Candidal endophthalmitis after keratoplasty

A Comprehensive Review of Donor Corneal Preservation Strategies

ABSTRACT

Successful corneal transplantation relies on the viability of the corneal endothelium. Although various preservation systems have been developed in the field of eye banking, long-term storage of the corneal endothelium poses challenges and is costly. Optisol-GS in the past has been the most commonly used solution for intermediate-term corneal storage in the United States. However, disruptions in the availability of Optisol-GS, caused by rising costs and supply shortages, have necessitated alternative methods of corneal preservation. Previously described preservation methods include hypothermia (2-8°C) for short-term storage (7-14 days), organ culture (28-37°C) for intermediate storage (4-7 weeks), and cryopreservation for longer-term storage. In this review, we examine standard practice and alternative methods for corneal storage.

Anti-fungal efficacy of combination of amphotericin B with colistin and gentamicin in McCarey-Kaufman corneal preservation medium

Purpose

To curtail the potential of donor corneal tissue disseminating fungi to the recipient's eye, we evaluated the addition of amphotericin B to McCarey-Kaufman (M-K)-corneal storage medium supplemented with colistin.

Methods

Amphotericin B was examined for its ability to inhibit the growth of Candida albicans and Aspergillus flavus using a microbroth dilution test and checkerboard assay in combination with only gentamicin and a combination of colistin, gentamicin, and amphotericin B. The safety on epithelium and endothelium was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Results

The minimal inhibitory concentration of gentamicin was found to be >256 μg/ml against both C. albicans and A. flavus, whereas that of amphotericin B was found to be in a range of 0.25-0.5 and 1-2 μg/ml for C. albicans and A. flavus, respectively. According to the checkerboard assay, 80% (4/5) of C. albicans isolates and 100% (5/5) of A. flavus isolates responded synergistically to the combination of amphotericin B and gentamicin, but only 20% (1/5) of C. albicans isolates showed an additive effect. None of the tested isolates displayed antagonism. The combined effect of the three drugs also did not display any antagonistic effect. Additionally, the MTT assay reveals no toxic effect of the antimicrobials used on corneal epithelial and endothelial cells.

Conclusion

In vitro experiments demonstrate that amphotericin B is not toxic to either epithelium or endothelium and is a promising additive to the M-K medium supplemented with colistin.

Toxicity of Amphotericin B in Rabbit Corneal Epithelial Cells Stored in Optisol™-GS: Corneal Epithelial Cell Morphology and Migration

PURPOSE

To evaluate the toxicity of Amphotericin B (AmB) in Optisol™-GS Corneal Storage Media (Bausch & Lomb) on corneal epithelial cell (CEC) morphology and migration ability.

METHODS

Sclerocorneal strips were removed from male Japanese white rabbits, and then stored at 4 °C in Optisol™-GS containing 0 µg/ml of AmB (control group) and 2.5, 5, 25, and 50 µg/ml of AmB (AmB groups; four eyes per group). After 7 days of storage, CEC morphology was evaluated by hematoxylin-eosin staining, immunohistochemical staining (ZO-1), and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Moreover, to evaluate CEC migration ability, three corneal blocks (6-8 × 3 mm each) from one preserved cornea were cultured for 24 h, and the area of CEC migration (2 mm at the central region) onto the stromal surface was then measured.

RESULTS

At 5, 25, and 50 µg/ml of AmB, deformation and vacuolation of CECs were observed in all preserved corneas. ZO-1 expression was significantly reduced in corneas preserved at AmB concentrations of 25 and 50 µg/ml. TUNEL Labeling Index was significantly increased at AmB concentrations of ≥5 µg/ml. CEC migration was inhibited in a dose-dependent manner at AmB concentrations of 25 and 50 µg/ml compared to the control group.

CONCLUSIONS

The addition of AmB to Optisol™-GS can be toxic to CECs and inhibit their migration at a concentration of ≥5 µg/ml. AmB at a concentration of 2.5 µg/ml can be considered safe for the preservation of donor corneal tissue used in corneal epithelial transplantation surgery.

Successful treatment of Candida albicans anterior chamber infection after penetrating keratoplasty

Purpose

To report the successful management of an anterior chamber (AC) infection after penetrating keratoplasty (PK) caused by Candida albicans.

