Eye banking and corneal transplantation communicable adverse incidents: current status and project NOTIFY

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.

Herpes simplex virus dissemination with necrotizing hepatitis following Descemet membrane endothelial keratoplasty

BACKGROUND

Corneal transplants are the most common type of transplant and increasing in frequency. Donor cornea tissues are a rare source of herpes simplex virus (HSV) transmission and not routinely tested for presence of HSV. Donor graft-to-recipient transmission typically causes graft failure and anterior uveitis, and extra-ocular HSV disease has not been previously reported. We present a case of HSV transmission from donor cornea tissue that nearly cost the corneal transplant recipient his life.

CASE REPORT

An elderly immunocompetent man developed an acute illness 10 days after having donor corneal tissue implanted in a Descemet membrane endothelial keratoplasty (DMEK). He was found to have HSV necrotizing hepatitis per liver biopsy, trilineage cytopenia, rhabdomyolysis, acute kidney failure, altered mental status, early-stage hemophagocytic lymphohistiocytosis (HLH), and donor corneal tissue implant infection resulting in graft failure and anterior uveitis. HSV DNA was detected in cerebral spinal fluid, peripheral blood, explanted donor corneal tissue, and anterior chamber fluid (220 million HSV DNA copies per mL). HSV-1 seroconversion denoted a primary HSV infection, and the patient had no other risk factor for HSV acquisition. Early recognition of HSV dissemination prompting treatment with intravenous acyclovir, as well as a short course of HLH-directed therapy, resolved the systemic illness. Vision was restored to near normal by replacement of the infected corneal graft with new donor DMEK tissue in conjunction with intravitreal foscarnet treatment.

CONCLUSION

Awareness of the potential risk of donor cornea tissue transmitting HSV and leading to life-threatening HSV disease is paramount to early diagnosis and treatment. The role of donor cornea tissue in HSV transmission and disease merits additional attention and investigation.

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.

Effect of the First Year of COVID-19 Pandemic on Ophthalmological Practice: A Multi-Centre Italian Study with a Focus on Medico-Legal Aspects

During the COVID-19 era, several restrictions on surgery have been imposed to reduce the infectious risk among patients and staff and further preserve the availability of critical care resources. The aim of the study was to assess their impact on the ophthalmological practice and its medico-legal implications. A retrospective review of electronic medical records of the ophthalmological departments of the University of Cagliari (SGD) and University Magna Græcia of Catanzaro (UMG), from 16 March 2020 to 14 March 2021 (52 weeks), were compared with data from the corresponding period of the previous year. Weekly data on the number and type of diagnoses and procedures performed were collected and analysed in relation to the weekly average of the total number of COVID-19 patients in intensive care units (ICUs) and inpatients in Sardinia and Calabria. Results showed a significant decrease in cataract surgery operations by 47% and 31%, respectively, in the SGD and UMG (p < 0.05) during the second semester of the year; this drop occurred at the same time as the increase in COVID-19 patients in ICU and those hospitalised in both regions. Additionally, anterior segment surgery decreased at the UMG by 30% (p < 0.05). Vitreoretinal surgery decreased by 27% at the SGD, differently increased amount 31.5% at UMG (p < 0.05). The pandemic had a dramatic impact on elective surgery in ophthalmology, quantifying the backlog is the first step in order to understanding the measures to be taken in near future.

Analysis of 23 Years of Cornea Donor Data From an Eye Bank in Turkey

OBJECTIVES

We evaluated 23 years of data for cornea donors at the Istanbul Faculty of Medicine Lions Eye Bank.

MATERIALS AND METHODS

Annual statistics of corneal donors between 1996 and 2019 were reviewed retrospectively. Records for 2008 and previous years were compared with records for 2009 and years thereafter,to assess donor demographics and reasons for discard of corneas.

