Infectious disease risk factors of corneal graft donors

Fungal Infection After Descemet Membrane Endothelial Keratoplasty: Incidence and Outcomes

PURPOSE

The aim of the study was to describe the incidence, presentation, management, and outcomes of fungal infection after Descemet membrane endothelial keratoplasty (DMEK).

METHODS

Retrospective case series of culture-proven fungal infections after DMEK reported in the literature, directly by surgeons, and to the Eye Bank Association of America from January 1, 2011, to December 31, 2020.

RESULTS

The domestic incidence of fungal infections, fungal keratitis, and fungal endophthalmitis after DMEK from 2011 to 2020 was 3.5, 1.3, and 2.2 per 10,000 cases, respectively, with no significant increasing trend. Thirty-four cases were identified, 14 (41.2%) published and 20 (58.8%) unpublished. Donor tissue fungal cultures were performed in 20 of the 34 (58.8%) cases and were positive in 19 of the 20 (95.0%), all but one Candida species. Recipient fungal cultures were performed in 29 of the 34 (85.3%) cases and were positive in 26 of the 29 (89.7%), all but one Candida species. Infection presented a mean of 33 ± 38 days (median 23, range 2-200, outlier 949) after transplantation: 25 (73.5%) with endophthalmitis and 9 (26.5%) with keratitis. Topical, intrastromal, intracameral, intravitreal, or systemic antifungal therapy was used in all 27 eyes with treatment data. Surgical intervention (DMEK explantation or partial removal, repeat endothelial keratoplasty, penetrating keratoplasty, and/or pars plana vitrectomy) was required in 21 of the 27 (77.8%) eyes. The corrected distance visual acuity at the last follow-up was ≥20/40 in 13 of the 27 (48.1%) eyes and counting fingers or worse in 6 of the 27 (22.2%) eyes.

CONCLUSIONS

Fungal infection is a rare but serious complication of DMEK that results in counting fingers or worse corrected distance visual acuity in nearly a quarter of eyes.

Comparison of Microbial Sampling Sites and Donor-Related Factors on Corneal Graft Contamination

Grafts used for corneal donation should be sterile to avoid transplantation failure and secondary infection. However, there are no clear and globally accepted specifications from eye banks on microbial sampling sites. The objective of this study was to analyze microbial contamination of corneal grafts collected from different sampling sites. We found that the contamination rates and strain compositions significantly differed at different sampling sites. To clarify the effect of the microbial sampling site on corneal graft contamination, microbial sampling was conducted using 30 corneal grafts at the extraocular and intraocular sides of the graft in 2020 from the National Eye Bank of Taiwan. Microbial contamination significantly differed (p < 0.05) between the different sampling sites on the graft according to McNemar’s test. Although the two sampling sites showed the same specificity (33.33%), the sensitivity of sampling on the extraocular side (82.35%) was higher than that on the intraocular side (17.65%) of the graft. Donor-associated factors, including the cause of death, operating place, and cold compression, were analyzed using chi-square statistics, which revealed no significant differences in microbial contamination. Thus, our data provide evidence for the microbial sampling site of donated grafts and clear specifications for maintaining the quality of corneal grafts.

The Cologne-Mecklenburg-Vorpommern DMEK Donor Study (COMEDOS) - design and review of the influence of donor characteristics on Descemet membrane endothelial keratoplasty (DMEK) outcome

Background

Posterior lamellar keratoplasty and especially Descemet membrane endothelial keratoplasty (DMEK) are gaining interest worldwide. Little is known about the influence of donor factors on DMEK outcome. Here we provide an overview of the existing peer-reviewed literature on this topic and present the design of the upcoming cooperation study COMEDOS (Cologne-Mecklenburg-Vorpommern DMEK Donor Study).

Methods

A literature search of PubMed and MEDLINE was conducted to retrieve articles published between September 2013 and May 2021. Seventeen peer-reviewed articles were selected. Design and concept of the prospective COMEDOS are outlined.

Results

Main interest parameters were the donor diabetes mellitus status, age, and lens status. There is a large heterogeneity regarding the sample size, study design, and investigated parameters. There seems to be a consensus that younger donors are associated with tighter rolls, a more difficult preparation, and unfolding setting. Diabetic donors seem to increase the risk of tissue tearing due to adherences and result more frequently in preparation failure. The COMEDOS aims not only to analyze the diabetes status of the donor, but also to correlate all donor systemic comorbidities and their ophthalmologic history to the DMEK clinical outcome. Furthermore, a correlation of Descemet membrane lamella preparation and surgery outcome is planned.

Conclusion

Currently, there is a lack of knowledge regarding the effect and impact of donor tissue characteristics on DMEK outcome and complications. An in-depth investigation is planned by the upcoming COMEDOS to close this knowledge gap.

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.

Three-Axis Tension-Measuring Vitreoretinal Forceps Using Strain Sensor for Corneal Surgery

Precise motion control is important in robotic surgery, especially corneal surgery. This paper develops a new tension-measurement system for forceps used in corneal surgery, wherein contact force is applied only to a specific location for precise control, with precise movements detected by attaching a nano-crack sensor to the corresponding part. The nano-crack sensor used here customizes the working range and sensor sensitivity to match the strain rate of the tip of the forceps. Therefore, the tension in the suture can be sufficiently measured even at suture failure. The printed circuit board attached to the bottom of the system is designed to simultaneously collect data from several sensors, visualizing the direction and magnitude of the tension in order to inform the surgeon of how much tension is being applied. This system was verified by performing pig-corneal suturing.

Use of Corneas From Septic Donors for Descemet Membrane Endothelial Keratoplasty

PURPOSE

To evaluate the suitability of corneas from septic donors for transplantation by analyzing the discard rate in the eye bank and the clinical outcome of Descemet membrane endothelial keratoplasty (DMEK) using organ-cultured corneal grafts from septic versus nonseptic donors.

