Repeat Descemet membrane endothelial keratoplasty after complicated primary Descemet membrane endothelial keratoplasty

Clinical Outcomes of Repeat Descemet Membrane Endothelial Keratoplasty After Graft Failure

PURPOSE

To evaluate the clinical outcomes after repeat Descemet membrane endothelial keratoplasty (DMEK) for technical failure (TF) and secondary graft failure (SGF).

METHODS

Retrospective analysis of 49 eyes that underwent repeat DMEK either for TF (ie, persistent graft detachment, n = 24) or for SGF (ie, late endothelial graft failure, n = 25). Surgery indications for primary DMEK were Fuchs endothelial corneal dystrophy (FECD, 80%) and bullous keratopathy (BK, 20%). Main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD), corneal backscattering, pachymetry, and graft survival. Outcomes were compared with an age-matched control group of 49 primary DMEK eyes.

RESULTS

Logarithm of the minimum angle of resolution BCVA improved from 0.92 ± 0.6 before to 0.20 ± 0.3 at 1 year after repeat DMEK with better outcomes for eyes with TF than those with SGF (P = 0.046). Donor ECD decreased from 2618 ± 171 cells/mm2 before to 1247 ± 422 cells/mm2 at 1 year postoperatively, with no difference between technical TF and SGF eyes (P > 0.05). One-year BCVA and ECD outcomes were better in the control group than in the repeat DMEK group (P < 0.05). Five-year graft survival probability after repeat DMEK was better for TF than for SGF eyes (100% vs. 75%, P = 0.010) and better for eyes with FECD than BK as primary indication for surgery (92% vs. 65%, P = 0.042).

CONCLUSIONS

Repeat DMEK gives acceptable clinical outcomes especially when performed for TF in the early period after primary DMEK. Long-term graft survival probability after repeat DMEK is comparable to primary DMEK for FECD eyes, whereas BK eyes may show an elevated risk to develop graft failure again.

Repeat corneal transplantation in Southern China: Indications, surgical technique, outcomes, and risk factors for repeat keratoplasty failure

PURPOSE

To report the indications, surgical techniques, and outcomes of repeat keratoplasty and evaluate the risk factors for graft failure in the Chinese population.

METHODS

The medical records of 216 patients (243 cases) who underwent at least two keratoplasties at a leading eye hospital in southern China between 2011 and 2020 were retrospectively reviewed. Indications and surgical procedures for repeat corneal transplantation were analyzed. Kaplan-Meier survival analysis was used to determine the graft survival rate after repeat keratoplasty. A multivariable survival model was used to assess the risk factors.

RESULTS

Repeated keratoplasties increased continuously from 2011 to 2020 (P = 0.002). The most common primary indication was infectious keratitis (38.7%), and the most common reason for repeat keratoplasty was graft rejection (30.04%). Regraft techniques included penetrating keratoplasty (PK) in 165 cases (67.9%), deep lamellar keratoplasty (DALK) in 52 cases (21.40%), and endothelial keratoplasty (EK) in 26 cases (10.7%). Median survival was 5.3, 6.8, and 6.4 years for PK, DALK, and EK, respectively. The 5-year survival rate was 53.5%, 66.6%, and 69.8% for PK, DALK, and EK, respectively. The median LogMAR visual acuity was 1.4 for PK, 0.75 for DALK, and 1.2 for EK at the end of the follow-up. Multivariate analysis revealed that graft rejection is a risk factor for repeat keratoplasty failure (P = 0.002).

CONCLUSIONS

DALK and EK may provide better outcomes than PK in treating graft failure. Preventing and treating postoperative graft rejection may be key to improving regraft survival. These findings will aid in the management of failed corneal grafts.

Rebubbling and graft detachment in Descemet membrane endothelial keratoplasty using a standardised protocol

OBJECTIVES

To analyse risk factors and long-term outcomes after rebubbling and graft detachment in Descemet membrane endothelial keratoplasty (DMEK).

METHODS

176 consecutive DMEK grafts of 125 patients performed by 8 surgeons with a standardised technique between January 2015 and July 2022 were analysed. Main outcome measures were graft detachments, rebubbling rate, postoperative outcomes, and risk factors for graft failure and rebubbling.

RESULTS

6 (3.4%) grafts required rebubbling (>1/3 area detached). 40 (22.7%) grafts developed self-resolving partial detachments (<1/3 area detached). The mean time to rebubble was 16 ± 9.4 days. Mean BSCVAs at 5 years postoperative were 0.03 ± 0.16, 0.03 ± 0.14, and 0.15 ± 0.31 logMAR in fully attached, partially detached and rebubbled grafts (P = 0.437). 5-year graft survival were 98%, 90%, and 83% in fully attached, partially detached and rebubbled eyes (P = 0.02). There was significantly greater endothelial cell loss (ECL) in the rebubbled eyes (P = 0.018). Intraoperative trauma was a risk factor for graft failure (HR 1.81; 95% CI: 1.33-2.50; P = 0.023). An indication for surgery other than Fuchs endothelial dystrophy was a risk factor for rebubbling (HR 5.28; 95% CI: 5.11-72.4; P = 0.007).

CONCLUSION

DMEK grafts had better graft survival if there was no partial detachment or rebubbling at 5 years postop. There was significant ECL associated with rebubbling. A standardised technique reduces rebubbling and graft failure risk.

Risk Factors for Descemet Membrane Endothelial Keratoplasty Rejection: Current Perspectives- Systematic Review

Descemet membrane endothelial keratoplasty (DMEK) is a corneal endothelial transplantation procedure with selective removal of a patient's defective Descemet membrane and endothelium. It is replaced with a healthy donor Descemet membrane and endothelium without a stromal component. Corneal graft rejection can be at the level of epithelium, stroma as well endothelium. DMEK graft rejection is relatively less common than rejection with DSAEK or penetrating keratoplasty, and a good outcome may be achieved with prompt management. The clinical picture of DMEK rejection is usually similar to endothelial rejection in Descemet Stripping Endothelial Keratoplasty (DSEK/DSAEK), which generally manifests as pain, redness, reduction in visual acuity, stromal edema, endothelial rejection line, keratic precipitates at the back of the cornea and corneal neovascularization. However, more subtle forms of rejection or immune reactions are more common in DMEK compared to DSAEK eyes. Early clinical diagnosis, prompt intervention, and meticulous management safeguard visual acuity and graft survival in these cases. Intensive topical steroids form the mainstay in the management of DMEK rejection. Sometimes, oral or intravenous steroids or other systemic immunomodulators may be required. DMEK graft failure can be primary or secondary, and failure usually requires a second procedure in the form of repeat DMEK or DSEK or penetrating keratoplasty (PKP). A detailed literature search was performed using search engines such as Google Scholar, PubMed, and Google books, and a comprehensive review on DMEK rejection was found to be lacking. This review is a comprehensive update on the risk factors, pathophysiology, primary and secondary graft failure, recent advances in diagnosis, prevention of rejection, and updates in the management of DMEK rejection. The review also discusses the differential diagnosis of DMEK failure and rejection, prognosis, and future perspectives considering DMEK failure and rejection.

Graft Failure after PKP and DMEK: What is the Best Option?

