Candida tropicalis endophthalmitis following penetrating keratoplasty

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.

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.

Infectious Disease Transmission through Cell, Tissue, and Organ Transplantation: Reducing the Risk through Donor Selection

The incidence of cell transplant-transmitted infection is unknown and can only be inferred from prospective studies–that have not yet been performed and reported. The possibility of donor-to-recipient disease transmission through cell transplant therapy can be considered by reviewing the risk associated with other transplanted tissues and organs. Viral, bacterial, and fungal infections have been transmitted via transplantation of organs, tissue allografts such as bone, skin, cornea, and heart valves, and cells such as islets, hematopoietic stem cells, and semen. Several types of protozoan and worm parasites have been transferred via organ transplants. Bone allografts have transmitted hepatitis, tuberculosis, and human immunodeficiency virus (HIV-1). Corneas have transmitted rabies, Creutzfeldt-Jakob disease (CJD), hepatitis B (HBV), cytomegalovirus (CMV), herpes simplex virus (HSV), bacteria, and fungi. Heart valves have been implicated in transmitting tuberculosis and hepatitis B. HIV-1 and CMV seroconversion has been reported in patients receiving skin from seropositive donors. CJD has been transmitted by dura and pericardium transplants. Over the past several years, improvements in donor screening criteria, such as excluding potential donors with infection and those with behaviors risky for HIV-1 and hepatitis infection, and introduction of new donor blood tests have greatly reduced the risk of HIV-1 and hepatitis and may have nearly eliminated the risk of tuberculosis and CJD. Prior to use, many tissues are exposed to antibiotics, disinfectants, and sterilants, which further reduce or remove the risk of transmitted disease. Because organs, cells, and some tissue grafts cannot be subjected to sterilization steps, the risk of infectious disease transmission remains and thorough donor screening and testing is especially important.

The intraoperative impression and postoperative outcomes of gamma-irradiated corneas in corneal and glaucoma patch surgery

PURPOSE

To report the short-term outcome of gamma-irradiated sterile cornea in corneal and glaucoma patch graft surgeries when viable endothelium is not necessary.

METHODS

Surgeons who have used the irradiated corneas were asked to rate their impression from 1 (fair) to 4 (very good). Specific intraoperative questions included availability, ease of use, clarity, thickness, tensile strength, and suturing. Postoperative outcomes included epithelialization, biological incorporation, and clarity of tissue, as well as any adverse outcomes.

RESULTS

Irradiated sterile cornea has been used in more than 150 surgeries so far. The major uses for irradiated cornea were as glaucoma patch graft (65.3%), as corneal patch graft (14%), in anterior lamellar keratoplasty (10.7%), and in keratoprosthesis (10%). The mean score for packaging of tissue was 3.75 (SD, 0.45), ease of use 3.83 (SD, 0.39), clarity 3.62 (SD, 0.51), thickness 3.67 (SD, 0.49), tensile strength 3.64 (SD, 0.50), and suturing 3.62 (SD, 0.65). Postoperative outcomes were also favorable, including epithelialization (mean ± SD, 3.46 ± 0.69), biological incorporation (mean ± SD, 3.46 ± 0.69), and clarity (mean ± SD, 3.43 ± 0.85). There were 4 episodes of corneal melt (all occurred in patients with previous corneal melt). There were no reported cases of tissue rejection or infection.

CONCLUSIONS

Gamma-irradiated sterile cornea is a promising new development that may help increase the supply of donor cornea tissue. It virtually eliminates the risk of infection while providing a long shelf life. It is particularly helpful in emergency situations or in remote areas. However, longer follow-up and a prospective study comparing the outcomes of the irradiated corneas with those of the optisol-stored corneas are needed.

Donor-related Candida keratitis after Descemet stripping automated endothelial keratoplasty

PURPOSE

To report 2 cases of donor-to-host transmission of Candida albicans interface keratitis after Descemet stripping automated endothelial keratoplasty (DSAEK).

METHODS

We performed clinical and microbiologic examinations on 2 patients who underwent DSAEK for pseudophakic corneal edema.

