Reports of Post-keratoplasty Infections for Eye Bank-prepared and Non-Eye Bank-prepared Corneas: 12 Years of Data From a Single Eye Bank

Andalusian Public Eye-Banks: a decade of continuous improvement

OBJECTIVES

To show donation data, number of keratoplasties and the changes in transplant indications and techniques that occurred in Andalusia in the period from 2013 to 2022.

MATERIALS AND METHODS

The present work is a retrospective and descriptive study that included all keratoplasties performed between January 2013 and December 2022 in Andalusia, as well as the evolution of the cornea donation and transplant activity of the public and private hospitals pertaining to the waiting list management system of the Public Health System of Andalusia. Transplants performed in private centers with corneas from outside Andalusia were excluded.

RESULTS

Cornea donation activity in Andalusia in the decade 2013-2022 has experienced a growth of more than 126%, while overall transplant activity has increased by 157% in public hospitals. Penetrating keratoplasty has decreased from 83% in 2013 to 43% in 2022, while lamellar techniques have increased from 17% to 57% in this same period. Since 2018, more lamellar transplants are performed than penetrating transplants. Regarding indications, endothelial conditions already represent the first cause of transplantation. In 2022 alone, the public Andalusian Eye Banks evaluated 1,054 corneas and prepared 281 endothelial grafts.

CONCLUSION

In the decade from 2013 to 2022 in Andalusia there has been an increase in donation activity and the number of keratoplasties. The public Eye Banks implementation in this period has played a key role in the widespread adoption of lamellar keratoplasty techniques and has enabled the transition to perform a greater number of lamellar keratoplasties compared to penetrating keratoplasty.

Donor related corneal graft infection: a review of literature and preventive strategies

PURPOSE

Donor-related infections are a serious threat to patient safety after corneal transplantation. We provide a concise review of literature from the last decade on donor-related graft infections, sources of contamination and means to reduce the contamination of donor tissue and preservation media.

METHODS

We reviewed 50 papers from year 2005 to 2021 related to donor-related graft infections. We included 14 studies related to the risk factors associated with post-keratoplasty infection and preventive methods.

RESULTS

Incidence of post-keratoplasty infections has been reported to be approximately 0.2%-0.77% for endophthalmitis and 6.5%-10.5% for microbial keratitis. We analyzed six important studies regarding the risk factors related to donor contamination. It was observed that younger donor age, increased death to retrieval time, warming cycles and increased eye bank processing time and positive corneo-scleral rim cultures were important risk factors for donor-related infections post keratoplasty. Eye banks have adapted newer protocols over the time period for prevention of donor-related contamination. Recommended preventive strategies were published in about eight important studies over the past decade. In addition to meticulous donor screening, rapid warming cycles, double contact with povidone iodine during retrieval and addition of antifungals like amphotericin B, Voriconazole and cycloheximide have been suggested over the last decade although their use is still in debate with regard to the efficacy, toxicity and cost-effectiveness.

CONCLUSION

The last decade has witnessed a relative rise of fungal infections and multidrug resistant bacterial infections post-keratoplasty. Eye bank prepared corneas for lamellar surgeries are at increased risk for donor contamination due to increased exposure to the higher temperatures during their processing. Addition of antifungals and broad spectrum antibiotics to the hypothermic preservation media needs to be considered in the new era of increasing trends of lamellar keratoplasty.

Comparison of Graft Outcomes Reusing Original Intermediate-Term Cold Storage Solution for Entire Corneal Donor Storage Period With Exchanged Fresh Storage Solution After Donor Preparation in the Cornea Preservation Time Study

PURPOSE

The purpose of this study was to evaluate outcomes of Descemet stripping automated endothelial keratoplasty comparing exchange with fresh intermediate-term cold storage solution after lenticule preparation versus reuse of the original solution in the Cornea Preservation Time Study.

METHODS

In the Cornea Preservation Time Study, 508 donor corneas had lenticules prepared by the eye bank with fresh solution exchange (Fresh group) and 283 with reuse of the original solution (Original group). Storage time for all donors was ≤11 days. Graft success rates, central endothelial cell loss at 3 years, and frequency of positive donor rim cultures were compared between the 2 groups.

RESULTS

The 3-year graft success rate (95% confidence interval) was 93.4% (90.7%-95.3%) in the Fresh group and 95.2% (91.8%-97.2%) in the Original group (adjusted hazard ratio for graft failure = 0.64, 95% confidence interval, 0.33-1.24, P = 0.19). The mean percentage endothelial cell loss was significantly greater in the Fresh group versus Original group (45% ± 22% vs. 38% ± 20%, respectively, P = 0.004). Cultures were positive in 4 (1.5%) of 267 donor rims (3 fungal and 1 bacterial) in the Fresh group and in 4 (2.5%) of 158 in the Original group (P = 0.57). There were 2 postoperative infections in the Original group and none in the Fresh group.

CONCLUSIONS

The use of the original intermediate-term cold storage solution did not reduce the 3-year graft success rate compared with exchanging with fresh solution after lenticule preparation for Descemet stripping automated endothelial keratoplasty, while the frequency of positive donor rim cultures did not significantly differ between groups.

