed
significantly better BCVA after PKP (MD 0.20 logMAR; 95% CI 0.10 to 0.30; P
= 0.0001). Only one RCT reported on irregular astigmatism (higher-order
aberration), which was less with EK than PKP (MD −1.20 µm; 95%
CI −1.53 to −0.87; P < 0.001). Only one RCT reported on
endothelial cell counts (lower after FLEK than PKP: MD −969
cells/mm²; 95% CI −1161 to −777; P < 0.001),
primary graft failure (higher after FLEK than PKP: RR 7.76; 95% CI 0.41 to
145.22; P = 0.10), and graft rejection (more after FLEK than PKP: RR 1.11;
95% CI 0.07 to 17.12; P = 0.94). Only one RCT reported that 27.8% of
participants had graft dislocation, 2.8% had epithelial ingrowth and
postoperative pupillary block, and 13.9% had intraocular pressure
(IOP)-related problems in the FLEK group compared with the PKP group, in
whom 10% had suture-related problems, 5% had wound dehiscence and 10% had
suture revision to correct astigmatism. Overall, the adverse events in the
FLEK group appeared to be more frequent than in the PKP group. No trials
reported information about quality of life or economic data. The overall
methodological quality of the three trials was not satisfactory as most did
not perform allocation concealment or masking of participants and outcome
assessors, and all trials had a small sample size.
The rapid growth of endothelial keratoplasty as the treatment of
choice for FED is based upon the belief that visual recovery is more rapid,
surgically induced astigmatism (regular and irregular) is less and rates of
transplant rejection are lower with EK. This change in practice also assumes
that the rates of long term transplant survival are equal for the two
procedures. The practical differences between the surgical procedures mean
that visual recovery is inherently more rapid following EK, but this review
found no strong evidence from RCTs of any difference in the final visual
outcome between EK and PKP for people with FED. This review also found that
higher order aberrations are fewer following EK but endothelial cell loss is
greater following EK. The RCTs that we included employed different EK
techniques, which may have a bearing on these findings. EK procedures have
evolved over the years and can be performed using different techniques, for
example deep lamellar endothelial keratoplasty, Descemets stripping
endothelial keratoplasty (DSEK), Descemets stripping automated endothelial
keratoplasty (DSAEK), femtosecond laser-assisted endothelial keratoplasty
and Descemet membrane endothelial keratoplasty (DMEK). More RCTs are needed
to compare PKP with commonly performed EK procedures such as DSEK, DSAEK and
DMEK in order to determine the answers to two key questions, whether there
is any difference in the final visual outcome between these techniques and
whether there are differences in the rates of graft survival in the long
Posterior lamellar grafting of the cornea has become the preferred technique for treatment of corneal endothelial dysfunction. Posterior lamellar grafts are usually cut by a micro-keratome or a femto-second laser after the epithelial side of the donor cornea has been applanated. This approach often results in variable central graft thickness in different grafts and an increase in graft thickness towards the periphery in every graft. The purpose of this study was to evaluate if posterior lamellar grafts can be prepared from the endothelial side by a femto-second laser, resulting in reproducible, thin grafts of even thickness.
A CZM 500 kHz Visumax femto-second laser was used. Organ cultured donor grafts were mounted in an artifical anterior chamber with the endothelial side up and out. Posterior grafts of 7.8 mm diameter and 130 micron thickness were prepared by femto-second laser cutting. A standard DSAEK procedure was performed in 10 patients with Fuchs endothelial dystrophy. Patients were followed-up regularly and evaluated by measurement of complications, visual acuity, corneal thickness (Pentacam HR), and endothelial cell density.
Femto-laser cutting of grafts and surgery was uncomplicated. Rebubbling was necessary in 5 of 10 cases (normally only in 1 of 20 cases). All grafts were attached and cleared up during the first few weeks. After six months, the average visual acuity was 0.30 (range: 0.16 to 0.50), corneal thickness was 0.58 mm (range 0.51 to 0.63), and endothelial cell density was 1.570 per sq. mm (range: 1.400 to 2.000 cells per sq. mm). The grafts were of uniform thickness, but substantial interface haze was present in most grafts.
