A serious adverse surgical event: Management of suspected HSV-1 keratitis in a donor cornea

Quality assurance in corneal transplants: Donor cornea assessment and oversight

The cornea is the most frequently transplanted human tissue, and corneal transplantation represents the most successful allogeneic transplant worldwide. In order to obtain good surgical outcome and visual rehabilitation and to ensure the safety of the recipient, accurate screening of donors and donor tissues is necessary throughout the process. This mitigates the risks of transmission to the recipient, including infectious diseases and environmental contaminants, and ensures high optical and functional quality of the tissues. The process can be divided into 3 stages: (1) donor evaluation and selection before tissue harvest performed by the retrieval team, (2) tissue analysis during the storage phase conducted by the eye bank technicians after the retrieval, and, (3) tissue quality checks undertaken by the surgeons in the operating room before transplantation. Although process improvements over the years have greatly enhanced safety, quality, and outcome of the corneal transplants, a lack of standardization between centers during certain phases of the process still remains, and may impact on the quality and number of transplanted corneas. Here we detail the donor screening process for the retrieval teams, eye bank operators. and ophthalmic surgeons and examine the limitations associated with each of these stages.

Occurrence of Herpes Viruses in Morphologically Normal Corneas

PURPOSE

The purpose of this study was to detect the occurrence of herpes simplex virus (HSV) types 1 and 2 and varicella zoster virus (VZV) DNA in transplanted corneas using polymerase chain reaction (PCR) and to determine the relationship between latent HSV and VZV and herpetic eye disease in recipients.

METHODS

This was a retrospective, interventional case series. Samples from 88 donor corneoscleral buttons (CSBs) were collected from the conjunctiva, iris, and endothelium and tested for HSV-1, HSV-2, and VZV DNA using PCR. All transplanted eyes were evaluated and followed up. The main outcome measures were HSV-1, HSV-2, and VZV DNA positivity rates in donor CSBs and the occurrence of herpetic eye disease or graft failure in recipients of positive corneas.

RESULTS

HSV-1 DNA was detected in 5 (5.7%) of 88 CSBs. HSV-2 was not detected in any CSBs, and VZV was found in 1 (1.2%) of the 82 examined CSBs. One recipient (16.7%) developed dendritic epitheliopathy and keratouveitis typical of HSV 12 months after transplantation, although the graft remained clear after treatment. One cornea was used for a tectonic graft and stayed edematous at the 20-month follow-up. The remaining corneas remained clear.

CONCLUSIONS

Morphologically normal donor corneas may be PCR-positive for herpes viruses, especially HSV-1. Recipients of herpes-positive corneal grafts could be at risk for herpetic eye disease. Further studies using viral RNA by reverse transcriptase PCR are needed to provide more information on HSV and VZV latency and active replication in donor corneas.

[Study of the antiviral activity of the liquid corneal storage medium in relation to the herpes simplex virus in vitro]

The aim of the study was to assess the antiviral activity of the 7 types of liquid corneal storage medium on an experimental model of herpesvirus infection in vitro.

MATERIAL AND METHODS

The study of antiviral activity of 7 samples of liquid corneal storage medium on a model of herpesvirus infection caused by the herpes simplex virus type 1 in Vero-cell using virological and statistical research methods was carried out.

RESULTS AND DISCUSSION

All the studied images of the corneal storage medium, including the Borzenka-Moroz base medium, did not have a cytotoxic effect on Vero cell culture. Out of of 7 samples of liquid corneal storage medium, 4 samples had reliable antiviral activity against HSV-1 when used under the therapeutic regimen (1 hour after infection) and under the preventive regimen (2 hours before infection). Antiviral activity was established in 2 samples containing the interferon inducer cycloferon at a concentration of 10 mg/kg and 30 mg/kg (sample 2, 3), in a sample containing the interferon inducer gamapren 15 mg/kg (sample 5), and in a sample containing a combination of drugs - 10 mg/kg cycloferon and an acyclic nucleoside analog-acyclovir 10 mg/kg (sample 6). According to the results of 2 test regimens, the maximum statistically significant inhibitory effect in relation to HSV-1 was detected in sample 6, containing a combination of drugs. Against the background of sample 6, the infectious activity of the test virus decreased by an average of 3.2 lg, the inhibition coefficient was 54.5%.

CONCLUSION

The results of the study indicate the prospects of using types of media with antiviral activity (samples 2, 3, 5, 6) for storing donor corneas in order to increase the effectiveness of keratoplasty in patients with ophthalmic herpes.