Complications and management in Descemet's stripping endothelial keratoplasty: analysis of consecutive 430 cases

Pediatric corneal transplantation: techniques, challenges, and outcomes

Pediatric corneal transplant is a highly demanding and technically challenging procedure for the cornea surgeon in today's era. These cases pose unique challenges in clinical and surgical management. The indications of pediatric corneal transplant can be therapeutic, tectonic, optical, and cosmetic. Pediatric patients undergoing corneal transplants are at a high risk of graft infection, failure, rejection, dehiscence, and amblyopia due to young age, robust immune system, increased incidence of trauma, and compliance issues. The other factors contributing to graft failure can be allograft rejection, secondary glaucoma, corneal vascularization, multiple surgeries, vitreous prolapse, and lack of treatment compliance. A successful corneal transplant in children depends on meticulous preoperative evaluation, uneventful surgery, the expertise of a corneal surgeon, and regular and timely postoperative follow-up. Therapeutic and optical penetrating keratoplasty are the most commonly performed transplants in children. However, with the advancements in surgical technique and management protocol, the current focus has shifted toward lamellar keratoplasty. Lamellar keratoplasty offers early visual recovery and potentially fewer complications. Visual rehabilitation through corneal transplant in otherwise blind eyes can be a boon for the children. Recently, keratoprostheses have been promising in children with multiple graft failures. The current review gives insights into epidemiology, etiology, indications, clinical characteristics, investigations, management options, recent advances, and the future of pediatric corneal transplants. As surgical techniques continue to grow and comprehension of pediatric corneal transplants is improving, we can safeguard these eyes with the best possible anatomical and functional outcomes.

Incidence and management of early postoperative complications in lamellar corneal transplantation

PURPOSE

To provide a comprehensive review of the incidence, risk factors, and management of early complications after deep anterior lamellar keratoplasty (DALK), Descemet stripping automated keratoplasty (DSAEK), and Descemet membrane endothelial keratoplasty (DMEK).

METHODS

A literature review of complications, that can occur from the time of the transplant up to 1 month after the transplant procedure, was conducted. Case reports and case series were included in the review.

RESULTS

Complications in the earliest postoperative days following anterior and posterior lamellar keratoplasty have shown to affect graft survival. These complications include, but are not limited to, double anterior chamber, sclerokeratitis endothelial graft detachment, acute glaucoma, fluid misdirection syndrome, donor-transmitted and recurrent infection, and Uretts-Zavalia syndrome.

CONCLUSION

It is essential for surgeons and clinicians to not only be aware of these complications but also know how to manage them to minimize their impact on long-term transplant survival and visual outcomes.

Fungal Infection After Descemet Membrane Endothelial Keratoplasty: Incidence and Outcomes

PURPOSE

The aim of the study was to describe the incidence, presentation, management, and outcomes of fungal infection after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Retrospective case series of culture-proven fungal infections after DMEK reported in the literature, directly by surgeons, and to the Eye Bank Association of America from January 1, 2011, to December 31, 2020.

RESULTS

The domestic incidence of fungal infections, fungal keratitis, and fungal endophthalmitis after DMEK from 2011 to 2020 was 3.5, 1.3, and 2.2 per 10,000 cases, respectively, with no significant increasing trend. Thirty-four cases were identified, 14 (41.2%) published and 20 (58.8%) unpublished. Donor tissue fungal cultures were performed in 20 of the 34 (58.8%) cases and were positive in 19 of the 20 (95.0%), all but one Candida species. Recipient fungal cultures were performed in 29 of the 34 (85.3%) cases and were positive in 26 of the 29 (89.7%), all but one Candida species. Infection presented a mean of 33 ± 38 days (median 23, range 2-200, outlier 949) after transplantation: 25 (73.5%) with endophthalmitis and 9 (26.5%) with keratitis. Topical, intrastromal, intracameral, intravitreal, or systemic antifungal therapy was used in all 27 eyes with treatment data. Surgical intervention (DMEK explantation or partial removal, repeat endothelial keratoplasty, penetrating keratoplasty, and/or pars plana vitrectomy) was required in 21 of the 27 (77.8%) eyes. The corrected distance visual acuity at the last follow-up was ≥20/40 in 13 of the 27 (48.1%) eyes and counting fingers or worse in 6 of the 27 (22.2%) eyes.

CONCLUSIONS

Fungal infection is a rare but serious complication of DMEK that results in counting fingers or worse corrected distance visual acuity in nearly a quarter of eyes.

Complications of Descemet stripping endothelial keratoplasty - A retrospective interventional study at a tertiary eye care center in Southern India

Purpose

To analyze the visual outcome and complications of Descemet stripping endothelial keratoplasty (DSEK) with their management in 256 eyes at a tertiary eye care center in southern India.

Methods

This is a retrospective interventional study of 62 months duration conducted at a tertiary eye care center in southern India. Two hundred and fifty-six eyes of 205 patients were included in the study after obtaining written informed consent from the patients. All cases of DSEK were performed by a single experienced surgeon. In all cases, donor dissection was performed manually. A Sheet's glide was inserted through the temporal corneal incision and donor button was placed on the Sheet's glide with the endothelial side down. The lenticule was separated and inserted into the anterior chamber by pushing the lenticule into the anterior chamber using Sinskey's hook. Any complication, either intraoperative or postoperative, was recorded and managed either medically or by appropriate surgical means.