RESULTS

A total of 3849 corneas were obtained from 2018 donors during a 23-year period. Of these, 26 donors (11.2%) were registered, whereas 1792 (88.8%) did not register any decision for donation. There were 210 (5.46%) corneas discarded for positive serology and 291 (7.56%) for unsuitable tissue morphology, and 3348 (86.98%) corneas were determined to be suitable for transplant. For the cause of death in 2009 and subsequent years, the incidence of trauma was lower (P = .001) compared with the years previous to 2009, whereas incidence of cardiac pathology (P = .014) was higher. The number of donors older than 50 years was higher for 2009 and years thereafter, compared with data from earlier years (P = .024). The rate of discarded corneas for unsuitable tissue morphology (P = .004) and total discarded corneas (P = .027) decreased in 2009 and years thereafter. The rate of discarded corneas for HIV was higher after for 2009 and years thereafter (P = .047), whereas the rate of discarded corneas for syphilis was significantly higher for 2015 and years thereafter (P = .001).

CONCLUSIONS

This study evaluated the most extensive eye bank data in Turkey and found that advances in lamellar surgery techniques and improvements in specular microscopic facilities have expanded the pool for cornealtransplants to include tissues from older donors. Moreover, the incidence rates for HIVpositive and syphilis-positive serology tests in discarded corneas have increased over time.

Vigilance for Medical Products of Human Origin-Progress on the Notify Library's Global Effort to Share Information and Learning

BACKGROUND

World Health Assembly Resolution 63.22 mandated World Health Organization to facilitate Member State access to appropriate information on medical products of human origin (MPHO), including collecting data on serious adverse events and reactions. To meet this challenge, the Italian National Transplant Center, with a mandate from World Health Organization, has built and maintained an open-access searchable database of instructive records on disease transmission and other MPHO adverse occurrences.

METHODS

One record in the Notify Library describes a specific type of adverse occurrence in 1 type of MPHO and might be linked with 1 or multiple different references. The record inclusion criteria are that it has been reliably documented in a published article or official vigilance reporting system and that it has instructive value for the fields of transfusion, transplantation, or assisted reproduction. The selection and review of references for publication is performed by international experts who collaborate in 5 topic-specific editorial groups: infection transmission, malignancy transmission, living-donor reactions, process-related incidents, and clinical complications. New relevant references are identified through systematic searches and proactive communication by the experts.

RESULTS

The Library contains 1733 records, quoting 2632 references. Of the records, 41.8% are related to organs, 20.8% to blood and blood components, 16.5% to hematopoietic progenitor cells, 15.2% to tissues, 4.2% to reproductive tissues and cells, and 1.5% to other MPHO.

CONCLUSIONS

Notify Library is the first open-access, searchable database of systematically identified reports of disease transmission and other adverse occurrences arising from the donation and clinical application of MPHO.

Role of Reverse Transcriptase Polymerase Chain Reaction in Cornea Donors During the COVID-19 Pandemic

PURPOSE

The purpose of this study was to report the analysis of reverse transcriptase polymerase chain reaction (RT-PCR) of nasopharyngeal (NP) samples of cornea donors dying because of causes unrelated to severe acute respiratory coronavirus (SARS-CoV-2).

METHODS

A retrospective analysis of all cornea donors dying from causes other than SARS-CoV-2 between August 2020 and December 2020 was performed. Informed consent was obtained from the next of kin of the deceased for RT-PCR testing from NP swabs. Rapid antigen testing from all the deceased was performed before in situ cornea excision. In addition, NP samples in viral transport media for RT-PCR were also collected for SARS-CoV-2 analysis. Corneas were released from the eye bank only after a negative RT-PCR report.

RESULT

One hundred eighteen corneas from 59 donors were obtained by the eye bank. Eleven donors (18.64%) were positive for SARS-CoV-2 on RT-PCR testing. Six of these 11 donors had a Ct value of E gene less than 25.

CONCLUSIONS

NP samples of cornea donors dying due to causes other than coronavirus disease-19 were positive for SARS-CoV-2 on RT-PCR. This implicates that donors could be having asymptomatic/undetected coronavirus disease infection. We recommend adding the routine testing of NP samples of all cornea donors in the eye banking protocol in this ongoing SARS-CoV-2 pandemic.

One threat, different answers: the impact of COVID-19 pandemic on cornea donation and donor selection across Europe

OBJECTIVES

To assess to which extent the COVID-19 pandemic affected corneal transplantation by virtue of donor selection algorithms in different European countries.

DESIGN

Survey.

SETTING

110 eye banks in 26 European countries.

