Comparison of Deep Lamellar Endothelial Keratoplasty and Penetrating Keratoplasty in Patients With Fuchs Endothelial Dystrophy

Different Course of Immune Reactions and Endothelial Cell Loss after Penetrating Low-Risk Keratoplasty and Descemet Membrane Endothelial Keratoplasty for Fuchs Endothelial Dystrophy

BACKGROUND

The aim of this study was to compare the incidence of immune reactions and endothelial cell loss after penetrating keratoplasty (PKP) vs. Descemet membrane endothelial keratoplasty (DMEK) in patients with Fuchs endothelial dystrophy (FED).

PATIENTS AND METHODS

In the present retrospective study, a total of 962 surgeries (225 excimer laser PKP and 727 DMEK) of 700 patients performed between 28.06.2007 and 27.08.2020 in the Department of Ophthalmology at Saarland University Medical Center UKS were statistically evaluated. On the one hand, the prevalence and the temporal course of the immune reactions that occurred were analysed using the Kaplan-Meier method, as well as the effect of the immune reactions on the endothelial cells and corneal thickness. Secondly, endothelial cell density, pleomorphism, and polymegethism of the endothelial cells were evaluated for the time points U1 = preoperative, U2 = 6 weeks postoperative, U3 = 6 to 9 months postoperative, U4 = 1 to 2 years postoperative, and U5 = 5 years postoperative. In addition, statistical tests were carried out for differences between the two types of surgery and in the longitudinal course.

RESULTS

A total of 54 immune reactions occurred during the observed period, whereby the probability of such a reaction was significantly greater in the PKP group with 8.9% than in the DMEK group with 4.5% (p = 0.011). The comparison of the two Kaplan-Meier curves also showed a significant difference between the two surgical techniques in the log-rank test (p = 0.012). The endothelial cell loss due to the immune reaction was only significant in PKP (p = 0.003). For all surgical procedures, endothelial cell density decreased significantly with time in both surgical techniques (p < 0.0001 in each case), but more strongly with DMEK than with PKP (p < 0.0001). Furthermore, this cell density was significantly higher with PKP than with DMEK for the whole observation time (p < 0.0001). Polymegethism decreased significantly in the DMEK group (p < 0.0001). Pleomorphism was significantly higher, on average, in DMEK than in PKP (p < 0.0001).

CONCLUSION

The prognosis of DMEK in patients with FED seems to be more favourable after immune reactions than that of PKP, as not only were immune reactions less frequent, but they were also milder. However, endothelial cell density was significantly higher in the PKP group during the entire follow-up.

Transplant rejection following endothelial keratoplasty and penetrating keratoplasty in the United Kingdom: incidence and survival

PURPOSE

To investigate the incidence and outcome of cornea transplant rejection following endothelial keratoplasty (EK) and penetrating keratoplasty (PK) for Fuchs endothelial dystrophy (FED) and pseudophakic bullous keratopathy (PBK).

DESIGN

Multicenter cohort study.

METHODS

Patients registered on the United Kingdom Transplant Registry (UKTR) who had an EK or PK for FED or PBK between April 1, 2005 and March 31, 2011 were included. Data were collected from UKTR forms at 1 and 2 years. Postoperative steroid use varies between surgeons and cannot be captured in this reporting system. Rejection events were identified as those recorded as endothelial rejection.

RESULTS

A total of 3486 corneal transplants were undertaken: 1973 for FED, 1513 for PBK. For FED, 2-year rejection-free survival was 93% (95% confidence interval [CI] 90%-94%) for PK and 94% (95% CI 92%-96%) for EK (P = .3). In transplants that had a rejection episode, 50% of PKs (17) and 60% of EKs (15) subsequently failed. For PBK, 2-year rejection-free survival for PK was 88% (95% CI 86%-90%) and 90% (95% CI 86%-92%) for EK (P = .6). In transplants that had a rejection episode, 85% of PKs (41) and 76% of EKs (22) subsequently failed. Inflammation (ie, conjunctival injection, presence of keratic precipitates and intraocular signs) at the time of surgery for patients with FED was significant for developing rejection: 3.5 times greater compared with those with no inflammation (P = .02).