Results

The mean best corrected visual acuity (BCVA) before surgery was CF-1 m, which improved to 6/18 after surgery. Intraoperative donor graft perforation during dissection was seen in 12 cases, thin lenticule in three eyes, and repeated artificial Anterior Chamber (AC) collapse in three eyes. Dislocation of lenticule was the most common complication seen in 21 eyes, which was managed by graft repositioning and rebubbling. Eleven cases had minimal separation of the graft and seven cases had interface haze. Pupillary block glaucoma was seen in two cases that resolved with partial release of bubble. Surface infiltrate was seen in two cases, which was managed with topical antimicrobial agents. Primary graft failure was seen in two cases.

Conclusion

DSEK is a promising alternative to penetrating keratoplasty for corneal endothelial decompensation, but it also has its own merits and limitations, and most often, merits overweigh limitations.

Long-term Outcomes After Lamellar Endothelial Keratoplasty Compared With Penetrating Keratoplasty for Corneal Endothelial Dysfunction: A Systematic Review

PURPOSE

The purpose of this study is to evaluate long-term outcomes of endothelial keratoplasty (EK) compared with penetrating keratoplasty (PK) for corneal endothelial dysfunction [Fuchs endothelial corneal dystrophy (FECD) and bullous keratopathy (BK)].

METHODS

In this systematic review, we searched PubMed, the Cochrane Library, and Embase up to May 2022 and considered all types of studies addressing our objective. Graft survival at 5, 10, and 15 years was the main outcome.

RESULTS

Fifty cohort studies were included. At 5 years, in FECD and BK, graft survival seemed higher after EK than PK. Two comparative studies showed either a higher 5-year graft survival after EK than PK or no significant differences. Including noncomparative studies, in FECD, the 5-year graft survival ranged from 0.69 to 0.98 for PK, from 0.93 to 1.00 for DSEK, and from 0.93 to 0.99 for Descemet membrane endothelial keratoplasty (DMEK). In BK, the 5-year graft survival ranged from 0.39 to 0.91 for PK, from 0.65 to 0.89 for DSEK, and from 0.84 to 0.95 for DMEK. The 10-year graft survival ranged from 0.20 to 0.90 for PK and from 0.62 to 0.92 for EK. The mean 5-year best spectacle-corrected visual acuity ranged from 0.73 to 0.43 LogMAR for PK, from 0.61 to 0.09 for DSEK, and from 0.31 to 0.05 for DMEK. The 5-year rejection rate ranged from 11.0% to 28.7% for PK, from 5.0% to 7.9% for DSEK, and from 1.7% to 2.6% for DMEK.

CONCLUSIONS

These results suggest a higher 5-year graft survival and better secondary outcomes after EK. Nevertheless, the level of evidence was low.

PROSPERO REGISTRATION

CRD42021260614.

A Novel Murine Model of Endothelial Keratoplasty

PURPOSE

The purpose of this study was to establish a murine model of endothelial keratoplasty.

METHODS

Endothelial keratoplasty (EK) was performed using C57BL/6 donor and BALB/c recipient mice. The central endothelium and Descemet membrane were removed from the recipient cornea, and a 1.5-mm posterior lamellar donor graft was made adherent to the recipient cornea with a small amount of viscoelastic. Mice were followed through slitlamp microscopy postoperatively, and OCT was used to assess the cornea and anterior chamber and measure central corneal thickness. Histology and immunohistochemistry were performed to confirm graft adherence and endothelial cell morphology.

RESULTS

Successfully attached EK grafts were visualized in all transplanted animals. Histology and immunostaining confirmed proper graft orientation and adherence, as well as the presence of donor endothelium on transplanted grafts. We observed maximal corneal edema in all animals at day 1 postoperatively which gradually subsided. EK graft survival was 97% at 8 weeks.

CONCLUSIONS

In this study, we describe a novel murine model for EK which we anticipate will enable detailed investigation into the cellular and molecular mechanisms involved in EK pathobiology.

Considerations for Corneal Surgery With Patients in the 10th Decade of Life

PURPOSE

The purpose of this study was to report the indications, ocular and systemic comorbidities, and surgical outcomes of corneal transplantation in patients older than 90 years.

METHODS

A retrospective review was conducted to identify individuals 90 years and older who underwent corneal transplantation surgery at the Bascom Palmer Eye Institute between January 2013 and October 2020. Outcomes included best-corrected visual acuity and graft survival over time. Paired t tests were used to compare visual acuity preoperatively versus postoperatively. Graft survival was evaluated with Kaplan-Meier curves.

RESULTS

Fifty-eight eyes of 52 consecutive individuals were included. The mean age of individuals was 92 ± 2 years; 26.9% were male; and 48.1% self-identified as non-Hispanic White and 38.5% as Hispanic. Postoperative follow-up was 14.7 ± 12.1 months. Of the 58 eyes, 44.8% (26/58) underwent penetrating keratoplasty, 46.6% (27/58) Descemet stripping automated endothelial keratoplasty, and 6.9% (4/58) keratoprosthesis. All surgeries were performed under monitored local anesthesia, without major complications. Surgical indications included pseudophakic bullous keratopathy (36.2%), glaucoma-associated corneal decompensation (27.6%), Fuchs endothelial dystrophy (25.9%), and perforated corneal ulceration (19.0%). The best-corrected visual acuity improved by 0.32 (95% confidence interval 0.14-0.50; P < 0.01) as early as 1 month postoperatively, and vision gains were sustained for at least 12 months. Graft survival probability at 12 months was 88%.