Corneal transplantation is the most commonly performed human tissue transplantation procedure worldwide. Due to the large number of grafts, corneal graft failure has become one of the most common indications for corneal transplantation for immunological and non-immunological reasons (e.g. recurrence of underlying disease, high intraocular pressure, grafted guttae, transmitted HSV or CMV infection). The relatively recently developed lamellar grafting techniques have introduced certain potential complications that may lead to graft failure and require approaches other than penetrating keratoplasty for re-grafting. On the other hand, these new lamellar techniques also offer new possibilities for salvaging failed penetrating grafts, with potential advantages over successive penetrating keratoplasties, such as lower intraoperative risks, faster visual rehabilitation and reduced risk of immune reaction. Today, the patient with good healing who is satisfied with his graft before endothelial decompensation, with low astigmatism and no stromal scars, represents the optimal condition for DMEK after PKP. This can also be combined with phacoemulsification (so-called triple DMEK). Otherwise, a penetrating re-keratoplasty with a larger graft (typically excimer laser repeat PKP 8.5/8.6 mm) is performed to treat edema, scars and irregular astigmatism simultaneously. The medical history carries weight in this decision! Re-DMEK in case of graft failure after DMEK and DSAEK does not require any modification of the standard technique and leads to good visual acuity results if performed quickly. If there is clear stromal scarring after multiple (external) DMEKs, PKP can also be considered to rectify the situation. Otherwise causeless recurrent graft failures must suggest herpetic or CMV endotheliitis and, after PCR analysis of the aqueous humour aspirate, be treated appropriately with medication.

Current Perspectives on Corneal Transplantation

Disease of the cornea is the third leading cause of blindness worldwide. Corneal graft surgery is one of the most successful forms of solid organ transplantations in humans, with ever-increasing developments in surgical technique. To date, approximately 4504 corneal transplants are performed in the United Kingdom each year. While full thickness transplantation was the most commonly performed keratoplasty over the last few decades, selective lamellar transplantation of the diseased layers of the cornea has been universally adopted. This comprehensive review aims to provide an updated synthesis on different types of corneal transplantations, their treatment outcomes, and the associated complications of each procedure in both adult and paediatric population. In addition, we also present an up-to-date summary of the emerging therapeutic approaches that have the potential to reduce the demand for donor-dependent keratoplasty.

Rotational alignment of corneal endothelial grafts and risk of graft detachment after Descemet membrane endothelial keratoplasty: a double-masked pseudo-randomized study

PURPOSE

The posterior cornea is rotationally asymmetric, and Descemet membrane endothelial keratoplasty (DMEK) grafts preferentially scroll vertically. This prospective study assessed whether graft attachment after DMEK differed depending on the rotational alignment of the donor graft in the recipient eye.

METHODS

Pseudo-randomization and blinding of the graft orientation in the recipient's eye were possible by procedural separation: (1) The eye bank recorded the position of an orientation marker in the donor cornea; (2) the surgeon preparing the DMEK graft recorded an upside-down marker relative to the eye bank marker; and (3) the surgeon assessed the position of the upside-down marker in the recipient after DMEK. Surgeons were masked towards the eye bank marker. Using mixed-effects models, we assessed graft attachment relative to the rotational alignment of the donor graft.

RESULTS

Postoperatively, the graft was not fully attached in 59 of 179 eyes (33%). A second air fill (rebubbling) was performed in 11%. The graft axis was in line with the recipient cornea axis in 40%, oblique in 28% and orthogonal in 32%. We did not detect an elevated risk of incomplete attachment (odds ratio [OR], 1.16; 95% CI, 0.61-2.20), risk of rebubbling (OR, 1.25; 95% CI, 0.47-3.31) or larger areas of graft detachment in non-aligned grafts compared to aligned grafts.

CONCLUSION

Rotational alignment was not strongly associated with the risk of incomplete graft attachment, although modestly elevated risks cannot be ruled out. Efforts are needed to reduce the need for rebubbling after DMEK and to identify modifiable risk factors for graft detachment.

Secondary Endothelial Keratoplasty-A Narrative Review of the Outcomes of Secondary Corneal Endothelial Allografts

BACKGROUND

We review the literature on the efficacy and safety outcomes of secondary Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Literature search of English-written publications up to September 27, 2020 in PubMed database, using the terms "endothelial keratoplasty" in combination with keywords "secondary" or "repeat." In addition, we manually searched the references of the primary articles.

RESULTS

Twenty-seven studies (n = 651 eyes) were retained and reviewed, including 10 studies on repeat DSEK, 8 studies on repeat DMEK, 6 studies of DMEK following DSEK, and 3 studies of DSEK after failed DMEK. All studies reported significant improvement in visual acuity after secondary endothelial keratoplasty (EK). Twelve studies compared visual outcomes between primary and secondary EK, reporting conflicting findings. Sixteen studies reported endothelial cell loss rates after secondary EK, and only 1 study reported significantly increased endothelial cell loss rates compared with primary EK. Allograft rejection episodes occurred in 1.8% of eyes (range, 0%-50%). Six studies compared complication rates between primary and secondary EK eyes, and only 1 study found a higher median number of complications. However, 2 studies reported higher regraft failure rates compared with primary EK eyes.

CONCLUSIONS

Secondary EK is surgically feasible and renders significant visual improvement after failed primary EK, although it is not clear whether visual outcomes and allograft survival are comparable with primary EK, raising the question of whether secondary EK eyes are "low risk" as primary EK eyes. Further larger, prospective studies are encouraged to obtain additional quality data on secondary corneal endothelial allotransplantation.

Indications and Surgical Techniques for Repeat Corneal Transplantation in Eastern China: A Twelve-Year Study

Purpose

To analyze the indications and surgical procedures for repeat keratoplasty in eastern China from 2008 to 2019.

Methods

This retrospective descriptive study included 418 eyes of 411 patients who underwent no less than 2 keratoplasties at the Eye, Ear, Nose and Throat Hospital of Fudan University from 2008 to 2019. Medical charts were reviewed. The primary indications for repeat keratoplasty, the reasons for regrafting, and the surgical techniques used in the treatment were collected and analyzed.

Results

Among 418 eyes, 337 eyes (80.6%) had one repeat keratoplasty, and 81 eyes (19.4%) had multiple repeat keratoplasties (≥2 repeat keratoplasties). The median interval between the initial keratoplasty and the first repeat keratoplasty was 25 months, and that between two keratoplasties after the first repeat keratoplasty was 27.5 months. Infectious keratitis was the leading primary indication for single repeat keratoplasty (80 cases, 23.7%) and multiple repeat keratoplasties (19 cases, 23.5%). The second most common primary indication was bullous keratopathy for single repeat keratoplasty (49 eyes, 14.5%) and chemical injury for multiple repeat keratoplasties (14 eyes, 17.3%). The main reason for regrafting was allograft rejection (262 cases, 49.3%), followed by endothelial dysfunction (92 cases, 17.3%), and for vision improvement after tectonic keratoplasty (60 cases, 11.3%). Penetrating keratoplasty (PKP) was the major technique used in repeat keratoplasty (447 cases, 84.2%). However, Descemet stripping endothelial keratoplasty was more frequently used than PKP (72.4% vs. 27.6%, P < 0.001) in the treatment of failed endothelial keratoplasty.