METHODS

This retrospective study included 1554 corneas of which 456 corneas (29%) were from septic and 1072 corneas (69%) from nonseptic donors [for 26 corneas (2%) sepsis status was unknown]. The clinical outcome at 6 months after DMEK was evaluated for 82 grafts (26 from septic and 56 from nonseptic donors). Outcome measures were endothelial cell density, central corneal thickness, and postoperative complications.

RESULTS

Primary discard rates were higher for corneas from septic than from nonseptic donors (32.9% vs. 24.5%, P = 0.001). The main discard reason was poor endothelial cell quality for both septic (13.8%) and nonseptic (11.8%) donor corneas. Eye bank contamination rates for septic and nonseptic donor corneas were 1.1% and 1.7%, respectively (P = 0.102). After DMEK, donor endothelial cell density at 6m postoperatively was comparable between grafts from septic and nonseptic donors (1410 ± 422 cells/mm vs. 1590 ± 519 cells/mm, P = 0.140). No differences in 6m central corneal thickness and in the rebubbling rate were observed between the 2 groups (P = 0.780 and P = 0.396, respectively). None of the cases had graft rejection nor endophthalmitis in both groups.

CONCLUSIONS

Provided strict adherence to donor screening and evaluation protocols, the use of organ-cultured corneas from septic donors for DMEK does not seem to increase the risk for recipients and allows for expansion of the donor pool for corneal tissue.

Infectious keratitis after lamellar keratoplasty

Infectious keratitis after lamellar keratoplasty is a potentially devastating complication that may severely limit the visual and anatomical outcomes. The deep-seated location of the infiltrates, sequestration of the pathogenic microorganisms and limited penetration of the currently available antimicrobial agents often results in delayed diagnosis that may jeopardize the management in these cases. Fungal keratitis is more common as compared with bacterial or viral keratitis and classically presents as white interface infiltrates that may not be associated with significant inflammation. Confocal microscopy may help to establish a rapid diagnosis in such cases, and anterior segment optical coherence tomography may be used to determine the extent of infection and monitor its progression. Conservative measures such as topical antimicrobials and interface irrigation with antimicrobial agents may be done. Surgical intervention in the form of partial excision/removal of the graft in endothelial keratoplasty or a full-thickness keratoplasty is often required for the effective management of deep-seated infections. Timely diagnosis and intervention may result in complete resolution of infection in both anterior lamellar and endothelial keratoplasty. Infections after anterior lamellar keratoplasty have a fair prognosis, and a clear graft with functional visual acuity may be achieved in most cases. By contrast, infections after endothelial keratoplasty have a guarded prognosis, and the presence of concomitant endophthalmitis may further complicate the graft survival and visual outcomes.

The incidence and influence of the donor corneas positive for herpesviridae DNA in keratoplasty

Purpose

We detected the DNA of herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), varicella-zoster virus (VZV), cytomegalovirus (CMV), and Epstein-Barr virus (EBV) in donor corneas and assessed the clinical outcomes of recipients who received virus-positive grafts.

Method

All donor corneas were analyzed for the presence of HSV-1, HSV-2, VZV, CMV, and EBV by real-time PCR from April 2017 to July 2019. The medical records of the transplant patients who received virus-positive grafts were reviewed.

Result

Twenty-three (2.44%) donor cornea buttons tested positive for herpesviridae DNA. The positivity rates of HSV-1, CMV, VZV, and EBV were 0.74%, 0.85%, 0.64%, and 0.21%, respectively.

Conclusion

We suggest that the corneas from donors who had cancer, donors who were inpatients, and donors who had immunodeficiency or who were on immunosuppressive therapy should be tested for herpesviridae DNA before transplantation. Finally, HSV-1 can be transmitted from graft to recipient, but that CMV cannot be transmitted according to our observations. The donor corneas found to be HSV-1-positive have to be discarded and not used for keratoplasty.

Intensive care unit time and prolonged enucleation to processing interval are associated with donor cornea contamination

PURPOSE

To determine donor cornea contamination rate and to determine factors associated with cornea contamination. To assess the effect of hospitalization, intensive care unit (ICU) time, and antibiotic use on corneal contamination rate. To determine the spectrum of the contaminating microorganisms.

METHODS

The contamination rate of 212 corneas, obtained by enucleation from April 2014 to January 2015 in a single eye bank, was assessed retrospectively according to age, sex, cause of death, systemic antibiotic use, hospitalization time, ICU time, mechanical ventilation (MV), death to enucleation interval (DEI), enucleation to processing interval (EPI), and corneal epithelial exposure grading. The relative risk (RR) and adjusted RR with a 95% confidence interval were calculated using IBM-SPSS 20.0.

RESULTS

The contamination rate was 35.6% (n = 75). On multivariate analysis, ICU stay of 4 days or longer and enucleation to processing interval (EPI) greater than 7.4 h (RR 1.58, CI 0.96-2.60, P = 0.06) were associated with donor cornea contamination. Corneal contamination risk was highest from 4 to 6 days at the ICU (RR 3.40, CI 1.54-7.51, P < 0.01) and decreased after 7 days (RR 2.22, CI 1.00-4.93, P = 0.05). Coagulase-negative Staphylococcus was the most common isolated bacteria (69.6%). The frequency of gentamicin-resistant bacteria was higher among patients who stayed 4 days or longer at the ICU.

CONCLUSION

Patients staying at the intensive care unit 4 days or longer showed increased risk of corneal contamination. This is an important result to consider further indication for cornea donation.

Sutureless Femtosecond Laser-Assisted Anterior Lamellar Keratoplasty Using a Bioengineered Cornea as a Viable Alternative to Human Donor Transplantation for Superficial Corneal Opacities

PURPOSE

To evaluate the safety and efficacy of a bioengineered corneal implant using femtosecond laser-assisted anterior lamellar keratoplasty for superficial corneal opacities.