CONCLUSIONS

Corneal transplantation is a safe and successful procedure in restoring the visual acuity for patients older than 90 years after careful preoperative evaluation. Further research is needed to evaluate the impact of corneal transplantation on quality of life in patients in the 10th decade of life.

Gonioscopic angle evaluation and its correlation with graft survival and post-operative ocular hypertension in patients of Descemet's stripping endothelial keratoplasty

Purpose

To evaluate the gonioscopic changes in patients receiving Descemet's stripping endothelial keratoplasty (DSEK) without pre-existing ocular hypertension (OHT) and to report its correlation with post-surgery OHT, graft survival, and visual outcomes.

Methods

Adult patients who underwent DSEK surgery from April 2014 to March 2018 with at least 2 years of follow-up were analyzed in this retrospective study. Demographic details, indication of DSEK, necessary anterior and posterior segment findings, and the post-DSEK OHT details were documented.

Results

A total of 58 patients (23 males and 35 females) with a mean age of 61.44 ± 8.8 years were included in the study. The most common etiology for DSEK surgery was pseudophakic bullous keratopathy in 47 eyes (81.03%). A total of 22.41% (13/58) eyes showed elevated intra-ocular pressure (IOP) following DSEK surgery. The most common cause of IOP elevation was steroid-induced OHT in seven eyes (12.06%). Gonioscopy examination revealed areas of peripheral anterior synechiae (PAS) in 17 (29.3%) eyes. OHT was found in 4/17 (23.5%) eyes having PAS. Three of these cases required trabeculectomy + goniosynechiolysis (GSL), and the fourth case required GSL alone to control IOP. These four cases also required repeat DSEK for failed grafts. The mean pre-operative best corrected visual acuity was 1.62 logMAR (range 1.17-1.77), which gradually improved to 0.79 logMAR (range 0.3-1.77) after 2 years (p < 0.00001).

Conclusion

PAS was found to be an important factor associated with post-DSEK ocular hypertension in our study. OHT in PAS cases required definitive surgical treatments to control IOP. It adversely affected the graft survival and in turn affected visual outcomes also.

Outcomes of Descemet stripping endothelial keratoplasty in cases of corneal endothelial dysfunction

BACKGROUND

Automated microkeratome is commonly used to get donor lenticules for Descemet stripping endothelial keratoplasty (DSEK); however, manual dissection of donor lenticules is also being done with good outcomes.

AIM

The aim of this study was to describe the results of manual DSEK performed in cases of corneal endothelial dysfunction caused due to pseudophakic bullous keratopathy, iridocorneal endothelial syndrome, and postpenetrating keratoplasty graft failure.

MATERIALS AND METHODS

This was a retrospective observational study. The medical records of all patients with corneal decompensation who underwent DSEK at a tertiary care center performed by the same surgeon were reviewed. A standard DSEK with manually dissected donor lenticules was performed in all cases with the exception of the Descemet membrane not being removed in two cases. A comprehensive ophthalmic examination was performed preoperatively and at each postoperative visit in all patients.

RESULTS

Eight eyes of seven patients (four males and three females) were included. The mean age was 64.8 years (range, 49-74 years). The average follow-up was 10.9 months (range, 5-22 months). There was one case of primary graft failure which was managed by repeat DSEK. In the rest, corneas remained clear at the last follow-up. No rebubbling was done as none of the cases showed graft detachment. The preoperative best-corrected visual acuity (BCVA) was 20/2000 or less, and postoperatively, BCVA attained was 20/30 in four eyes and one eye achieved 20/80.

CONCLUSIONS

Manual DSEK performed in eyes with corneal decompensation allowed rapid restoration of corneal clarity while minimizing intraoperative and postoperative complications.

Descemet-stripping automated endothelial keratoplasty with intrascleral haptic-fixated intraocular lens in a sequential vs simultaneous approach

PURPOSE

To compare the outcomes of Descemet-stripping automated endothelial keratoplasty (DSAEK) with intrascleral haptic-fixated intraocular lens (IOL) in a sequential and simultaneous approach.

SETTING

Tertiary eyecare center.

DESIGN

Prospective randomized comparative study.

METHODS

Patients with aphakic or complicated pseudophakic bullous keratopathy visiting a tertiary eyecare center were included in the study. A total of 40 patients were randomized into 2 groups of 20 each. Group 1 had subjects who underwent scleral-fixated IOL (SF IOL) implantation by intrascleral haptic fixation technique, followed by DSAEK (sequential procedure) with an interval of at least 3 months. Group 2 (simultaneous) had subjects who underwent DSAEK with SF IOL as a combined procedure. Graft survival, endothelial cell loss (ECL), corrected distance visual acuity (CDVA), and need for any intervention such as rebubbling were evaluated for both the groups at the end of 6 months.