CONCLUSIONS

There is no significant difference in rejection-free survival between EK and PK for FED or PBK. The presence of inflammation is an important risk factor, and attention to its control before and following surgery is important.

Graft rejection rate and graft failure rate of penetrating keratoplasty (PKP) vs lamellar procedures: a systematic review

Purpose

The aim of our investigation was to conduct a quantitative meta-analysis of the present world literature comparing the major surgical outcomes of penetrating keratoplasty (PKP) to lamellar procedures. Our goal is that clinicians, eye bank administrators, and health policy makers will be able to utilize this study in implementing decisions in regards to corneal transplantation.

Methods

Pooled measures of association were with odds ratios and because of study heterogeneity, the pooled effects were assumed to follow a random effects model (DerSimonian-Laird). The comparisons were between 1) PKP’s and all lamellar procedures (anterior AND posterior) and then 2) between PKP’s and all anterior lamellar procedures and 3) PKP and all posterior lamellar procedures.

Results

For PKP vs anterior lamellar procedures, the pooled odds ratio for rejection of PKP over lamellar keratoplasty (LK) was 3.56 (95% CI: 1.76-7.20) and for outright failure, the pooled odds ratio of PKP failure vs LK was 2.85 (95% CI: 0.84-9.66). For posterior lamellar procedures, the pooled odds ratio for rejection of PKP over LK was 1.52 (95% CI: 1.00-2.32). The pooled odds ratio for outright failure of PKP over posterior lamellar procedures was 2.09 (95% CI: 0.57-7.59). The follow up time was significantly longer for full transplants than for lamellar procedures.

Conclusions

For both anterior and posterior lamellar procedures, the odds ratios comparing rejection of full transplants to lamellar procedures (both anterior and posterior individually) were significantly higher in the PKP group. For outright failure, the PKP group also had a higher risk of failure than the lamellar groups but this was not statistically significant in either instance (anterior or posterior). Some of the clinical differences benefitting lamellar procedures may at least be partly explained by follow up time differences between groups and this needs to be accounted for more rigorously in future studies.

Corneal blindness and xenotransplantation

Approximately 39 million people are blind worldwide, with an estimated 285 million visually impaired. The developing world shoulders 90% of the world's blindness, with 80% of causative diseases being preventable or treatable. Blindness has a major detrimental impact on the patient, community, and healthcare spending. Corneal diseases are significant causes of blindness, affecting at least 4 million people worldwide. The prevalence of corneal disease varies between parts of the world. Trachoma, for instance, is the second leading cause of blindness in Africa, after cataracts, but is rarely found today in developed nations. When preventive strategies have failed, corneal transplantation is the most effective treatment for advanced corneal disease. The major surgical techniques for corneal transplantation include penetrating keratoplasty (PK), anterior lamellar keratoplasty, and endothelial keratoplasty (EK). Indications for corneal transplantation vary between countries, with Fuchs' dystrophy being the leading indication in the USA and keratoconus in Australia. With the exception of the USA, where EK will soon overtake PK as the most common surgical procedure, PK is the overwhelming procedure of choice. Success using corneal grafts in developing nations, such as Nepal, demonstrates the feasibility of corneal transplantation on a global scale. The number of suitable corneas from deceased human donors that becomes available will never be sufficient, and so research into various alternatives, for example stem cells, amniotic membrane transplantation, synthetic and biosynthetic corneas, and xenotransplantation, is progressing. While each of these has potential, we suggest that xenotransplantation holds the greatest potential for a corneal replacement. With the increasing availability of genetically engineered pigs, pig corneas may alleviate the global shortage of corneas in the near future.

Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy

BACKGROUND

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.

