Donor-related Candida keratitis after Descemet stripping automated endothelial keratoplasty

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.

Suture-Related Fungal Interstitial Interface Keratitis in Deep Anterior Lamellar Keratoplasty: A Case Report

Interstitial interface keratitis (IIK) in lamellar keratoplasty is a term used to describe infectious keratitis that primarily involves the graft-host interface. It poses specific challenges due to impaired access for microbiological testing and poor penetration of antimicrobial drugs, as well as ease of deeper extension of the microorganism. A 33-year-old male with a medical history of left eye deep anterior lamellar keratoplasty (DALK) with keratoconus, subsequently complicated with steroid-induced glaucoma controlled with Xen tube insertion, presented with acute left eye pain and redness for two days due to one broken corneal graft suture at 5 o’clock position with infiltrate at the graft-host junction. He was treated for suture-related bacterial keratitis (culture-negative) with intensive single broad-spectrum topical antibiotic after suture removal. However, the condition worsened, with dense stromal infiltrate extending into the graft-host interface junction which further progressed to an endothelial plaque. Systemic and topical antifungal treatments were started with adjunctive intracameral and subconjunctival voriconazole before improvement was observed. The condition was resolved with localized scarring without the need for repeat keratoplasty. The best-corrected vision was maintained at 6/36 due to residual sutured-related astigmatism with no signs of corneal graft rejection. Lamellar keratoplasty poses an increased risk of fungal IIK even after several years if there is a predisposing factor e.g., steroid usage and broken suture. Timely diagnosis and intervention are the keys to ensure an optimal outcome.

Efficacy of voriconazole and amphotericin B in corneal preservative media

Purpose:

To evaluate the efficacy of voriconazole and amphotericin B in McCarey–Kaufman (MK) media.

Methods:

MK media vials were supplemented with either voriconazole at 1, 2, 20, 50, 100 μg/mL or amphotericin B at 0.5, 1, 2, 10, 20 μg/mL. The standard inoculum of the American Type Culture Collection (ATCC) strain of Candida albicans, Aspergillus flavus, and Fusarium keratinoplasticum was added to the set of vials. The efficacy outcomes were calculated as ‘viable fungal colony counts’ determined from the samples taken on Days 0 and 4. MK media containing fungal inoculum but without antifungal supplements were used as control.

Results:

In the voriconazole arm, on Day 4, a reduction in the colony count was observed for Candida albicans (1 μg/mL, 36%; 100 μg/mL, 100%), Aspergillus flavus (1 μg/mL, 53.8%; 100 μg/mL, 80.4%), and Fusarium keratinoplasticum (1 μg/mL, 39.0%; 100 μg/mL, 72.2%). Similarly, in the amphotericin B arm, on Day 4, a reduction in the colony count was observed for Candida albicans (0.5 μg/mL; 99.9%; 20 μg/mL, 100%), Aspergillus flavus (0.5 μg/mL, 65.2%; 20 μg/mL, 84.8%), and Fusarium keratinoplasticum (0.5 μg/mL, 90.1%; 20 μg/mL, 100%).

Conclusion:

Compared to voriconazole, the addition of amphotericin B significantly reduces fungal contamination in MK media.

Ex vivo photoactivated chromophore for keratitis-corneal crosslinking on inverted graft: new approach to manage interface infectious keratitis after deep anterior lamellar keratoplasty

A 44-year-old man affected by keratoconus underwent deep anterior lamellar keratoplasty (DALK). Two weeks postoperatively, slitlamp examination showed grayish-white lesions in the donor-host interface. Corneal scraping and donor broth culture tested negative for both bacteria and fungi. In vivo confocal microscopy showed elongated particles resembling Candida pseudofilaments. Despite antimicrobial therapy, the clinical picture worsened, and surgical approach was chosen: the graft was peeled off and inverted (epithelium facing down), and ex vivo photoactivated chromophore for infectious keratitis-corneal crosslinking (PACK-CXL) was performed; the recipient bed was washed with antibiotics/antifungals and the graft resutured. Microbiological and histological evaluations of biopsy specimen tested positive for Candida albicans. Postoperative slitlamp examination revealed a progressive recovery of graft transparency with disappearance of the infiltrates. To the authors' knowledge, this is the first report of ex vivo PACK-CXL on inverted DALK graft for the treatment of interface infectious keratitis. This technique allowed the resolution of the infection while sparing the use of new donor tissue.

Post-keratoplasty Infectious Keratitis: Epidemiology, Risk Factors, Management, and Outcomes

Post-keratoplasty infectious keratitis (PKIK) represents a unique clinical entity that often poses significant diagnostic and therapeutic challenges. It carries a high risk of serious complications such as graft rejection and failure, and less commonly endophthalmitis. Topical corticosteroids are often required to reduce the risk of graft rejection but their use in PKIK may act as a double-edged sword, particularly in fungal infection. The increased uptake in lamellar keratoplasty in the recent years has also led to complications such as graft-host interface infectious keratitis (IIK), which is particularly difficult to manage. The reported incidence of PKIK differs considerably across different countries, with a higher incidence observed in developing countries (9.2-11.9%) than developed countries (0.02-7.9%). Common risk factors for PKIK include the use of topical corticosteroids, suture-related problems, ocular surface diseases and previous corneal infection. PKIK after penetrating keratoplasty or (deep) anterior lamellar keratoplasty is most commonly caused by ocular surface commensals, particularly Gramme-positive bacteria, whereas PKIK after endothelial keratoplasty is usually caused by Candida spp. Empirical broad-spectrum antimicrobial treatment is the mainstay of treatment for both PKIK, though surgical interventions are required in medically refractory cases (during the acute phase) and those affected by visually significant scarring (during the late phase). In this paper, we aim to provide a comprehensive overview on PKIK, encompassing the epidemiology, risk factors, causes, management and outcomes, and to propose a treatment algorithm for systematically managing this challenging condition.

