Preventive treatment of allograft rejection after endothelial keratoplasty: A systematic review and meta-analysis

The progress and future of corneal endothelial transplantation

Endothelial transplantation has recently been accepted worldwide, in the long history of corneal transplantation. The introduction of endothelial keratoplasty (Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty) has enabled us to expand the surgical indications owing to the low incidence of rejection and quick recovery of visual function. New technologies have been developed to ensure stable postoperative outcomes with a shorter learning curve, such as transplantation using cultured human endothelial cells and induced pluripotent stem cells (iPS) or new devices such as artificial endothelium. This review discusses the history and characteristics of corneal transplantation alongside new treatment options that may offer hope for patients with endothelial disease in the future.

The Efficacy and Safety of Standard versus Soft Topical Steroids after Cataract Surgery: A Systematic Review and Meta-analysis

TOPIC

Review of the efficacy and safety of standard versus soft topical steroid application after cataract surgery.

CLINICAL RELEVANCE

The control of postoperative inflammation is the mainstay of treatment after cataract surgery. However, no consensus exists regarding the postoperative steroid of choice. Basing the choice of topical postoperative steroidal treatment on high-quality data regarding both risks and benefits of various drugs would be advantageous for both patients and clinicians.

METHODS

A systematic search of the PubMed, Scopus, and Embase electronic databases for all peer-reviewed published randomized control trials that included clinical outcomes of topical steroidal treatment after uneventful cataract surgery was performed. Individual study data were extracted and evaluated in a weighted pooled analysis including grading of total anterior chamber (AC) inflammation, AC cells, AC flare, postoperative visual acuity (VA), intraocular pressure (IOP), and rate of adverse events (AEs).

RESULTS

Overall, 508 studies were found, of which 7 were eligible for the systematic review and ultimately were included for analysis, reporting on 593 patients from 5 countries. Age of included patients, when available, ranged between 3.7 and 73.4 years. Follow-up data were available for analysis at 1, 7, and 28 days after surgery. Except for a significantly lower grade of AC flare in the standard steroid group at day 7 (standardized mean difference, 0.26; 95% confidence interval, 0.05-0.47; I2 = 0%), inflammatory activity measurements displayed insignificant differences at every other follow-up (days 1 and 28 after surgery). Pooled analysis of IOP at each follow-up demonstrated a higher IOP at the 7-day visit in the standard steroid group, whereas IOP at other time points was comparable among the groups. Qualitative analysis of ocular AEs showed similarities among the groups.

DISCUSSION

The findings of this study suggest that for the average patient, both groups produce a comparable effect on both AC inflammation and postoperative IOP and VA.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

PCR testing for herpesviruses in aqueous humor samples from patients with and without clinical corneal endothelial graft rejection

To compare prevalence of positive PCR tests for herpesviruses between patients with and without a history of clinical corneal endothelial allograft rejection (AGR). Retrospective cross-sectional study with two-group comparison. A total of 307 aqueous humor (AH) samples from 235 Patients and 244 eyes who underwent penetrating keratoplasty or Descemet membrane endothelial keratoplasty or had a diagnostic AH aspiration due to clinical AGR between 2019 and 2023 were tested for DNA of herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV). PCR test results were compared between the two groups (with/without AGR). Another sub-analysis examined the results of patients without a history of herpetic keratitis. A total of 8% of eyes with clinical AGR (9/108) had a positive PCR result for one of the herpesviruses (HSV:3, CMV:3, EBV:2, VZV:1). All patients in the group without AGR had negative PCR results for all previous viruses (0/136). The difference was statistically significant (p < 0.001). The sub-analysis of eyes without a history of herpetic keratitis also revealed significantly more positive herpes PCR results (7/87) in eyes with AGR than in eyes without AGR (0/42, p = 0.005). Clinical AGR after keratoplasty shows a significant correlation to viral replication. Herpetic infection and AGR could occur simultaneously and act synergistically. Timely differentiation between active herpetic infection and/or AGR is pivotal for proper treatment and graft preservation.

Gomes J, Güell JL, Casaroli-Marano RP. Corneal Endothelial Cell Cultures from Organotypic Preservation of Older Donor Corneas Are Suitable for Advanced Cell Therapy

INTRODUCTION

The purpose of this work was to evaluate the in vitro growth capacity and functionality of human corneal endothelial cells (hCEC) expanded from corneas of elderly (>60 years) donors that were preserved using an organotypic culture method (>15 days, 31°C) and did not meet the clinical criteria for keratoplasty.