OBJECTIVES

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 FED.

SEARCH METHODS

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.

SELECTION CRITERIA

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.

MAIN RESULTS

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.

AUTHORS' CONCLUSIONS

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 term?

Lamellar corneal transplantation

Penetrating keratoplasty (PK) has been the gold standard for the surgical treatment of most corneal pathologies; lamellar keratoplasty that only replaces the diseased corneal layers has recently evolved as an alternative, however. Innovations in surgical technique and instrumentation provide visual outcomes comparable to PK. We review the indications and outcomes of various techniques of anterior lamellar surgery developed to treat stromal disorders. Similarly, we discuss posterior lamellar keratoplasty techniques such as Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty. Posterior lamellar keratoplasty provides faster visual rehabilitation than PK in cases of Fuchs endothelial dystrophy and pseudophakic bullous keratopathy. In addition, for medically unresponsive infectious keratitis, therapeutic anterior lamellar keratoplasty yields similar graft survival to PK without an increased risk of disease recurrence.

Outcomes of repeat endothelial keratoplasty in patients with failed Descemet stripping endothelial keratoplasty

PURPOSE

To report the outcomes of repeat endothelial keratoplasty (EK) in patients with failed Descemet stripping endothelial keratoplasty (DSEK).

METHODS

The clinical records of patients with failed DSEK who underwent repeat EK surgery at a single institution were reviewed.

RESULTS

A total of 20 eyes of 20 patients (8 men and 12 women) were included. The mean age at initial DSEK surgery was 69.9 ± 11.9 years (range, 41-83 years). The causes of DSEK failure included progressive endothelial failure (8 eyes; 40%), primary graft failure (8 eyes; 40%), and endothelial rejection (4 eyes; 20%). The mean duration from primary DSEK to repeat EK was 13.1 ± 10.3 months (range, 2-33 months). Removal of the failed DSEK donor disc was performed in all eyes. Mean preoperative corrected distance visual acuity (logMAR) before repeat EK surgery was 1.76, and this improved to 0.5 (P < 0.001) at the final follow-up at 27 months. Three eyes had limited corrected distance visual acuity secondary to ocular comorbidities (age-related macular degeneration and advanced glaucomatous optic neuropathy).

CONCLUSIONS

Repeat EK in patients with DSEK failure is an effective treatment modality. This is the preferred management option compared with penetrating keratoplasty because the advantages of EK surgery are maintained with repeat EK surgery.

Comparison of the Surgical Outcomes of Various Methods of Endothelial Keratoplasty

PURPOSE

The objective of this study was to evaluate the outcomes of various techniques of endothelial keratoplasty (EK) including deep lamellar endothelial keratoplasty (DLEK), Descemet stripping endothelial keratoplasty (DSEK), and Descemet stripping automated endothelial keratoplasty (DSAEK).

DESIGN

This was a retrospective comparative case series.

METHODS

The medical records of 48 consecutive patients who have undergone EK in a tertiary eye center between January 2005 and June 2011 were reviewed. Information related to demographics, visual acuity, corneal endothelial cell count, and postoperative complications was recorded.

RESULTS

The series included 11 eyes with DLEK, 11 eyes with DSEK, and 26 eyes with DSAEK. There was no significant difference in visual outcomes, endothelial cell loss, and postoperative complications between the 3 groups 1 year after surgery. The mean logMAR visual acuity at 12 months was 0.54 (SD, 0.26) for DLEK, 0.55 (SD, 0.47) for DSEK, and 0.63 (SD, 0.48) for DSAEK, respectively. The 6-month endothelial cell density loss was 48.4%, 39.2%, and 47.5% for the DLEK, DSEK, and DSAEK groups, respectively. Early postoperative graft dislocation occurred in 1 (9%) of the DLEK cases, 2 (18%) of the DSEK cases, and 1 (4%) of the DSAEK cases. All of these cases were successfully repositioned.