Observation

A 53-year-old female had a PK in her right eye. The donor rim tested positive for Candida albicans one week later. Despite initiation of prophylactic topical 1% voriconazole drops, the patient presented with a white mass in the anterior chamber one month later. Biopsy confirmed Candida. Antifungal therapy was intensified with the addition of intravenous fluconazole, and with repeated irrigations of the AC and intracameral administration of amphotericin B (off-label use). After two weeks of apparent lack of treatment response, the infection suddenly quiesced. The final outcome was visual acuity of 0.2 and a clear graft with an endothelial cell density of 2260 cells/mm. 2.

Conclusions and Importance

Fungal intraocular infections after PK are usually devastating. Due to low intraocular penetration of topical antifungals, serial intracameral injections were used to maintain a therapeutic concentration of amphotericin B within the anterior chamber, and intravenous fluconazole was administered to protect against the spread of infection into the vitreous. A clinical response developed after two weeks. The reported case represents a favorable outcome using a multimodal approach.

Endophthalmitis secondary to donor to host infection in posterior lamellar keratoplasties: A systematic review

Donor to host transmission of infectious agents is a well-recognized entity, more commonly related to Endothelial Keratoplasty (EK) than to Penetrating Keratoplasty (PK), that involves complications ranging from interface keratitis to endophthalmitis. A systematic review of the literature was conducted to identify the published articles until December 2020 reporting cases of endophthalmitis secondary to corneal graft contamination in posterior lamellar keratoplasties (DSAEK and DMEK) along with donor characteristics, microbiological profile, treatment and outcomes. Each identified article was assessed to meet donor to host infection criteria, defined as a post-procedural infection in which the same microbiological agent was identified in both the donor corneoscleral rim or preservation medium and receptor ocular tissue. From 23 research articles, eight reports of endophthalmitis in nine patients following DSAEK or DMEK secondary to donor to host infection fulfilled the inclusion criteria. The majority were male and the median age was 72.0 (45.0-81.0) years old. Indications of surgery were primarily pseudophakic bullous keratopathy and Fuchs dystrophy. A fungal pathogen was identified in eight of nine patients. All the cases underwent surgical management with lenticule removal or endothelial plaque aspiration. The final corrected distance visual acuity (CDVA) in all cases was 20/200 or better. Endophthalmitis after an EK procedure is a rare complication whose outcome depends on the aggressive and precocious treatment. Identification of early signs of interface keratitis and lenticule removal seems mandatory in patients undergoing DSAEK or DMEK to prevent further involvement of the globe.

Genipin in an Ex Vivo Corneal Model of Bacterial and Fungal Keratitis

Purpose

To determine whether genipin (a natural crosslinker) could reduce the colonization and proliferation of bacteria and fungi in an ex vivo model of corneal infection.

Methods

This study, using an ex vivo model of bacterial and fungal keratitis, investigated the antimicrobial efficacy of genipin crosslinking. Excised corneoscleral buttons were wounded by scalpel incision and subsequently infected with Staphylococcus aureus, Pseudomonas aeruginosa, or Candida albicans. After inoculation, corneas were treated with genipin for 24 hours at 37°C. Histologic examinations were carried out, and the number of viable colony-forming units (CFU)/cornea was determined.

Results

Genipin exerts bactericidal action against S. aureus and P. aeruginosa, as well as fungicidal action against C. albicans and significantly reduced the CFU compared to contralateral eyes that received saline treatment (P < 0.05).

Conclusions

These data identify genipin as a novel ocular antimicrobial agent that has the potential to be incorporated into the therapeutic armamentarium against microbial keratitis.

Translational Relevance

This study provided evidence for the antimicrobial and antifungal properties of genipin as an alternative crosslinker that could be used in the management of infectious keratitis.

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.

Efficacy of Amphotericin B in Corneal Preservation Media After Extended Frozen Storage

PURPOSE

To investigate the antimycotic activity of amphotericin B deoxycholate that has been previously frozen for 28 days before supplementation of Optisol-GS.

METHODS

Triplicate Optisol-GS samples were inoculated with 10 colony-forming units (CFU) of Candida albicans. Each set of triplicate cultures was supplemented with 2.5 μg/mL of amphotericin B that was either freshly resuspended and never frozen, frozen overnight at -20°C and thawed, or frozen at -20°C for 4 weeks and thawed. The cultures were stored at 4°C, with aliquots taken at 0, 6, 24, and 72 hours for quantification. The efficacy of each preparation of amphotericin B in reducing C. albicans growth was assessed at these time points.