RESULTS

Two patients underwent uneventful DSAEK surgery using corneal tissue from the same donor. The donor corneoscleral rims were cultured at the time of surgery and both rims subsequently grew C. albicans and Candida glabrata. Approximately 5 weeks after surgery, infiltrates were noted in the DSAEK interface in both of these patients. Despite treatment with antifungal therapy, the Candida keratitis was unable to be controlled medically and required surgical intervention in each case, after which there was no recurrence of infection.

CONCLUSIONS

Candida interface keratitis can occur after DSAEK. These 2 cases emphasize the importance of donor corneoscleral rim cultures, especially with the increase in lamellar and endothelial keratoplasty, which can make such interface infections more difficult to diagnose and treat. Patients with fungal positive donor corneal rim cultures should be prophylactically treated with antifungal therapy.

Late-Onset Donor-to-Host Transmission of Candida glabrata Following Corneal Transplantation

OBJECTIVE

To demonstrate the potential value of obtaining routine fungal cultures of donor rims at the time of corneal transplantation and instituting prophylactic therapy in culture-positive cases, even in the absence of clinical evidence of established microbial keratitis or endophthalmitis.

METHODS

Interventional case report and literature review.

RESULTS

A 69-year-old Saudi man underwent penetrating keratoplasty with donor tissue that was culture-positive for Candida glabrata. The postoperative course was complicated by slight override of the graft associated with an associated epithelial defect, but there was no evidence of microbial keratitis or significant anterior chamber inflammation. Following repair of the graft override on postoperative day 42, the epithelial defect healed. The subsequent clinical course was unremarkable until postoperative day 146, when a deep stromal infiltrate was present at the graft-host junction, associated with a dense endothelial plaque. Cultures of the anterior chamber were positive for Candida glabrata. Treatment with topical and intracameral amphotericin B and systemic fluconazole, along with topical corticosteroids and intracameral t-PA, was successful in eradicating the corneal infiltrate and resolving intraocular inflammation. Four months after treatment was initiated, there was no evidence of recurrent fungal keratitis or endophthalmitis.

CONCLUSION

This case provides support for the practice of obtaining routine fungal cultures of donor rims at the time of corneal transplantation and for the implementation of prophylactic antifungal therapy in culture-positive cases.

Donor-to-Host Transmitted Candida Endophthalmitis After Penetrating Keratoplasty

OBJECTIVE

To report the first case of Candida albicans endophthalmitis following penetrating keratoplasty after warm preservation.

DESIGN

Observational case report.

METHODS

We reviewed the patient's chart and the available literature on fungal endophthalmitis after keratoplasty.

RESULTS

After keratoplasty, a 45-year-old man developed an endophthalmitis on the first postoperative day. The same day, results of the culture of the transportation medium were available and revealed Candida albicans. Despite therapy with topical and subtenon amphotericin B, there was no clinical improvement, and a regraft was performed 4 days after the initial corneal transplant. A best corrected visual acuity of 20/32 was achieved.

CONCLUSION

The majority of reported cases of postkeratoplasty candidal endophthalmitis are associated with cold storage preservation and a poor prognosis of the affected eye. We describe a case of postkeratoplasty candidal endophthalmitis after organ-cultured preservation, with a final visual acuity above expectations. In our opinion, early diagnosis based on routine culturing of the transportation medium and early removal of the infected corneal graft when local antifungal therapy failed are important factors contributing to the good clinical outcome.

Efficiency of blood culture bottles for the fungal sterility testing of corneal organ culture media

BACKGROUND/AIM

The consequences of fungal contamination of an organ cultured cornea, though exceptional, are often disastrous for the recipient. Consequently, eye banks often quarantine corneas for 10 days or more before passing them for grafting. This period, though detrimental to the endothelial cell density of the delivered cornea, is necessary to detect contamination using conventional microbiological methods. The authors previously validated the use of a pair of aerobic and anaerobic blood bottles for sensitive and rapid detection of bacteria. To allow a short quarantine period, it remained only to optimise detection of fungi. The authors aimed to compare sensitivity and rapidity of fungal contamination detection by three methods: blood bottles, Sabouraud, and daily visual inspection of the organ culture medium.