Posterior lamellar corneal grafts can be prepared from the endothelial side using a femto-second laser. All grafts were clear after 6 months with satisfying endothelial cell counts. Poor visual acuity caused by interface scatter was observed in most patients. Femto-second laser cutting parameters needs to be optimised to enable smooth cutting in the posterior stroma.
Corneal grafts; Femto-laser; cornea; DSAEK.
To compare the 3-year incidence of de novo ocular hypertension (OHT) after Descemet stripping automated endothelial keratoplasty (DSAEK) and penetrating keratoplasty (PK). For DSAEK, to evaluate predictors for OHT and 2-year outcomes after OHT development.
This was a review of the prospective Singapore Corneal Transplant Study at a single tertiary referral center. Consecutive DSAEKs and PKs for Fuchs’ endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK) in eyes without pre-existing glaucoma were analyzed. OHT incidence after DSAEK and PK were compared using Kaplan–Meier survival analysis, and OHT risk factors identified using Cox proportional regression. OHT was defined: intraocular pressure (IOP) ≥ 24 mmHg or ≥ 10 mmHg from baseline. Secondary outcomes 2 years after OHT development in DSAEK were rates of glaucoma medical therapy failure, IOP success, graft failure and rejection, and best-spectacle corrected visual acuity (BSCVA).
There were 108 (96.4%) DSAEKs and 216 (96%) PKs. The 1-, 2- and 3-year de novo OHT incidence was not significantly different between DSAEK (36.1%, 47.2%, 47.2%, respectively) and PK (35.7%, 44.9%, 45.8%, respectively; P = 0.914). OHT incidence did not differ in subgroup analyses of multiple clinical variables (P > 0.1). OHT predictors after DSAEK were: fellow eye glaucoma (hazard ratio [HR] 3.20, P = 0.004), age <60 years (HR 2.41, P = 0.016), concurrent goniosynechiolysis (HR 3.29, P = 0.021), post-graft complications or procedures (HR 2.85, P = 0.006). Two years after OHT onset, 29.7% of DSAEKs failed glaucoma medical therapy requiring trabeculectomy. Complete and qualified IOP success was achieved in 23.5% and 76.5%, respectively. Graft failure developed in 9.8% and graft rejection in 5.9%. At 6 months, 1, and 2 years from OHT onset, 86.3%, 88.3%, and 92.1% achieved BSCVA 20/40, respectively.
DSAEK and PK have comparable OHT risks. A significant 30% of DSAEK eyes with OHT require filtration surgery. Effective IOP control and good graft and visual outcomes are achieved with treatment.
DSAEK; glaucoma; ocular hypertension; risk factors
To determine the influence of pre-operative donor tissue characteristics on the graft dislocation rate after Descemet’s stripping automated endothelial keratoplasty (DSAEK).
We retrospectively analyzed associations between donor tissue characteristics and graft dislocation rates for consecutive DSAEK surgeries performed in a four year period at a single institution.
From June 2007 to June 2011, 64 (18%) of 355 eyes underwent a procedure for graft dislocation. There were no differences in donor age, pre-operative endothelial graft thickness, pre-processing endothelial cell density, change in endothelial cell density after processing, time from death to tissue processing, or time from tissue processing to surgery between eyes that experienced dislocations and those that did not (P>.05 for each). The graft recipient’s corneal disease diagnosis, pre-operative corneal thickness, pre-operative visual acuity, glaucoma status, history of glaucoma surgery, and cataract surgery at the time of DSAEK were not associated with an increased rate of dislocation (P>.05 for each). Recipients who experienced graft dislocation were significantly older (73.6 vs. 70.2 years, P=.03) and more likely to undergo subsequent repeat transplantation (29.7% vs. 10.7%, P<.0001).
We found no correlation between any corneal donor tissue characteristic and graft dislocation after DSAEK. Graft dislocation was more common in older recipients. Patients with dislocation had a higher rate of subsequent transplantation.