RESULTS

At 6 months, the sequential group had significantly better CDVA of 0.62 ± 0.17 logMAR compared with 0.87 ± 0.19 logMAR in the simultaneous group (P = .002). Group 1 had significantly better overall cumulative graft survival (100% vs 60%, P = .002), significantly lower ECL (P = .006), lesser mean central corneal thickness (P = .03), and significantly thinner donor lenticule (P = .009). Rebubbling rate was significantly higher in Group 2 (P = .025). The mean hyperopic shift was significantly more in Group 2 (P = .02).

CONCLUSION

The sequential procedure of SF IOL followed by DSAEK has better visual outcomes and graft survival when compared with simultaneous procedure in cases of aphakic or complicated pseudophakic bullous keratopathy.

Management of Corneal Clouding in Patients with Mucopolysaccharidosis

Mucopolysaccharidoses (MPS) are a rare group of lysosomal storage disorders characterized by the accumulation of incompletely degraded glycosaminoglycans (GAGs) in multiple organ systems including the eye. Visual loss occurs in MPS predominantly due to corneal clouding and retinopathy, but the sclera, trabecular meshwork and optic nerve may all be affected. Despite the success of therapies such as enzyme replacement therapy (ERT) and hematopoietic stem-cell transplantation (HSCT) in improving many of the systemic manifestations of MPS, their effect on corneal clouding is minimal. The only current definitive treatment for corneal clouding is corneal transplantation, usually in the form of a penetrating keratoplasty or a deep anterior lamellar keratoplasty. This article aims to provide an overview of corneal clouding, its current clinical and surgical management, and significant research progress.

Dye-based identification of the orientation of tissue for Descemet stripping automated endothelial keratoplasty: A laboratory-based study

Purpose:

To describe the features enabling the identification of the orientation of Descemet stripping automated endothelial keratoplasty (DSAEK) lenticule with the assistance of vital dyes.

Methods:

This is a blinded experimental lab-based study, including 30 microkeratome prepared precut DSAEK lenticules. The lenticules were divided into control and study arms which included 10 unstained and 20 stained lenticules, respectively. In the study arm, vital dyes like trypan blue (TB), brilliant blue (BB), indocyanine green (ICG) and fluorescein stain (FS) were used to stain 5 lenticules each. They were examined by experienced (group 1) and novice surgeons (group 2) to identify the correct orientation of the lenticule. The results were tabulated and analyzed.

Results:

Of the 30 lenticules examined, the average of total scores obtained by each observer was higher (78%) in group 1 as compared to group 2 (65.3%) which was statistically significant (P < 0.005). In group 1, the accuracy of identifying the correct orientation of unstained lenticules was 70% which improved to 82% on staining. The accuracy in group 2 was 58% with unstained lenticules which improved to 69% on staining. Within the study arm, irrespective of surgical experience, the accuracy was highest with BB (86%), followed by TB (82%), ICG (72%) and FS (62%).

Conclusion:

This study found that the accuracy of identifying the orientation of DSAEK lenticules increased with experience and with the assistance of staining using vital dyes. This accuracy improved with blue dyes like brilliant blue and trypan blue, irrespective of the level of experience.

Early postoperative infection following lamellar keratoplasty: a review

With the growing popularity of lamellar keratoplasty for selective replacement of diseased corneal tissue, it is important to understand the risk of developing an infection after the procedure. Although lesser than that postpenetrating keratoplasty, the reports on post lamellar keratoplasty infectious keratitis are not negligible. Trends of acute infections arising within 2 months of surgery are a subject of interest. Most of these infections are reported post Descemet's stripping endothelial keratoplasty with a preponderance of Candida species. A donor to host transmission of infection is not uncommon. Among the Candida cases, about 80% seem to occur due to a donor to host transmission. Infections presenting as or progressing to endophthalmitis lead to a poor visual outcome. Strict aseptic measures and protocols during corneal tissue harvesting, tissue processing, tissue storage and surgery are essential to prevent occurrence of these infections. After the infection has occurred, determining the aetiology and drug susceptibility through microbiological testing is vital. This helps to guide treatment protocols and hence determines final outcome of these cases. Most cases require some form of surgical management for resolution of infection, most often a graft removal and therapeutic keratoplasty. Secondary surgical interventions are performed to restore graft clarity and achieve a good final visual outcome.

[UT-DSAEK using grafts provided by a tissue bank, a one-year follow-up study of 79 grafts]

INTRODUCTION

UT-DSAEK is a recent technique developed in order to obtain grafts thinner than a conventional DSAEK (less than 100 microns). The goal of this study was to evaluate the anatomic and clinical results over a period of one year for a retrospective series of UT-DSAEK procedures at the University Hospital of Nantes, using pre-cut grafts provided by a tissue bank, and to compare results with other existing techniques: DSAEK and DMEK.

METHODS

In this retrospective, single-center study, all patients requiring an endothelial graft over a one-year period were included. The criteria studied were visual acuity, graft thickness, pachymetry and specular microscopy, recorded on the preoperative visit, D7, M1, M3, M6 and M12.