Conclusion

Infectious keratitis was still the leading cause of repeat keratoplasty in eastern China. Although PKP remains the major technique of repeat keratoplasty, the application of customized lamellar keratoplasty has greatly expanded in the last decade. Cautious selection of indications, surgical techniques, and timing for surgery is crucial for a good prognosis after repeat keratoplasty.

Secondary DMEK following failed primary DMEK

PURPOSE

To report the outcomes of secondary Descemet Membrane Endothelial Keratoplasty (DMEK) performed for failed primary DMEK.

METHODS

The medical records of all patients undergoing secondary DMEK due to failure of primary DMEK were reviewed. Reasons for failure were sought and best-corrected visual acuity (BCVA), endothelial cell density (ECD) and complications of secondary DMEK were evaluated.

RESULTS

A total of 10 cases undergoing secondary DMEK following failed primary DMEK were identified. Presumed reasons for failure included donor ECD ≤ 2300 cells/mm² (n = 4), difficulty during graft preparation (n = 2), graft detachment (n = 2), acute angle closure due to retroiridal air dislocation (n = 1), inverse graft positioning (n = 1) and phacoemulsification (n = 1). Eyes with low visual potential were not excluded from the study group. We should note that one patient (case no7) had both low ECD and graft detachment as reasons for failure and as a result he is counted twice. Median BCVA (decimal fraction) increased from 0.1 (range, 0.01; 0.3) to 0.5 (0.05; 1.0) at one month and remained stable thereafter. A BCVA of 0.5 or higher was achieved in 7 cases at the final follow-up. Mean ECD fell from 2628 ± 284 cells/mm² to 1391 ± 252cells/mm² at 6 months (47% reduction) and 959 ± 225cells/mm² at 24 months (64% reduction) (P ≤ 0.028). Complications included the incomplete removal of the primary graft and mild iris bleeding, decompensation of a preexisting primary open-angle glaucoma and retroiridal air dislocation.

CONCLUSIONS

Apart from low donor ECD, surgical challenges, i.e., difficulty with graft preparation, inverse graft positioning, and retroiridal air dislocation, were main reasons for failure of primary DMEK. Secondary DMEK showed a good safety profile and reasonable visual outcomes.

Risk Factors for Repeat Descemet Membrane Endothelial Keratoplasty Graft Failure

PURPOSE

To evaluate repeat Descemet membrane endothelial keratoplasty (re-DMEK) success rates and to identify risk factors for re-DMEK failure.

DESIGN

Retrospective case series.

METHODS

Settings: Institutional.

PATIENTS AND INTERVENTIONS

A chart review was performed, including all eyes with primary DMEK failure that underwent re-DMEK between 2013 and 2019 at the Toronto Western Hospital and the Kensington Eye Institute (Toronto, Ontario, Canada) and had at least 6 months of follow-up.

MAIN OUTCOME MEASURE

Predicting factors for re-DMEK outcome.

RESULTS

Of 590 consecutive DMEK surgeries, 40 eyes (6.7%) were identified for having a secondary DMEK surgery after primary DMEK failure. Etiologies for primary DMEK were Fuchs endothelial corneal dystrophy (32.5%), pseudophakic bullous keratopathy (35%), previous failed graft (27.5%), and other indications (5%). Fifty-five percent of the cohort were categorized as having a complicated anterior segment including 11 eyes with previous glaucoma surgery, 7 eyes post-penetrating keratoplasty, 4 eyes post-Descemet stripping automated endothelial keratoplasty, 3 eyes peripheral anterior synechia, 3 eyes previous pars plana vitrectomy, 2 eyes aphakia, and 1 eye each with aniridia, anterior chamber intraocular lens, and iris-fixated intraocular lens. Re-DMEK failure was documented in 12 eyes (30%) of the entire cohort. The risk factor for re-DMEK failure was the presence of a complicated anterior segment (P = .01, odds ratio = 17.0 [95% confidence interval: 1.92-150.85]), with 50% re-DMEK failure rate in this subgroup.

CONCLUSION

Re-DMEK is a viable option for cases of primary DMEK failure, especially for eyes with Fuchs endothelial corneal dystrophy as the indication for primary DMEK without other ocular morbidities; however, eyes categorized with a complicated anterior segment had high re-DMEK failure rates.</ABSTRACT>.

Non stripping descemet membrane endothelial keratoplasty in difficult cases: A case series

Endothelial keratoplasty (EK) has been increasingly used instead of penetrating keratoplasty (PK) in the management of post PK graft rejection. Both DSAEK and DMEK involve the surgical removal of the diseased host endothelial cell layer and Descemet's membrane (DM) (descemetorhexis) before transplantation, a technically challenging step, especially in post-PK eyes. Understandably, interest arose when non-stripping DMEK (nDMEK) was described in 2013, and recent studies suggested encouraging results without increased early postoperative failures or complications requiring rebubbling. The purpose of our series was to further study the feasibility and safety of nDMEK and to compare the results with traditional DMEK. This is a single center case series of 3 eyes which underwent nDMEK performed by experienced surgeons (C.P, A.M). Two eyes had nDMEK as a secondary procedure following a failed/rejected PK, while the third case underwent nDMEK on a virgin eye. Undiseased donor DM and a regular host endothelium were required to be eligible for nDMEK. The average change in CCT at last follow-up was -21.2% (±13.3). All required intracameral air injection (rebubbling) within the first few days, with a mean of 2.33 rebubblings per eye, the first one occurring at 6.33±2.52 days after surgery. Non-stripping DMEK surgery appears to be a feasible option, and results are satisfactory at mid to long term. However, in our series, the immediate postoperative period was marked by an increased rebubbling rate. While foreseeable particularly in high-risk cases, surgeons considering this technique should expect a higher risk of early rejection.

Graft detachments in endothelial keratoplasty

Graft detachment is the most common complication of endothelial keratoplasty. With the ongoing advancements in the field of endothelial keratoplasty, our understanding of risk factors of graft detachments and its management has been evolving. Various prevention measures have been described in literature including presoaking the donor graft, anterior chamber tamponade, venting incisions, sutures to prevent dislocation of graft. Management of a detached graft involves secondary interventions such as rebubbling, suturing and regrafts. In this review, we discuss graft detachment in different types of endothelial keratoplasty techniques including Descemet stripping endothelial keratoplasty, Descemet stripping automated endothelial keratoplasty and Descemet's membrane endothelial keratoplasty; with emphasis on incidence, risk factors, preventive measures and their management.

Postoperative Complications in Medicare Beneficiaries Following Endothelial Keratoplasty Surgery

PURPOSE

To determine national-level incidence rates of major postoperative complications following endothelial keratoplasty (EK) procedures and to stratify these rates based on EK indications over an 8-year period using Medicare claims data.

DESIGN

Retrospective, cohort study.

METHODS

Setting: population-based; study population: Medicare beneficiaries aged ≥65 years who underwent EK procedures; main outcome measurements: 1) occurrence of major postoperative complications (i.e., endophthalmitis, choroidal hemorrhage, infectious keratitis, cystoid macular edema [CME], retinal detachment [RD], or RD surgery) following EK surgery; 2) time-to-event analysis for glaucoma surgery; and 3) occurrence of graft complications.