endothelial keratoplasty; dislocation; rebubble; donor characteristics
Subepithelial fibrosis (SEF) and the transdifferentiation of keratocytes into fibroblasts or myofibroblasts (Fbs/MFbs) have been detected in the cornea of individuals with bullous keratopathy. We examined the anterior cornea of bullous keratopathy patients for such changes after Descemet’s stripping automated endothelial keratoplasty (DSAEK). Twenty-two individuals who underwent unilateral DSAEK at Yamaguchi University Hospital were enrolled in the study. The subjects were divided into groups A (n = 10) and B (n = 12) with a preoperative duration of stromal edema of less than or at least 12 months, respectively. The structure of the anterior stroma was examined by in vivo laser confocal microscopy at various times after surgery. SEF was detected in 1 (10.0%) and 11 (91.7%) cases in groups A and B, respectively, before surgery as well as in 0 (0%) and 7 (58.3%) cases, respectively, at 6 months after DSAEK. Fb/MFb transdifferentiation was detected in 0 (0%) and 8 (66.7%) cases in groups A and B, respectively, before surgery as well as in 0 and 1 (8.3%) case, respectively, at 6 months postsurgery. Anterior stromal scattering (ASS) was detected in 10 (100%) and 12 (100%) cases in groups A and B, respectively, before surgery as well as in 0 (0%) and 6 (50.0%) cases, respectively, at 6 months after DSAEK. Changes in anterior stromal structure apparent before surgery were thus also detected in bullous keratopathy patients after DSAEK. SEF and ASS persisted for more than 6 months in a substantial proportion of individuals with a preoperative duration of stromal edema of at least 12 months.
To report a case of corneal graft failure due to epithelial ingrowth after an uneventful combined Descemet stripping automated endothelial keratoplasty (DSAEK) and phacoemulsification cataract surgery with intraocular lens implant treated successfully with a repeat DSAEK.
A 77-year-old male patient underwent combined DSAEK and phacoemulsification with intraocular lens implant implantation for Fuchs’ endothelial dystrophy plus cataract in the right eye. The donor cornea was cut on the Moria ALTK system and introduced using a suture pull-through technique. After an episode of endothelial rejection, the graft failed, with signs suggesting epithelial ingrowth. It was stripped from the host cornea using a Descemet’s membrane stripper, and a Simcoe irrigation-aspiration cannula was used to remove all traces of interface material. The excised lenticule was examined histologically using a hematoxylin and eosin stain.
The patient regained and maintained excellent visual acuity with no sign of recurrence of epithelial ingrowth. Histopathological evaluation of the donor tissue of the first graft showed epithelial ingrowth on the stromal surface of the graft and very few endothelial cells, in keeping with the diagnosis of graft failure.
Epithelial ingrowth is a possible cause of endothelial graft failure, but histologically proven cases are rare. Surgical intervention can achieve successful clearance, with the potential for cure and an excellent outcome.
epithelial ingrowth; Descemet stripping automated endothelial keratoplasty; graft failure
Purpose. To report the use of femtosecond laser-assisted in situ keratomileusis (LASIK) in the treatment of hyperopia subsequent to Descemet stripping-automated endothelial keratoplasty (DSAEK). Methods. Interventional case report. Results. A 66-year-old woman with Fuchs endothelial dystrophy developed bullous keratopathy after cataract surgery in her right eye. She underwent DSAEK with a significant postoperative hyperopic shift in her refraction. Thirteen months after DSAEK, she underwent wavefront-guided, femtosecond laser-assisted LASIK (IntraLase, Inc., Irvine, CA/AMO, Inc., IL, USA). Pretreatment unaided visual acuity was 20/120, and best-corrected visual acuity was 20/20 with a refraction of +3.25/−0.50 × 170. One year after laser refractive correction, unaided visual acuity was 20/20 with a refraction of +0.25/−0.75 × 160. Conclusion. To our knowledge, this is the first paper on the successful treatment of hyperopic shift related to DSAEK with wavefront-guided, femtosecond laser-assisted LASIK.
To evaluate the visual acuity and endothelial cell density according to the thickness in Descemet's stripping automated endothelial keratoplasty (DSAEK) one year after surgery.
DSAEK patients' data were reviewed. Thirty-seven eyes of 37 patients who underwent DSAEK for pseudophakic bullous keratopathy (PBK) were included in this study. Graft thickness was measured with optical coherence tomography (OCT) 12mo after DSAEK. Eyes were divided into 3 groups based on the graft thickness: thick (>200 µm), medium-thick (150-200 µm) and thin (<150 µm). Best corrected visual acuity (BCVA), endothelial cells density (ECD) and complications were assessed and comparisons were done between groups.