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.

Incidence of Fungal Infection in Positive Donor Rim Cultures after Corneal Transplantation

PURPOSE

To determine the clinical outcomes of corneal transplant patients that had positive rim cultures for fungi.

METHODS

Retrospective study.

RESULTS

Of 1276 rim cultures obtained between 2009 and 2019, 16 were positive for fungus (incidence of 1.25%). Clinical data were available for 12 patients. Candida and Cladosporium species were the most common organisms. Recipient ages ranged from 51 to 86 (median age 69 years; 9 males, 7 females). The most common surgery was Endothelial Keratoplasty (n = 8). There were no instances of fungal keratitis or endophthalmitis. Three patients were treated with prophylactic antimycotics. One patient developed bacterial keratitis. One patient had a varicella zoster virus reactivation without corneal involvement.

CONCLUSIONS

This study adds to the growing data on the low rate of fungal keratitis and endophthalmitis after a corneal transplant, even in the case of positive rim cultures. This study also suggests that positive rim cultures do not advance the risk of postoperative fungal infection in the recipient.

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.

Excisional penetrating keratoplasty for fungal interface keratitis after endothelial keratoplasty: surgical timing and visual outcome

PURPOSE

In this paper, we describe two cases of fungal interface infectious keratitis (IIK) developed after endothelial keratoplasty (EK) who underwent delayed therapeutic penetrating keratoplasty (TPK) with a poor visual outcome. Furthermore, we conducted a review of the literature and analyzed the visual outcomes of TPK in relation to the time from IIK diagnosis.

METHODS

We searched the literature for fungal IIK cases occurred after EK and treated by TPK. We identified 17 cases of fungal IIK, mostly caused by Candida spp. (88%).

RESULTS

Infection was diagnosed at a median time of 21 (range 1-90 days) days after EK. The median lag time between infection diagnosis and TPK was 30 (range 7-393) days. The median distance corrected visual acuity (DCVA) measured 4-12 months after surgery was 20/40 (range 20/200-20/20). When TPK was performed within one month from diagnosis, the final median DCVA was 20/30 (range 20/100-20/20), with 83% of patients achieving ≥ 20/40 vision. When TPK was carried out later, the final median DCVA was 20/50 (range 20/200-20/22) with 44% of patients achieving ≥ 20/40 vision. One patient in the early surgery and four patients in the late surgery group showed postoperative DCVA ≤ 20/100 despite clear grafts.

CONCLUSION

TPK with removal of the sequestered infection is advocated as a safe and effective measure to treat a post-EK infection. Early surgery allows a reduced exposure time to infection and therefore may result in better visual outcomes and lower risk of complications caused by prolonged inflammation.

Late-onset fungal interface keratitis following endothelial keratoplasty with positive donor fungal culture

Purpose

To describe late-onset fungal keratitis after Descemet's stripping endothelial keratoplasty (DSEK) with positive fungal culture of the donor corneal rim.

Observations

A case report of a patient undergoing DSEK is described whereby the donor corneal rim culture grew fungus. No infection was initially noted, but the patient developed fungal keratitis 1 year after the original DSEK procedure, despite prophylactic treatment at the time of the positive donor culture. The patient responded to antifungal therapy, but fungal keratitis recurred following completion of a 1-year course of antifungal treatment. The patient eventually underwent full thickness keratoplasty.

Conclusions and importance

A positive fungal culture of the donor rim tissue at the time of endothelial keratoplasty is a risk factor for fungal keratitis. Even with prophylactic antifungal treatment, fungal keratitis may eventually develop as late as 1 year after the initial endothelial keratoplasty procedure. Treatment may need to be aggressive, but keratitis may recur despite resolution with antifungal treatment.

Microbiological Screening of Hypothermic Preserved Donor Corneas in Keratoplasty

Purpose: To determine the prevalence, risk factors and microbial profiles of donor corneal contamination and its association with postoperative infection. Materials and Methods: 1348 hypothermic preserved donor corneas were screened during keratoplasty to assess the impacts of donor age, gender, cause of death and corneal preservation time on the contamination risk. The microbial spectrum and antibiotic sensitivity of causative microorganisms and the prognostic role of corneoscleral rim cultures were analyzed. Results: 111 donor corneas (8.2%) had positive microbial cultures, with 84 contaminated by bacteria, 25 by fungi and 2 by both. Acinetobacter baumannii complex (19.8%) and Candida spp. (9.0%) were the most commonly isolated bacteria and fungi, respectively. Two patients (1.8%) who received contaminated corneal buttons developed postoperative infections. Death due to cardiac disease led to more corneal contaminations than death due to brain disease (odds ratio (OR) = 2.59, P = .009). Longer preservation time was associated with a trend toward increasing contamination rate (from 8.3% to 15.0%). Moreover, fungal-contaminated corneas were preserved longer than bacterial-contaminated corneas (6.6 ± 4.5 versus 10.2 ± 5.4 days, P = .001). Corneas from donors who died from cardiac diseases and trauma showed the highest prevalence of bacterial (10.9%) and fungal (2.6%) contamination, respectively. Antibiotic sensitivity testing revealed that the third-generation fluoroquinolone levofloxacin had high rates of susceptibility to both gram-positive (G+) (60.0%) and gram-negative (G-) (44.6%) bacteria. Conclusions: The causes of donor corneal contamination are multifactorial. The antibiotic resistance rate of contaminating microbes seems to be increasing. Whether antibiotic usage in storage medium and postoperative prophylaxis should be updated accordingly warrants further investigation.

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

PURPOSE

To examine postoperative reports of infection rates for eye bank-prepared and non-eye bank-prepared corneas from January 1, 2006 to December 31, 2017, from a single eye bank.