RESULTS

A total of 94,829 EK procedures (n = 71,040 unique patients) were included in the analysis. Of the total, 29% of patients had pre-existing glaucoma. The overall 90-day cumulative incidence of postoperative endophthalmitis and choroidal hemorrhage following EK was 0.03% and 0.05%, respectively. The overall 1-year cumulative rates of RD or RD surgery, infectious keratitis, and CME were 1.0%, 0.8%, and 4.1%, respectively. Approximately 7.6%, 12.2%, and 13.8% of all eyes in this study needed glaucoma surgery at 1-, 5-, and 8-years of follow-up, respectively. The probability of glaucoma surgery among patients with pre-existing glaucoma was 29% vs. 8% among those without pre-existing glaucoma at 8 years. The cumulative probabilities of developing any graft complications were 13%, 23.2%, and 27.1% at 1, 5, and 8 years, respectively, of follow-up. On average, patients undergoing EK procedures for a prior failed graft had the highest rate of complications, whereas those with Fuchs' corneal endothelial dystrophy had the lowest.

CONCLUSIONS

The incidence of major postoperative complications including endophthalmitis, retinal detachment, and choroidal hemorrhage following EK procedures is low. A high proportion of eyes undergoing EK eventually require glaucoma surgery and experience graft-related complications. Postoperative outcomes are typically worse for patients undergoing EK for prior failed grafts than for those undergoing EK for Fuchs' corneal endothelial dystrophy.

Corneal transplantation after failed grafts: Options and outcomes

Corneal transplantation is the most commonly performed human tissue transplantation procedure worldwide. Because of the large number of transplants, corneal graft failure has become one of the most common indications for corneal transplantation. The relatively recently developed lamellar transplant techniques have brought about specific potential complications leading to graft failure that may require different approaches to repeat transplantation other than penetrating keratoplasty. On the other hand, these new lamellar techniques also provide novel ways of rescuing failed penetrating grafts, with potential advantages over successive penetrating keratoplasties, such as reduced intraoperative risks and faster visual rehabilitation. We summarize the incidence and risk factors of graft failure for penetrating and lamellar (stromal and endothelial) corneal transplants and discuss the various surgical alternatives currently available to rescue such failed grafts, with a focus on the reported outcomes and limitations.

Repeat Descemet Membrane Endothelial Keratoplasty for Failed Primary Descemet Membrane Endothelial Keratoplasty at a Referral Center for Keratoplasty in Spain: DIMOEK Study

PURPOSE

To analyze the clinical results of repeat Descemet membrane endothelial keratoplasty (re-DMEK) for failed primary DMEK graft at a referral center for keratoplasty in Spain.

DESIGN

Retrospective, interventional, comparative case series.

METHODS

From a single-center, single-surgeon series of 189 consecutive DMEK surgeries, 14 (7.41%) were re-DMEK eyes. The primary outcome was best-corrected visual acuity change (ΔBCVA, logarithm of minimal angle of resolution [logMAR]) from baseline (before first DMEK) to last follow-up. Secondary outcomes were ΔBCVA from baseline at 3, 6, and 12 months postoperatively, endothelial cell loss (%ECL), rebubbling rate, and re-DMEK graft failure. Outcomes were compared with an age-matched control group of 18 successful primary DMEK eyes.

RESULTS

After re-DMEK (median follow-up time 14.5 [42.5] months), mean BCVA improved from 0.55 (0.42) logMAR (Snellen 20/71 [20/53]) at baseline to 0.09 (0.26) logMAR (Snellen 20/25 [20/36]; P = .037). ΔBCVA from baseline was statistically significant at months 3 (P = .028), 6 (P = .023), and 12 (P = .012), and ΔBCVA was significant observed between months 6 and 12 (P = .028). BCVA differences between patient groups were statistically nonsignificant at 3 (P = .397), 6 (P = .468), and 12 months (P = .647). Mean %ECL in re-DMEK eyes with follow-up ≥12 months was 48.2 (15.1%), and the rebubbling rate was 28.6%; differences between groups were statistically nonsignificant for both variables (P = .580 and P = .669, respectively). Three re-DMEK eyes developed graft failure, all achieving final BCVA ≤0.30 logMAR (Snellen ≥20/40) after tertiary keratoplasty.

CONCLUSIONS

Repeat DMEK produces significant, continuous visual improvement after failed primary DMEK. Although visual outcomes and %ECL were comparable to primary DMEK, there was a relatively high rate of graft failure after re-DMEK.

Free-Floating DMEK in the Host Anterior Chamber: Surgical Management

PURPOSE

To describe a method to visualize and manage a completely detached Descemet membrane endothelial keratoplasty (DMEK) tissue scroll in the anterior chamber.

METHODS

A 56-year-old male patient with pseudophakic bullous keratopathy, who underwent uncomplicated DMEK surgery, had a complete graft detachment diagnosed at 1-week follow-up. The graft was reattached using a new technique, that is, the free-floating graft was stained in the anterior chamber with trypan blue, immediately followed by air injection to separate the host stroma from the dye. The stained DMEK graft was opened by gentle tapping and attached to the host stroma by air tamponade.

RESULT

This technique allowed sufficient staining of DMEK tissue to further evaluate and correct the graft orientation inside the anterior chamber without compromising the stroma. The DMEK graft was attached 1 week after the reattachment procedure. The cornea cleared confirming the functionality of the endothelial cells.

CONCLUSIONS

The technique described may be useful in the cases of complete detachment of DMEK tissue and poor visualization of the DMEK tissue orientation. Staining with trypan blue under a "protective" air bubble can provide sufficient visualization to ensure the unfolding of DMEK tissue and reduce the risk of host stromal staining.

Management of Upside-Down Descemet Membrane Endothelial Keratoplasty: A Case Series

Purpose

To present the management of upside-down Descemet membrane endothelial keratoplasty (DMEK) following combined phacoemulsification with DMEK (phaco-DMEK) in cases of Fuchs endothelial dystrophy (FED).

Methods

This is a comparative interventional case series extracted from a prospective interventional case series (clinical outcome of DMEK combined with phacoemulsification for FED). We report five cases of upside-down DMEK. Two cases of upside-down DMEK were managed with re-orientation and the other two with repeat DMEK. The 5^th case underwent an initial re-orientation and then a subsequent repeat graft. Graft re-orientation and repeat surgery were performed 9-20 days after initial phaco-DMEK. All the five cases were followed up over a 6-month period, and the following outcomes were assessed: best corrected visual acuity (BCVA), contrast sensitivity (CS), central corneal thickness, endothelial cell density (ECD), and central macular thickness.

Results

At the final 6-month postoperative follow-up, all the five cases achieved good outcomes in terms of BCVA and CS. Overall, the results were comparable to 32 control cases. One case of re-orientation and the case of re-orientation with subsequent repeat DMEK performed slightly less well than control cases in terms of postoperative ECD.

Conclusions

Re-orientation of the original DMEK scroll in cases of upside-down DMEK can be a safe and cost-effective alternative to repeat DMEK. If re-orientation does not result in corneal deturgescence, a repeat DMEK may be done subsequently.

Differential Survival of Penetrating and Lamellar Transplants in Management of Failed Corneal Grafts

Importance

An increasing proportion of corneal transplant procedures are undertaken for replacement of a failed previous graft. The proportion of lamellar transplant procedures has significantly increased. There are limited large-scale reports on regraft procedures that may help guide surgeons and patients in their choice of surgery.