METHODS

Six eyes of 6 consecutive patients with superficial corneal stromal opacities involving <220 μm owing to various pathologies were included in the study. Preoperatively, all patients underwent anterior segment optical coherence tomography (Visante; Carl Zeiss Meditec AG) to evaluate the depth of the corneal opacity. All patients underwent sutureless femtosecond laser-assisted anterior lamellar keratoplasty using a bioengineered collagen corneal implant (linkcor). Visual indices, refraction, and keratometry were evaluated preoperatively and 12 months postoperatively.

RESULTS

Corrected distance visual acuity improved significantly in all patients (P = 0.02). A significant decrease was seen in refractive astigmatism postoperatively (P = 0.04). Flat keratometry reduced significantly 12 months after the intervention (P = 0.04). No intraoperative or early postoperative complications were noticed. All implants were fully covered by healthy epithelium within a month after the surgery and remained clear at follow-up visits. The results of this procedure remained stable throughout the follow-up period. In 1 patient, mild inferior collagen melting and epithelial defect formation occurred at 1-year follow-up. Despite frequent topical corticosteroid therapy the melting progressed, the collagen tissue was removed and the patient was treated accordingly with good visual outcomes.

CONCLUSIONS

Femtosecond laser-assisted anterior lamellar keratoplasty with bioengineered corneal (linkcor) implantation is an effective treatment for improving vision quality in anterior stromal opacities. This procedure reduces the need for human donor tissue and avoids human donor-related and suturing complications.

Donor characteristics and risk factors for methicillin-resistant Staphylococcus aureus contamination in storage medium for corneal transplantation: A 10-year retrospective study

PURPOSE

This study investigated the donor characteristics of methicillin-resistant Staphylococcus aureus (MRSA) contamination in storage medium before transfer of corneas to preservation medium for corneal transplantation, in order to identify donor characteristic risk factors for MRSA contamination.

METHODS

This retrospective, cross-sectional study was performed using Juntendo Eye Bank records for all corneal transplantation procedures. Storage medium (EP-II^® ) cultures for right eyes were included for the period between July 2008 and December 2017. The following donor characteristics were collected: age, sex, cause of death, history of cataract surgery, death-to-enucleation interval, death-to-preservation interval, and endothelial cell density (ECD). Donor characteristics were compared between MRSA and non-MRSA contamination groups. Odds ratios (ORs) for donor-related risk factors for MRSA contamination were determined using logistic regression.

RESULTS

In total, 370 storage medium samples were examined; 222 were positive for bacterial cultures (60.0%) and 36 were MRSA-positive (9.7%). Donor age was significantly higher in the MRSA contamination group than in the non-MRSA contamination group (86.1 ± 9.5 years vs 75.9 ± 15.9 years, P < 0.001). Univariate logistic regression analysis showed that MRSA contamination risk factors were older age (OR = 1.07; 95% confidence interval [95% CI]: 1.03-1.11) and decreased ECD (OR = 0.9993; 95% CI: 0.9986-0.9992). The fully adjusted OR for every year of age as a risk factor for MRSA contamination was 1.07 (95% CI: 1.03-1.11).

CONCLUSIONS

Aging was a risk factor for MRSA contamination in storage medium. Careful pre-banking assessment of elderly donor corneas is needed to prevent intractable postoperative MRSA infection.

Interferon-stimulated gene 15 (ISG15) restricts Zika virus replication in primary human corneal epithelial cells

PURPOSE

Zika virus (ZIKV) has emerged as an important human pathogen causing ocular complications. There have been reports of the shedding of ZIKV in human as well as animal tears. In this study, we investigated the infectivity of ZIKV in corneal epithelial cells and their antiviral immune response.

METHODS

Primary human corneal epithelial cells (Pr. HCECs) and an immortalized cell line (HUCL) were infected with two different strains of ZIKV (PRVABC59 & BeH823339) or dengue virus (DENV, serotypes 1-4). Viral infectivity was assessed by immunostaining of viral antigen and plaque assay. qRT-PCR and immunoblot analyses were used to assess the expression of innate inflammatory and antiviral genes. Supplementation of recombinant ISG15 (rISG15) and gene silencing approaches were used to elucidate the role of ISG15 in corneal antiviral defense.

RESULTS

Pr. HCECs, but not the HUCL cells, were permissive to both ZIKV strains and specifically to DENV3 infection. ZIKV induced the expression of viral recognition receptors (TLR3, RIG-I, &MDA5), and genes involved in inflammatory (CXCL10 & CCL5) and antiviral (IFNs, MX1, OAS2, ISG15) responses in Pr. HCECs. Furthermore, ZIKV infection caused Pr. HCECs cell death, as evidenced by TUNEL staining. Silencing of ISG15 increased ZIKV infectivity while supplementation with rISG15 reduced ZIKV infection by direct inactivation of ZIKV and inhibiting its entry.

CONCLUSIONS

Our study demonstrates for the first time, that ZIKV can readily infect and replicate in Pr. HCECs. Therefore, ZIKV may persist in the cornea and pose the potential risk of transmission via corneal transplantation.

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.

Prevalence of bacteria and fungi in samples of cornea preservation fluid

INTRODUCTION

Recipients of corneal transplants are at risk of healthcare-associated infections, which, apart from other causes of surgical site infections, may also occur as a result of the transfer of infected corneal tissue. In this study we assessed the risk of bacterial and fungal infections based on the results of routine microbiological testing of cornea preservation fluid samples.

MATERIAL AND METHODS

We examined a total of 725 samples of corneal preservation fluid, obtained during a period of 3 years (2011-2013). Corneal preservation fluid samples were cultured and identified in accordance with standard microbiological methods.