METHOD

A retrospective review of reported fungal and bacterial infections with corneal transplant surgeries using corneas distributed by our eye bank was conducted. The reported number of infections for corneas that underwent eye bank preparation (pre-cut and pre-stripped corneas) and for those distributed without eye bank preparation was quantified. The potential association between infection rates in tissue prepared by the eye bank and those in corneas that had no additional eye bank processing was also examined.

RESULTS

Four of 17,035 corneas distributed during the study period were associated with fungal infections (1 eye bank-prepared and 3 non-eye bank-prepared corneas) and were attributed to the tissue after investigation by eye bank medical directors. There was no ascending trend of infections reported with eye bank-prepared corneas in the first 3 years (2 of 1054 corneas, 0.19%) compared with that in the last 3 years of the study period (6 of 3500 corneas, 0.17%; P = 0.901) when the eye bank distributed 3 times more prepared corneas than non-eye bank-prepared corneas. A significant increase in the numbers of reported infections for non-eye bank-prepared corneas was observed between these 3-year intervals (0.1% in the first 3 years to 1.58% in the last 3 years; P = 0.001).

CONCLUSIONS

Reports of infections remained low despite increased use of eye bank-prepared tissue. These results suggest that factors other than eye bank tissue preparation should be considered when investigating potential sources of pathogen contamination in donor corneas.

Fungal infection after endothelial keratoplasty: association with hypothermic corneal storage

PURPOSE

To compare the incidence of fungal infection after endothelial keratoplasty (EK) when donor tissue had been stored in hypothermic medium or organ culture.

METHODS

We describe the clinical features of 10 cases of fungal infection (keratitis or endophthalmitis) following EK identified at three European centres. Case definition was the culture of fungus or a positive PCR from the host cornea or anterior chamber after EK. A survey of the incidence of infection after EK was conducted by the European Eye Bank Association. The main outcome measure was the number of cases in which donor tissue had been stored in hypothermic medium compared with organ culture.

RESULTS

The 10 cases occurred between 2014 and 2017. All donor corneas had been stored in hypothermic medium sourced from three US eye banks. Three pairs of mate corneas caused infections in six recipients. Candida spp were identified from nine cases, with one isolate of Purpureocillium lilacinum. Data on 16 862 corneas supplied for EK were available from 16 European eye banks for the 5-year period from 2012. There were 17 reported cases of infection, of which 15 (88%) were fungal infections and 14 (82%) were Candida spp. Fungal infection was reported from 3 of 14 476 (0.02%) corneas supplied in organ culture compared with 12 of 2386 (0.50%) corneas supplied in hypothermic medium (p<0.0001). The incidence of infection after hypothermic storage was similar for material sourced from Europe (0.52%) or the USA (0.61%).

CONCLUSIONS

Infection after EK is strongly associated with Candida spp. The possible explanations for the higher incidence of infection when tissue is stored in hypothermic medium are discussed.

Interface infectious keratitis after anterior and posterior lamellar keratoplasty. Clinical features and treatment strategies. A review

Interface infectious keratitis (IIK) is a novel corneal infection that may develop after any type of lamellar keratoplasty. Onset of infection occurs in the virtual space between the graft and the host where it may remain localised until spreading with possible risk of endophthalmitis. A literature review identified 42 cases of IIK. Thirty-one of them occurred after endothelial keratoplasty and 12 after deep anterior lamellar keratoplasty. Fungi in the form of Candida species were the most common microorganisms involved, with donor to host transmission of infection documented in the majority of cases. Donor rim cultures were useful to address the infectious microorganisms within few days after surgery. Due to the sequestered site of infection, medical treatment, using both topical and systemic antimicrobials drugs, was ineffective on halting the progression of the infection. Injection of antifungals, right at the graft–host interface, was reported successful in some cases. Spreading of the infection with development of endophthalmitis occurred in five cases after Descemet stripping automated endothelial keratoplasty with severe sight loss in three cases. Early excisional penetrating keratoplasty showed to be the treatment with the highest therapeutic efficacy, lowest rate of complications and greater visual outcomes.

Incidence and Outcomes of Positive Donor Rim Cultures and Infections in the Cornea Preservation Time Study

PURPOSE

To assess donor rim culture results and outcomes of ocular infections in the Cornea Preservation Time Study (CPTS).

METHODS

Donor corneal rim cultures were optional. Donor characteristics were assessed for association with positive cultures using the Fisher exact test and Poisson regression analyses. Incidence rates of ocular infections were estimated, and 95% confidence intervals were calculated.

RESULTS

Cultures were performed in 784 (58.9%) of the 1330 cases. For the 0 to 7-day versus 8 to 14-day preservation time groups, respectively, positive fungal growth occurred in 10 of 397 (2.5%) versus 5 of 387 (1.3%) corneas (P = 0.30), whereas positive bacterial cultures occurred in 6 of 397 (1.5%) versus 4 of 387 (1.0%) corneas (P = 0.75). Surgeon-prepared tissue remained a significant risk for positive fungal cultures [relative risk (RR) of surgeon- versus eye-bank-prepared, 2.85; 95% CI (1.02-7.98)], whereas younger donors [RR per year of age, 0.96; 95% CI (0.93-1.00)] and accidental death donors [RR of accident versus disease, 3.71; 95% CI (1.36-10.13)] were at a greater risk for positive bacterial cultures. Fungal infection (Candida glabrata) developed in 1 (6.7%) of 15 recipients with a positive fungal culture, and no recipient infections occurred with positive bacterial culture. With one additional fungal keratitis (Candida albicans) and one bacterial endophthalmitis (E. coli) with no rim culture performed, a total of 2 of 1330 eyes (0.15%) developed fungal and 1/1330 eyes (0.08%) developed bacterial postkeratoplasty infections.