RESULTS

Six hours after antifungal supplementation, there was a 1.33 log10 CFU reduction with freshly resuspended amphotericin B, compared with a 1.31 log10 reduction with amphotericin B that was frozen overnight (P = 0.20) and a 1.18 log10 reduction with amphotericin B that was frozen for 4 weeks (P = 0.05). After 72 hours, there was a 2.72 log10 CFU reduction with freshly resuspended amphotericin B, a 2.64 log10 CFU reduction with amphotericin B that was frozen overnight (P = 0.45), and a 2.18 log10 CFU reduction with amphotericin B that was frozen for 4 weeks (P = 0.05).

CONCLUSIONS

Previously frozen amphotericin B remains highly effective against C. albicans. Optisol-GS supplemented with 2.5 μg/mL amphotericin B that was frozen for 4 weeks at -20°C resulted in >90% CFU reduction by 6 hours and >99% reduction by 72 hours.

Microbiological contamination in donor corneas preserved for medium-term

To evaluate the characteristics of microbiological contamination in donor corneas preserved for medium-term. A total of 82 donated corneas from June 1, 2014 to November 30, 2014 were retrospectively analyzed. The corneas were preserved in cornea chambers medium-term solution at 4-8 °C for keratoplasty. After removal of the central corneas for transplantation, the corneoscleral rims were put back into the medium for 1 month at room temperature (20-25 °C). The suspicious contaminated storage solutions indicated with transparency or color change were examined with bacteria and fungi cultivation for strain identification. The data collected included gender, age, procurement site and causes of death of donors, and follow-up of recipients. Statistical analysis was performed using Microsoft Excel and SPSS 24.0. Significance level was set at a P value < 0.05. The overall pathogen positive rate was 9.8% (n = 8), including 7 (87.5%) fungi and 1 (12.5%) bacteria. They were 2 (2.44%) Fusarium, 2 (2.44%) Chromomycosis, 1 (1.22%) Candida albicans, 1 (1.22%) Aspergillus versicolor, 1 (1.22%) Acremonium species, and 1 (1.22%) Enterococcus. 5 contaminated corneas were used for penetrating keratoplasty; although four out of five (80%) had not been given antifungal drugs during more than 6 months following-up period, none of the recipients was infected with a graft. Donor age (P = 0.839), gender (P = 0.062), procurement sites (P = 0.713) and cause of death (P = 0.711) had no statistically significant influence on the contamination rate. All donor corneas have a possibility of microbiological contamination. Strict tissue preservation protocol but not antifungal drugs following keratoplasty seems necessary to prevent graft infection.

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.

A presentation of culture-positive corneal donors and the effect on clinical outcomes

PURPOSE

Donor-to-host transmission of infectious agents is a rare but well-recognised complication of corneal transplantation and may carry a grave visual prognosis. In this case series, we describe the clinical features and risk factors of using culture-positive donor corneas for transplantation.

METHODS

Retrospective chart review of a series of patients who underwent either penetrating keratoplasty (PK) or Descemet's stripping automated endothelial keratoplasty (DSAEK) with positive microbiology cultivation during routine assessment of donor corneal tissue obtained at the time of surgery. Donor and recipient characteristics, tissue preparation and surgical parameters, clinical signs and outcomes were registered.

RESULTS

Eleven patients who received culture-positive corneal grafts were identified: six with Candida, three with Gram-positive bacteria and two with Gram-negative bacteria. Three patients developed clinical keratitis after routine DSAEK using corneas contaminated with Candida species. The median death-to-preservation time (DPT) of these three donor corneas was 18.08 (range 18.08 to 20.90) h, while in the remaining eight donors, it was 12.27 (range 9.32 to 20.47) h. Despite the initiation of antifungal treatment, all three cases required explantation of the graft and a subsequent re-DSAEK.

CONCLUSIONS

The use of donor corneas that are culture-positive for Candida carries a risk for developing postoperative keratitis and the risk may be higher in DSAEK. Unlike the cold storage technique employed for donor corneas described in this case series, organ culture technique requires microbiological screening and supplementation of an antifungal agent which may reduce the risk of donor-to-host transmission of fungal infection.

