Donor eye contamination

Usability of donor corneas harvested from the deceased having septicaemia or malignancy

CONTEXT

There is a wide gap between supply and demand in relation to healthy corneal grafts. Specific contraindications like infection and malignancy lead to non-usage of many grafts, despite the fact that deeming graft unhealthyness for these two contraindications is debatable.

AIMS

This study was conceptualized to assess if corneas donated from the deceased with septicaemia or malignancy can be deemed fit for implantation.

SETTINGS AND DESIGN

Retrospective histopathological and microbiological analysis of cadaveric donor corneas.

METHODS

A total of 76 donor corneas from 38 patients rejected for corneal transplantation in view of patient having septicaemia or malignancy were analysed for pathological and microbiological workup, to look for dissemination of disease within corneal tissue. Pathology workup included gross and microscopic histopathological evaluation of tissue. Microbiology workup included Grams stain and KOH with calcofluor mount, culture in blood agar, chocolate agar, Sabourauds dextrose agar and Mc Conkeys broth.

RESULTS

A total of 46 donor corneas of 23 septicaemia patients when evaluated showed presence of culture positive infection in 18 patients (78.2%). Histopathological examination done for 30 donor corneas from 15 cancer patients did not reveal presence of tumour cells in the specimen. Corneas of two of cancer patients having septicaemia revealed growth on cultures.

CONCLUSIONS

Corneal tissues harvested from septicaemia donors showed significantly higher incidence of corneal contamination, confirming their unsuitability for usage. However, there was no incidence of tumour transmission in corneal tissues of the patients with malignancies, suggesting that they can be considered for ophthalmic purpose.

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.

The Efficacy of Postenucleation Saline Wash and the Effect of Different Antimicrobial Agents on Microbial Contamination of Donor Eyes

OBJECTIVES

To evaluate the efficacy of postenucleation saline wash and the effect of different antimicrobial agents on the microbial contamination of donor eyes.

METHODS

Two hundred donor eyes were given saline wash and treated with any one of the following 5 randomly selected antimicrobial solutions: 1% povidone-iodine for 3 min, 0.3% gentamycin for 10 min, 0.3% ciprofloxacin for 10 min, a combination of neomycin 1,700 IU, gramicidin 0.025% and polymyxin B 5,000 IU (Neosporin(R)) for 10 min and a combination of 0.3% amikacin for 10 min, followed by 2.5% cefazolin for 10 min. Limbal swabs were sent for culture before and after saline wash and after treatment with antimicrobial agents.

RESULTS

On culture of the pretreatment swabs, 77.5% were positive for growth with 75.5% bacterial and 11.5% fungal. Coagulase-negative Staphylococcus (29.1%) was the most common bacterial contamination followed by Pseudomonas aeruginosa (18.5%), Acinetobacter sp. (18.5%) and Alcaligenes faecalis (13.2%). A 20-ml sterile saline wash resulted in a 20% decrease (p < 0.01) in the amount of contamination. The maximum antimicrobial effect with regard to bacterial decontamination was achieved with povidone-iodine (64% decrease in the amount of contamination, p < 0.01) followed by ciprofloxacin (47.6% decrease, p < 0.05), the combination of cefazolin and amikacin (42.5%, p < 0.05), Neosporin (38.5%, p < 0.05) and then gentamycin (21.7%, p = NS).

CONCLUSIONS

A thorough saline wash and treatment with 1% povidone-iodine for 3 min is a more effective method for the decontamination of donor eyes as compared to most currently available and frequently used antibiotics.

Organ-cultured corneal grafts from septic donors: a retrospective study

PURPOSE

To evaluate the quality of corneal grafts from donors, who have died from septic multi-organ failure and who are called septic donors in the following.

METHODS

One hundred and eighty-two corneal grafts from septic donors were stored in organ culture for 10-14 days. Graft evaluation was performed according to the criteria of the European Eye Bank Association. Only donor corneas with cell density values above 2000 cells/mm(2) were transplanted. Ninety-one patients who received these transplanted corneas were examined retrospectively with special emphasis on endophthalmitis, graft failure and incidence of immune reactions.

RESULTS

Ninety-one of 182 donor corneas (50%) from septic donors were discarded mainly due to endothelial damage (61; 67%). Only seven (8%) were discarded due to medium contamination. In contrast, 452 of 1261 donor corneas (36%) from non-septic donors during the same period were discarded, again mainly due to endothelial damage (264; 58%). In this group, 48 donor corneas (11%) were discarded due to medium contamination. No patient who had received a graft from a septic donor has experienced endophthalmitis. The rate of immune reactions and graft failure was in the same range when compared to a larger group who received grafts from non-septic donors.

CONCLUSION

Our data reveal no contraindication against the use of corneal grafts derived from septic donors, critical graft assessment in organ culture provided.

Effectiveness of a decontamination method for donor corneas

A retrospective study was made of the effectiveness of an eye bank decontamination and storage method. A comparison was made between microbial cultures taken from the limbus at enucleation and from scleral remnants recovered after surgery. Organisms were isolated from the limbus of 73% of donor eyes and from 4% of remnants. Standard eye bank procedures were found to eradicate gut and skin organisms, including candida, from donor tissue.

Survival of corneal grafts from donors supported by mechanical ventilation

Eighty-five patients undergoing penetrating keratoplasty with tissue from donors supported by mechanical ventilation (Ventilator group) were compared to a surgeon- and diagnosis-matched group (Control group). Age at surgery, duration of follow-up, and sex of recipient patients were similar in the two groups. The mean donor age in the Ventilator group (26.4 years) was significantly less than in the Control group (45.8 years, P less than 0.0001). Mean time on the ventilator was 99.4 hours (range, 4 hours to 21 days). Overall graft survival rates in the Ventilator and Control groups were similar (P greater than or equal to 0.72). Time on the ventilator did not affect graft survival. Cultures of corneoscleral donor rims were positive more often in the Ventilator group than in Controls (39.7 versus 23.1%), but the difference was not significant (P = 0.09). Prolonged ventilator time was not associated with a higher rate of positive corneoscleral rim cultures, nor did positive cultures affect graft survival. The most common cause of graft failure in both groups was allograft rejection. In no case could postoperative bacterial infection be attributed to contamination of the donor material. One case of primary donor failure occurred in the Ventilator group, but the incidence (1.2%) is similar to that of previously reported studies. The data indicate that corneal tissue from ventilator-supported donors should be considered for use in penetrating keratoplasty.

Contamination of donor cornea by gentamicin-resistant organisms

Cultures of the donor corneoscleral rims in 70 consecutive penetrating keratoplasties showed microbial contamination in 14 cases. All positive cultures were tested by standard microdilution broth method for sensitivities to gentamicin, an antibiotic routinely used in McCarey-Kaufman transport medium. Seven of 15 organisms demonstrated resistance to gentamicin at concentrations above 100 micrograms/ml. These results indicated the selection of more antibiotic-resistant microorganisms in antibiotic-supplemented medium and the need for appropriate antibiotic prophylaxis at the time of surgery.