CONCLUSIONS

A longer preservation time was not associated with a higher rate of positive donor rim cultures. The overall rate of infection across the entire cohort was low.

Candida Endophthalmitis After Descemet Stripping Automated Endothelial Keratoplasty With Grafts From Both Eyes of a Donor With Possible Systemic Candidiasis

PURPOSE

To report 2 cases with late postoperative Candida albicans interface keratitis and endophthalmitis after Descemet stripping automated endothelial keratoplasty (DSAEK) with corneal grafts originating from a single donor with a history of presumed pulmonary candidiasis.

METHODS

Two patients underwent uncomplicated DSAEK by 2 corneal surgeons at different surgery centers but with tissue from the same donor and were referred to the Bascom Palmer Eye Institute with multifocal infiltrates at the graft-host cornea interface 6 to 8 weeks later, and anterior chamber cultures that were positive for the same genetic strain of C. albicans. Immediate explantation of DSAEK lenticules and daily intracameral and instrastromal voriconazole and amphotericin injections failed to control the infection. Thus, both patients underwent therapeutic penetrating keratoplasty with intraocular lens explantation, pars plana vitrectomy, and serial postoperative intraocular antifungal injection.

RESULTS

Both patients are doing well at 2 years postoperatively with best-corrected vision of 20/20 and 20/30+ with rigid gas permeable lenses. One patient required repeat optical penetrating keratoplasty and glaucoma tube implantation 1 year after the original surgery. Literature review reveals that donor lenticule explantation and intraocular antifungals are often inadequate to control fungal interface keratitis, and a therapeutic graft is commonly needed.

CONCLUSIONS

Interface fungal keratitis and endophthalmitis due to infected donor corneal tissue is difficult to treat, and both recipients of grafts originating from the same donor are at risk of developing this challenging condition.

Reduction of Donor Cornea Exposure to Repeat Warming Cycles and Evaluation Times After Implementation of a Rapid Warming Protocol

PURPOSE

To compare tissue evaluation times and specular image quality before and after the implementation of rapid tissue warming at a single eye bank.

METHODS

This retrospective study compares the evaluation of 494 donor corneas. All corneas were stored in Optisol-GS. Group 1 contained 247 corneas evaluated immediately before implementation of a tissue incubator and tissue warming protocol. Group 2 contained 247 corneas evaluated immediately after implementation. Total evaluation times (including specular microscopy, optical coherence tomography for corneal thickness measurements, and 2 slit-lamp examinations) were calculated and compared. Representative specular images of donor corneas were rated and compared using a previously described scale by 2 masked readers.

RESULTS

Donor tissue characteristics were not significantly different between both groups (age, P = 0.87; sex, P = 0.93; endothelial cell densities, P = 0.47; and death-to-preservation times, P = 0.18). The mean total evaluation time for group 2 corneas was ∼3 hours, with 97% (201/208) of evaluations completed on the same day. In contrast, only 73% (164/225) of corneas from group 1 were completely evaluated in 1 day, and the mean evaluation time for those corneas was ∼4.25 hours (P < 0.01). Specular images of corneas from group 2 were rated 1 grade higher, on average, than those from group 1 (n = 247 in each group, P < 0.01). Furthermore, 71% of specular images from group 2 were categorized as "good" or "excellent" quality, whereas only 30% of corneas from group 1 received those ratings.

CONCLUSIONS

Rapid tissue warming cuts down on tissue evaluation time and reduces the time donor corneas are out of cold storage. Better specular images were obtained after implementation of the rapid warming protocol.

Association Between Fungal Contamination and Eye Bank-Prepared Endothelial Keratoplasty Tissue: Temperature-Dependent Risk Factors and Antifungal Supplementation of Optisol-Gentamicin and Streptomycin

Importance

Fungal contamination and infection from donor tissues processed for endothelial keratoplasty is a growing concern, prompting analysis of donor tissues after processing.

Objective

To determine whether eyebank-processed endothelial keratoplasty tissue is at higher risk of contamination than unprocessed tissue and to model eyebank processing with regard to room temperature exposure on Candida growth in optisol-gentamicin and streptomycin (GS) with and without antifungal supplementation.

Design, Setting, and Participants

An examination of the 2013 Eversight Eyebank Study follow-up database for risk factors associated with post-keratoplasty infection identified an increased risk of positive fungal rim culture results in tissue processed for endothelial keratoplasty vs unprocessed tissue. Processing steps at room temperature were hypothesized as a potential risk factor for promotion of fungal growth between these 2 processes. Candida albicans, Candida glabrata, and Candida parapsilosis endophthalmitis isolates were each inoculated into optisol-GS and subjected to 2 different room temperature incubation regimens reflective of current corneal tissue handling protocols.

Main Outcomes and Measures

Eversight Eyebank Study outcomes and measures were follow-up inquiries from 6592 corneal transplants. Efficacy study outcomes and measures were fungal colony-forming units from inoculated vials of optisol-GS taken at 2 different processing temperatures.

Results

Donor rim culture results were 3 times more likely to be positive for fungi in endothelial keratoplasty-processed eyes (1.14%) than for other uses (0.37%) (difference, 0.77%; 95% CI, 0.17-.1.37) (P = .009). In vitro, increased room temperature incubation of optisol-GS increased growth of Candida species over time. The addition of caspofungin and voriconazole decreased growth of Candida in a species-dependent manner.

Conclusions and Relevance

Detectable Candida growth in donor rim cultures, associated with a higher rate of post keratoplasty infection, is seen in endothelial keratoplasty tissue vs other uses at the time of transplantation, likely owing in part to eyebank preparation processes extending the time of tissue warming. Reduced room temperature incubation and the addition of antifungal agents decreased growth of Candida species in optisol-GS and should be further explored to reduce the risk of infection.