RESULTS

The analysis comprised 725 samples of corneal preservation fluid, of which 32 (4.4%) samples tested positively in microbiological cultures. In total, 34 strains of bacteria and fungi were cultured. Gram-positive bacteria, Gram-negative bacteria and fungi comprised 85.3%, 8.8% and 5.9% of these strains, respectively. Analysis of the susceptibility of the cultured bacterial isolates to gentamicin was also performed, as this antibiotic is present in the composition of corneal preservation fluid. Among the cultured bacterial strains, 10 (33.3%) were resistant to gentamicin. None of the 32 patients who received a cornea stored in preservation fluid contaminated with bacteria and/or fungi demonstrated infectious complications in the surgical site within 1 year following cornea transplantation.

CONCLUSIONS

We postulate that perioperative antibiotic prophylaxis in cornea transplant recipients is important in preventing bacterial infections derived from the donor cornea. We believe that the addition of an antifungal agent to commercially available cornea preservation fluids should also be considered.

Post-keratoplasty Endophthalmitis by Multidrug-resistant Pseudomonas Aeruginosa With Positive Culture of the Contralateral Donor Cornea: A Case Report

PURPOSE

The aim of this paper is to present the case report of a patient developing endophthalmitis after penetrating keratoplasty caused by a multidrug-resistant Pseudomonas aeruginosa, detected only in the contralateral donor tissue.

CASE REPORT

A 77-year-old man underwent an uneventful penetrating keratoplasty with a preoperative culture-negative donor cornea; however, the fellow cornea grew multidrug-resistant Pseudomonas aeruginosa. The patient developed and was treated for endophthalmitis after penetrating keratoplasty, and aqueous and vitreous taps grew P. aeruginosa with antibiotic resistance identical to the isolate from the mate cornea. Sequence analysis of the 16S ribosomal gene from the two isolates and confirmation analyzing the sequence of P. aeruginosa heat shock protein gene (groES) were performed showing the same strain for both organisms.

CONCLUSION

This case report documents the presence of the same multidrug-resistant P. aeruginosa causing endophthalmitis after penetrating keratoplasty and in the contralateral donor tissue, suggesting that we must be cautious in deciding to transplant tissues with positive culture in the contralateral donor cornea.

The influence of donor factors on corneal organ culture contamination

PURPOSE

To evaluate the contamination rate and the corresponding spectrum of microbes and to identify donor risk factors for corneal organ culture contaminations.

METHODS

A total of 3306 organ-cultured donor corneas were included in the study. We performed a retrospective database analysis to evaluate donor factors such as gender, age, death-to-explantation interval (DEI), procurement site and cause of death and to determine their influence on donor cornea contaminations. Odds ratios (ORs) were calculated for each factor.

RESULTS

The overall contamination rate was 7.8% (n = 259). Younger donor age (OR: 2.2, p = 0.003, chi-squared test), a DEI of more than 24 hr (OR: 1.6, p < 0.001), hospitalization prior to death (OR: 2.2, p < 0.001) and death caused by sepsis (OR: 2.7, p < 0.001) were associated with an increased risk of contamination, whereas donor gender did not have an effect on donor cornea contaminations. The most frequently isolated microbes were Enterococci (19%), Staphylococci (10.8%) and Candida (37.4%).

CONCLUSION

This study helps to estimate the contamination risk of a cultured cornea based on specific donor factors. However, donors with risk factors should not be generally excluded from cornea donation. Further studies including antibiograms might clarify whether a change in the antibiotic composition of the culture medium would be useful to deal with the increasing number of multi-resistant microbes.

Pre-banking microbial contamination of donor conjunctiva and storage medium for penetrating keratoplasty

PURPOSE

The aims of this study were to investigate the incidence of positive donor tissue cultures before transfer to preservation medium (Optisol™-GS) for penetrating keratoplasty, to verify the efficacy of antibiotics contained in Optisol™-GS by examining the drug susceptibility and to assess the relationship between the results of our microbial assessments as well as donor factors and the incidence of contamination.

METHODS

We conducted a retrospective, cross-sectional study using Juntendo Eye Bank records for all corneal transplantations. Two hundred donor conjunctiva harvestings and storage medium (EP-II^®) cultures were performed between July 2008 and June 2011. We analyzed the associations between donor factors (age, gender, history of cataract surgery, death-to-preservation interval, cause of death) and contamination rates using multivariate analysis by the generalized estimating equation model.

RESULTS

We obtained positive bacterial cultures from 154 of the 200 eyes (77.0%). The isolated bacteria were indigenous, such as coagulase-negative Staphylococci, Corynebacterium sp., and methicillin-resistant Staphylococcus aureus (MRSA). There was significant resistance to levofloxacin (18 eyes, 9.0%) and gentamicin (12 eyes, 6.0%), and no vancomycin-resistant bacteria were detected. The donor factors did not correlate with the prevalence of bacterial contamination in our criteria.

CONCLUSIONS

Pre-banking microbial assessment allows for microbial detection, bacterial susceptibility and resistance testing. This is useful for developing preservation mediums containing effective spectrum antibiotic agents for high quality control of corneal banking.

Report of the Eye Bank Association of America Medical Review Subcommittee on Adverse Reactions Reported From 2007 to 2014

PURPOSE

To investigate the incidence of adverse reactions after corneal transplantation, reported to the Eye Bank Association of America.

METHODS

Incidence of adverse reactions from January 1, 2007, to December 31, 2014, was analyzed.