RESULTS

Seventy-nine grafts were performed on 75 patients. The mean age was 72 years. Between the 7th day and the end of the first year, the graft thickness in the visual axis decreased from 75±29 to 60±21 microns rapidly over the first three months. The pachymetry decreased from 706±95 microns preoperatively to 561±54 microns with the same kinetics. The cell density of the graft decreased from 2604±13 cell/mm² prior to the procedure to 1551±124 cell/mm² (40% loss) at one year. The preoperative visual acuity was 1.16 logMAR, rapidly improving to 0.65 logMAR at the first month and 0.40 logMAR at one year.

CONCLUSION

This study provides a fair amount of data on the progression of UT-DSAEK grafts: a decrease in graft thickness over the first three months, corresponding to an increase in visual acuity over this same period, with a good endothelial survival rate. This technique opens new avenues for the treatment of endothelial diseases, being complementary to DMEK in terms of surgical indications.

Infectious keratitis after lamellar keratoplasty

Infectious keratitis after lamellar keratoplasty is a potentially devastating complication that may severely limit the visual and anatomical outcomes. The deep-seated location of the infiltrates, sequestration of the pathogenic microorganisms and limited penetration of the currently available antimicrobial agents often results in delayed diagnosis that may jeopardize the management in these cases. Fungal keratitis is more common as compared with bacterial or viral keratitis and classically presents as white interface infiltrates that may not be associated with significant inflammation. Confocal microscopy may help to establish a rapid diagnosis in such cases, and anterior segment optical coherence tomography may be used to determine the extent of infection and monitor its progression. Conservative measures such as topical antimicrobials and interface irrigation with antimicrobial agents may be done. Surgical intervention in the form of partial excision/removal of the graft in endothelial keratoplasty or a full-thickness keratoplasty is often required for the effective management of deep-seated infections. Timely diagnosis and intervention may result in complete resolution of infection in both anterior lamellar and endothelial keratoplasty. Infections after anterior lamellar keratoplasty have a fair prognosis, and a clear graft with functional visual acuity may be achieved in most cases. By contrast, infections after endothelial keratoplasty have a guarded prognosis, and the presence of concomitant endophthalmitis may further complicate the graft survival and visual outcomes.

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.

Comparative observation of the efficacy of simplified Descemet stripping endothelial keratoplasty and penetrating keratoplasty in treating bullous keratopathy

The aim of the present study was to compare the clinical efficacy between simplified Descemet stripping endothelial keratoplasty (DSEK) and penetrating keratoplasty (PKP) in the treatment of patients with bullous keratopathy (BK). A cohort of 65 patients (65 eyes) with BK recruited between December 2002 and June 2018 was divided into two groups according to the treatment they received: The simplified DSEK group (n=38) and the PKP group (n=27). The best-corrected visual acuity (BCVA) during the follow-up at 1, 3, 6 and 12 months and postoperative complications were all recorded. Furthermore, the graft survival rate after 1 year was recorded. The mean BCVA in the simplified DSEK group was significantly better than that in the PKP group after 1, 3, 6 and 12 months (P<0.05). Furthermore, the 1-year graft survival rate in the simplified DSEK group (91.2%) was significantly higher than that in the PKP group (70.4%; P=0.039). A total of 13 eyes (34.21%) in the simplified DSEK group and 11 eyes (40.74%) in the PKP group were diagnosed with glaucoma; there was no significant difference between the rate of glaucoma diagnosis between the two groups (P=0.591). Graft rejection was observed in 5 eyes (13.16%) of the simplified DSEK group and 8 eyes (29.63%) of the PKP group and the rate of graft rejection did not differ significantly between the groups (P=0.279). Graft infection occurred in 1 eye (2.63%) in the simplified DSEK group and 6 eyes (22.22%) in the PKP group. Simplified DSEK achieved better visual acuity and longer graft survival rates than PKP. The incidence of postoperative secondary glaucoma, graft rejection and graft infection after simplified DSEK was lower than that in the PKP group, but only the incidence of graft infection was significantly different.

Corneal graft failure: an update

Corneal graft surgery is one of the most successful forms of human solid-tissue transplantation, and nowadays, there is a worldwide expansion of the surgical volume of corneal grafts. This surgery is continuously evolving, with new surgical techniques and postoperative treatments that have considerably increased the chance of survival for the grafts. Despite the high rate of success, corneal transplantation is still complicated by a relevant risk of graft failure. This study investigates the causes that lead to the failure of the different corneal graft surgical techniques and provides an updated synthesis on this topic. A comprehensive review of the main pathological pathways that determine the failure of corneal grafts is provided, analysing the main risk factors and disclosing the survival rates of the principal form of corneal grafts. Our results revealed that penetrating keratoplasty has higher failure rates than lamellar keratoplasty, with immunological rejection being the leading cause of graft failure, followed by late endothelial failure (LEF) and ocular surface disorders. Postoperative glaucoma and dehiscence of the surgical wound represent other important causes of failure. Endothelial keratoplasty showed the lowest rates of failure in the mid-term, with LEF, detachment of the graft and primary graft failure representing the most common pathological reasons for failure.

An endothelial rejection line following Descemet stripping automated endothelial keratoplasty

Background

The endothelial rejection line is rarely seen after Descemet stripping automated endothelial keratoplasties (DSAEKs). Here, we present a case of endothelial graft rejection with an endothelial rejection line occurring 1 year after the procedure.