Objective

To examine the corneal transplant replacement survival rates for the 3 main indications and types of regraft surgery.

Design, Setting, and Participants

This national transplant registry study examined surgery and follow-up data on all corneal transplants performed in the United Kingdom from April 1, 1999, through March 31, 2016.

Main Outcomes and Measures

Actuarial regraft 5-year survival rates were compared for the 3 main indications and types of graft: penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty for keratoconus, PK and endothelial keratoplasty (EK) for Fuchs endothelial dystrophy (FED), and pseudophakic bullous keratopathy (PBK).

Results

A total of 9925 regrafts were analyzed during the 17-year study period. Penetrating keratoplasty represented 7261 cases (73.2%) in the cohort. Endothelial keratoplasty increased by 1361.5%, from 12 (2.6%; 95% CI, 1.3%-4.5%) of all 467 regrafts during 2005-2006 to 292 (38.0%; 95% CI, 34.6%-41.6%) of 768 during 2015-2016. The median time to first regraft for all graft types was 28 months (interquartile range, 10-64 months). When examining all graft types performed for all indications, stratification of 5-year survival was found for successive grafts, with a difference in survival of 25 270 (72.5%; 95% CI, 71.7%-73.2%) from the first graft to 4224 (53.4%; 95% CI, 51.4%-55.4%) from the second graft and 1088 (37.3%; 95% CI, 33.4%-41.3%) from the second to third graft. For first regrafts in keratoconus and PBK, survival after lamellar and PK procedures was similar. For FED, there was a higher regraft survival after PK (375 [70.8%]; 95% CI, 64.6%-76.1%) compared with EK (303 [54.7%]; 95% CI, 45.8%-62.8%) (P < .001). For FED and PBK, there was no difference in first regraft survival identified between EK followed by PK vs PK followed by PK or EK followed by EK vs PK followed by EK.

Conclusions and Relevance

In this large registry-based analysis of corneal regraft survival, regraft survival was found to vary with indication for first graft surgery and for FED with type of regraft procedure performed. For FED and PBK, the permutation of graft and subsequent first regraft procedure were not associated with any survival benefit for the first regraft. These reported outcomes may assist decision-making in management of a failed corneal transplant.

Descemet's Membrane Endothelial Keratoplasty with Split Corneal Grafts: The Influence of Tamponade Material and Endothelial Storage Time

Purpose: The aim of this study was to describe the clinical outcome of Descemet's membrane endothelial keratoplasty (DMEK) performed with split corneal grafts and to evaluate the influence of tamponade material and endothelial storage time on DMEK success. Material and Method: The records of 43 patients who underwent DMEK surgery with a split corneal graft were reviewed. Diagnosis of the patients, preoperative and postoperative best-corrected visual acuity (BCVA), corneal and endothelial storage time, tamponade material, complications, and success rates were specifically tabulated. Results: The most common indication for DMEK was pseudophakic bullous keratopathy (n = 25, 58.2%). Re-bubbling was needed in 10 cases (23.2%), and a re-DMEK was scheduled in 2 cases and penetrating keratoplasty in 4 cases (9.3%). BCVA improved significantly postoperatively (p < .001). There was an insignificant trend towards a lower re-bubbling rate and better long-term anatomic outcome in favor of 20% SF6 group compared to air tamponade (p = .18 and p = .25). There was no significant difference between the early endothelial transplant (<24 h) and delayed endothelial transplant (3 to 14 days) groups for anatomic success, corneal thickness or BCVA (p = .94, p = .13 and p = .35). Conclusion: The success rate of DMEK was satisfactory with split corneal grafts. There was no adverse influence of delayed endothelial transplantation on clinical outcome. The success rate of 20% SF6 tamponade was slightly better than room air.

Immune reactions after modern lamellar (DALK, DSAEK, DMEK) versus conventional penetrating corneal transplantation

In the past decade, novel lamellar keratoplasty techniques such as Deep Anterior Lamellar Keratoplasty (DALK) for anterior keratoplasty and Descemet stripping automated endothelial keratoplasty (DSAEK)/Descemet membrane endothelial keratoplasty (DMEK) for posterior keratoplasty have been developed. DALK eliminates the possibility of endothelial allograft rejection, which is the main reason for graft failure after penetrating keratoplasty (PK). Compared to PK, the risk of endothelial graft rejection is significantly reduced after DSAEK/DMEK. Thus, with modern lamellar techniques, the clinical problem of endothelial graft rejection seems to be nearly solved in the low-risk situation. However, even with lamellar grafts there are epithelial, subepithelial and stromal immune reactions in DALK and endothelial immune reactions in DSAEK/DMEK, and not all keratoplasties can be performed in a lamellar fashion. Therefore, endothelial graft rejection in PK is still highly relevant, especially in the "high-risk" setting, where the cornea's (lymph)angiogenic and immune privilege is lost due to severe inflammation and pathological neovascularization. For these eyes, currently available treatment options are still unsatisfactory. In this review, we will describe currently used keratoplasty techniques, namely PK, DALK, DSAEK, and DMEK. We will summarize their indications, provide surgical descriptions, and comment on their complications and outcomes. Furthermore, we will give an overview on corneal transplant immunology. A specific focus will be placed on endothelial graft rejection and we will report on its incidence, clinical presentation, and current/future treatment and prevention options. Finally, we will speculate how the field of keratoplasty and prevention of corneal allograft rejection will develop in the future.

Corneal clearance and central endothelial cell repopulation despite graft detachment after Descemet membrane endothelial keratoplasty

Objective: Descemet membrane endothelial keratoplasty (DMEK) is the gold standard procedure for treatment of primary corneal endothelial disorders. Graft detachment is a frequent complication of DMEK, which often requires re-operation or re-bubbling. However, several cases of spontaneous corneal clearance despite graft detachment after DMEK have been reported. The underlying mechanisms of this phenomenon are poorly understood. We report three cases of corneal clearance after graft detachment in patients with Fuchs endothelial dystrophy and provide a review of the literature.

Methods: An 81-year-old and a 69-year-old phakic patient as well as a 56-year-old pseudophakic patient with Fuchs endothelial dystrophy underwent Triple-DMEK and DMEK, respectively. All three patients presented postoperatively with blurred vision due to an almost complete detachment of the graft, as shown by slit-lamp photography and anterior segment optical coherence tomography (OCT).

Results: Without additional intervention, gradual corneal clearance and presence of endothelial cells on the posterior recipient’s stroma were observed in all patients three months postoperatively. Increase in endothelial cell density, decrease in central corneal thickness (CCT), recovery of corneal transparency, and improvement of visual acuity were documented in all patients.

Conclusions: Our findings support the theory of corneal clearance after Descemet membrane endothelial transfer (DMET) (“free-floating” donor Descemet graft in the recipient anterior chamber after descemetorhexis). Further understanding on endothelial homeostasis might lead to innovative approaches in handling endothelial disorders.

Outcome of Descemet membrane endothelial keratoplasty for graft failure after Descemet stripping automated endothelial keratoplasty

Purpose

To investigate the efficacy and safety of Descemet membrane endothelial keratoplasty (DMEK) for corneal decompensation following primary Descemet stripping automated endothelial keratoplasty (DSAEK).