PARTICIPANTS

64 eye banks covering 95% of European corneal transplantation activity.

INTERVENTIONS

A questionnaire listing the number of corneas procured and distributed from February to May 2018-2020 was circulated to eye banks.

MAIN OUTCOME MEASURES

The primary outcome was the number of corneal procurements. Additional outcomes were national algorithms for donor selection, classified according to their stringency (donors with COVID-19 history, suspected for COVID-19, asymptomatic, PCR testing) and the pandemic severity in each country. We calculated Spearman's correlation coefficient to determine, two by two, the relationship between the 3-month decline in eye banking activity (procurement), the stringency of donor selection algorithm and the grading of pandemic severity (cases and deaths). A partial correlation was run to determine the relationship between decline and stringency while controlling for pandemic severity.

RESULTS

Procurements decreased by 38%, 68% and 41%, respectively, in March, April and May 2020 compared with the mean of the previous 2 years, while grafts decreased, respectively, by 28%, 68% and 56% corresponding to 3866 untreated patients in 3 months. Significant disparities between countries and the decrease in activity correlated with stringency in donor selection independent of pandemic severity.

CONCLUSIONS

Our data demonstrate significant differences between countries regarding donor screening algorithms based on precautionary principles and, consequently, a decrease in the donor pool, already constrained by a long list of contraindications. Fundamental studies are needed to determine the risk of SARS-CoV-2 transmission by corneal transplantation and guide evidence-based recommendations for donor selection to justify their substantial medical and economic impact.

Face and content validity of an artificial eye model for Ab-Interno Goniotomy

PURPOSE

To determine the face and content validity of an artificial eye model for ab-interno goniotomy (SimulEYE KDB model, InsEYEt, Westlake Village, CA) by surveying ophthalmologists with varying experience using a Kahook Dual Blade (KDB; New World Medical, Rancho Cucamonga, CA, USA) following a 90-min wet-lab course using the model.

PARTICIPANTS

Overall 13 ophthalmologists participated following a surgical simulation session on goniotomy using the goniotomy blade at the 2019 Canadian Ophthalmological Society annual meeting.

METHODS

A 17-question survey to assess the face and content validity of the model was given immediately following the surgical simulation session on goniotomy using the goniotomy blade. Responses to each survey question were recorded on a 5-point Likert scale ranging from (1) strongly agree to (5) strongly disagree.

RESULTS

Respondents rated statements regarding the model with a median response of 1 (Strongly Agree) to 3 (Neither agree or disagree). Mann-Whitney U nonparametric analysis revealed no significant difference in responses between instructor vs. non-instructor or between prior experience vs. no prior experience for any of the survey statements. The model received highest survey ratings for utility in training residents, acquisition of surgical skills, accessibility, and higher likelihood of success with the procedure than theory and observation alone. Lowest ratings were for realism of the model compared to a human cadaveric eye.

CONCLUSION

Our results suggest the SimulEYE KDB model is a reasonably cost-effective solution for simulating angle-based surgeries. Additionally, our project shows that experienced ophthalmologists found the artificial eye models useful and helpful for angle-based surgery training.

Risks Posed to Corneal Transplant Recipients by COVID-19-Affected Donors

The recent emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resultant human disease, COVID-19, will likely have a significant impact on the corneal tissue donor pool. Current recommendations from the United States and global eye bank associations call for the outright avoidance of tissues from donors recently infected with or exposed to COVID-19. This conservative recommendation is currently appropriate given the reported ocular sequelae, tear film viral detectability, and transmissibility of COVID-19. However, the rapidly increasing global prevalence and mortality of COVID-19 threatens the tenability of current tissue exclusion guidelines, and may necessitate their relaxation in the near future.

Construction of a full-thickness human corneal substitute from anterior acellular porcine corneal matrix and human corneal cells

AIM

To construct functional human full-thickness corneal replacements.