There was no significant difference in age, sex, preoperative BCVA, or follow-up period between DSAEK groups. At postoperative 12mo, mean BCVA was 0.28±0.10 in thick graft group, 0.52±0.08 in medium-thick graft group, and 0.72±0.06 in thin graft group. Thin grafts showed better postoperative BCVA as compared with the medium-thick and thick grafts (P=0.001). Thick graft group had 1637.44±88.19-mm2, medium thick graft had 1764.50±34.28-mm2 and thin graft group had 1845.30±65.62-mm2 ECD at 12mo after the surgery. Thin graft group had better ECD at 12mo after surgery (P=0.001).
Thin grafts after DSAEK ensure better visual rehabilitation. Eyes with thin grafts had significantly lesser loss of ECD compared to eyes with medium-thick and thick grafts one year after surgery.
Corneal endothelial cell density; Descemet's stripping endothelial keratoplasty; graft thickness; visual acuity
To investigate the outcomes and complications of suture pull-through insertion techniques for Descemet stripping automated endothelial keratoplasty (DSAEK) in Chinese phakic eyes.
Patients and Methods
Retrospective case series. Included in the study were all Chinese patients with phakic eyes who underwent DSAEK at Peking University Third Hospital from August 2008 to August 2011. All ocular diseases of the patients were recorded. Distance visual acuity (DVA), near visual acuity (NVA), intraocular pressure (IOP), anterior chamber depth (ACD), central corneal thickness (CCT), and corneal endothelial cell density (ECD) were compared prior to and 12 months after DSAEK. The DSAEK success rate, endothelial cell loss (ECL), complications, and prognosis were analyzed. All patients had at least 12 months of follow up.
Twenty-one eyes of 16 patients were included (11 males and 5 females). Ages ranged from 2 to 47 years with an average age of 29.8 years. The average follow up was 15.4 months (ranging from 12 to 36 months). Diagnoses included 7 eyes (4 patients) with corneal endothelial dystrophy and 14 eyes (12 patients) with bullous keratopathy. Presurgical DVA and NVA (LogMAR) were 1.7±0.7 and 1.2±0.4; postsurgical DVA and NVA were 0.8±0.6 and 0.7±0.5; Z = −3.517, −2.764; P<0.001 and P = 0.006 respectively. Presurgical IOP was 15.8±3.7 mm Hg; postsurgical IOP was 15.2±2.6 mm Hg; Z = −0.505, P = 0.614. Presurgical ACD was 3.00±0.74 mm; postsurgical ACD was 2.72±0.59 mm; Z = −0.524, P = 0.600. Donor ECD was 2992±163 cells/mm2, ECD was 1836±412 cells/mm2 with a 12-month postsurgical ECL of 39%. Success rate was 86%. Surgery complications included pupillary block-induced hypertension in 5 eyes (24%), graft detachment in 3 eyes (14%), and graft dislocation in 1 eye (5%).
DSAEK on Chinese phakic eyes can significantly improve DVA and NVA by preserving the patient’s own crystalline lens. DSAEK is an optional surgery for patients who need to preserve accommodative function. More attention should be given to postsurgical pupillary block-induced hypertension.
To report the 6-month clinical outcome of Descemet’s stripping automated endothelial keratoplasty (DSAEK) for bullous keratopathy (BK) secondary to argon laser iridotomy (ALI), and compare the results with those of DSAEK for pseudophakic bullous keratopathy (PBK) or Fuchs’ endothelial dystrophy (FED).
A total of 103 patients (54 with ALI, 28 with PBK, 21 with FED) undergoing DSAEK were retrospectively analyzed. Simultaneous cataract surgery was performed in 37 patients with ALI and 13 with FED. Preoperative ocular conditions, best spectacle-corrected visual acuity (BSCVA), spherical equivalent refraction (SE), induced astigmatism, keratometric value, endothelial cell density (ECD), and complications were determined over 6 months postoperatively.
Mean axial length in the ALI group (21.8 ± 0.8 mm) was significantly shorter than that in the FED (P = 0.02) or PBK groups (P = 0.003). Severe corneal stromal edema (n = 6), advanced cataract (n = 10), posterior synechia (n = 3), poor mydriasis (n = 5), and Zinn zonule weakness (n = 1) were found only in the ALI group. A significant improvement was observed in postoperative BSCVA in all groups. No significant difference was observed in BSCVA, SE, induced astigmatism, keratometric value, ECD, or complications among the three groups.