CONCLUSIONS

Despite the various evolution and surgical modifications and development in EK in the past few years, the visual outcomes and postoperative complications between DLEK, DSEK, and DSAEK were comparable.

Descemet membrane endothelial keratoplasty combined with phacoemulsification and intraocular lens implantation: advanced triple procedure

PURPOSE

To evaluate the functional and morphologic outcome of Descemet membrane endothelial keratoplasty (DMEK) combined with phacoemulsification and intraocular lens implantation in patients suffering from endothelial dysfunction and cataract.

DESIGN

Retrospective, single-center, consecutive case series.

METHODS

Triple-DMEK (DMEK with simultaneous cataract surgery) was performed in 61 consecutive eyes of 56 patients using corneal donor tissue pre-stored in either short-term culture (Optisol-GS) at 4 C or organ culture (Dulbecco's modified Eagle's medium, CorneaMax medium) at 34 C. Main outcome measures included the number of air injections necessary for graft attachment as well as best-corrected visual acuity (BCVA [logMAR]), central corneal thickness (CCT), endothelial cell density (ECD), refractive spherical equivalent, refractive cylinder, and topographic cylinder at 1, 3, and 6 months postoperatively.

RESULTS

BCVA increased from 0.6 ± 0.23 logMAR preoperatively (n = 54) to 0.19 ± 0.22 logMAR at 6 months (n = 27) after surgery (P ≤ .05). ECD of donor corneas decreased from 2573 ± 235 cells/mm(2) (n = 61) to 1550 ± 326 cells/mm(2) (n = 29) after 6 months (P ≤ .05). CCT decreased from 651 ± 69 μm (n = 54) preoperatively to 521 ± 65 μm (n = 27) after 6 months (P ≤ .05). Refractive spherical equivalent was -0.3 ± 2.8 D (n = 27) preoperatively and 0.9 ± 1.5 D 6 months (n = 27) after surgery. A total of 54.5% of eyes were within 1 D of emmetropia (n = 12) and 77.3% were within 2 D of emmetropia (n = 17) 6 months (n = 22) after surgery. Refractive cylinder was -0.9 ± 1.0 D preoperatively (n = 49) and -1.5 ± 1.0 D 6 months (n = 23) after surgery. The change in refractive cylinder within the first month was statistically significant (P ≤ .05; Wilcoxon test). Topographic cylinder was 2.1 ± 1.7 D preoperatively (n = 58) and 1.7 ± 1.1 D 6 months (n = 28) after surgery. Between 3 and 6 months a significant change in topographic cylinder towards lower values was measured (P ≤ 0.05; Wilcoxon test). Optimized spherical results were achieved by selecting intraocular lenses based on a hyperopic shift of -0.75 D.

CONCLUSION

DMEK combined with cataract surgery (triple procedure) can routinely be performed in cases of endothelial dystrophy and cataract. The addition of cataract surgery to DMEK had no adverse effect on endothelial function or graft adhesion and did not increase the likelihood of postoperative complications.

Histological evaluation of corneal scar formation in pseudophakic bullous keratopathy

PURPOSE

To evaluate histological changes in the corneal stroma in pseudophakic bullous keratopathy.

METHODS

Twenty-eight patients (28 eyes) with pseudophakic bullous keratopathy underwent therapeutic penetrating keratoplasty at Shandong Eye Institute between January 2006 and November 2011. The patients were divided into two groups according to the duration of bullous keratopathy (<1.0 year group or >1.0 year group), and three buttons from enucleated eyes with choroidal melanoma served as a control. In vivo confocal microscopy examination, hematoxylin-eosin, Masson's trichrome stain and Van Gieson staining were used for microscopic examination. The histological evaluation and scoring of the buttons for morphological changes, including the degree of stromal scars, neovascularization and inflammatory cells within the corneal buttons, were compared. To study the underlying mechanism, connective tissue growth factor (CTGF) and TGF-β immunohistochemistry were performed.