Candida albicans endophthalmitis following penetrating keratoplasty: A case report

Endophthalmitis is one of the most serious complications of intraocular surgeries, and Candida albicans constitutes the majority of cases of post penetrating keratoplasty (PK) endophthalmitis. The presenting case is a 21-year-old woman with known case of advanced keratoconus and vernal keratoconjunctivitis who underwent PK, and developed recalcitrant anterior uveitis and subsequent whitish lesion on the superonasal of the lens. She was on topical steroids with possible impression of Uretts Zavalia syndrome versus phacoantigenic uveitis following traumatic cataract up to the 50^th day of post operation that manifested symptoms of frank endophthalmitis; and underwent deep vitrectomy, lensectomy, localized iridectomy and irrigation with diluted Imipenem and Amphotericin-B. Microbiologic study of a vitreous sample revealed growth of Candida albicans, however optisol culture was negative and donor rim was not evaluated. One week later, intravitreal Amphotericin-B was administered. The patient remained aphakic with clear graft in the 6^th month follow up. Due to great correlation of positive donor rim culture with fungal endophthalmitis and the devastating effect of delayed diagnosis, routine donor rim culture is recommended, to aid us in earlier diagnosis in the presence of nonspecific early signs of fungal endophthalmitis.

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.

In Vitro Antimicrobial Long-Term Evaluation of Corneal Preservation Media Against Microorganisms Using A Closed-Chamber Study Model

PURPOSE

To evaluate the existence of in vitro long-term antimicrobial activity of Optisol-GS against microorganisms related to corneal infection using a closed-chamber study model.

METHODS

Optisol-GS was contaminated with microorganisms related to corneal infections, and different times after contamination was analyzed using a closed-chamber study model. Microbial growths were analyzed by macroscopic observation.

RESULTS

For Staphylococcus aureus and Pseudomonas aeruginosa, bacterial growth was observed in samples taken 1 hour through 7 days and 14 days after contamination occurred. For Staphylococcus epidermidis, Streptococcus agalactiae, and Candida albicans, microbial growth was observed in all samples studied. For Streptococcus pneumoniae, bacterial growth was observed in samples taken 1 hour through 72 hours after contamination. For Streptococcus pyogenes, bacterial growth was observed in samples taken 1 hour through 7 days after contamination. For Escherichia coli, bacterial growth was observed in samples taken 1 hour through 48 hours after contamination occurred.

CONCLUSIONS

We conclude that no in vitro antimicrobial effect for any microorganism analyzed was observed in contaminated Optisol-GS after 72 hours; however, effective antimicrobial activity was observed for S. aureus, Str. pneumoniae, Str. pyogenes, P. aeruginosa, and E. coli after 7 to 10 days.

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.

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.

Nosocomial acute-onset postoperative endophthalmitis at a university teaching hospital (2002-2009)

PURPOSE

To evaluate acute-onset postoperative endophthalmitis occurring at an academic medical center and to compare rates over the last 25 years at a single institution.

DESIGN

Retrospective, consecutive case series.

METHODS

Medical records were reviewed for all patients diagnosed with acute-onset postoperative nosocomial endophthalmitis from 2002 through 2009 associated with surgery at Bascom Palmer Eye Institute.

RESULTS

The 8-year frequency of acute-onset postoperative endophthalmitis was 0.025% (14 of 56 672 intraocular surgeries). The rate was 0.028% (8/28 568) for cataract surgery and 0.011% (2/18 492) for pars plana vitrectomy (PPV). Both PPV endophthalmitis cases followed 20-gauge surgery and no cases followed small-gauge, transconjunctival PPV (n = 2262). Three cases occurred following penetrating keratoplasty (3/2788, 0.108%). The most common bacterial isolate was Staphylococcus (n = 7, 50%). Initial treatment involved ocular paracentesis (n = 8, 57%) or vitrectomy (n = 5, 36%), in combination with injection of intraocular antibiotics (n = 14, 100%). Vancomycin and ceftazidime were used in 13 eyes (93%) and intraocular steroids were given initially to 9 eyes (64%). Final visual acuity was > or =20/200 in 9 eyes (64%) and 2 eyes (14%) were no light perception. At this institution since 1984, there has been a statistically significant trend for a decreasing rate of acute-onset postoperative endophthalmitis (1984-1994: 0.09%; 1995-2001: 0.05%; 2002-2009: 0.025%; P < .001).

