Endothelial Keratoplasty: A Review of Indications at a Tertiary Eye Care Centre in South India

Outcomes of Descemet-Stripping Endothelial Keratoplasty in 52 Eyes With Iridocorneal Endothelial Syndrome

PURPOSE

To evaluate the long-term outcomes of Descemet-stripping endothelial keratoplasty (DSEK) in 52 eyes with iridocorneal endothelial (ICE) syndrome.

METHODS

Retrospective study of 52 eyes of 52 patients who were diagnosed with ICE syndrome and underwent DSEK between January 2010 and December 2019 with a follow-up of at least 6 months.

RESULTS

The mean age was 48.8 ± 10.8 years. Female patients (n = 33) constituted 63.5%. The median duration of follow-up was 2.4 years (range, 0.5-9.1 yrs). The mean best-corrected visual acuity improved significantly after surgery and remained stable (∼20/50) through 5 years. The mean endothelial cell loss was 28%, 37.9%, 43.6%, and 56.9% at 6 months and at 1, 2, and 3 years, respectively. Graft rejection was noted in 5 eyes (9.6%). Postoperatively, increased intraocular pressure (IOP) was seen in 17 eyes (32.7%), and 10 eyes (19.2%) underwent glaucoma surgeries. Fourteen eyes (26.9%) had secondary graft failures. The estimates of graft success were 93.6% ± 3.6% at 1 year, 85.6% ± 5.5% at 2 years, 79.3% ± 6.7% at 3 years, 69.0% ± 8.9% at 4 years, and 59.1% ± 11.9% at 5 years. Postoperative increased IOP was found to be the only significant (P = 0.05) risk factor (hazard ratio 8.92) associated with graft failure. The clinical variant of ICE syndrome did not seem to influence the graft survival (P = 0.68).

CONCLUSIONS

In this study, DSEK had a success rate of ∼60% at 5 years. Increased IOP post-DSEK is a significant risk factor for graft failure. Graft survival is not affected by the clinical variant of ICE syndrome.

Outcomes of Descemet Membrane Endothelial Keratoplasty in Bangkok, Thailand

Purpose

To investigate the medium-term clinical outcomes and risk factors for primary graft failure after Descemet membrane endothelial keratoplasty (DMEK) in Thai patients.

Patients and Methods

This is a single-center retrospective cohort study. Sixty-two eyes of 62 patients who underwent DMEK at Ramathibodi Hospital, Bangkok, Thailand, with a minimum of 24-month follow-up were recruited. Preoperative donor and recipient characteristics, intraoperative data, and postoperative outcomes including best-corrected visual acuity (BCVA), graft clarity, endothelial cell density (ECD), central corneal thickness (CCT), and complications were evaluated at 1, 3, 6, 12, and 24 months after surgery.

Results

The mean age of the patients was 67.2 ± 9.9 years, and 52% were female. The mean follow-up time was 37.5 ± 11.0 months. The most common indications for DMEK were Fuchs' endothelial corneal dystrophy (FECD) (53.2%) and pseudophakic bullous keratopathy (PBK) (17.7%). Nearly half of patients had triple-DMEK. The median preoperative BCVA was 20/400. Postoperative BCVA of ≥ 20/40 was reached in 37.1% and of ≥ 20/20 in 6.5% after 1 month which increased to 54.8% and 17.7% after 3 months; and to 67.7% and 27.4% after 24 months. Endothelial cell loss (ECL) at 3, 6, 12, and 24 months was 30.5%, 33.8%, 44.4%, and 45.9%, respectively. Graft diameter was the single factor, showing a significant relationship with postoperative ECD. Most frequent postoperative complications included graft detachment (22.6%), increased IOP/glaucoma (17.7%), and primary graft failure (16.1%). In univariate analysis, death-to-operation time and the diagnosis of PBK were significantly associated with the occurrence of primary graft failure.

Conclusion

DMEK is a safe, effective, and feasible treatment for endothelial failure in Asian eyes. Careful case selection, use of relatively fresh donor tissues, and appropriate surgical techniques can prevent primary graft failure and facilitate optimal outcomes following surgery.