RESULTS

Confocal microscopy examination and histological evaluation and scoring of the buttons showed that compared with the <1.0 year group, stromal scars, neovascularization and inflammatory cells were more severe in the >1.0 year group (P<0.05). There was an increase in CTGF- and TGF-β1-positive stromal cells in the >1.0 year group.

CONCLUSIONS

During the progression of pseudophakic bullous keratopathy, stromal scars occurred more often in the patients that had a longer duration of disease. Cytokines such as CTGF and TGF-β1 may play a role in this pathological process and deserve further investigation.

Endothelial keratoplasty versus penetrating keratoplasty for Fuchs endothelial dystrophy

BACKGROUND

Fuchs endothelial dystrophy (FED), first described by Ernst Fuchsis in 1910, 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 cadaveric donor. The established procedure, penetrating keratoplasty (PKP), has been used for many years and its safety and efficacy are well known. Endothelial keratoplasty (EK) is a relatively new surgical procedure and the safety and efficacy relative to PKP are unknown.

OBJECTIVES

The objective of this review is to collate information on the benefits and complications related to two surgical methods (PKP and EK) of replacing the diseased endothelial layer of the cornea with a healthy layer in people with FED.

SEARCH STRATEGY

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 2), MEDLINE (January 1950 to February 2011), EMBASE (January 1980 to February 2011), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to February 2011), 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 6 February 2011.

SELECTION CRITERIA

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. When assessing the primary and secondary outcome measures, only RCTs were included in the analysis. As per our protocol a description of data from non-randomised comparative studies is also reported. As RCTs may not detect differences in frequency of adverse events, when assessing these we included data from cohort studies with more than 50 participants and a follow-up of up to five years.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data.

MAIN RESULTS

The electronic searches identified one RCT, five non-randomised comparative studies and 34 cohort studies with a sample size of over 50 participants for inclusion. The RCT was conducted in the USA and included 28 eyes of 25 participants with FED. Although this is a very good RCT, there may be potential for bias due to lack of masking of assessors and possible selective reporting not being clearly reported. In this RCT, comparing EK versus PKP, best corrected visual acuity (BCVA) was similar at 24 months (PKP 0.20 ± 0.20 logMAR; EK 0.34 ± 0.35 logMAR; P = 0.23) and higher order aberrations (HOAs) (deviations of the performance of an optical system from the predictions of paraxial optics) were lower with EK. No other data were reported by the trial. Based on data obtained from both non-randomised comparative studies and individual cohort studies the endothelial rejection rate was between 5.3% and 23.2% for PKP and 2% and 4% for EK. However the mean follow-up duration in the EK cohort studies was noticeably shorter. The rate of EK graft dislocation requiring repositioning ranged from 3% to 63%, with the majority of studies having a rate of < 10%.

AUTHORS' CONCLUSIONS

There is no high quality evidence that EK is superior to PKP in the treatment of FED considering the studies that satisfied our primary and secondary outcome measures. One RCT demonstrated that HOAs are lower following EK and some lower quality evidence suggests that endothelial rejection episodes may be less with EK. These findings should be interpreted with caution as they are based on data with risk of biases. Further RCTs of visual and refractive outcomes needs to be performed in this field, comparing EK to PKP, with a larger sample size and at least five years of follow up. To avoid bias due to a surgeon's learning curve, procedures should be performed by experienced surgeons only. Quality of life and vision should also be evaluated. The risk of endothelial rejection will be difficult to address in the context of a RCT because of power considerations but large non-randomised comparative case series and corneal graft registry outcome data will be useful in this regard.

Optical coherence tomography anatomy of the corneal endothelial transplantation wound

PURPOSE

The goal of this study was to prospectively assess the deep lamellar endothelial keratoplasty (DLEK) wound anatomy and its evolution during the 12 months after surgery, using optical coherence tomography (OCT).