CONCLUSION

At a university teaching hospital involving resident, fellow, and faculty surgeons, the frequency of acute-onset postoperative nosocomial endophthalmitis is low, has not increased in the era of sutureless clear corneal cataract surgery, and has steadily decreased when compared to prior time periods from the same institution.

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.

Donor-to-host transmission of Candida glabrata to both recipients of corneal transplants from the same donor

PURPOSE

To report 2 cases of exogenous Candida glabrata endophthalmitis after penetrating keratoplasty in recipients of corneas from the same donor transplanted on the same day.

METHODS

Case reports with ophthalmologic, electron microscopic, and microbiological findings including fungal strain analysis.

RESULTS

Two patients developed fungal keratitis and endophthalmitis caused by the same C. glabrata strain within 1 day after penetrating keratoplasty of corneas from the same donor on the same day. Donor-to-host transmission was postulated when eye bank sterility checks were repeatedly negative.

CONCLUSIONS

A short death-to-harvesting time, routine donor rim cultures, and respecting of a time interval before transplantation may provide an additional safety feature in dealing with corneal tissue from high-risk donors.

Candida albicans Interface Infection After Deep Anterior Lamellar Keratoplasty

PURPOSE

To report a case of interface infection by Candida albicans after deep anterior lamellar keratoplasty (DALK).

METHODS

A 30-year-old man with keratoconus underwent DALK. Four weeks after surgery, the patient developed multiple infiltrates in the graft-host interface with absence of intraocular infection. Donor rim cultures grew C. albicans. Penetrating keratoplasty (PK) was performed because of worsening of the infection despite topical, local, and systemic antifungal therapy.

RESULTS

Cultures carried out on the excised donor cornea confirmed donor-to-host transmission of C. albicans. An aqueous tap taken before PK was negative. Six months after PK, the corneal graft was clear with no recurrence of infection.

CONCLUSIONS

After DALK, in cases of donor graft microbial contamination, infection may develop at the graft-host interface. This may delay or prevent direct intraocular penetration of microorganisms, reducing the risk of development of endophthalmitis. PK may be needed to eradicate the infection in cases where conservative treatment fails.

Efficacy and safety of voriconazole as an additive in Optisol GS: a preservation medium for corneal donor tissue

PURPOSE

To assess the endothelial toxicity and the microbiological efficacy of voriconazole (100 microg/mL) as an antimicrobial additive to Optisol GS.

METHODS

A total of 533 donor rims were studied. One half of each donor rim was placed in standard Optisol GS and the other half rim in Optisol GS fortified with voriconazole (100 microg/mL). All rims were refrigerated for 24 hours at 3 degrees C and placed in thioglycolate broth and incubated at 37 degrees C for 7 days. A pair of donor buttons not used in transplantation was stored for 2 days in each solution and examined for endothelial changes with electron microscopy (EM). A second pair of cornea buttons was examined for toxicity by endothelial staining with 0.3% trypan blue and 0.2% alizarin red.

RESULTS

Seven of 533 corneal rim cultures were positive for fungal organisms in the Optisol GS group. No rims were positive for fungal growth in the voriconazole-fortified Optisol GS medium. The difference was statistically significant (P = 0.015; Fisher exact test). There was no difference in the cellular morphology of the button stored in voriconazole fortified Optisol GS compared with Optisol GS using EM. In the bioassay, the percentage of nonviable cells in the voriconazole-fortified medium compared with the control medium was nonsignificant (P < 0.05, Student t test).

CONCLUSIONS

Voriconazole seems to be safe as a fortifying agent for cornea storage medium. It significantly reduces the rate of positive fungal rim cultures and shows no signs of endothelial cytotoxicity as viewed by EM and by a bioassay of trypan blue and alizarin red.

The prognostic role of donor corneoscleral rim cultures in corneal transplantation

PURPOSE

To examine the discriminatory performance of donor corneoscleral rim cultures for predicting endophthalmitis after corneal transplantation.

DESIGN

Systematic literature review.

PARTICIPANTS

Studies that reported the prevalence of donor rim cultures after refrigerated preservation of donor corneas distributed for keratoplasty.