Recent indications of endothelial keratoplasty at a tertiary eye care center in South India

PURPOSE

To describe the patient demographics and recent clinical indications of endothelial keratoplasty (EK) in patients presenting to a tertiary eye care center in India.

METHODS

This cross-sectional hospital-based study included 2,182 patients who underwent EK between Jan 2016 and Dec 2019 (4 years period). The data were collected using an electronic medical record system.

RESULTS

Overall, 2,632 eyes of 2,182 patients underwent EK during the study period. Median age was 62 (IQR: 48-70) years and adults (94.45%) comprised most of the cohort. More commonly, the patients were male (55.59%) and from the higher socioeconomic strata (67.51%). The corneal signs included corneal edema (70.93%), corneal scarring (29.60%), corneal vascularization (16%) and guttae (12.88%). The major indications of EK were post-cataract surgery corneal edema in 1331 (50.57%) patients, endothelial dystrophy in 537 (20.4%) patients, failed graft in 535 (20.33%) patients causing a vision impairment of > 20/400-20/1200 in about a half (45.55%) of the patients. Descemet stripping endothelial keratoplasty (DSEK) and Descemet membrane endothelial keratoplasty (DMEK) were performed in 2075 (78.84%) and 557(21.16%) patients, respectively.

CONCLUSION

EK is commonly performed during the sixth decade of life and in males. The most performed procedure is DSEK. The commonest indication was post-cataract surgery corneal edema.

Overall clinical outcomes of Descemet membrane endothelial keratoplasty in 600 consecutive eyes: A large retrospective case series

Purpose:

To analyze the overall clinical outcomes of Descemet membrane endothelial keratoplasty (DMEK) in 600 consecutive cases.

Methods:

Retrospective, consecutive interventional case series operated by a single surgeon. Six hundred consecutive eyes of 524 patients with endothelial dysfunctions of different etiologies scheduled for DMEK were included in this study. All donor tissues were prepared by the operating surgeon during the procedure, using McCarey Kaufman medium or Cornisol-preserved cornea with endothelial cell density (ECD) of ≥2500 cells/mm². Indications, postoperative best spectacle-corrected visual acuity (BSCVA), ECD, endothelial cell loss (ECL), and complications were analyzed postoperatively between 3 months and 2 years.

Results:

The commonest indication was post-cataract corneal edema/bullous keratopathy in 262 (43.7%) eyes followed by Fuchs′ endothelial corneal dystrophy 218 (36.3%). Vision affected comorbidities were present in 91 (15.2%) eyes. In phakic eyes with cataract (222; 37%), DMEK was combined with cataract surgery (Triple-DMEK). BSCVA of ≥20/25 was achieved in 41.0%, 46.4%, 49.2%, and 48.7% of eyes at 3, 6, 12, and 24 months, respectively and stabilized at 6 months (P = 0.54). Mean ECD decreased from 2884 ± 178 cells/mm² (n = 600) before surgery to 2223 ± 321 (n = 597), 2099 ± 354 (n = 524), 1918 ± 373 (n = 374), and 1772 ± 439 cells/mm² (n = 158) at 3, 6, 12, and 24 months respectively. The corresponding mean ECL was 22.9 ± 11.4%, 27.2 ± 12.4%, 33.5 ± 13.0%, and 38.6 ± 14.3%, respectively (P < 0.05 for all-time points). The commonest complication was DM detachment in 59 (9.8%) eyes of which 23 (3.8%) eyes required rebubbling. Three (0.5%) eyes had primary graft failure. Endothelial rejection occurred in 7 (1.2%) eyes until the last follow-up.

Conclusion:

DMEK is a safe and effective procedure in different types of endothelial diseases with encouraging surgical and clinical outcomes. Complications are less and ECL percentage up to 2 years is acceptable.