Descemet’s stripping automated endothelial keratoplasty for BK secondary to ALI showed rapid postoperative visual improvement, with similar efficacy and safety to that observed in DSAEK for PBK or FED.
Descemet’s stripping automated endothelial keratoplasty; Argon laser iridotomy; Fuchs’ dystrophy; Pseudophakic bullous keratopathy; Posterior lamellar keratoplasty
Descemet’s stripping automated endothelial keratoplasty (DSAEK) has been shown to have superior refractive and visual results compared with penetrating keratoplasty, but higher rates of primary graft failure (PGF). This paper presents donor and surgical risk factors for PGF in DSAEK cases in Asian eyes.
Retrospective case-control study.
All consecutive patients who underwent DSAEK at a tertiary referral teaching hospital from March 2006–December 2008.
Donor details analyzed were: age of donor, cause of donor death, death to harvesting time, donor storage time, distribution distance of tissue, preoperative endothelial cell count. Surgical factors analyzed were: donor diameter, donor thickness, and method of donor insertion. These risk factors in cases of PGF were compared with patients with successful DSAEK as the control group.
Main outcome measure
A total of 124 DSAEK procedures were performed. Six DSAEK procedures (five eyes of five patients; one eye with two failures) resulted in PGF (4.8%). Significant risk factors were found for PGF to include graft insertion using a folding technique (odds ratio [OR], 34.03; 95% confidence interval [CI], 3.75–314.32; P = 0.0017) and a small donor diameter (OR, 39.94; 95% CI, 2.18–732.17; P = 0.013).
The results of this study suggest that in Asian eyes with shallow anterior chambers, surgical trauma relating to the technique of donor insertion, and the use of a small donor are major risk factors for PGF following DSAEK.
DSAEK; PGF; penetrating keratoplasty
To assess 3-year outcomes of Descemet stripping automated endothelial keratoplasty (DSAEK) in comparison with penetrating keratoplasty (PKP) from the Cornea Donor Study (CDS).
Prospective, multicenter, nonrandomized clinical trial.
A total of 173 subjects undergoing DSAEK for a moderate risk condition (principally Fuchs’ dystrophy or pseudophakic corneal edema) compared with 1101 subjects undergoing PKP from the CDS.
The DSAEK procedures were performed by two experienced surgeons using the same donor and similar recipient criteria as for the CDS PKP procedures, performed by 68 surgeons. Graft success was assessed by Kaplan Meier survival analysis. Central endothelial cell density (ECD) was determined from baseline donor and postoperative central endothelial images by the reading center used in the CDS Specular Microscopy Ancillary Study.
Main Outcome Measures
Graft clarity and endothelial cell density
The donor and recipient demographics were comparable in the DSAEK and PKP groups, except the proportion of Fuchs’ dystrophy cases was higher in the DSAEK cohort. The 3-year survival rate did not differ significantly between DSAEK and PKP procedures performed for either Fuchs’ dystrophy (96% for both, P=0.81) or non-Fuchs cases (86% vs. 84%, respectively, P=0.41). Principal causes of graft failure/regraft within 3 years after DSAEK and PKP were immunologic graft rejection (0.6% vs. 3.1%), endothelial decompensation in the absence of documented rejection (1.7% vs 2.1%), unsatisfactory visual or refractive outcome (1.7% vs. 0.5%), and infection (0% vs. 1.1%), respectively. The 3-year predicted probability of a rejection episode was 9% with DSAEK vs. 20% with PKP (P=0.0005). The median 3-year cell loss for DSAEK and PKP was 46% and 51%, respectively (P=0.33) in Fuchs’s dystrophy cases, and 59% and 61%, respectively (P=0.70), in the non-Fuchs’ cases. At 3 years, use of a smaller DSAEK insertion incision was associated with significantly higher cell loss (60% vs. 33% for 3.2- and 5.0-mm incisions, respectively, P=0.0007) but not a significant difference in graft survival (P=0.45).
The graft success rate and endothelial cell loss were comparable at 3 years for DSAEK and PKP procedures. A 5-mm DSAEK incision width was associated with significantly less cell loss than a 3.2-mm incision.