Rapid Warming of Donor Corneas Is Safe and Improves Specular Image Quality

PURPOSE

To determine whether warming donor corneas to near-physiological temperatures can safely shorten warming times while providing high-quality specular images during tissue evaluation.

METHODS

Mated corneas were warmed at room temperature (RT) or at 35°C for 4 hours upon removal from cold storage. Specular images and endothelial cell densities were acquired and rated every hour. Additional mated corneas were subjected to 2 rounds of 4-hour incubation at either RT or 35°C. Endothelial cell loss (ECL) was quantified 14 days after the initial incubation using Calcein-acetoxymethyl (Calcein-AM) and FIJI trainable segmentation. Cultures inoculated with common ocular pathogens were subjected to 2 warming cycles at RT for 4 hours or 35°C for 2 hours. Colony counts were taken over the course of 2 weeks after inoculation.

RESULTS

Specular image quality ratings were consistently higher for corneas warmed at 35°C compared with those at RT. Image quality ratings for corneas warmed at 35°C for 1.5 hours were higher than corneas warmed at RT for 4 hours (P = 0.04). No differences in ECL were observed between the 2 warming conditions (RT = 13.1% ± 7.6% ECL, 35°C = 13.9% ± 6% ECL, P = 0.75). There was no difference in colony counts for pathogens tested between the 2 warming conditions.

CONCLUSIONS

Warming donor corneas to near-physiological temperatures for a short time can increase specular image quality while reducing the time tissues are unrefrigerated at eye banks. This method allows for more efficient specular imaging without inducing additional ECL or increasing pathogen growth.

Descemet stripping automated endothelial keratoplasty

Endothelial keratoplasty is at present the gold standard for surgical treatment of corneal endothelial pathologies not associated with significant corneal scar. Tremendous progress has been made in recent years in improving the technology of endothelial keratoplasty techniques, such as descemet stripping automated endothelial keratoplasty (DSAEK) and descemet membrane endothelial keratoplasty. In this review, we discuss the current techniques and outcomes of DSAEK.

First Reported Case of Donor Related Candida Endophthalmitis after Descemet Membrane Endothelial Keratoplasty

Purpose:

To report the first case of Candida donor to host transmission following descemet membrane endothelial keratoplasty (DMEK)

Methods:

A retrospective case report.

Results:

A patient underwent uneventful DMEK. Following surgery the donor rim was culture positive for Candida. The patient developed fungal endophthalmitis that was treated medically with multiple injections of voriconazole and amphotericin. Medical treatment was unable to clear the infection and removal of the donor material was required. Following removal the infection subsided.

Conclusion:

Candida interface keratitis and endophthalmitis can occur following DMEK and may be difficult to treat medically. Early removal of the donor material should be considered.

A case of fungal keratitis and endophthalmitis post penetrating keratoplasty resulting from fungal contamination of the donor cornea

Purpose

Fungal infections post keratoplasty due to contamination of the donor corneal graft have become important issues that need to be addressed. Here we report a case of fungal keratitis and endophthalmitis post penetrating keratoplasty (PKP) due to fungal contamination of the donor corneal graft.

Observations

We present a 52-year-old male who underwent PKP with a donor corneal graft that was later found to be contaminated with fungus. At 4-weeks postoperative, infectious infiltrates suddenly appeared at the border between the host and donor corneal graft, and endophthalmitis concomitantly occurred. A culture of the remnant donor corneoscleral rims and the vitreous fluid obtained during vitreous surgery was found to be positive for Candida albicans. At 6-months post vitreous surgery and intensive anti-fungal medical treatment, both corneal infiltrates and vitreous opacity completely disappeared, and the patient's best-corrected visual acuity recovered to 20/40, with a transparent cornea.

Conclusions and importance

The findings of this case show that prompt intensive medical treatment and surgical intervention effectively saved the vision in a patient with fungal keratitis and endophthalmitis due to contamination of the donor corneal graft.

Systemic Fungal Infections in Donors for Corneal Transplantation

PURPOSE

To determine the prevalence of postkeratoplasty fungal infection when corneal tissue from donors with a recent medical history of oral thrush or respiratory, urine, wound, sputum, bronchial, tracheal, or throat culture positive for fungus is identified before recovery and after decontamination of the corneal tissue with 5% povidone-iodine flush to the donors' eyes during recovery.

METHODS

This is a prospective analysis of corneas from 42 donors with a documented medical history of fungus or positive fungal culture, which were recovered between January 2010 and November 2010. Standard aseptic swab of the donors' corneas before and after application of 5% povidone-iodine solution was performed. Culture results were analyzed in relationship to the donors' medical history and potential posttransplantation infections.

RESULTS

Eighty-four eyes from 42 patients were swabbed for cultures during the study period. Seven eyes (8.3%) were positive for fungal growth before treatment with 5% povidone-iodine, whereas there were no positive fungal cultures after treatment (P = 0.007). Fifty-four corneas from this study group were used for corneal transplantation. There were no cases of fungal infection in any postkeratoplasty eyes transplanted from this study group.

CONCLUSIONS

In this small study, the overall prevalence of fungal infections after corneal transplantation using corneal donor tissue from donors with a fungal-positive medical history is low. Corneal fungal contamination in donors with a history of fungal infection or a positive fungal culture can be significantly reduced with a 5% povidone-iodine flush.

Incidence and Outcomes of Positive Donor Corneoscleral Rim Fungal Cultures after Keratoplasty

PURPOSE

To determine the incidence of positive corneoscleral donor rim fungal cultures after keratoplasty and to report clinical outcomes of grafts with culture-positive donor rims.

DESIGN

Retrospective cohort study.

PARTICIPANTS

Consecutive donor corneas and keratoplasty recipients at a single tertiary referral center over 20 years.

METHODS

Patient charts were reviewed to determine the incidence of positive donor rim fungal cultures and clinical outcomes of all grafts using contaminated tissue.