METHODS

The eyes of 8 patients (1 eye per patient) who consecutively underwent DLEK for Fuchs dystrophy or pseudophakic bullous keratopathy were prospectively studied before and 1, 3, 6, and 12 months after surgery. The Stratus OCT apparatus (Carl Zeiss Meditec, Dublin, CA) was used to acquire central and radial scans perpendicular to the wound at 3-, 6-, 9-, and 12-o'clock positions. The following parameters were analyzed: central total thickness, posterior donor-recipient edges gap, donor-recipient height mismatch, tissue compression, and graft detachment.

RESULTS

A posterior gap was observed in 4 of the 8 DLEK eyes. At 12 months, the mean gap contour, depth, and width were 242 +/- 67, 101 +/- 45, and 87 +/- 29 microm, respectively. A step was documented in all DLEK eyes (average step height 108 +/- 24 microm). A micrograft detachment was observed in one case and tissue compression in another. In all corneas, the mean central corneal thickness returned to normal range and almost normal anatomy with time after surgery.

CONCLUSIONS

OCT was found to be a very useful tool for DLEK corneal wound architecture analysis. It revealed microscopic wound irregularities and allowed their quantitative follow-up with time.

Fuchs' corneal dystrophy

Fuchs' corneal dystrophy (FCD) is a progressive, hereditary disease of the cornea first described a century ago by the Austrian ophthalmologist Ernst Fuchs. Patients often present in the fifth to sixth decade of life with blurry morning vision that increases in duration as the disease progresses. Primarily a condition of the posterior cornea, characteristic features include the formation of focal excrescences of Descemet membrane termed 'guttae', loss of endothelial cell density and end-stage disease manifested by corneal edema and the formation of epithelial bullae. Recent advances in our understanding of the genetic and pathophysiological mechanisms of the disease, as well as the application of new imaging modalities and less invasive surgical procedures, present new opportunities for improved outcomes among patients with FCD.

Endothelial cell density after descemet membrane endothelial keratoplasty: 1- to 2-year follow-up

PURPOSE

To evaluate donor endothelial cell density (ECD) after Descemet membrane endothelial keratoplasty (DMEK).

DESIGN

Nonrandomized, prospective clinical study.

METHODS

From a larger group of patients who underwent DMEK for Fuchs endothelial dystrophy or pseudophakic bullous keratopathy, complete ECD measurements were available of 26 patients with 6 and 12 months of follow-up, of whom 7 also had 24 months of follow-up.

RESULTS

For the group with 24 months of follow-up, ECD averaged 2700 (+/- 260) cells/mm(2) before surgery, 2200 (+/- 460) cells/mm(2) at 6 months after surgery, 2050 (+/- 330) cells/mm(2) at 12 months after surgery, and 1780 (+/- 390) cells/mm(2) at 24 months after surgery. For the group with 12 months of follow-up, ECD averaged 2620 (+/- 210) cells/mm(2) before surgery, 1850 (+/- 540) cells/mm(2) at 6 months after surgery, and 1680 (+/- 550) cells/mm(2) at 12 months after surgery. In both groups, the ECD decreased significantly between the preoperative and 6-month measurement (P < .05).

CONCLUSIONS

Similar to earlier endothelial keratoplasty techniques, DMEK may be associated with a decrease in donor ECD of approximately 25% in the early postoperative phase.

Endothelial keratoplasty for Fuchs' dystrophy with cataract: complications and clinical results with the new triple procedure

PURPOSE

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.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

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.

METHODS

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.

MAIN OUTCOME MEASURES

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.

RESULTS

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.

CONCLUSIONS

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.

Precut tissue for Descemet's stripping automated endothelial keratoplasty: vision, astigmatism, and endothelial survival

PURPOSE

To report 6 and 12 month results using precut tissue for Descemet's stripping automated endothelial keratoplasty (DSAEK) and correlate donor characteristics with clinical outcomes.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

We reviewed 100 donor corneas precut for 100 eyes of 90 DSAEK patients.