Methods

This was a retrospective case series of 15 patients that underwent DMEK surgery for corneal decompensation after failed DSAEK. Main outcome parameter was corrected distance visual acuity (CDVA) after DMEK and DSAEK. Secondary outcome measures included central corneal thickness (CCT), endothelial cell density (ECD), rebubbling rate, and primary graft failure after DMEK. Explanted DSAEK grafts were evaluated by light microscopy.

Results

The mean (±SD) time period between DSAEK and DMEK surgery was 15±8 months (range, 6–31 months). Preoperative CDVA was 1.72±0.62 (logMAR). After DMEK, CDVA improved significantly to 0.78±0.48 at 1 month and to 0.23±0.24 after 12 months (P=0.022). Visual acuity data after DMEK were significantly better compared to preoperative values. The average CCT after DMEK decreased significantly from 869±210 µm (preoperative) to 505±45 µm (1 month postoperative) (P<0.001) and remained stable over 12 months. The ECD decreased from 2,589±209/mm² (preoperative) to 1,691±589/mm² (12 months postoperative). Rebubbling DMEK was required in three patients (=20%).

Conclusion

DMEK represents a feasible and safe procedure in achieving better functional results compared to DSAEK. Visual acuity and optical quality can be effectively reestablished after unsuccessful primary DSAEK surgery even in patients with long-standing corneal decompensation. Further investigations are required to validate the preliminary clinical findings.

Functional outcome of repeat Descemet membrane endothelial keratoplasty (DMEK) for corneal decompensation following graft failure after primary DMEK

Purpose

To evaluate if repeat Descemet membrane endothelial keratoplasty (DMEK) is appropriate to achieve functional improvements in patients with corneal decompensation from secondary graft failure after primary DMEK.

Methods

This is a retrospective monocentric cohort study including 13 eyes of 13 patients with repeat DMEK for corneal decompensation following primary DMEK. Eyes with primary DMEK only and comparable preoperative corrected distance visual acuity (CDVA) served as control. Main outcome parameter was CDVA. Secondary outcome measures were central corneal thickness (CCT), endothelial cell density, and rebubbling rate (RR).

Results

The average time interval (±SD) between primary and secondary DMEK was 12.5±6 months. Preoperative CDVA (logMAR) was 1.97±0.90 in the repeat DMEK group and 1.38±0.92 in the primary DMEK group. At 6 months, both groups showed significant improvement in visual acuity (repeat DMEK group, 0.49±0.35, P<0.01 and primary DMEK group, 0.40±0.36, P<0.01). CDVA did not differ significantly between both groups at all time points examined (1, 3, and 6 months postoperatively). Mean CCT values at 3 and 6 months postoperatively did not differ significantly between the two groups (P>0.05). The RR was 23% (n=3) in both groups.

Conclusion

Repeat DMEK is a useful therapeutic approach in the setting of corneal decompensation following primary DMEK. Functional results of repeat DMEK, visual acuity in particular, are comparable to patients with single DMEK only.

Cost-Effectiveness Analysis of Descemet's Membrane Endothelial Keratoplasty Versus Descemet's Stripping Endothelial Keratoplasty in the United States

PURPOSE

To determine the cost-effectiveness of Descemet's membrane endothelial keratoplasty (DMEK) compared with Descemet's stripping automated endothelial keratoplasty (DSAEK) in the United States.

DESIGN

Cost-effectiveness analysis in a surgical center in the United States.

PARTICIPANTS

Binocular adult patient undergoing endothelial keratoplasty.

METHODS

A base case of a 70-year-old man undergoing his first endothelial keratoplasty for bilateral Fuchs endothelial dystrophy. The cost-effectiveness of DMEK was compared with DSAEK over a 15-year time horizon. The incidences and costs of complications were derived from PubMed English literature searches, Medicare reimbursements, and average wholesale prices. All costs were discounted 3% per annum and adjusted for inflation to 2018 U.S. dollars. Uncertainty was evaluated using deterministic and probabilistic sensitivity analyses.

MAIN OUTCOME MEASURES

Incremental cost-effectiveness ratios and incremental cost-utility ratios, measured in cost per quality-adjusted life-years (QALYs).

RESULTS

Performing a DMEK instead of a DSAEK generated an extra 0.4 QALYs over a 15-year period. From a societal and third-party payer perspective, DMEK was cost-saving when compared with DSAEK in improving visual acuity in the base case. Probabilistic sensitivity analyses with variations in the costs and rebubble rates revealed that DMEK was cost-saving compared with DSAEK in 38% of iterations and was within a societal willingness-to-pay threshold of $50 000 in 98% of models.

CONCLUSIONS

From the societal and third-party payer perspectives in the United States, DMEK generated greater utilities and was less costly than DSAEK. Therefore, DMEK was the dominant procedure and was cost-saving with respect to DSAEK. The economic model was robust based on sensitivity analyses.

"PI-less DMEK": results of Descemet's membrane endothelial keratoplasty (DMEK) without a peripheral iridotomy

PURPOSE

To assess Descemet's membrane endothelial keratoplasty (DMEK) without performing a peripheral iridotomy (PI) prior to or during surgery ("PI-less DMEK").

MATERIALS AND METHODS

This retrospective study included consecutive patients that underwent PI-less DMEK by a single surgeon (E.L) between February 2016 and February 2017 at the Rabin Medical Center, a Tertiary Hospital. Intraoperative and postoperative complications were assessed.

RESULTS

Thirty-one patients, mean age 75.9 ± 7.9 years with 58.1% female were included. Leading indications for surgery were pseudophakic bullous keratopathy (18/31) and Fuchs' endothelial dystrophy (9/31). Preoperative best-corrected distance visual acuity was 1.13 ± 0.59 logMAR (~6/80 Snellen). For 12/31 that had postoperative endothelial cell count measurements, cell loss was 49 ± 20%. Intraoperative complications included anterior chamber (AC) hyphema during graft insertion requiring reinsertion (n = 1), and minor hyphema from the main corneal incision (n = 1). Partial slit lamp gas evacuation was performed in all patients 1.5 h postoperatively. Postoperative complications included partial graft detachment requiring rebubbling (n = 5), self-resolving minimal peripheral graft detachment (n = 5), uncontrolled intraocular hypertension requiring trabeculectomy in a patient with a history of medically controlled glaucoma (n = 1), postoperative cystoid macular edema that resolved medically (n = 1) and graft failure 5 months postoperatively (n = 1). No patients developed pupillary block. Excluding graft failure (n = 1), preoperative amblyopia (n = 2) and premature loss to follow-up (n = 1), final corrected distance visual acuity was 0.18 ± 0.14 logMAR (~20/30 Snellen) with 44.4% reaching 6/7.5 (Snellen) or more.

CONCLUSIONS

PI-Less DMEK is a safe, technically easy, and effective modification that avoids the time and complications associated with performing a PI before or during surgery.

Outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) performed in eyes with failure of primary Descemet membrane endothelial keratoplasty (DMEK)

AIM

To evaluate the outcomes of ultrathin Descemet stripping automated endothelial keratoplasty (UT-DSAEK) performed in eyes after failure of primary Descemet membrane endothelial keratoplasty (DMEK).