METHODS

Acellular porcine corneal matrix (APCM) was developed from porcine cornea by decellulariztion. The biomechanical properties of anterior-APCM (AAPCM) and posterior-APCM (PAPCM) were checked using uniaxial tensile testing. Human corneal cells were obtained by cell culture. Suspending ring was designed by deformation of an acupuncture needle. MTT cytotoxicity assay was used to check the cytotoxicity of suspending ring soaking solutions. A new three-dimensional organ culture system was established by combination of suspending ring, 48-well plate and medium together. A human full-thickness corneal substitute was constructed from human corneal cells with AAPCM in an organ coculture system. Biochemical marker expression of the construct was measured by immunofluorescent staining and morphological structures were observed using scanning electron microscopy. Pump function and biophysical properties were examined by penetrating keratoplasty and follow-up clinical observations.

RESULTS

There were no cells in the AAPCM or PAPCM, whereas collagen fibers, Bowman's membrane, and Descemet's membrane were retained. The biomechanical property of AAPCM was better than PAPCM. Human corneal cells grew better on the AAPCM than on the PAPCM. There was no cytotoxicity for the suspending ring soaking solutions. For the constructed full-depth human corneal replacements keratocytes scattered uniformly throughout the AAPCM and expressed vimentin. The epithelial layer was located on the surface of Bowman's membrane and composed of three or four layers of epithelial cells expressing cytokeratin 3. One layer of endothelial cells covered the stromal surface of AAPCM, expressed Na⁺/K⁺ATPase and formed the endothelial layer. The construct was similar to normal human corneas, with many microvilli on the epithelial cell surface, stromal cells with a long shuttle shape, and zonula occludens on the interface of endothelial cells. The construct withstood surgical procedures during penetrating keratoplasty. The corneal transparency increased gradually and was almost completely restored 7d after surgery.

CONCLUSION

AAPCM is an ideal scaffold for constructing full-thickness corneal replacement, and functional human full-thickness corneal replacements are successfully constructed using AAPCM and human corneal cells.

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.

Comparison of seropositivity of human immunodeficiency virus, hepatitis B virus, hepatitis C virus, and syphilis among Hospital Cornea Retrieval Programme-Donors versus voluntary cornea donors at a large eye bank in Eastern India

Purpose:

To compare the serology profile of donors from Hospital Cornea Retrieval Programme-donors (HCRP-D) and voluntary cornea donors (VC-D) from a large eye bank in Eastern India.

Methods:

This is a retrospective analysis of donor details from January 2011 to December 2016. Donor demographics, cause of death, and serology reports were compiled. Postmortem blood was tested for human immunodeficiency virus 1 and 2 (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and syphilis using government-approved kits as per the National Programme for Control of Blindness Standards of Eye Banking. Donors for whom serology was not possible were excluded.

Results:

A total of 4300 of 4353 donors were included of which 74.3% were hospital donors and 25.7% were voluntary donors. A total of 93 (2.2%) donors with 94 seropositive reports were noted: 79 (84.9%) from HCRP-D and 14 (15.1%) from VC-D which was statistically significantly higher (P = 0.02). Among seropositive reports, HIV, HBV, HCV, and syphilis accounted for 12 (12.8%), 38 (40.4%), 36 (38.3%), and eight (8.5%), respectively. There was no correlation between the cause of death and seropositivity. A statistically significant decreasing trend in seroprevalence among hospital donors was observed over the years (5.3% in 2011 to 1.4% in 2016; P = 0.004). Two (0.47%) of 421 hospital donors with prior negative serology were found to be seropositive.

Conclusion:

Seropositive rates are significantly higher among hospital donors in spite of medical prescreening compared to nonscreened voluntary donors. Serology should be repeated even when prior reports are available.

Tissue banking, biovigilance and the notify library

This issue is dedicated to the contributions of Professor Glyn O. Phillips to the field of tissue banking and the advancement of science in general. The use of ionizing radiation to sterilize medical products drew the interest of the International Atomic Energy Agency (IAEA). A meeting in 1976 in Athens Greece to present work on the effects of sterilizing radiation doses upon the antigenic properties of proteins and biologic tissues was my first introduction of Professor Phillips and the role that he was to play in Tissue Banking (Friedlaender, in Phillips GO, Tallentine AN (eds) Radiation sterilization. Irradiated tissues and their potential clinical use. The North E. Wales Institute, Clwyd, p 128, 1978). The IAEA sponsored subsequent meetings in the Republic of Korea, Czechoslovakia and Rangoon, the later including a visit to the tissue bank by Professor Phillips. His advocacy resulted in multiple workshops and teaching opportunities in a variety of countries, one of which led to the establishment of the Asia Pacific Surgical Tissue Banking Association in 1989 (Phillips and Strong, in Phillips GO, Strong DM, von Versen R, Nather A (eds) Advances in tissue banking, vol 3. World Scientific, Singapore, pp 403-417, 1999).