Case presentation

A 58-year-old female presented with graft rejection 1 year following a DSAEK procedure. The episode started when she tapered down her loteprednol to once a day. Slit-lamp examination showed a mildly injected conjunctiva with 1+ corneal oedema. On the posterior surface of the cornea, there was an endothelial rejection line (Khodadoust line) with keratic precipitates and multiple areas of anterior synechia.

Conclusion

The classic endothelial rejection line should be kept in mind as a rare sign of DSAEK graft rejection.

Standardized pachymetry-assisted manual lamellar dissection for Descemet stripping endothelial keratoplasty

PURPOSE

To present an alternative technique (Pachy-DSEK) for the manual preparation of thin endothelial lamellae in Descemet stripping endothelial keratoplasty (DSEK), as well as to evaluate its visual and anatomic outcomes.

METHODS

A retrospective chart review was conducted in 15 cases who underwent DSEK at a private eye clinic in Brazil (INOB, Brasília) from June 2017 to December 2019. All patients had ocular comorbidities and relative contraindications to Descemet membrane endothelial keratoplasty (DMEK). All endothelial lamellae were manually prepared by using a standardized technique. Best corrected visual acuity (BCVA), tomographic parameters and graft's thickness were evaluated preoperatively and at 6 months. Endothelial cell counts were evaluated preoperatively and at 12 to 24 months.

RESULTS

During preparation there was one case (6%) of peripheral tear and no tissue was lost. At 6 months, the median BCVA improved from 1.60 to 0.40 logMAR (p = 0.0009). There was no significant change in anterior (p = 0.507) and posterior astigmatism (p = 0.483), anterior (p = 0.683) and posterior mean keratometry (p = 0.767), and total corneal power (p = 0.952). The median central graft thickness at 6 months was 80 µm. Ultrathin grafts (<130 µm) were achieved in 80% of cases. At 12 to 24 months endothelial cell count decreased significantly. Graft's detachment occurred in two cases (13%) and endothelial rejection in one case (6%).

CONCLUSION

By using ultrasonic pachymetry intra-operatively and standardizing graft preparation, most manually dissected endothelial lamellae were ultrathin. Pachy-DSEK was safe and effective for treating endothelial disfunction in eyes with ocular comorbidities. It may be a cost-effective alternative to automated dissection methods.

Sheets glide-assisted versus Busin glide-assisted insertion techniques for descemet stripping endothelial keratoplasty (DSEK): A comparative analysis

Background

The donor lenticule insertion techniques play a crucial role in outcomes following descemet stripping endothelial keratoplasty (DSEK) and the current study is aimed to compare two of the commonly performed donor lenticule insertion techniques in DSEK.

Method

Descemet stripping endothelial keratoplasty was performed in 48 eyes of 48 patients at two tertiary eye care centers from January 2014 to December 2016. At one center (Group 1), 26 patients had Sheets glide-assisted lenticule insertion whereas at other center (Group 2), 22 patients had Busin glide-assisted insertion of donor lenticule. Best corrected visual acuity (BCVA), manifest spherical equivalent, manifest cylinder, endothelial cell density (ECD) and percentage of endothelial cell loss (ECL) were compared between the two groups at 6 months after DSEK. In addition, intraopertaive and postoperative complications were also compared.

Results

At 6 months after DSEK, an insignificant difference was observed in BCVA [Group 1: 0.48 logarithm of the minimum angle of resolution (log MAR); Group 2: 0.50 log MAR (p = 0.74)], mean manifest spherical equivalent [Group 1: 0.64 diopter (D); Group 2: 0.59 D (p = 0.74)], mean manifest cylinder [Group 1: 1.35 D; Group 2: 1.32 D (p = 0.92)] and mean ECL [Group 1: 26.75%; Group 2: 28.76 (p = 0.44)] between the two groups. In addition, the rate of complications is similar between the two groups.

Conclusions

Both Sheets glide-assisted and Busin glide-assisted donor lenticule insertion techniques are associated with similar surgical outcomes after DSEK.

Endophthalmitis Rates and Clinical Outcomes Following Penetrating and Endothelial Keratoplasty

PURPOSE

To evaluate endophthalmitis rates after penetrating keratoplasty (PK) and endothelial keratoplasty (EK) and to compare clinical outcomes.

DESIGN

Retrospective cohort study.

METHODS

The medical and billing records of several large academic private practices in Philadelphia, PA were electronically queried for all surgical visits during which a PK or EK was performed between April 1, 2012 and August 31, 2018. Demographic information and transplant characteristics were recorded for each patient and office visit. An additional query was performed to identify all cases of endophthalmitis based on diagnosis and procedure billing codes. Charts of patients with endophthalmitis were individually reviewed, and information was collected on triggering factors, clinical evaluation at presentation, management, culture data, visual outcomes, and graft survival rates. The main outcome measure was incidence of presumed infectious endophthalmitis following PK or EK.

RESULTS

During the study period, 1676 PKs and 2292 EKs for 3069 patients were performed. The mean age of patients in this transplant cohort was 66.4 (± 17.5) years and 54.6% of patients were women. Sixteen cases of endophthalmitis occurred during the study period; 12 cases of endophthalmitis occurred after PK and 4 cases occurred after EK. The rate of endophthalmitis after EK (4 of 2292; 0.2%) was significantly lower than that after PK (12 of 1676; 0.7%) (P = .01). In addition, the odds of developing endophthalmitis after PK or EK performed in conjunction with anterior vitrectomy were significantly higher than after either PK or EK alone (odds ratio 8.66; 95% confidence interval 2.98-25.18; P < .001). Visual acuity outcomes were poorer after PK-related endophthalmitis than EK-associated cases (P = .01). The rate of graft failure at final follow-up was significantly higher in post-PK endophthalmitis (P = .02).