RESULTS

Of the 354,930 transplants performed in the United States, adverse reactions were reported in 494 cases (0.139%). Primary graft failure (PGF) predominated (n = 319; 0.09%) followed by endophthalmitis (n = 99; 0.028%) and keratitis (n = 66; 0.019%). The procedure type predominantly associated with PGF was endothelial keratoplasty (EK) in 56% (n = 180; 11 per 10,000 grafts), followed by penetrating keratoplasty (PK) in 42% (n = 135; 6.9 per 10,000 grafts). The procedure type predominantly associated with endophthalmitis and keratitis was EK in 63% (n = 104; 6.3 per 10,000 grafts) followed by PK in 34% (n = 56; 2.8 per 10,000 grafts), anterior lamellar keratoplasty in 1% (n = 2; 2.7 per 10,000 grafts), and keratoprosthesis in 1% (n = 2; 12.4 per 10,000 grafts). Although the incidence of PGF and endophthalmitis between PK and EK was noteworthy, the difference was not statistically significant (P = 0.098). Endophthalmitis-associated pathogens were isolated in 78% of cases: predominantly Candida species (65%), gram-positive organisms (33%), and gram-negative rods (2%). Keratitis-associated pathogens were isolated in 64% of cases: predominantly Candida species (81%), Herpes simplex virus (7%), gram-negative organisms (7%), and gram-positive organisms (5%).

CONCLUSIONS

PGF was the most commonly reported adverse reaction, disproportionately associated with EK. An increasingtrend in the rate of endophthalmitis and keratitis was observed, disproportionately associated with EK and Candida species.

Collagen membranes crosslinked by β-cyclodextrin polyrotaxane monoaldehyde with good biocompatibilities and repair capabilities for cornea repair

Better mechanical properties; suturability; corneal regeneration.

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.

Occurrence of viral DNA in paired samples of corneal rim and cornea preservation fluid

Corneal transplants have one of the highest success rates among all transplantological procedures. Corneas intended for transplantation are stored in a preservation fluid, which is then tested for bacterial and fungal infections. Among all analyses of infectious complications following corneal transplants, infections caused by bacteria or fungi are the most prominent. Surprisingly, however, apart from a few publications, there is a lack of data regarding the occurrence of viruses in donor corneas and the risk of transmitting these to their recipients. The intention of this research was therefore to determine the frequency with which human herpesvirus 1 (HHV-1), human herpesvirus 2 (HHV-2), and human adenovirus (HAdV) occur in transplanted corneal tissue, as well as in samples of preservation fluid. The study comprised 57 paired samples, with each pair consisting of a fragment of the corneal tissue remaining after its trepanation for transplantation surgery and a sample of corneal preservation fluid. Sample pairs were all tested for the presence of the DNA of three viruses (HHV-1, HHV-2, and HAdV) using real time PCR technique. Viral DNA was found in three of the tested corneas-HHV-1 DNA in one paired sample (1.8%) and adenovirus DNA in two single samples (3.5%). We postulate that virological testing of corneas for transplantation should be considered, particularly in the case of donors with increased risk factors for herpesvirus and adenovirus reactivation. J. Med. Virol. 89:732-736, 2017. © 2016 Wiley Periodicals, Inc.

Current Perspectives of Prophylaxis and Management of Acute Infective Endophthalmitis

Endophthalmitis is an intraocular inflammatory condition which may or may not be caused by infective agents. Noninfectious (sterile) endophthalmitis may be attributable to various causes including postoperative retained soft lens matter or toxicity following introduction of other agents into the eye. Infectious endophthalmitis is further subdivided into endogenous and exogenous. In endogenous endophthalmitis there is hematogenous spread of organisms from a distant source of infection whereas in exogenous endophthalmitis direct microbial inoculation may occur usually following ocular surgery or penetrating eye injury with or without intraocular foreign bodies. Acute infective endophthalmitis is usually exogenous induced by inoculation of pathogens following ocular surgery, open-globe injury and intravitreal injections. More infrequently the infective source is internal and septicemia spreads to the eye resulting in endogenous endophthalmitis. Several risk factors have been implicated including immunosuppression, ocular surface abnormalities, poor surgical wound construction, complicated cataract surgery with vitreous loss and certain types of intraocular lens. Comprehensive guidelines and recommendations on prophylaxis and monitoring of surgical cases have been proposed to minimize the risk of acute endophthalmitis. Early diagnosis and prompt management of infective endophthalmitis employing appropriately selected intravitreal antibiotics are essential to optimize visual outcome.

Iranian homograft tissue processing

Tissue transplantation is a life-enhancing therapeutic modality for damaged or non-functioning tissues. In most cases, there is no alternative other than human tissue as replacement, and taking into account the ever-increasing demand for tissue grafts, it makes sense to set up an establishment in charge of human tissue procurement to meet local needs. A quality assurance system, clearly defined standards, and regular audits complement the infrastructure which make this activity feasible. The process of tissue procurement consists of donor identification, consent, tissue recovery, donor screening and testing, tissue processing, preservation, packaging, labeling, terminal sterilization, storage and distribution. The transplantation of homograft heart valves remains controversial, due to the availability of prosthetic and bioprosthetic alternatives. The limited durability of homografts has not yet outweighed the advantages which this graft offers. Adherence to regulations and regularly revised guidelines improve long-term efficacy and minimizes complications or malfunction. Furthermore, the lower price of homograft heart valves and the removal of the need for a lifetime of anticoagulation therapy are noteworthy advantages of this replacement. In our practice, the proportion of homograft heart valves meeting release criteria and successfully implanted grafts were 83% and 95%, respectively.

Endophthalmitis after penetrating keratoplasty

PURPOSE

To determine the incidence of endophthalmitis after penetrating keratoplasty (PK) and patient and donor risk factors.

DESIGN

Retrospective cohort study using national transplant registry data.

PARTICIPANTS

All corneal transplant recipients (n = 11 320) registered on the United Kingdom Transplant Registry undergoing their first PK between April 1999 and December 2006.

METHODS

Patients who developed endophthalmitis were identified on the transplant registry. In addition, cases where the fellow cornea from the same donor had been transplanted were included. Clinical information regarding donor and recipient characteristics, surgical details, and postoperative outcomes were collected and analyzed. In cases where endophthalmitis was reported, the diagnosis was verified by a follow-up supplementary questionnaire to the surgeon. Logistic regression was used to investigate differences in the factors associated with the development of endophthalmitis.

MAIN OUTCOME MEASURES

Incidence of endophthalmitis and graft survival.