METHODS

Four inocula (10(6), 10(4), 10(2), 10 colony forming unit (CFU) per ml) of 11 fungi (Candida albicans, C tropicalis, C glabrata, Saccharomyces cerevisiae, Rhodotorula rubra, Cryptococcus neoformans, Fusarium oxysporum, Aspergillus niger, A fumigatus, A flavus, Acremonium falciforme) were inoculated in a commercial organ culture medium containing a coloured pH indicator (CorneaMax, Eurobio, Les Ulis, France). The real live fungal inoculum was verified immediately after inoculation. After 48 hours at 31 degrees C, samples of the contaminated media were inoculated in three blood bottles: Bactec Aerobic/F, Bactec Mycosis IC/F, and Bactec Myco/F Lytic (Becton Dickinson, Le Pont de Claix, France), then placed in a Bactec 9240 rocking automat, and in four Sabouraud media (solid and liquid, 28 degrees C and 37 degrees C) with daily observation. Contaminated organ culture media were also checked daily for any change in turbidity and/or colour. Experiments were performed in triplicate.

RESULTS

Mycosis IC/F and Myco/F Lytic bottles were neither faster nor more sensitive than the aerobic bottle. The three methods were positive for all inocula, even the lowest (viable inoculum below 10 CFU/ml for each fungus). Contamination was detected within 24 hours by the aerobic bottles in 91% (40/44), by Sabouraud in 98% (43/44) (no significant difference) and by visual inspection in 66% of cases (29/44) (p<0.001 with the two others). Maximum times to detection were 46, 48 and 72 hours respectively.

CONCLUSION

This study further counters the preconception that fungal contamination is hard to detect in corneal organ culture media. This study is the last step in validating the use of a pair of blood bottles for the sterility testing of organ culture media, this time for fungi. Their use should make it possible to shorten microbiological quarantine and thus deliver corneas with higher endothelial cell density, without increasing the risk of recipient contamination.

Donor-to-host transmission of Candida albicans after corneal transplantation

PURPOSE

To report donor-to-host transmission of Candida albicans after penetrating keratoplasty.

DESIGN

Interventional case report.

METHODS

A 15-year-old boy who underwent penetrating keratoplasty for keratoconus with donor tissue from a drowning victim developed keratitis and a lenticular abscess 26 days postoperatively.

RESULTS

Candida albicans was cultured from the donor rim and the recipient cornea. Antifungal sensitivity profiles were identical for the two isolates. DNA profiles were identical for both isolates, confirming the donor as the source of the infection.

CONCLUSION

This case demonstrates the value of routine culture of corneal donor rims and the advisability of close follow-up and possible antifungal prophylaxis when donor rims are positive for fungus.

Candidal endophthalmitis after keratoplasty

PURPOSE

To report a case of explosive fungal endophthalmitis after penetrating keratoplasty and to review additional published and unpublished cases to consider possible strategies for prevention.

METHODS

Records of this patient with postkeratoplasty candidal endophthalmitis and previously reported cases of postkeratoplasty candidal endophthalmitis were reviewed. Additional information of 26 unpublished cases was obtained from the Eye Bank Association of America.

RESULTS

After standard keratoplasty, the patient developed precipitous endophthalmitis on the second postoperative day. Abundant contamination with Candida was found in the residual donor corneoscleral rim, and Candida albicans was isolated from the aqueous humor of the recipient. Despite therapy with local antimicrobial agents, intraocular amphotericin B, and systemic fluconazole, the patient had a poor outcome with hand-motion visual acuity. Of the 44 collected cases of postkeratoplasty candidal endophthalmitis, 40 (91%) had the same organism cultured from the donor rim or medium. Forty-three donor corneas had been preserved in cold storage medium at 4 degrees C. Of 15 cases in which the outcome was available, 9 (60%) resulted in visual acuity of 20/200 or worse.

CONCLUSION

Case reports confirm the occurrence of donor-to-host transmission of postkeratoplasty candidal endophthalmitis. Despite the low reported incidence, the poor prognosis of the affected eye in the ajority of these cases suggests the need for antifungal supplementation of cold preservation media and other preventative strategies.