CONCLUSIONS

In this large cohort of patients undergoing either PK or EK, rates of endophthalmitis were low for both procedures and significantly lower for EK compared with PK. Eyes with endophthalmitis after PK had poorer visual acuity outcomes and graft prognosis compared with those with endophthalmitis after EK.

Endothelial keratoplasty for corneal endothelial dystrophy in a dog

OBJECTIVE

To assess the efficacy of an endothelial keratoplasty procedure at defined intervals to 1 year postoperatively for the treatment of corneal endothelial dystrophy (CED) in a canine patient.

PROCEDURE

A dog diagnosed with CED with progressive corneal edema underwent an endothelial keratoplasty. The patient was examined pre- and postoperatively with slit lamp biomicroscopy and ultrasonic pachymetry.

RESULTS

Mean central corneal thickness (CCT) measured with pachymetry was >1400 μm preoperatively and decreased postoperatively to 725 μm. The transplanted donor tissue became transparent 2 weeks postoperatively and incorporated with the recipient cornea. The graft remained transparent throughout the duration of the postoperative period evaluated in this study (2 weeks postoperatively to 1 year). The canine patient was comfortable pre- and postoperatively.

CONCLUSIONS

Endothelial keratoplasty is a potential therapeutic option for canine cases with progressive corneal thickening due to CED. As this is a single case study, further investigation into the use of endothelial keratoplasty to treat CED is warranted. Moreover, canine patients with CED might serve as a surgical model for human patients with Fuchs' Endothelial Corneal Dystrophy.

Association between positive corneal rim cultures and microbiology screening protocols in Ontario

OBJECTIVE

(i) To assess the rate of positive microbiological cultures of corneas prepared by the Eye Bank of Canada (Ontario Division) between January 1, 2012, and December 31, 2013; (ii) to review the microbiology protocols at the 5 major transplant centres in Ontario; and (iii) to assess the incidence of endophthalmitis during the study period.

DESIGN

Retrospective chart review.

PARTICIPANTS

A total of 4186 consecutive cultured corneal tissues prepared by the Eye Bank from January 1, 2012, to December 31, 2013.

METHODS

Rates of culture-positive cornea rims and incidence of postkeratoplasty endophthalmitis at 5 surgical centres in Ontario were determined, and the protocols used to culture rims at each site were concurrently reviewed. Culture results were analyzed via logistic regression for positive cultures.

RESULTS

The rate of positive cultures at each sites were as follows: centre A, 3.74%; centre B, 3.26%; centre C, 0.51%; centre D, 0.48%; and centre E, 0.04%. Centres A, B, and D were noted to have significantly higher positive rates than centre E. In comparing microbiology protocols, longer incubation period (11 days) was 12 times more likely to be associated with higher positive culture rates than shorter period (4-5 days). Six-month follow-up of all keratoplasties revealed zero reported cases of endophthalmitis.

CONCLUSIONS

A literature review regarding the predictive value of routine culturing reveals conflicting data. Our findings suggest that differences in the microbiology protocols directly influence the rates of positive rim cultures. Without a standardized protocol, it is not possible to evaluate the predictive value of routine corneal rim culturing in predicting postkeratoplasty endophthalmitis.

Clinical outcomes after Descemet's stripping endothelial keratoplasty using donor corneas from children younger than 3 years

Importance

There is limited literature on paediatric donors in endothelial keratoplasty.

Background

This study investigated the efficacy of and appropriate paediatric donor age for Descemet’s stripping endothelial keratoplasty (DSEK).

Design

Retrospective and observational case series.

Participants

Thirty‐eight consecutive patients underwent DSEK with paediatric donor corneas.

Methods

The age of the donors ranged from 32 weeks gestation (premature neonate) to 3 years old. All donor consents were obtained from the parents. The causes of donor death included traffic accident, congenital heart disease and neonatal respiratory distress syndrome.

Main Outcome Measures

The outcome measures included best‐corrected visual acuity, endothelial cell loss and complications.

Results

Best‐corrected visual acuity at last follow‐up was >20/40 in 28 of 38 eyes (73.7%). The mean preoperative endothelial cell density of donor corneas was 4682 ± 520 cells/mm². The mean endothelial cell density of grafts was 3977 ± 556 cells/mm² at 18 months postoperatively. Three lenticules from premature neonate donors exhibited severe contraction postoperatively. The edge of six lenticules from donors <1‐year‐old exhibited contraction in the early postoperative period and gradually flattened spontaneously. Graft detachment occurred in one patient.

Conclusions and Relevance

DSEK with paediatric donor corneas can achieve good clinical outcomes. The corneal lenticules from 1‐ to 3‐year‐ old donors are suitable for DSEK while those from donors <1‐year‐old are less suitable due to the possibility of severe postoperative graft contraction.