METHODS

Our first 100 consecutive cases of DSAEK with precut tissue were entered into a prospective protocol. Donor characteristics and the visual, refractive, topographic, and specular microscopy results at 6 and 12 months were analyzed. Correlation analysis comparing donor characteristics with clinical outcomes was performed.

MAIN OUTCOME MEASURES

Six- and 12-month postoperative best spectacle-corrected visual acuity (BSCVA), refractive astigmatism, topographic keratometry (K), and specular endothelial cell densities (ECD) were measured prospectively and then compared with preoperative values. Donor characteristics analyzed included death to preservation time, death to surgery time, precutting resection to surgery time, and graft thickness.

RESULTS

Six months after DSAEK surgery, BSCVA improved from 20/83 to 20/38. (P<0.01). In eyes with no known comorbidity (n = 60), 92% had a vision of >/=20/40 at 6 months and 20% obtained > or =20/20. Astigmatism changed an average of 0.09 diopters (D) and K changed by +0.09 D, both of which were not significant and were stable to 12 months. The postoperative mean ECD (n = 65) was 1918 cells/mm(2) at 6 months, and represented a 31% cell loss from preoperatively (P<0.001). The mean ECD (n = 61) was 1990 cells/mm(2) at 12 months, and represented a 29% cell loss from preoperatively (P<0.001) with no significant change from 6 to 12 months (P = 0.172). Improvement of visual acuity from preoperative to postoperative in eyes without comorbidity was not correlated with any donor characteristic. Greater endothelial cell loss correlated with higher preoperative ECD levels (P<0.001) and with a trend toward longer precut resection to surgery times at both 6 months (P = 0.049) and 12 months (P = 0.051).

CONCLUSIONS

Precut tissue by Eye Banks for use in DSAEK surgery provides an improvement in vision with no significant change in astigmatism. Donor endothelial cell loss from 6 to 12 months is stable and is comparable with reports involving tissue that is cut intraoperatively.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosures may be found after the references.

Descemet stripping and endothelial keratoplasty in endothelial dysfunctions: three-month results in 75 eyes

PURPOSE

To analyze the results of Descemet stripping and endothelial keratoplasty (DSEK) in the first consecutive 75 cases.

MATERIALS AND METHODS

Prospective, non-randomized, non-comparative interventional case series. Seventy-five eyes of 75 patients with endothelial dysfunctions of different etiology, scheduled for DSEK, were included in this study. Healthy donor cornea with a cell count of> 2000 cells/sq mm was considered for transplantation in each case. Indications, operative problems and postoperative complications were noted. Best corrected visual acuity (BCVA), refractive and keratometric astigmatism, central corneal thickness (CCT) and endothelial cell density (ECD) were analyzed for each patient after a minimum follow-up of three months.

RESULTS

Main indication was pseudophakic corneal edema and bullous keratopathy in 53 (70.7%) eyes. Seventeen (22.7%) cases had moderate to severe Fuchs' dystrophy with various grades of cataract; and DSEK was combined with manual small-incision cataract surgery (MSICS) with posterior chamber intraocular lens (PCIOL) in those cases. After three months, BCVA was 20/60 or better in 62 (82.7%) cases. Mean refractive and keratometric astigmatism were 1.10 +/- 0.55 diopter cylinder (DCyl) and 1.24 +/- 0.92 DCyl. The CCT and ECD were 670.8 +/- 0.32 microm and 1485.6 +/- 168.6/sq mm respectively. The mean endothelial cell loss after three months was 26.8 +/- 4.24% (range: 13.3-38.4%). Dislocation of donor lenticule occurred in six (8.0%) eyes. Graft failure occurred in one case.

CONCLUSIONS

Descemet stripping and endothelial keratoplasty is a safe and effective procedure in patients with endothelial dysfunctions with encouraging surgical and visual outcomes. It can be safely combined with MSICS with PCIOL in patients with moderate to severe Fuchs' dystrophy with cataract.