RESULTS

The overall incidence of endophthalmitis occurring after primary PK in the UK was 0.67%. The incidence of endophthalmitis occurring within 6 weeks of surgery was 0.16%. Graft survival after endophthalmitis was 27% (95% confidence interval, 16-38) at 5 years, with a mean best-corrected visual acuity of 1.13 (logarithm of the minimum angle of resolution) for surviving grafts. Factors associated with endophthalmitis were donor cause of death (infection), high-risk cases, and indication for corneal transplantation.

CONCLUSION

Endophthalmitis remains a serious issue, with those affected having reduced graft survival and poor visual outcomes. Management of the identified recipient and donor risk factors are important to reduce endophthalmitis risk. In particular, the increased incidence of endophthalmitis when the donor dies of infection requires further explanation and review of current donor eye retrieval and eye bank practices. The delayed presentation of endophthalmitis cases also raises questions regarding possible sequestration of microbes within the corneal tissue and the effect of antimicrobials in storage media.

Activation of Master Autophagy Regulator TFEB During Systemic LPS Administration in the Cornea

The involvement of autophagy in the cornea during the systemic inflammatory response elicited by intravenous administration of lipopolysaccharide (LPS) was investigated. Eight-week-old male Sprague-Dawley rats were injected i.v. with 15 mg/kg body weight LPS. RC4 rabbit corneal keratocytes were also used and treated with 100 ng/mL of tumor necrosis factor α (TNFα) and/or cycloheximide (CHX). The nuclear translocation of transcription factor EB (TFEB), the master transcriptional regulator for autophagy, was observed after LPS administration in the corneal epithelium. Induction of autophagy-related proteins was observed in the cornea after LPS administration, as well as in RC4 cells after treatment with TNFα. Administration of trehalose, an inducer of TFEB, mitigated RC4 cell death caused by TNFα/CHX. These results demonstrate the importance of TFEB activation in cellular defense against the systemic inflammatory response in the cornea.

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.

Endophthalmitis following keratoplasty: incidence, microbial profile, visual and structural outcomes

PURPOSE

To identify the causative organisms of post-keratoplasty endophthalmitis and to report its visual and structural outcomes.

METHODS

A chart review was performed of all patients diagnosed with endophthalmitis after keratoplasty at a tertiary hospital between January 1990 and January 2007.

RESULTS

Endophthalmitis developed in 55 cases in the penetrating keratoplasty group and in no cases in the lamellar keratoplasty group. The majority of isolated microbes were gram-positive (86.3%). Only 1 eye retained a clear graft with 20/25 vision; other cases had ≤20/200 vision. Four of 13 eyes that underwent vitrectomy and 28 of 42 that did not undergo vitrectomy ended up with no light perception. One eye that underwent vitrectomy and 21 eyes that did not undergo vitrectomy were eviscerated.

CONCLUSIONS

Post-keratoplasty endophthalmitis was associated with poor visual and structural outcome. Gram-positive organisms were the most common cause of infection. Early vitrectomy may reduce functional and structural damage associated with endophthalmitis.

Assessment of tissue allograft safety monitoring with administrative healthcare databases: a pilot project using Medicare data

Assess whether Medicare data are useful for monitoring tissue allograft safety and utilization. We used health care claims (billing) data from 2007 for 35 million fee-for-service Medicare beneficiaries, a predominantly elderly population. Using search terms for transplant-related procedures, we generated lists of ICD-9-CM and CPT(®) codes and assessed the frequency of selected allograft procedures. Step 1 used inpatient data and ICD-9-CM procedure codes. Step 2 added non-institutional provider (e.g., physician) claims, outpatient institutional claims, and CPT codes. We assembled preliminary lists of diagnosis codes for infections after selected allograft procedures. Many ICD-9-CM codes were ambiguous as to whether the procedure involved an allograft. Among 1.3 million persons with a procedure ascertained using the list of ICD-9-CM codes, only 1,886 claims clearly involved an allograft. CPT codes enabled better ascertainment of some allograft procedures (over 17,000 persons had corneal transplants and over 2,700 had allograft skin transplants). For spinal fusion procedures, CPT codes improved specificity for allografts; of nearly 100,000 patients with ICD-9-CM codes for spinal fusions, more than 34,000 had CPT codes indicating allograft use. Monitoring infrequent events (infections) after infrequent exposures (tissue allografts) requires large study populations. A strength of the large Medicare databases is the substantial number of certain allograft procedures. Limitations include lack of clinical detail and donor information. Medicare data can potentially augment passive reporting systems and may be useful for monitoring tissue allograft safety and utilization where codes clearly identify allograft use and coding algorithms can effectively screen for infections.

Aspergillus flavus keratitis after deep anterior lamellar keratoplasty

PURPOSE

To report the clinical, microbiologic, confocal scan and histopathologic features of Aspergillus flavus keratitis which developed immediately after deep anterior lamellar keratoplasty (DALK).

CASE REPORT

A 28-year-old woman underwent DALK using the big-bubble technique for keratoconus. The operation was uneventful, yielding a bare Descemet's membrane (DM) followed by transplantation of a corneal graft devoid of DM and endothelium. Four days after keratoplasty, mild infiltrates were noticed in the inferonasal margin of the graft, which rapidly progressed to involve the adjacent recipient cornea. Confocal scan findings suggested filamentous fungal keratitis, leading to initiation of topical and systemic antifungal medications followed by immediate replacement of the graft. Histopathologic examination disclosed keratitis caused by a filamentous fungus, which was determined by microbiologic cultures to be Aspergillus flavus. Early diagnosis and appropriate management resulted in complete recovery from this potentially devastating infection.

CONCLUSION

Aspergillus Flavus can cause graft ulcers immediately after DALK. Confocal scan proved to be a valuable tool for early diagnosis and prompt intervention to control this otherwise devastating infection.