METHODS

Random-effects meta-analysis estimated pooled sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Meta-regression and stratification explored study-level reasons for diagnostic performance.

MAIN OUTCOME MEASURES

Incidence of postkeratoplasty endophthalmitis.

RESULTS

Of 17,614 corneal grafts, 2459 (14%) had a positive donor rim culture and 31 (0.2%) developed endophthalmitis. Twenty-one had concordant donor and recipient isolates, including 10 with Candida species. The sensitivity of donor rim cultures among 10 studies reporting postsurgical endophthalmitis was 67% (95% confidence interval [CI], 47%-83%), and specificity averaged 85%. Endophthalmitis occurred 12 (95% CI, 5-29) times more often among recipients of a culture-positive donor cornea. With Bayesian analysis, a culture-positive donor cornea would raise the infection risk to 1%, whereas fungal isolation from the donor rim predicts a 3% probability of fungal endophthalmitis. Pooling of studies was limited by a significant discrepancy among reports that could not be explained by differences in antibiotic supplementation of the preservation medium, method of culture inoculation, or type of culture medium.

CONCLUSION

Endophthalmitis after penetrating keratoplasty is more likely with a culture-positive donor rim, notably candidal endophthalmitis from fungal contaminants, but better evidence is needed to determine the prognostic value and manner of routine microbiological screening.

Human tissue oversight in hospitals: an AABB survey

BACKGROUND

Reports of human tissue allograft-transmitted infections have underscored the need for better accounting of allografts in health-care facilities. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) implemented new storage and issuance tissue standards for hospital oversight as of July 1, 2005. This study sought to survey hospital tissue responsibilities.

STUDY DESIGN AND METHODS

The AABB Tissue Task Force conducted a Web-based survey distributed to all 904 hospital institutional members in January 2005. The survey asked about tissue type used, breadth of responsibility, hospital department involvement, and views on AABB involvement. Data from 402 of 904 (45%) respondents were tabulated and analyzed.

RESULTS

Among the 402 respondents, 325 (81%) used allogeneic and/or autologous human tissue. The most frequently used tissues were musculoskeletal (n = 240, 74%) and skin (n = 169, 52%) allografts. The department of surgery (e.g., operating room; n = 245, 76%) most often had responsibility for tissue use, followed by the blood bank (i.e., transfusion service; n = 164, 51%); surgery most frequently had responsibility for all tissue types except peripheral blood progenitor cells. Only 32 of 402 (8%) respondents had plans for increased oversight in the next 12 months; 129 of 178 (72%) thought there was a role for AABB in developing guidance on hospital tissue responsibilities.

CONCLUSIONS

In this survey, most AABB member hospital respondents indicated facility use of allogeneic and/or autologous tissues. Although tissue allograft responsibility by surgery was extensive, hospital blood banks also had significant involvement. Few blood banks, however, plan increased oversight in the near future. Given JCAHO standards, blood banks have an opportunity to assist their hospital in planning for assigned tissue responsibilities and oversight to ensure patient safety.

Ecologic effects on eye banking

PURPOSE

To examine the climatic conditions at corneal donation for microbial categories of postkeratoplasty endophthalmitis that have been reported to a national surveillance registry.

DESIGN

Retrospective case-control study.

METHODS

Local weather information on the date of donor corneal procurement was tabulated for reported cases of endophthalmitis after penetrating keratoplasty and then compared between candidal endophthalmitis and postsurgical endophthalmitis that yielded bacteria or no microorganisms or that were not cultured.

RESULTS

Compared with other postkeratoplasty endophthalmitis, candidal endophthalmitis after corneal transplantation occurred significantly (P < .001) more often when outdoor afternoon temperatures exceeded 75 F at the source eye bank than on cooler days.

CONCLUSION

Higher exterior temperatures at donation may be associated with an increased relative risk of candidal transmission by keratoplasty, but a chain of causation that links the donor's environment to the recipient's infection remains to be elucidated.

Deep anterior lamellar keratoplasty for keratoconus

PURPOSE

To investigate surgical outcomes after deep anterior lamellar keratoplasty (DALKP) in eyes with keratoconus.