Descemet stripping endothelial keratoplasty; posterior lamellar keratoplasty; DSAEK; DSEK endothelial cell loss
Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes1,2. Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK), transplanting only the posterior corneal stroma, Descemet's membrane, and endothelium, has dramatically changed treatment of corneal endothelial disease. DSEK is performed through a smaller incision; this technique avoids 'open sky' surgery with its risk of hemorrhage or expulsion, decreases the incidence of postoperative wound dehiscence, reduces unpredictable refractive outcomes, and may decrease the rate of transplant rejection3-6.
Initially, cornea donor posterior lamellar dissection for DSEK was performed manually1 resulting in variable graft thickness and damage to the delicate corneal endothelial tissue during tissue processing. Automated lamellar dissection (Descemet's stripping automated endothelial keratoplasty, DSAEK) was developed to address these issues. Automated dissection utilizes the same technology as LASIK corneal flap creation with a mechanical microkeratome blade that helps to create uniform and thin tissue grafts for DSAEK surgery with minimal corneal endothelial cell loss in tissue processing.
Eye banks have been providing full thickness corneas for surgical transplantation for many years. In 2006, eye banks began to develop methodologies for supplying precut corneal tissue for endothelial keratoplasty. With the input of corneal surgeons, eye banks have developed thorough protocols to safely and effectively prepare posterior lamellar tissue for DSAEK surgery. This can be performed preoperatively at the eye bank. Research shows no significant difference in terms of the quality of the tissue7 or patient outcomes8,9 using eye bank precut tissue versus surgeon-prepared tissue for DSAEK surgery. For most corneal surgeons, the availability of precut DSAEK corneal tissue saves time and money10, and reduces the stress of performing the donor corneal dissection in the operating room. In part because of the ability of the eye banks to provide high quality posterior lamellar corneal in a timely manner, DSAEK has become the standard of care for surgical management of corneal endothelial disease.
The procedure that we are describing is the preparation of the posterior lamellar cornea at the eye bank for transplantation in DSAEK surgery (Figure 1).
Medicine; Issue 64; Physiology; Cornea; transplantation; DSAEK; DSEK; endothelial keratoplasty; lamellar; graft; Moria; microkeratome; precut; Fuchs dystrophy
To report the outcomes of DSAEK surgery performed in pediatric patients.
Noncomparative interventional case series.
Subjects and methods
All pediatric patients (age up to 16 years) undergoing Descemet automated stripping endothelial keratoplasty (DSAEK) at our Institution since January 2008 have been enrolled in a prospective study. A standard DSAEK, involving delivery of an 8.5–9.5 mm graft by Busin glide, was performed under general anesthesia in 19 eyes of 11 pediatric patients (congenital hereditary endothelial dystrophy n = 13; congenital glaucoma n = 2; posterior polymorphous dystrophy n = 2, and failed penetrating keratoplasty n = 2). Slit-lamp examination, refraction and visual acuity as well as endothelial cell density were evaluated preoperatively as well as 1, 3, 6, 12, and 18 months postoperatively.
All surgical procedures were uneventful. Graft detachment occurred in 4 cases and was managed successfully with repeat air injection. All corneas cleared within a week from surgery. Follow-up was 3–18 months. At last follow-up examination, best-corrected visual acuity (BCVA) was better than 20/40 in 8 of the 13 cases of patients old enough to assess vision. A graft rejection episode was seen in 1 case within 3 months from surgery but was reverted with steroidal treatment. No graft failures were observed.
DSAEK is an appropriate surgical intervention for children with corneal endothelial failure. In contrast to penetrating keratoplasty (PK), DSAEK is performed under “closed system” conditions, thus minimizing intraoperative risks. Finally, healing is much faster than with PK and all sutures can be removed within 2–4 weeks from surgery, thus allowing fast visual recovery and prompt starting of amblyopia treatment.
DSAEK; Corneal endothelial failure; Pediatric patients
To compare the response of the cornea to laser in situ keratomileusis (LASIK) with flap creation using the IntraLase FS15, FS30, and FS60 femtosecond lasers.
A retrospective analysis of 55 patients (55 eyes) who underwent LASIK with flap creation using IntraLase was performed. Twelve FS15 patients (12 eyes), 14 FS30 patients (14 eyes), and 29 FS60 patients (29 eyes) were examined 3 months postoperatively by in vivo confocal microscopy. The accuracy of flap thickness, number of interface particles, interface backscatter, epithelial thickness, and activation of keratocytes were determined from the confocal data.