Endophthalmitis: A review of recent trends

Endophthalmitis is a feared complication of trauma, surgical procedures and septicemia. Although uncommon, its potential for significant visual loss is well recognized. Especially over the past decade, complicated surgeries and medical techniques have increased and seriously ill patients are being sustained in ever increasing numbers. New pathogens are being recognized and known ones reclassified thanks to advances in molecular analysis. Continuously evolving PCR methodologies also add a new dimension to the diagnosis of infectious endophthalmitis. As well, medical literature is now truly international, encompassing studies from around the world that expand our understanding of ocular infectious disease. This report reviews some of these changes as they relate to endophthalmitis and particularly to the spectrum of organisms involved.

The safety and efficacy of linezolid and daptomycin as an additive in Optisol-GS against methicillin-resistant Staphylococcus aureus

PURPOSE

To evaluate the efficacy of adding either linezolid or daptomycin to Optisol-GS donor storage medium in reducing methicillin-resistant Staphylococcus aureus (MRSA) contamination of donor corneas.

METHODS

Optisol-GS was supplemented with either linezolid at 2×, 4×, or 10× minimum inhibitory concentration (MIC) or daptomycin and calcium at 5× or 50× MIC. Unsupplemented control groups were also used. Gentamicin-sensitive and gentamicin-resistant isolates of MRSA were added, and vials were refrigerated for 48 hours followed by sampling for viable colony counts immediately upon removal from refrigeration and after warming to room temperature for 3 hours. Safety studies of Optisol-GS supplemented with 50× MIC daptomycin and calcium were performed by evaluating the central corneal thickness and endothelial cell density of the donor cornea. Stability of daptomycin in Optisol-GS at storage was also tested.

RESULTS

No added benefit was observed with linezolid supplementation to Optisol-GS against gentamicin-sensitive MRSA, with reduction in viable colony counts by >90% in all groups. No benefit was observed with linezolid supplementation against gentamicin-resistant MRSA, with the majority of inocula remaining viable in all groups. Viable counts of gentamicin-sensitive MRSA and gentamicin-resistant MRSA were effectively reduced with both 5× MIC and 50× MIC daptomycin supplementation. 50× MIC daptomycin-supplemented Optisol-GS had no appreciable effect on the central corneal thickness or endothelial cell density of the donor cornea and was stable at storage for 14 days.

CONCLUSIONS

The addition of daptomycin to Optisol-GS significantly increases the anti-MRSA activity of the medium without any apparent negative effects on donor corneal tissue.

A zygomycetes-contaminated corneal graft harvested from a donor with signs of orbital trauma

PURPOSE

To report the clinical features and histopathology of a transplanted cornea that was immediately replaced because of the possible diagnosis of lattice corneal dystrophy in the graft in which histopathologic examination revealed a Zygomycetes infection.

METHODS

A 19-year-old patient with keratoconus underwent deep anterior lamellar keratoplasty (DALK) in the right eye. The operation was uneventful, transplanting a corneal graft without Descemet membrane, harvested from a donor with signs of orbital trauma.

RESULTS

Three days after keratoplasty, multiple refractile lines involving the entire donor stroma were observed. With the potential diagnosis of lattice dystrophy of the donor cornea, the graft was replaced and sent for histopathologic analysis, which revealed a Zygomycetes graft infection.

CONCLUSIONS

This case report introduces Zygomycetes as a cause of donor-to-host infection and also suggests that corneas harvested from donors with signs of orbital trauma may be a risk factor for donor-to-recipient transmission of such fungal infections.

Pseudomonas aeruginosa endophthalmitis after penetrating keratoplasty transmitted from the same donor to two recipients confirmed by pulsed-field gel electrophoresis

Two devastating cases of multidrug-resistant Pseudomonas aeruginosa endophthalmitis after keratoplasty as the result of transmission from the same donor were confirmed by pulsed-field gel electrophoresis. Strategies for preventing donor-to-host transmission, such as the use of antimicrobial agents of greater efficacy and better methods for detecting microorganisms in preservation medium, could minimize this type of transmission.

Conjunctival swabs and corneoscleral rim cultures from corneal transplantation donors as possible early indicators for posttransplant endopthalmitis

PURPOSE

To determine by microbiological examinations the rate of conjunctiva and corneoscleral rim contamination of cadaver donor tissues.

METHODS

A prospective review of culture results for 98 cadaver donor conjunctival swabs [mean age 76.4 ± 12.9 years (±SD)]. Transplant patients were evaluated both before and after disinfection with gentamicin. Individual parameters evaluated included detection rates of bacteria, variety of detected bacteria, time interval from donor death to tissue harvest and age of donors.

RESULTS

Before disinfection, 60 out of 98 conjunctival swabs exhibited microbial growth, while only 36 out of 98 exhibited growth after disinfection (p = 0.0006). Longer intervals between death and tissue harvest were associated with higher positive microbial growth rates. Prior to disinfection, culture-positive donors (74.1 ± 13.6 years) were significantly younger than culture-negative donors (79.8 ± 10.8 years) (p = 0.024). Positive donor rim cultures were noted in 2 out of the 22 corneal transplantations. Microorganisms isolated from the corneal grafts matched those found in the conjunctiva.

CONCLUSIONS

It is recommended that the corneoscleral buttons be removed as soon as possible. Cultures of conjunctival swabs collected from donors after disinfection may be useful in determining treatment for postoperative infections occurring after corneal transplantation.