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.

The promise of stem cell-based therapeutics in ophthalmology

The promising role of cellular therapies in the preservation and restoration of visual function has prompted intensive efforts to characterize embryonic, adult, and induced pluripotent stem cells for regenerative purposes. Three main approaches to the use of stem cells have been described: sustained drug delivery, immunomodulation, and differentiation into various ocular structures. Studies of the differentiation capacity of all three types of stem cells into epithelial, neural, glial and vascular phenotypes have reached proof-of-concept in culture, but the correction of vision is still in the early developmental stages, and the requirements for effective in vivo implementation are still unclear. We present an overview of some of the preclinical findings on stem-cell rescue and regeneration of the cornea and retina in acute injury and degenerative disorders.

Three-Dimensional Construction of a Rabbit Anterior Corneal Replacement for Lamellar Keratoplasty

The aim of this study was to construct a rabbit anterior corneal replacement for transplantation using acellular porcine corneal matrix (APCM) and rabbit epithelial or stromal cells. APCM was prepared from fresh porcine cornea treated with 0.5% (wt./vol.) sodium dodecyl sulfate (SDS) solution. The expanded stromal cells were first injected into APCM parallel to its surface and were cultured in a shaking culture system for 7 days to obtain the stromal construct. Next, corneal epithelial cells were cultured on the stromal construct surface for another 7 days to obtain rabbit anterior corneal lamella. The construct had a phenotype similar to that of normal cornea, with high expression of cytokeratin 3 in the epithelial cell layer and vimentin in the stromal cells. More importantly, the construct integrated well with the implanted host corneal tissue, and the implant cornea maintained transparency in the 6-month follow-up, although there was a slight haze in the central corneal area. The endothelium in the surgery cornea had a similar cell density and mosaic pattern with normal cornea as shown by confocal laser corneal microscopy, and the regenerated corneal epithelial cells on the implant surface showed a similar morphology to that of natural epithelial cells. These results demonstrate that the constructed anterior corneal replacement exhibits an excellent biological property for lamellar keratoplasty and might be a possible alternative to human corneal tissue in the future.

The use of human cornea organotypic cultures to study herpes simplex virus type 1 (HSV-1)-induced inflammation

PURPOSE

To determine the utility of human organotypic cornea cultures as a model to study herpes simplex virus type 1 (HSV-1)-induced inflammation and neovascularization.

METHODS

Human organotypic cornea cultures were established from corneas with an intact limbus that were retrieved from donated whole globes. One cornea culture was infected with HSV-1 (10(4) plaque-forming units), while the other cornea from the same donor was mock-infected. Supernatants were collected at intervals post-culture with and without infection to determine viral titer (by plaque assay) and pro-angiogenic and proinflammatory cytokine concentration by suspension array analysis. In some experiments, the cultured corneas were collected and evaluated for HSV-1 antigens by immunohistochemical means. Another set of experiments measured susceptibility of human three-dimensional cornea fibroblast constructs, in the presence and absence of TGF-β1, to HSV-1 infection in terms of viral replication and the inflammatory response to infection as a comparison to the organotypic cornea cultures.

RESULTS

Organotypic cornea cultures and three-dimensional fibroblast constructs exhibited varying degrees of susceptibility to HSV-1. Fibroblast constructs were more susceptible to infection in terms of infectious virus recovered in a shorter period of time. There were changes in the levels of select pro-angiogenic or proinflammatory cytokines that were dictated as much by the cultures producing them as by whether they were infected with HSV-1 or treated with TGF-β1.

CONCLUSION

Organotypic cornea and three-dimensional fibroblast cultures are likely useful for the identification and short-term study of novel antiviral compounds and virus replication, but are limited in the study of the local immune response to infection.