MAIN OUTCOME MEASURES

The primary outcome measures were positive donor rim fungal culture results and the development of postkeratoplasty fungal infection using corresponding corneal tissue. The secondary outcome measure was the impact of postoperative prophylaxis on donor tissue-associated infections.

RESULTS

A total of 3414 keratoplasty cases were included in the statistical analysis. Seventy-one cases (2.1%) were associated with a fungal culture-positive donor rim. Candida species were cultured in 40 cases (56.3%). There was a higher incidence of positive rim cultures over the last 5 years of the analytic period compared with the first 15 years (P = 0.018). Fungal keratitis developed in 4 cases (5.6%), and all patients required further surgical intervention to achieve cure. There were no cases of fungal endophthalmitis. Empiric antimycotic prophylaxis initiated at the time of positive culture result reduced the incidence of keratitis from 15.8% in untreated cases to 1.9% in treated cases (P = 0.056).

CONCLUSIONS

Positive donor rim fungal cultures are uncommon, but carry an unacceptably high risk of postoperative fungal infection. This risk may be reduced with prophylactic antimycotic therapy when culture-positive donor rims are identified.

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.

Early-Onset Candida glabrata Interface Keratitis after Deep Anterior Lamellar Keratoplasty

PURPOSE

Fungal interface keratitis by Candida species can occur several weeks to several months after deep anterior lamellar keratoplasty (DALK). Here, we report a case of early-onset fungal interface keratitis by Candida glabrata after DALK.

CASE REPORT

A 31-year-old Chinese man complained of decreased vision 4 days after an uneventful DALK for keratoconus. White to cream-colored interface deposits were identified under slit-lamp examination. The confocal scan disclosed clusters of hyperreflective granular deposits of 2 to 4 μm at the interface, without evidence of inflammation or hyphae-like structures. The graft was then removed, along with interface irrigation, and another graft was sutured. Finally, a penetrating keratoplasty was performed because the interface opacities recurred and deteriorated after graft replacement. Histopathological examination disclosed yeast-like structures at the retrocorneal side. The microbiologic results of both corneal scrapings taken from the recipient stromal bed and the removed half cornea button showed C. glabrata.

CONCLUSIONS

Candida glabrata interface keratitis can occur early after DALK, which can only be effectively treated with penetrating keratoplasty. Confocal microscopy is a promising tool to diagnose this rare complication. The importance of donor corneoscleral rim cultures should be emphasized during DALK.

Current Concepts in the Management of Unique Post-keratoplasty Infections

As corneal transplantation has evolved, the spectrum of post-surgical infection has changed and often presents a diagnostic and therapeutic challenge. Lamellar techniques hold the potential of improved outcomes and decreased post-operative complications, however, they create a lamellar interface, which is a potential space for sequestration of infectious organisms. In addition, while keratoprosthesis offers vision to patients who are poor candidates for traditional keratoplasty, infectious complications can be severe and sight threatening. Although antimicrobials remain the mainstay of treatment, definitive management often requires surgical intervention.

Interface infection after descemet stripping automated endothelial keratoplasty: outcomes of therapeutic keratoplasty

PURPOSE

The aim of this study was to evaluate the visual outcomes and graft survival rate after therapeutic keratoplasty performed for interface infection after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

This is a retrospective, interventional case series. The study population comprised 7 patients who developed unilateral post-DSAEK interface infection unresponsive to conservative treatment, with or without graft exchange, and were treated with penetrating keratoplasty (PK), 9 to 9.5 mm in diameter, with en bloc excision of the recipient cornea and DSAEK graft. The main outcome measures included best spectacle-corrected visual acuity, refractive error, histological examination, reinfection, and rejection and graft survival rates.

RESULTS

Interface infection was diagnosed in 10 (0.92%) of 1088 eyes that underwent DSAEK at our institution between 2005 and 2013. Seven of 10 eyes (0.64% of the total) were unresponsive to conservative treatment and underwent therapeutic keratoplasty. Candida and Staphylococcus species were identified in 3 cases each, and Nocardia species was identified in 1 case. With a mean post-PK follow-up of 25.4 months (range 4-60 months), no recurrence of infection was seen in any eye, and 5 of 7 PK grafts remained clear. Best spectacle-corrected visual acuity was 20/20 in 2 eyes, better than 20/50 in 4 eyes, and 20/100 or worse in 3 eyes, in 2 of which the graft had failed within 1 year of performing the PK.

CONCLUSIONS

Therapeutic keratoplasty is instrumental in eliminating interface infection after DSAEK, possibly leading to excellent visual outcomes with a relatively high graft survival rate.

Intrastromal antifungal injection with secondary lamellar interface infusion for late-onset infectious keratitis after DSAEK

PURPOSE

The aim of this study was to report the successful medical management of 2 cases of late-onset endothelial keratoplasty-related stromal interface infections.

METHODS

All cases of endothelial keratoplasty-related infections treated with intrastromal antifungal injections were compiled. The following information was collected: demographic data, surgical indications, donor rim cultures, donor mate outcomes, clinical course, diagnostic tests, and clinical outcome.

RESULTS

Two cases of interface fungal keratitis diagnosed on clinical appearance and confocal microscopy were identified. Both patients refused to undergo further surgery and failed systemic and/or topical therapy. Each received 3 to 4 intrastromal injections, with secondary infusion into the graft-host interface, which resulted in the complete involution of their interface opacities.

CONCLUSIONS

Intrastromal antifungal injection may be an effective alternative to surgical intervention in late-onset fungal Descemet stripping endothelial keratoplasty interface keratitis. Early treatment may preserve graft viability and result in a good visual outcome without the need for either penetrating keratoplasty or potential pathogen exposure to the anterior chamber.