Fuchs endothelial corneal dystrophy: The vicious cycle of Fuchs pathogenesis

Fuchs endothelial corneal dystrophy (FECD) is the most common primary corneal endothelial dystrophy and the leading indication for corneal transplantation worldwide. FECD is characterized by the progressive decline of corneal endothelial cells (CECs) and the formation of extracellular matrix (ECM) excrescences in Descemet's membrane (DM), called guttae, that lead to corneal edema and loss of vision. FECD typically manifests in the fifth decades of life and has a greater incidence in women. FECD is a complex and heterogeneous genetic disease where interaction between genetic and environmental factors results in cellular apoptosis and aberrant ECM deposition. In this review, we will discuss a complex interplay of genetic, epigenetic, and exogenous factors in inciting oxidative stress, auto(mito)phagy, unfolded protein response, and mitochondrial dysfunction during CEC degeneration. Specifically, we explore the factors that influence cellular fate to undergo apoptosis, senescence, and endothelial-to-mesenchymal transition. These findings will highlight the importance of abnormal CEC-DM interactions in triggering the vicious cycle of FECD pathogenesis. We will also review clinical characteristics, diagnostic tools, and current medical and surgical management options for FECD patients. These new paradigms in FECD pathogenesis present an opportunity to develop novel therapeutics for the treatment of FECD.

Outcomes of therapeutic penetrating keratoplasty in 198 eyes with fungal keratitis

Purpose:

To study the outcomes of therapeutic penetrating keratoplasty in fungal keratitis.

Methods:

This retrospective, observational, interventional case series involved an audit of 198 consecutive eyes that underwent therapeutic penetrating keratoplasty (ThPK) for fungal keratitis at L V Prasad Eye Institute between January 2008 and December 2010 was performed. The data on demographics, clinical characteristics, intraoperative, and late postoperative complications were noted. The primary outcome measure was eradication of infection and postoperative anatomical success. Secondary outcome measures were graft survival, risk factors, clinical features, and management of recurrent fungal keratitis post ThPK.

Results:

Mean follow-up after ThPK was 24 ± 17 months. A total of 178 (89.9%) eyes had complete eradication of fungal infection, whereas 20 (10.1%) eyes developed recurrence. Anatomical restoration was achieved in majority of cases (192 eyes; 97%). Larger infiltrate size was associated with a higher risk of recurrence of infection. The median graft survival rate was 5.9 months. The graft survival was better for grafts <8 mm versus those with >8 mm (P = 0.026) and not found significantly related to the species of fungus. Twenty-seven eyes underwent re-grafting: penetrating keratoplasty in 14 eyes, and Descemet's stripping endothelial keratoplasty in 13 eyes.

Conclusion:

As larger infiltrate prior to therapeutic keratoplasty had much higher risk of recurrences; timely surgical intervention should be considered in cases not responding to medical therapy. Alternative strategies of management of postoperative inflammation need to be considered to prevent graft failures.

Fuchs endothelial corneal dystrophy and corneal endothelial diseases: East meets West

Fuchs endothelial corneal dystrophy (FECD) is amongst one of the most common indications for endothelial keratoplasty worldwide. Despite being originally described among Caucasians, it is now known to be prevalent among a large number of populations, including Asians. While the FECD phenotype is classically described as that of central guttate and pigment deposits associated with corneal endothelial dysfunction, there are subtle yet important differences in how FECD and its phenocopies may present in Caucasians vs Asians. Such differences are paralled by genotypic variations and disease management preferences which appear to be geographically and ethnically delineated. This article provides a succinct review of such differences, with a focus on diagnostic and management issues which may be encountered by ophthalmologists practicing in the different geographic regions, when evaluating a patient with FECD.

rs4246215 is targeted by hsa-miR1236 to regulate FEN1 expression but is not associated with Fuchs' endothelial corneal dystrophy

Fuchs' Endothelial Corneal Dystrophy (FECD) is a genetically complex disorder that affects individuals above 40 years of age; molecular pathogenesis of its associated genes is poorly understood. This study aims at assessing the association of flap endonuclease 1 (FEN1) polymorphisms, c.-69G>A (rs174538) and c.4150G>T (rs4246215) with FECD. Comet assay analysis reaffirmed that endogenous DNA damage was greater in FECD individuals. However, genetic analysis in 79 FECD patients and 234 unrelated control individuals prove that both the FEN1 polymorphisms, c.-69G>A (rs174538) and c.4150G>T (rs4246215), failed to show any genetic association with the FECD disease phenotype. In silico analysis and luciferase reporter assay identified 'G' allele of the 3'UTR located FEN1 polymorphism c.4150G>T as the target for binding of hsa-miR-1236-3p. This study indicates that although FEN1 polymorphisms, c.-69G>A (rs174538) and c.4150G>T (rs4246215) are not genetically associated with FECD, its transcript regulation reported in other diseases such as lung cancer which are genetically associated by rs4246215 could be mediated through miRNA, hsa-miR-1236-3p.