A biosynthetic alternative to human donor tissue for inducing corneal regeneration: 24-month follow-up of a phase 1 clinical study

Corneas from human donors are used to replace damaged tissue and treat corneal blindness, but there is a severe worldwide shortage of donor corneas. We conducted a phase 1 clinical study in which biosynthetic mimics of corneal extracellular matrix were implanted to replace the pathologic anterior cornea of 10 patients who had significant vision loss, with the aim of facilitating endogenous tissue regeneration without the use of human donor tissue. The biosynthetic implants remained stably integrated and avascular for 24 months after surgery, without the need for long-term use of the steroid immunosuppression that is required for traditional allotransplantation. Corneal reepithelialization occurred in all patients, although a delay in epithelial closure as a result of the overlying retaining sutures led to early, localized implant thinning and fibrosis in some patients. The tear film was restored, and stromal cells were recruited into the implant in all patients. Nerve regeneration was also observed and touch sensitivity was restored, both to an equal or to a greater degree than is seen with human donor tissue. Vision at 24 months improved from preoperative values in six patients. With further optimization, biosynthetic corneal implants could offer a safe and effective alternative to the implantation of human tissue to help address the current donor cornea shortage.

Coding and traceability for cells, tissues and organs for transplantation

Modern transplantation of cells, tissues and organs has been practiced within the last century achieving both life saving and enhancing results. Associated risks have been recognized including infectious disease transmission, malignancy, immune mediated disease and graft failure. This has resulted in establishment of government regulation, professional standard setting and establishment of vigilance and surveillance systems for early detection and prevention and to improve patient safety. The increased transportation of grafts across national boundaries has made traceability difficult and sometimes impossible. Experience during the first Gulf War with mis-identification of blood units coming from multiple countries without standardized coding and labeling has led international organizations to develop standardized nomenclature and coding for blood. Following this example, cell therapy and tissue transplant practitioners have also moved to standardization of coding systems. Establishment of an international coding system has progressed rapidly and implementation for blood has demonstrated multiple advantages. WHO has held two global consultations on human cells and tissues for transplantation, which recognized the global circulation of cells and tissues and growing commercialization and the need for means of coding to identify tissues and cells used in transplantation, are essential for full traceability. There is currently a wide diversity in the identification and coding of tissue and cell products. For tissues, with a few exceptions, product terminology has not been standardized even at the national level. Progress has been made in blood and cell therapies with a slow and steady trend towards implementation of the international code ISBT 128. Across all fields, there are now 3,700 licensed facilities in 66 countries. Efforts are necessary to encourage the introduction of a standardized international coding system for donation identification numbers, such as ISBT 128, for all donated biologic products.

Development of a transplantation transmission sentinel network to improve safety and traceability of organ and tissues

The US lags behind other developed countries in creating a system to monitor disease transmission and other complications from human allograft use, despite a pressing need. The risks of transmission are amplified in transplantation, since at least 8 organs and more than 100 tissues can be recovered from a single common organ and tissue donor. Moreover, since many allografts collected in the US are distributed internationally, tissue safety is a global concern. In June 2005, participants of a US government-sponsored workshop concluded that a communication network for the tracking and reporting of disease transmissions for tissues and organs was critically needed. The United Network for Organ Sharing (UNOS) entered into a cooperative agreement with the Centers for Disease Control and Prevention (CDC) in 2006 to develop a system prototype. Over the following 3 years, the Transplantation Transmission Sentinel Network (TTSN) was developed and piloted with the participation of organ procurement organizations, tissue banks and transplant centers. The prototype centered around three elements of data entry: (1) donation, (2) tissue implantation, and (3) adverse event. The pilot proved that a system can be built and operated successfully, but also suggested that users may be hesitant to report adverse events. CDC has requested further input on scope and cost to build a transplant surveillance infrastructure for a fully functional national system. For tissues however, in contrast to organs, tracking from recovery to implantation will be necessary before a system is operable, requiring common identifiers and nomenclature. Until a US sentinel network is operational, future transmission events that are preventable may result nationally and globally due to its absence.

Endophthalmitis: Pathogenesis, clinical presentation, management, and perspectives

Endophthalmitis is a rare but sight-threatening complication that can occur after ocular surgery or trauma or as a consequence of systemic infection. To optimize visual outcome, early diagnosis and treatment are essential. Over recent decades, advances in hygienic standards, improved microbiologic and surgical techniques, development of powerful antimicrobial drugs, and the introduction of intravitreal antibiotic therapy have led to a decreased incidence and improved management of endophthalmitis. However, endophthalmitis still represents a serious clinical problem. This review focuses on current principles and techniques for evaluation and treatment of endophthalmitis. In addition, it addresses recent developments regarding antimicrobial treatment and prophylaxis of infectious endophthalmitis.

Influencing factors on the suitability of organ-cultured corneas

PURPOSE

To determine the factors related to donor and tissue retrieval, which influence the suitability of organ-cultured corneas for transplantation.

PATIENTS AND METHODS

We retrospectively analysed 2596 donor corneas. Polytomic logistic regression analysis was used to assess the influence of various factors (that is, donor age, cause of death, death-to-tissue retrieval time, tissue retrieval-to-reception time, and tissue retrieval method) on the suitability of grafts for transplantation. Positive predictive values (PPVs) were computed.

RESULTS

Forty-three percent (1118/2596) of corneas were discarded. The leading cause for discarding corneas was poor endothelial quality (21.5%). Corneas from donors older than 80 years were more likely to be discarded because of endothelial insufficiency (OR=2.37, P=0.001). Longer time between death and tissue retrieval was associated with increased risk of positive serology (OR=1.43, P=0.02). Increased time between tissue retrieval and reception was associated with increased risk of contamination (OR=1.57, P=0.03). PPV increased from 38.5% for corneas retrieved from donors older than 80 years featuring a death-to-tissue retrieval time of more than 6 h and a tissue retrieval-to-reception time of more than 24 h to 64.7% for corneas retrieved from donors younger than 80 years featuring a death-to tissue retrieval time shorter than 6 h and a tissue retrieval-to-reception time shorter than 24 h.

CONCLUSION

The percentage of discarded corneas can be reduced by including donors aged 80 years or less, using a time from donor's death to tissue retrieval shorter than 6 h, and a tissue retrieval-to-reception time shorter than 24 h.