The clinical characteristics of fungal keratitis in eyes after Descemet's stripping and automated endothelial keratoplasty

The purpose of this study was to describe the clinical characteristics of fungal keratitis caused by Candida albicans in an eye after Descemet stripping automated endothelial keratoplasty (DSAEK). A 72-year-old male with a history of three trabeculectomies, cataract surgery, and two DSAEK procedures developed a corneal ulcer in his right eye two years after his last DSAEK. Fungal keratitis was most likely related to the immunosuppressive conditions that occurred due to the previous operations, the continuous use of steroid eye drops, and the use of disposable soft contact lenses. A smear and culture from the ulcer detected Candida albicans. Slit-lamp examination showed the characteristic feature was the presence of interface infiltrates located between the host and the graft cornea and in the enlarged area around the ulcer. Two weeks after intense antimycotic treatments with voriconazole, miconazole, and natamycin, perforation of the cornea occurred and further therapeutic penetrating keratoplasty was required. Histological analysis revealed an accumulation of infiltrated cells and fibrotic tissue. The poor prognosis for fungal keratitis that occurs in eyes after undergoing DSAEK may be related to the rapid expansion of inflammatory cells through the interface between the host and the graft. In eyes that develop fungal keratitis after DSAEK, special attention should be paid to the possibility that perforation could occur in these patients.

Eye banking and corneal transplantation communicable adverse incidents: current status and project NOTIFY

PURPOSE

Evidence of the transmission of disease via donor ocular tissue has been demonstrated for adenocarcinoma, rabies, hepatitis B virus, cytomegalovirus, herpes simplex virus, Creutzfeldt-Jakob disease, and a variety of bacterial and fungal infections.

METHODS

Although there is no evidence to date of disease transmission for HIV infection, syphilis, hepatitis C, hepatitis A, tuberculosis, HTLV-1 and -2 infection, active leprosy, active typhoid, smallpox, and active malaria, these entities remain contraindications for transplantation for all eye banks nationally and internationally. The potential sources of contamination include infected donors, during the process of removing tissue from cadaveric donors, the processing environment, and contaminated supplies and reagents used during processing. The transmissions of Herpes simplex virus and HSV via corneal graft have been shown to be responsible for primary graft failure. HSV-1 may also be an important cause of PFG.

RESULTS

The long latency period of some diseases, the emergence of new infectious disease, and the reemergence of others emphasize the need for long-term record maintenance and effective tracing capabilities.

CONCLUSIONS

The standardization of definitions for adverse events and reactions will be necessary to support the prevention and transmission of disease. International classification of a unique identification system for donors will be increasingly important for vigilance and traceability in cross-national exportation of human cells, tissues, and cellular- and tissue-based products. Opportunities for continuous improvement exist as does the need for constant vigilance and surveillance.

Clinical outcomes in descemet stripping automated endothelial keratoplasty with internationally shipped precut donor corneas

PURPOSE

To report the endothelial cell loss and clinical outcomes in Descemet stripping automated endothelial keratoplasty (DSAEK) with internationally shipped, precut donor corneas.

DESIGN

Retrospective analysis of a noncomparative case series.

METHODS

The setting was a single hospital. The clinical results of 134 eyes of 128 patients who underwent DSAEK in Kyoto, Japan, with internationally shipped precut donor corneas from Portland, Oregon, or Seattle, Washington, were evaluated. In addition, 40 precut donor corneas from Seattle were evaluated in respect to the postprecut international shipment-related loss of corneal endothelial cell density (ECD). Observation procedures were noncontact specular microscopy. The main outcome measures were the evaluation of international shipment-related ECD loss, postoperative ECD, visual recovery, and complications.

RESULTS

The mean postprecut ECD loss in 40 donor corneas during international shipment was 2.3%. The mean elapsed time from cut to surgery was 63.2 ± 31.1 hours. At 6, 12, 24, and 36 months postoperatively, the mean ECD of the internationally shipped donor corneas was 2038, 1933, 1670, and 1431 cells/mm(2), respectively. The mean ECD loss at 6, 12, 24, 36 months after DSAEK was 30%, 34%, 44%, and 51%, respectively. Preoperative logarithm of the minimum angle of resolution (logMAR) best spectacle-corrected visual acuity was 1.40 ± 0.55, and at 12 months after DSAEK was 0.22 ± 0.19. Complications included graft dislocation in 12 eyes (8.9%) and graft rejection in 3 eyes (2.2%).

CONCLUSIONS

The present study shows that the outcomes of DSAEK with internationally shipped precut donor corneas were acceptable and that the additional endothelial cell loss associated with international shipment was minimal and did not affect the clinical results.

Report of the Eye Bank Association of America medical advisory board subcommittee on fungal infection after corneal transplantation

PURPOSE

To investigate the incidence of fungal infections after corneal transplantation to determine whether storage media supplementation with an antifungal should be considered.

METHODS

Adverse reactions reported to the Eye Bank Association of America through the online adverse reaction reporting system between January 1, 2007, and December 31, 2010, were reviewed to identify cases of recipient fungal infection. Data were collected regarding the donor, the donor cornea, recovery and processing, and mate culture and clinical course of the recipients.

RESULTS

Thirty-one cases of culture-proven fungal keratitis (n = 14) and endophthalmitis (n = 17) were reported out of 221,664 corneal transplants performed using corneal tissue distributed by domestic eye banks (1.4 cases per 10,000 transplants performed). Although the annual incidence of postkeratoplasty fungal infection has not increased significantly since 2005, a trend toward an increasing rate of fungal infection has been observed. Fungal infections were more commonly reported after endothelial keratoplasty procedures (0.022%) than penetrating keratoplasty procedures (0.012%), but the difference was not statistically significant (P = 0.076). Additionally, no association was found between fungal infection after endothelial keratoplasty and whether the lamellar tissue cut was performed by the surgeon or the eye bank technician. Seventy-three percent (16 of 22) of the fungal cultures performed on the mate corneas were positive, with infection developing in 67% (10 of 15) of recipient eyes (endophthalmitis in 6 eyes and keratitis in 4 eyes).