New trends in corneal transplants at the University of Toronto

OBJECTIVE

To assess trends in surgical procedures and indications for all corneal transplants performed at the University of Toronto.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

One thousand one hundred and four consecutive corneal transplants performed at the Kensington Eye Institute (KEI).

METHODS

Demographic, clinical, and pathological data retrieved from the Ophthalmic Pathology Laboratory on all corneal transplants performed at the KEI from January 2014 to December 2016.

RESULTS

Over 3 years, partial-thickness lamellar keratoplasties were performed in 880 cases (80%) while full-thickness penetrating keratoplasties (PKP) accounted for 224 cases (20%). Leading causes of corneal transplant were Fuchs' dystrophy (42%), graft failure (17%), bullous keratopathy (15%), and keratoconus (15%). Graft failure (40%) and keratoconus (31%) were the leading causes for PKP. Descemet's membrane endothelial keratoplasty (DMEK) accounted for 37% of cases, Descemet's stripping automated endothelial keratoplasty (DSAEK) for 30%, and deep anterior lamellar keratoplasty (DALK) for 13%. By 2016, partial-thickness procedures had increased by 10%, accounting for 85% of all procedures. In addition, DMEK increased by 26%, DSAEK decreased by 13%, and PKP decreased by 11%. Fuchs' dystrophy remained the leading indication for DMEK (67%) and DSAEK (42%) procedures. In 2016, 73% of DALK procedures were for the treatment of keratoconus.

CONCLUSIONS

Partial-thickness corneal transplants now account for 85% of all current graft procedures, and DMEK has emerged as the procedure of choice. Graft failure continues to be the leading indication for full-thickness grafts. Longitudinal studies are needed to determine whether these new trends persist and their future impact on graft failures.

Iridocorneal endothelial syndrome: clinical perspectives

This article aims to review the clinical management strategies available for the rare iridocorneal endothelial syndrome. The different clinical variations as well as the imaging techniques available to aid diagnosis are discussed. We then present the evidence available to help the reader to understand how the condition can be managed medically and also the important surgical aspects of treatment. This involves raised intraocular pressure management in addition to the visual management options of partial or full thickness keratoplasty. We hope that this review provides an exhaustive but also succinct review of the literature available on what is a rare and difficult condition to treat.

Outcomes of endothelial keratoplasty in pseudophakic corneal oedema: with or without Descemet's membrane stripping

AIMS

To evaluate and compare outcomes of Descemet's stripping endothelial keratoplasty (DSEK) with non-DSEK (nDSEK) in pseudophakic corneal oedema (PCE).

METHODS

The study was a prospective, non-consecutive, comparative, interventional case series. Twenty-six patients with PCE were randomised into two groups. Group 1 comprised of those cases that had undergone conventional DSEK, and group 2 consisted of those that had nDSEK for PCE between 2010 and 2012. The data on demographics and clinical characteristics were collected from all patients. Any intraoperative and early and late postoperative complications were also noted. The primary outcome measure was postoperative functional success. Graft survival and complications were analysed as secondary outcomes.

RESULTS

The median best-corrected visual acuities at 6 months postoperatively in groups 1 and 2 were 0.18 (IQR 0.10-0.30) and 0.44 (IQR 0.18-0.51), respectively (p=0.11). Corneal oedema cleared in all patients. During the early postoperative period, a patient in group 2 had lenticule detachment managed by rebubbling.

CONCLUSIONS

nDSEK has outcomes similar to DSEK in PCE with advantages of decreased surgical time and avoidance of inadvertent pull on the posterior stromal fibres that may occur during Descemet's stripping.