Antifungal Efficacy and Safety of Cycloheximide as a Supplement in Optisol-GS

PURPOSE

The incidence of fungal infection after corneal transplant has increased significantly in recent years, especially Candida spp. This study aimed to evaluate the efficacy and safety of the addition of cycloheximide in Optisol-GS media in decreasing the growth of Candida spp. strains.

METHODS

This in vitro laboratory efficacy study measured fungal colony growth in 24 vials of Optisol-GS that were divided into 6 groups of 4 vials each, as follows: (1) MIC/2 cycloheximide, (2) MIC cycloheximide, (3) MICx5 cycloheximide, (4) MICx10 cycloheximide, from MIC values obtained for each strain, (5) unsupplemented optisol-GS as a positive control (added inoculum), and (6) unsupplemented optisol-GS as a negative control (no inoculum). In each group was added Candida albicans, C. glabrata and C. parapsilosis, except in the negative control. The evaluated variables were fungal colony growth from the Optisol-GS vials, corneal endothelial cell density and endothelial cell viability at different concentrations of cycloheximide.

RESULTS

In the efficacy study, all strains showed a reduction in fungal cell growth from the second day at all evaluated concentrations of optisol-GS supplemented with cycloheximide, even at subinhibitory concentrations (MIC/2). For C. glabrata, the colony count was reduced to 99%. No evidence of corneal endothelial toxicity was found at any concentration, in the safety study, compared with the paired control.

CONCLUSION

The addition of cycloheximide to optisol-GS decreased the fungal growth, demonstrating fungicide action against C. glabrata and fungistatic action against C. albicans and C. parapsilosis. This drug did not demonstrate toxicity to the corneal endothelium at different concentrations.

Corneal transplantation activity in Catalonia, Spain, from 2011 to 2018: Evolution of indications and surgical techniques

Purpose

To report corneal transplant activity carried out in Catalonia (Spain) and the evolving indications for keratoplasty over an 8-year period.

Methods

Annual reports from the Catalan Transplant Organization, Spain, on corneal graft indications and techniques from 2011 to 2018 were reviewed.

Results

A total of 9457 keratoplasties were performed in Catalonia, from January 2011 to December 2018. The most frequent indications were bullous keratopathy (BK; 20.5%), Fuchs endothelial dystrophy (FED; 17.9%), re-graft (13.7%), and keratoconus (11.3%). Penetrating keratoplasty (PKP) accounted for 63.4% of all performed keratoplasties. Since the introduction of eye bank precut tissue for Descemet stripping automated endothelial keratoplasty (DSAEK) in 2013 and for Descemet membrane endothelial keratoplasty (DMEK) in 2017 the number of endothelial keratoplasties has drastically increased. An increasing trend of posterior lamellar techniques over the total of keratoplasties was found (p<0.001). Endothelial keratoplasties for different endothelial diseases indications (BK, FED, and re-graft), also showed and increasing trend (p<0.001). DMEK is the technique with the highest increase (statistically significantly different from linearity) over other endothelial keratoplasties in FED (p<0.001) but not in BK (p = 0.67) or re-grafts (p = 0.067).

Conclusion

Endothelial diseases represented the top indication for keratoplasty over the 8-year period. PKP is still the most used technique in Catalonia, but endothelial keratoplasties and especially DMEK showed a significant increasing trend over the last years. This is congruent with the main rationale nowadays for keratoplasties: to customize and transplant as less tissue as possible. Therefore, the availability of precut tissue could have definitely enforced such approach.

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.

The Role of Donor Rim Fungal Cultures

ABSTRACT

Culturing all donor rims for fungus makes no sense. Only 1% of all cultures will be positive, and of those positive cultures, only 6% will also have a clinical infection. Prophylactically treating all positive cultures means 94% of patients will be treated unnecessarily. Fungal cultures do not reliably direct specific medication choice, and fungal infections of the interface in endothelial keratoplasty and deep anterior lamellar keratoplasty are nearly impervious to medical therapy. Suspected fungal infections of the deep stromal interface should be treated expeditiously with penetrating keratoplasty before peripheral spread or endophthalmitis occur.

Rhino-orbito-cerebral mucormycosis following penetrating keratoplasty

Rhino-orbito-cerebral mucormycosis (ROCM) is a potentially devastating fungal infection with a significant fatality rate. Early diagnosis and prompt management are crucial to ensure a favorable outcome due to the recognized rapid progression. This case is a rare presentation of ROCM in a patient with uncontrolled diabetes following a corneal transplant. The procedure required early surgical resection in the first 30 hours of hospitalization. The patient received wide-spectrum antibiotics and antifungal treatment and underwent extensive debridement of the necrotic area. A high index of suspicion is needed to diagnose ROCM. Any diabetic patient with sinonasal disease and/or cranial nerve involvement, irrespective of their serum glucose or glycated hemoglobin levels, is a candidate for prompt evaluation to exclude mucormycosis. The rapid evolution of our case highlights the importance of treating ROCM promptly and aggressively.