Keratocyte activation was detected in 14 of 55 eyes. In general, keratocyte activation was limited to 1 or 2 cell layers adjacent to the interface. However, 2 eyes exhibited multiple layers of activation by confocal microscopy as well as significant clinical haze by slit-lamp examination. Keratocyte activation and interface backscatter were positively correlated with the raster energy used during surgery (R = 0.51, P < .01) and increased when the steroid treatment time was reduced. Overall, the difference between actual and intended flap thickness was 11.2 ± 8.6 μm, and the density of interface particles was 19.9 ± 12.1 particles/mm2.
LASIK with IntraLase provides more reproducible flap thickness and fewer interface particles than previously observed with use of mechanical microkeratomes. However, IntraLase can induce more significant keratocyte activation, which may underlie clinical observations of haze and transient light sensitivity syndrome in some patients. Activation can be avoided by using lower raster energies and an extended steroid treatment regimen.
To assess outcomes 1 year after Descemet’s stripping automated endothelial keratoplasty (DSAEK) in comparison with penetrating keratoplasty (PKP) from the Specular Microscopy Ancillary Study (SMAS) of the Cornea Donor Study.
Multicenter, prospective, nonrandomized clinical trial.
A total of 173 subjects undergoing DSAEK for a moderate risk condition (principally Fuchs’ dystrophy or pseudophakic/aphakic corneal edema) compared with 410 subjects undergoing PKP from the SMAS who had clear grafts with at least 1 postoperative specular image within a 15-month follow-up period.
The DSAEK procedures were performed by 2 experienced surgeons per their individual techniques, using the same donor and similar recipient criteria as for the PKP procedures in the SMAS performed by 68 surgeons at 45 sites, with donors provided from 31 eye banks. Graft success and complications for the DSAEK group were assessed and compared with the SMAS group. Endothelial cell density (ECD) was determined from baseline donor, 6-month (range, 5–7 months), and 12-month (range, 9–15 months) postoperative central endothelial images by the same reading center used in the SMAS.
Main Outcome Measures
Endothelial cell density and graft survival at 1 year.
Although the DSAEK recipient group criteria were similar to the PKP group, Fuchs’ dystrophy was more prevalent in the DSAEK group (85% vs. 64%) and pseudophakic corneal edema was less prevalent (13% vs. 32%, P<0.001). The regraft rate within 15 months was 2.3% (DSAEK group) and 1.3% (PKP group) (P = 0.50). Percent endothelial cell loss was 34±22% versus 11±20% (6 months) and 38±22% versus 20±23% (12 months) in the DSAEK and PKP groups, respectively (both P<0.001). Preoperative diagnosis affected endothelial cell loss over time; in the PKP group, the subjects with pseudophakic/aphakic corneal edema experienced significantly higher 12-month cell loss than the subjects with Fuchs’ dystrophy (28% vs. 16%, P = 0.01), whereas in the DSAEK group, the 12-month cell loss was comparable for the 2 diagnoses (41% vs. 37%, P = 0.59).
One year post-transplantation, overall graft success was comparable for DSAEK and PKP procedures and endothelial cell loss was higher with DSAEK.
To report a patient with penetrating keratoplasty (PKP) graft endothelial failure implanted with toric intraocular lens (IOL) who was treated with Descemet stripping endothelial keratoplasty (DSAEK).
A 40 year old male patient implanted with toric intraocular lens for the treatment of post PKP astigmatism, presented for the treatment of graft endothelial failure’. The patient had uncorrected distance visual acuity (UDVA) 20/200 not correcting with manifest refraction. The patient reported excellent visual acuity after cataract surgery and toric IOL implantation. DSAEK was performed in order to minimally affect keratometry and retain correspondence of the anterior cornea astigmatism with the toric IOL astigmatic power. Three months postoperatively the cornea was clear with no edema. UDVA was 20/40 and corrected distance visual acuity was 20/25 with +1.50-1.00 × 20.
This report describes a unique case of DSAEK for treatment of a failed PKP in a patient previously implanted with a toric IOL. DSAEK was an effective alternative of PKP in this patient for the preservation of the toric IOL’s effect.
Descemet stripping automated endothelial keratoplasty; Post penetrating keratoplasty astigmatism; Toric intraocular lens