METHODS

Cell cultures were obtained from prior descemetorhexis (≥10 mm) and a controlled incubation with collagenase type I followed by recombinant trypsin. Cells were seeded on coated plates (fibronectin-albumin-collagen I) and cultures were expanded using the dual supplemented medium approach (maintenance medium and growth medium), in the presence of a 10 μm Rho-associated protein kinase inhibitor (Y-27632). Cell passages were obtained at culture confluency (∼2 weeks). A quantitative colorimetric WST-1 cell growth assay was performed at different time points of the culture. Morphometric analysis (area assessment and circularity), immunocytochemistry (ZO-1, Na+/K+-ATPase α, Ki67), and transendothelial electrical resistance (TEER) were performed on confluent monolayers.

RESULTS

There was no difference between the cell growth profiles of hCEC cultures obtained from corneas older than 60 years, whether preserved cold or cultivated organotypic corneas. Primary cultures were able to maintain a certain cell circularity index (around 0.8) and morphology (hexagonal) similar to corneal endothelial mosaic. The ZO-1 and Na+/K+-ATPase pump markers were highly positive in confluent cell monolayers at 21 days after isolation (passage 0; P0), but significantly decreased in confluent monolayers after the first passage (P1). A weak expression of Ki67 was observed in both P0 and P1 monolayers. The P0 monolayers showed a progressive increase in TEER values between days 6 and 11 and remained stable until day 18 of culture, indicating a state of controlled permeability in monolayers. The P1 monolayers also showed some functional ability but with decreased TEER values compared to monolayers at P0.

CONCLUSIONS

Our results indicate that it is possible to obtain functional hCEC cultures in eye banks, using simplified and standardized protocols, from older donor corneas (>60 years of age), previously preserved under organotypic culture conditions. This tissue is more readily available in our setting, due to the profile of the donor population or due to the low endothelial count (<2,000 cells/mm2) of the donated cornea.

Systematic Review and Meta-analysis: Outcomes After Descemet Membrane Endothelial Keratoplasty Versus Ultrathin Descemet Stripping Automated Endothelial Keratoplasty

PURPOSE

To compare the efficacy and safety of ultrathin Descemet stripping (automated) endothelial keratoplasty (UT-DS(A)EK) versus Descemet membrane endothelial keratoplasty (DMEK) for the treatment of Fuchs endothelial dystrophy (FED) and bullous keratopathy (BK).

DESIGN

Systematic review and meta-analysis.

METHODS

Literature containing DMEK and UT-DSAEK were searched in the Cochrane Database of Systematic Reviews, PubMed, EMBASE, LILACS, and through manual reference searching. Studies were included that measured the outcome of interventions-including best corrected visual acuity (BCVA), endothelial cell density (ECD), and postoperative complications, especially graft detachment with the need of re-bubbling, graft rejection, graft failure, and postoperative elevated intraocular pressure (IOP)-in patients with FED and BK. Included outcomes were pooled as standardized mean differences (SMD) or risk ratios (RR) using random effects models. Inter-study heterogeneity was assessed using the Q-test and I2 statistic.

RESULTS

Seven (of 163) studies met all the inclusion and exclusion criteria. Meta-analysis showed a significantly better BCVA 12 months postoperatively, but an increased re-bubbling rate in eyes after DMEK compared with eyes after UT-DS(A)EK (BCVA: SMD = 0.50 [95% CI 0.27-0.74] and re-bubbling rate: RR = 0.33 [95% CI 0.16-0.67]). All other parameters did not differ significantly between both interventions, although estimates were imprecise (graft failure: RR = 0.65 [95% CI 0.18-2.30], graft rejection: RR = 1.40 [95% CI 0.27-7.30], and postoperative intraocular pressure elevation: RR = 1.14 [95% CI 0.60-2.18]). Postoperative SMDs of ECD could not be evaluated due to significant heterogeneity between studies.

CONCLUSIONS

Although the improvement in BCVA was higher after UT-DS(A)EK than after conventional DS(A)EK, the BCVA after DMEK was still superior. The complication rates were comparable for both procedures, except for the higher rate of re-bubbling after DMEK.