METHODS

This was a retrospective, non-comparative interventional case series done in a tertiary care hospital. The study group included 21 eyes of patients which underwent UT-DSAEK following the failure of primary DMEK. Outcome measures included best spectacle-corrected visual acuity (BSCVA) and endothelial cell density (ECD) both recorded 6 and 12 months postoperatively as well as central graft thickness (CGT) measured 6 months after UT-DSAEK.

RESULTS

When considering only eyes without comorbidities (17 of 21), 12 months after UT-DSAEK, BSCVA was ≥20/25 in 12/13 (92%) eyes and ≥20/20 in 4/13 (30%) eyes. Mean ECD loss rate was 38.9% at 12 months postoperatively (range 8%-57%). Six months postoperatively, CGT averaged at 81±34 µm (range 34-131 µm). No intraoperative complications were recorded. Postoperatively, one patient (no. 8) had graft wrinkles that were fixed 2 days following UT-DSAEK. Four patients have developed intraocular lens (IOL) opacification, and two of them underwent IOL exchange. No other postoperative complications were recorded.

CONCLUSIONS

UT-DSAEK is instrumental in the management of primary DMEK graft failure, allowing visual rehabilitation which is comparable with that of repeat DMEK.

Comparison of densitometric profile after deep lamellar keratoplasty with two different techniques for treatment of keratoconus

PURPOSE

To compare densitometric outcome of two techniques of deep lamellar keratoplasty using Pentacam HR corneal densitometry software.

METHODS

Postoperative outcomes of 31 patients with big bubble (BB) and 28 patients with Melles (M) surgery for the treatment of keratoconus were evaluated. Data were gathered at least 3 months after the removal of all sutures including demographic data, uncorrected distance visual acuity (UCDVA), best spectacle-corrected visual acuity (BSCVA), refraction and endothelial cell count. Moreover, the Scheimpflug images were taken by Pentacam^® HR to assess keratometric profile, densitometric outcomes in different depths and zones of the cornea and central corneal thickness. Anterior segment OCT was performed in ten cases of M group.

RESULTS

Thirty-one eyes with BB and 27 eyes M surgery were enrolled. Comparison of densitometric profile between groups revealed no statistical significance in zone 0-2 mm, zone 2-6 mm and zone 10-12 mm in all depths (all P values >  0.05). Zone 6-10 mm of M group had lower densitometric readings (more transparent) in anterior, central and posterior layers of the cornea in comparison with BB group (all P <  0.05). Also no statistical difference was found in UCDVA, BSCVA, spherical or cylindrical refractive error, and spherical equivalent, keratometric readings, endothelial cell count and central corneal thickness in two groups (all P values >  0.05).

CONCLUSION

Densitometric profiles were identical in both methods in visually important zones so as visual and refractive outcomes.

Prevention and Management of Descemet Membrane Endothelial Keratoplasty Complications

PURPOSE

To describe Descemet membrane endothelial keratoplasty (DMEK) complications and strategies for their prevention and management.

METHODS

Five hundred consecutive eyes with DMEK of 393 patients were reviewed in this retrospective study for intraoperative and postoperative complications up to 2 years and for corresponding management.

RESULTS

Intraoperative challenges (difficult graft unfolding/positioning, high vitreous pressure, iris root hemorrhage, and Descemet membrane remnants) were encountered in 81 eyes (16.2%). Visually significant graft detachment was the main postoperative complication (34 eyes, 6.8%). Graft failure occurred in 8 eyes (1.6%). Other postoperative complications were an increase of intraocular pressure/decompensated glaucoma in 48 eyes (9.6%), significant cataract in 11 of 124 phakic eyes (8.9%), allograft rejection in 7 eyes (1.4%), cystoid macular edema in 5 eyes (1.0%), microbial keratitis in 2 eyes (0.4%), and retinal detachment in 1 eye (0.2%). Different strategies for prevention and management of these complications have been identified.

CONCLUSIONS

DMEK shows acceptable rates of complications up to 2 years after surgery, which can be managed successfully. Anticipation of potential challenges and difficulties may aid in modifying intraoperative strategies for predisposed eyes. This knowledge may further minimize complications, in particular, when performing DMEK for an extended spectrum of corneal endothelial disorders.

Graft detachment and rebubbling rate in Descemet membrane endothelial keratoplasty

Descemet membrane endothelial keratoplasty (DMEK) is a selective replacement of dysfunctional endothelium with healthy donor Descemet membrane and endothelium. Although the donor preparation and surgical methods still remain a challenge, DMEK is gaining popularity in terms of early rehabilitation and visual outcomes. New and improved donor preparation techniques like prestripped DMEK tissues are being taken up rapidly because of less manipulation that is required in the surgical theatre. Donor graft delivery in the recipient eye has also been improved because of new products like prestripped and preloaded membranes. As DMEK is at its budding stage, only early outcomes have been known so far. Early graft detachment, rebubbling rates, and primary failures are still being studied in DMEK. As there are different techniques that are currently used for preparation and injection of the graft, it becomes difficult to judge the results based on specific inclusion and exclusion criteria. Graft detachment and rebubbling rates have been a huge challenge both during the surgery and also while reporting postoperative data. We highlight the importance of defining graft detachment and rebubbling rates and their surgical relevance, which may also have an impact on graft preparation and insertion techniques.

Descemet membrane endothelial keratoplasty and refractive surgery

PURPOSE OF REVIEW

Descemet membrane endothelial keratoplasty (DMEK) has become a first-line treatment in corneal endothelial diseases because of its exceptional clinical outcomes and low complication rates. Because of its improved refractive predictability, DMEK is now also considered for managing cases with endothelial decompensation following previous refractive procedures, or in combination with those. This article reviews the clinical outcomes in these cases and discusses the possibility of refractive interventions following DMEK.

RECENT FINDINGS

DMEK has been successfully performed in eyes after laser in-situ keratomileusis, eyes after anterior chamber intraocular lens (IOL) implantation and aphakic eyes. Often, DMEK is combined with cataract surgery (triple-DMEK). Initial reports on reducing the refractive cylinder by toric IOL implantation are available. Although there are some reports on phacoemulsification and IOL implantation after phakic DMEK, reports on laser refractive procedures following DMEK are lacking.

SUMMARY

In contrast to earlier keratoplasty techniques, DMEK induces on average only mild refractive shifts owing to the 'natural' restoration of the cornea. As such, DMEK may be ideal in managing corneal decompensation in refractive patients. However, further studies are required to assess the safety and efficacy of DMEK after refractive treatment and of refractive procedures following DMEK.

Influence of Early Descemet Stripping Endothelial Keratoplasty on Visual Outcomes in Pseudophakic Corneal Edema

PURPOSE

Longstanding corneal edema can lead to anterior stromal scarring that may limit visual acuity following Descemet stripping endothelial keratoplasty (DSEK). The ideal time to perform DSEK to prevent permanent changes is unclear. Our aim is to determine whether earlier DSEK is associated with improved visual outcomes.

DESIGN

Cohort study.

METHODS

Setting: Institutional.

STUDY POPULATION

Total of 120 eyes of patients who underwent DSEK for corneal edema following cataract surgery (CE); 87% of eyes had a diagnosis of Fuchs dystrophy.