METHODS

Retrospective review of 127 eyes of 118 keratoconus patients who underwent DALKP at King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia between January 1, 1998 and November 30, 2001. The mean age of all patients was 25.9 years (range 11-70 years). The mean follow-up for all patients was 10.9 months (range 4-61 months). Baring of Descemet's membrane (DM) during DALKP was achieved in 47 (37%) eyes; some stroma was left during operation in the remaining 80 (63%) eyes. Snellen visual acuity, intraoperative complications, and postoperative graft status were assessed.

RESULTS

At the last follow-up visit, 74% of all eyes were able to achieve a best-corrected visual acuity of 20/50 or better. This level of improvement was more statistically significant with baring of DM (P = 0.005). Intraoperative perforation of DM occurred in 16 (13%) cases and was statistically significant in eyes with deep corneal scars (P = 0.012). However, this perforation did not seem to have an impact on the final visual acuity (P = 0.48). Main graft-related complications included graft-host vascularization (7/127), stromal graft rejection (4/127), graft infection (1/127), and persistent epithelial defect (1/127).

CONCLUSIONS

Deep lamellar keratoplasty provides a safer and successful alternative to penetrating keratoplasty for keratoconus patients but remains a challenging procedure. Endothelial graft rejection is absent after DALKP. However, stromal graft rejection, although very rare, does occur.

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.

Eye-banking risk factors for fungal endophthalmitis compared with bacterial endophthalmitis after corneal transplantation

PURPOSE

To track the relative frequency and explore possible risk factors of fungal compared with bacterial endophthalmitis after corneal transplantation.

DESIGN

Case-comparison study nested in a surveillance registry.

METHODS

We examined, among recipients who underwent surgery from January 1991 through December 2003, demographic and eye-banking characteristics of postkeratoplasty endophthalmitis cases that were reported to the Eye Bank Association of America by US eye banks. Potential predictors of fungal compared with bacterial endophthalmitis were examined using multiple logistic regression.

RESULTS

Of 234 reported cases of postkeratoplasty endophthalmitis reported by US eye bank, 46 cases (19.7%) were fungal, and 130 cases (55.6%) were bacterial. Concordant cultures of the residual donor corneoscleral rim or preservation medium occurred significantly more often with fungal than bacterial endophthalmitis (P = .009). After the introduction of Optisol-GS, the odds of bacterial relative to fungal endophthalmitis decreased by 77% (95% confidence interval, 44% - 91%). After adjustment for the preservation method and other eye-banking variables, the odds of fungal endophthalmitis was 3.4 (95% confidence interval, 1.6 - 7.4) times that of bacterial endophthalmitis, when donor corneal preservation was 4 days or longer.

CONCLUSIONS

The frequency of postkeratoplasty bacterial endophthalmitis compared with fungal endophthalmitis fell after widespread use of a corneal preservation medium supplemented with gentamicin and streptomycin. Further improvements in corneal preservation procedures are needed.

The Incidence of Fungal Keratitis and Endophthalmitis Following Penetrating Keratoplasty

PURPOSE

To determine the incidence of postkeratoplasty fungal endophthalmitis and keratitis at the New York Eye and Ear Infirmary. To determine whether there is a relationship between culture-positive corneoscleral donor material and postoperative infection.

METHODS

The microbiologic records of corneoscleral donor rims submitted for culture following penetrating keratoplasty at the New York Eye and Ear Infirmary between January 1998 and January 2003 were reviewed. The incidence of rim cultures positive for fungi was tabulated. Clinical outcome measures were recorded for each patient receiving corneal donor tissue.

RESULTS

Of 2466 donor corneoscleral rims cultured during the study period, 344 were positive for microbial growth (13%). Of those rims with positive cultures, 28 (8.6%) were positive for fungus. All fungi cultured were Candida species. Four of the 28 recipient eyes (14%) who received contaminated donor material went on to develop postkeratoplasty fungal infections. There were no cases of fungal infection in any postkeratoplasty patients in the absence of contaminated donor rims during the study period. Overall, there was a 0.16% incidence of fungal infection (4/2466) following penetrating keratoplasty. There were 18 positive donor rims identified in the first 4 years of the study, but there were 10 cases in the last 10 months of the study.

CONCLUSIONS

The overall incidence of fungal infection following penetrating keratoplasty is low, but all cases in our study were associated with positive rim cultures. Whether prophylactic antifungal therapy would be of any benefit in the presence of a positive corneoscleral rim culture has not yet been determined.