CONCLUSIONS

Although a nonsignificant increasing trend in the rate of fungal infection has been observed over the past 6 years, it is not sufficiently compelling to pursue antifungal supplementation of donor storage media.

Lamellar corneal transplantation

Penetrating keratoplasty (PK) has been the gold standard for the surgical treatment of most corneal pathologies; lamellar keratoplasty that only replaces the diseased corneal layers has recently evolved as an alternative, however. Innovations in surgical technique and instrumentation provide visual outcomes comparable to PK. We review the indications and outcomes of various techniques of anterior lamellar surgery developed to treat stromal disorders. Similarly, we discuss posterior lamellar keratoplasty techniques such as Descemet stripping automated endothelial keratoplasty and Descemet membrane endothelial keratoplasty. Posterior lamellar keratoplasty provides faster visual rehabilitation than PK in cases of Fuchs endothelial dystrophy and pseudophakic bullous keratopathy. In addition, for medically unresponsive infectious keratitis, therapeutic anterior lamellar keratoplasty yields similar graft survival to PK without an increased risk of disease recurrence.

Fungal interface keratitis by Candida orthopsilosis following deep anterior lamellar keratoplasty

A 39-year-old male patient underwent uncomplicated deep anterior lamellar keratoplasty due to keratoconus. On day 5 after surgery, small whitish infiltrates developed in the corneal interface. The diagnosis of fungal keratitis was made when the culture medium of the graft grew Candida after the surgical intervention. Despite intensive antimycotic treatment and irrigation of the interface, the infiltrates persisted and eventually enlarged. Therefore, revision surgery with penetrating keratoplasty was performed. Microbiological analysis showed Candida orthopsilosis in the culture of the excised graft button. Histopathological staining of the excised graft showed periodic acid-Schiff-positive and Grocott methenamine silver-positive clusters of yeast between Descemet's membrane and the deep corneal stroma with focal perforations through Descemet's membrane. The treatment of mycotic keratitis caused by C orthopsilosis is challenging. Antimycotic treatment was unsuccessful in this case. Progression of the keratitis and perforation of Descemet's membrane suggest that early surgical intervention by penetrating keratoplasty is required.

Impact of eye bank lamellar tissue cutting for endothelial keratoplasty on bacterial and fungal corneoscleral donor rim cultures after corneal transplantation

PURPOSE

To determine if the lamellar cut of donor tissue for endothelial keratoplasty (EK) by an eye bank facility is associated with a change in the prevalence of positive bacterial or fungal donor rim cultures after corneal transplantation.

METHODS

A retrospective review was conducted of bacterial and fungal cultures of donor rims used for corneal transplantation at a tertiary eye care center from January 1, 2003, to December 31, 2008, with tissue provided by a single eye bank. The cases were divided into 2 groups. Group 1 ("no-cut") included keratoplasty procedures in which a lamellar cut was not performed. Group 2 ("precut") included EK procedures in which a 4-hour period of prewarming of tissue followed by a lamellar cut was performed in the eye bank before tissue delivery to the operating surgeon.

RESULTS

There were 351 donor rim cultures in group 1 and 278 in group 2. Bacterial cultures were positive in 30 donor rims (8.5%) in group 1 and 13 (4.7%) in group 2 (P = 0.058). Positive bacterial cultures were not associated with any postoperative infections. Fungal cultures were positive in 8 donor rims (2.3%) in group 1 and 7 (2.5%) in group 2 (P = 1.0). Positive fungal cultures were associated with 2 cases (13.3%) of postoperative fungal infections.

CONCLUSIONS

Corneal donor tissue can be precut for EK by trained eye bank personnel without an increased risk of bacterial or fungal contamination.

Convergent Evolution of Calcineurin Pathway Roles in Thermotolerance and Virulence in Candida glabrata

Candida glabrata is an emerging human fungal pathogen that is frequently drug tolerant, resulting in difficulties in treatment and a higher mortality in immunocompromised patients. The calcium-activated protein phosphatase calcineurin plays critical roles in controlling drug tolerance, hyphal growth, and virulence in diverse fungal pathogens via distinct mechanisms involving survival in serum or growth at host temperature (37° and higher). Here, we comprehensively studied the calcineurin signaling cascade in C. glabrata and found novel and uncharacterized functions of calcineurin and its downstream target Crz1 in governing thermotolerance, intracellular architecture, and pathogenesis in murine ocular, urinary tract, and systemic infections. This represents a second independent origin of a role for calcineurin in thermotolerant growth of a major human fungal pathogen, distinct from that which arose independently in Cryptococcus neoformans. Calcineurin also promotes survival of C. glabrata in serum via mechanisms distinct from C. albicans and thereby enables establishment of tissue colonization in a murine systemic infection model. To understand calcineurin signaling in detail, we performed global transcript profiling analysis and identified calcineurin- and Crz1-dependent genes in C. glabrata involved in cell wall biosynthesis, heat shock responses, and calcineurin function. Regulators of calcineurin (RCN) are a novel family of calcineurin modifiers, and two members of this family were identified in C. glabrata: Rcn1 and Rcn2. Our studies demonstrate that Rcn2 expression is controlled by calcineurin and Crz1 to function as a feedback inhibitor of calcineurin in a circuit required for calcium tolerance in C. glabrata. In contrast, the calcineurin regulator Rcn1 activates calcineurin signaling. Interestingly, neither Rcn1 nor Rcn2 is required for virulence in a murine systemic infection model. Taken together, our findings show that calcineurin signaling plays critical roles in thermotolerance and virulence, and that Rcn1 and Rcn2 have opposing functions in controlling calcineurin signaling in C. glabrata.