INTERVENTION

Post-DSEK visual acuity was compared in patients who underwent DSEK ≤6 months vs >6 months after CE. Linear and logistic regression were performed to assess the relationships between DSEK timing and best spectacle-corrected visual acuity (BSCVA) while accounting for baseline preoperative patient characteristics.

MAIN OUTCOME MEASURES

Postoperative best-corrected visual acuity 6 months after DSEK (POM6 BSCVA).

RESULTS

Median CE-to-DSEK time was 8.62 (interquartile range [IQR] 12.28) months (n = 120). Overall median preoperative VA and POM6 BSCVA were 0.54 (IQR 0.68) and 0.24 (IQR 0.16), respectively. Median POM6 BSCVA was better in patients with CE-to-DSEK time ≤6 months (median 0.18, IQR 0.19) vs >6 months (median 0.30, IQR 0.21) (P = .014). A significant relationship was found between CE-to-DSEK time and POM6 BSCVA (coefficient = 0.002, P = .033), accounting for preoperative vision and pachymetry. Patients who underwent DSEK ≤6 months after CE were more likely to achieve POM6 BSCVA better than 20/40 (odds ratio = 3.73 P = .035).

CONCLUSION

Performing earlier DSEK for pseudophakic corneal edema appears to be associated with improved vision. Further prospective study is warranted to determine the optimal time to perform DSEK in patients with pseudophakic corneal edema.

Midterm Results of Descemet Membrane Endothelial Keratoplasty: 4 to 7 Years Clinical Outcome

PURPOSE

To evaluate the midterm outcomes of Descemet membrane endothelial keratoplasty (DMEK) up to 4-7 years postoperatively.

DESIGN

Retrospective, consecutive interventional case series.

METHODS

A total of 250 consecutive eyes of 209 patients who underwent DMEK at our institute and had potentially at least 4 years of follow-up. Main outcome measures were best-corrected visual acuity (BCVA), endothelial cell density (ECD), central corneal thickness (CCT), graft survival rate, and postoperative complications.

RESULTS

At 6 months postoperatively, 73% of the eyes reached a BCVA of ≥20/25 (0.8) and 44% ≥20/20 (1.0), and remained stable up to 7 years (P = .7114). ECD dropped by 33.9% in the first 6 months, and then declined by a yearly rate of 9.0%. CCT did not show a significant change after 6 months up to 7 years (P = .8447). The cumulative graft survival rate at 4 and 7 years was 0.96 (95% confidence interval [0.93, 0.99]). Rebubbling procedures were performed in 4.4% of eyes, all within the first 6 postoperative months. Repeat transplantations were performed in 15.2% of cases to manage greater than one third graft detachment (11.6%), primary graft failure (1.6%), or secondary graft failure (2.0%), with the majority (79%) of repeat transplantations performed within the first year. After 6 months, the main complications were allograft rejection (2.4%) and secondary graft failure (2.0%).

CONCLUSIONS

The visual acuity level achieved at 6 months after DMEK may remain stable up to at least 4-7 years; ECD shows a constant, slow decrease; and complications after the first 6 months occur in <5% of cases.

Descemet-membrane endothelial keratoplasty in patients with retinal comorbidity-a prospective cohort study

AIM

To investigate indications, surgical challenges, and outcome of Descemet-membrane endothelial keratoplasty (DMEK) in patients with retinal comorbidities (RC).

METHODS

In a prospective cohort study, 8 eyes of 8 DMEK-patients with known RC were compared to 38 eyes of 38 DMEK-patients without RC. The duration of surgery, the degree of difficulty graded by the surgeon, and the complications through DMEK-surgery were analyzed for each patient. The best-corrected visual acuity (BCVA), the endothelial cell count, the intraocular pressure, and the subjective satisfaction was evaluated after a 6-month follow-up. Data were compared applying the non-parametric Wilcoxon-, Chi-square- and Fisheŕs-exact-test with P≤0. 05 as level of significance.

RESULTS

RC-patients had dry age-related macular degeneration (n=4) or history of pars-plana vitrectomy (n=4). The main indication for DMEK was pain due to bullous keratopathy for the RC-patients (n=7, 88%) and visual impairment due to Fuchs endothelial keratoplasty for the non-RC-patients (n=33, 87%). The BCVA increased for both groups (P=0.01, P<0.001) and all corneas cleared. For the RC-patients, the subjective satisfaction improved significantly (P=0.02). Oil-filling and missing support of the vitreous body complicated surgery in vitrectomized eyes.

CONCLUSION

DMEK is a favorable technique to treat endothelial disorders even if patients suffer from a retinal comorbidity. By enhancing the corneal clarity, it enables retinal examination or intraocular surgery and increases the patientś satisfaction. However, in vitrectomized or silicone-oil filled eyes, the duration of surgery and degree of complexity are increased. An experienced surgeon should perform DMEK in these patients.

CLINICAL TRIAL REGISTRATION NUMBER

DRKS00007566.

Corneal High-Order Aberrations and Backscatter in Fuchs' Endothelial Corneal Dystrophy

PURPOSE

Suboptimal visual acuity after endothelial keratoplasty has been attributed to increased anterior corneal high-order aberrations (HOAs). In this study, we determined anterior and posterior corneal HOAs over a range of severity of Fuchs' endothelial corneal dystrophy (FECD).

DESIGN

Cross-sectional study.

PARTICIPANTS

A total of 108 eyes (62 subjects) with a range of severity of FECD and 71 normal eyes (38 subjects).

METHODS

All corneas were examined by using slit-lamp biomicroscopy to determine the severity of FECD versus normality. Fuchs' endothelial corneal dystrophy corneas were categorized as mild, moderate, or advanced according to the area and confluence of guttae and the presence of clinically visible edema. Normal corneas were devoid of any guttae. Wavefront errors from the anterior and posterior corneal surfaces were derived from Scheimpflug images and expressed as Zernike polynomials through the sixth order over a 6-mm diameter optical zone. Backscatter from the anterior 120 μm and posterior 60 μm of the cornea also was measured from Scheimpflug images and was standardized to a fixed scatter source. Variables were compared between FECD and control eyes by using generalized estimating equation models to adjust for age and correlation between fellow eyes.

MAIN OUTCOME MEASURES

High-order aberrations, expressed as root mean square of wavefront errors, and backscatter of the anterior and posterior cornea.

RESULTS

Total anterior corneal HOAs were increased in moderate (0.61±0.27 μm, mean ± standard deviation; P = 0.01) and advanced (0.66±0.28 μm; P = 0.01) FECD compared with controls (0.47±0.16 μm). Total posterior corneal HOAs were increased in mild (0.22±0.09 μm; P = 0.017), moderate (0.22±0.08 μm; P < 0.001), and advanced (0.23±0.09 μm; P < 0.001) FECD compared with controls (0.16±0.03 μm). Anterior and posterior corneal backscatter were higher for all severities of FECD compared with controls (P ≤ 0.02, anterior; P ≤ 0.001, posterior).

CONCLUSIONS

Anterior and posterior corneal HOAs and backscatter are higher than normal even in early stages of FECD. The early onset of HOAs in FECD might contribute to the persistence of HOAs and incomplete visual rehabilitation after endothelial keratoplasty.