Results of Femtosecond Laser-Assisted Descemet Stripping Automated Endothelial Keratoplasty

Purpose

To evaluate femtosecond laser in DSAEK surgery as an improvement to manual DSAEK.

Settings

Department of Ophthalmology, Cairo University.

Design

A retrospective observational clinical study.

Methods

20 eyes with SBK and Fuchs' dystrophy underwent a Femto-assisted DSAEK by laser cutting of two matching posterior stromal discs in the recipient and donor corneas and then fitting the donor disc in the posterior corneal defect of the recipient using Busin's glide or Terry forceps.

Results

Corneal thickness decreased significantly from a mean of 900-micron preoperative values (900.7 m) to 562 m postoperatively. Evidence of side healing was documented by OCT. One patient had a double AC, one patient had an air interface entrapment “Double Bubble,” one patient had a fungal infection and was treated by a therapeutic penetrating keratoplasty, and one patient had a CMO.

Conclusion

Femtolaser-assisted DSAEK may be superior to manual techniques as it offers better centration, thinner graft/host complex, earlier corneal detergecense, and stronger healing. This study was registered at Researchregistry.com with a UID: researchregistry2274.

Candida Interface Infections After Descemet Stripping Automated Endothelial Keratoplasty

PURPOSE

To describe 2 Candida interface keratitis infections occurring in the setting of positive donor rim cultures from precut corneal tissue used for Descemet stripping automated endothelial keratoplasty (DSAEK) and the ensuing public health investigation.

METHODS

Following 2 clinical Candida interface keratitis infections, patients from 2012 to 2014 in the same surgical center were evaluated for bacterial and fungal rim cultures and subsequent infection. All cases of fungal infections occurring post-DSAEK were analyzed. Data included patient demographics, surgical technique, donor rim cultures, donor mate outcomes, clinical courses, and outcomes. A review of the relevant literature was also undertaken.

RESULTS

From 2012 to 2014, among 99 DSAEK procedures performed, 7 (7.1%) donor rim cultures were positive for fungi. Use of this tissue with positive donor rim cultures resulted in 2 (28.6%) episodes of confirmed fungal interface keratitis, both Candida species, and presumptive treatment in an additional 2 patients. An investigation did not identify any breach in sterile technique or procedures by the surgeon or surgery center. Our literature review identified 15 reports of postoperative fungal infection associated with DSAEK, of which 11 involved Candida spp.

CONCLUSIONS

While postoperative infection remains rare, our 2 additional cases along with those previously reported suggest that DSAEK may be susceptible to infection with Candida spp. Furthermore, this report of correlated rim cultures and clinical infection suggests a need for reevaluation of the utility of obtaining routine corneoscleral donor rim fungal culture.

Corneal transplantation and glaucoma

Glaucoma is the leading cause of irreversible vision loss post-keratoplasty and an important cause of graft failure. With newer techniques, such as lamellar, endothelial, and laser-assisted keratoplasty as well as keratoprosthesis gaining popularity, clinicians will need to consider the incidence, risks, evaluation, and management of glaucoma for each type of keratoplasty when determining which type of transplant may be most appropriate. A comprehensive literature search of glaucoma in the setting of corneal transplantation was performed and serves as the basis for this review. Preexisting glaucoma and aphakia are notable risk factors. Patients that are candidates for deep anterior lamellar keratoplasty may benefit from reduced rates of post-keratoplasty glaucoma. Although glaucoma also complicates eyes with Descemet stripping endothelial keratoplasty, the severity is less and the intraocular pressure is more easily controlled when compared to penetrating keratoplasty. Endothelial keratoplasty creates unique perioperative issues mostly related to management of anterior chamber air bubbles.

Endothelial cell loss and complication rates with combined Descemets stripping endothelial keratoplasty and cataract surgery in a UK centre

PURPOSE

To report 6-month, 1- and 2-year endothelial cell loss (ECL), intra- and postoperative complications in a large series of patients undergoing either Descemets stripping endothelial keratoplasty (DSEK) or a combined phacoemulsification and DSEK in a UK centre.

PATIENTS AND METHODS

Patients undergoing DSEK with or without concurrent cataract surgery were included in this retrospective study. Surgeries were performed between January 2006 and May 2013. Main outcomes included intra- and postoperative complications and percentage ECL.

RESULTS

DSEK was performed in 226 eyes (210 patients). Of these, 141 eyes (126 patients) underwent DSEK alone and 85 eyes (84 patients) underwent DSEK combined with cataract surgery. Excluding complex anterior segment pathology the mean percentage ECL at 6, 12 and 24 months was 40.5±13.4, 45.1±14.6 and 53.1±13.0 in the DSEK group and 40.7±15.4, 42.6±15.3 and 49.6±16.5 in patients undergoing the combined procedure, respectively. There was no significant difference in percentage ECL at 6 or 24 months between the two groups both in complex and routine cases. Intraoperative complications occurred in four patients undergoing DSEK and three undergoing combined procedure. Postoperative complication rates did not reach statistical significance between the groups.

CONCLUSION

Mean ECL and complication rates were comparable at 6, 12 and 24 months in routine cases undergoing concurrent DSEK with cataract surgery and those undergoing DSEK. These data support the combined procedure in patients requiring both cataract surgery and endothelial keratoplasty. Further collaboration to report endothelial cell counts from other UK centres should be encouraged.