Eye Banking and Corneal Transplantation in New Zealand
Nigel Brookes
Technical Officer
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“The acquisition, evaluation & supply of high-quality corneal and other tissue to all New Zealanders needing a transplant to restore their sight”
• Overview of Service• History• Corneal Structure• Corneal Disorders• Corneal Transplant• Eye Banking• Eye Donation
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What Tissues?
• Amniotic membrane [30 - 50]– Structural/biological, surface
‘bandage’– Stored frozen (-80oC), up to 2
years
• Sclera [120 – 150]– Structural, reconstruction – Stored refrigerated, up to 1 year
• Corneas [300 - 350]– Viable, unaltered, sight-restoring– Stored in warm organ culture
(34OC), up to 28 days
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Transplant:CorneaSclera
Research:CorneaLensRetina
Medically unsuitable for transplant
Failed Eye Bank evaluation/testing
Amniotic membrane
Fresh donor eyes
Donor ‘rim’ after trephinationLimbal cells
Post-surgery:Cornea Defective tissue eg. keratoconic
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1905 First corneal transplant – Eduard Zirm, Czech.
1930 First whole eye storage
1944 First Eye Bank – New York
Up to 1970’s Moist pot whole globe storage
1988-1991 Cold storage in K-sol/ Optisol
1991 NZNEB started organ culture storage
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Cross-section Endothelial evaluation (in vivo)
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A: Superficial epithelium
B: Basal epithelium
C: Bowman’s layer with nerves
D: Bowman’s layer
E: Stroma with keratocytes
F: Endothelium
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• Since 1939, only 13 reports of disease transmission from
cornea: 9 rabies, 2 cancers, 2 Hep B
• Bacterial infection demonstrable but endophthalmitis after
corneal transplant similar to cataract surgery
• Cornea is highly inefficient transmitter of disease
• 3 reports of sCJD transmission: 1 now thought only possible
• No reports of transmission by sclera or amniotic membrane
Modern blood testing is highly sensitiveNAT testing further narrows ‘window period’
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• Donor acquisition from mainly Auckland area – within 24 hours• Links with donor sources: Mortuary, Hospitals, other transplant services• Donors selected by strict criteria for suitability• Long-term storage in 34oC culture system – up to 28 days• Extensive testing for infectious disease & contamination• Quality control / sterility of highest standard• Minimum endothelial cell count
• Supply 100% of all transplanted corneas in NZ
• Schedule of planned, elective surgery: 8+ grafts per week• Reduction of surgical waiting lists
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200
250
300
350
400
19911992199319941995199619971998199920002001200220032004200520062007200820092010201120122013201420152016201720182019
Transplanted Not Transplanted
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• 8+ cornea bookings per week
• 23 corneal surgeons
• 16 centres
Public hospitals: 75 %
Private hospitals: 25 %
Scheduled: ~85%
Emergency: ~15%
AUCKLAND
Whangarei
Tauranga
New Plymouth
Hamilton
Wanganui
Hamilton
Wellington
Palmerston North
Dunedin
Christchurch
Nelson
Blenheim
Napier, Hastings
GisborneRotorua
Timaru
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A B C D
• Oldest form of transplant – 1905• 12.7 million people waiting for a corneal transplant• 185,000 transplants in 116 countries• Penetrating Keratoplasty most common form of transplant – USA 45,000 pa
UK 9,000NZ 350
Avascular – few rejection problems– no immunosuppression
12-18 months for optimal vision
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Corneal Transplant
Before After
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Keratoconus• Acquired abnormality – cornea protrudes, thin & distorted• Bilateral, progressive, occurs at young age (teens, twenties)• High prevalence in NZ – 50% of transplants• Does keratoconus progress more rapidly in NZ?
50%
Keratopathy/oedema• Painful epithelial blisters, scarring• Association with glaucoma & following cataract surgery
18%
Dystrophy• Intrinsic genetic disorders, or aging• Epithelial abrasion/erosion, endothelial cell loss & dysfunction 10%
Viral or bacterial infection• Inflammation – opacification – vascularisation - ulcers• Risk of rejection higher – blood vessels reduces graft tolerance 10%
Trauma• Perforation – physical/chemical injury• Heavy male preponderance 6%
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Dystrophy Bullous keratopathy
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MelanomaPterygium
Acid burn Perforated ulcer
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0
50
100
150
200
250
300
1st 2nd 3rd 4th 5th 6th 7th 8th 9th 10th
Age (decade)
Num
ber
Average: 47.5 years Trauma
RegraftViral keratitis
corneal oedema
KeratoconusMale: 52.4%Female: 42.9%
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• Full thickness of cornea replaced
• No host tissue remains
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• Leave host endothelium• Remove host anterior• Add donor anterior
minus endothelium
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• Leave host anterior• Remove host endothelium• Add isolated donor
endothelium
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• Centralise purchase cost of expensive equipment
• Quality checking prior to tissue use: endothelial density and quality.
• Technicians become proficient due to high volumes: consistent donor size, thickness.
• Surgeon and theatre time is saved: 30 mins approx.
• No cancellation of surgery when tissue ruined.
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Organs: heart, lungs, kidneys, liver, pancreas
• Only brain death - ICU• Specialist medical care of donor & family
Tissues: heart valves, skin
• Brain or circulatory death - autopsy• Repair defective heart valves, skin grafts
Eyes: corneas, sclera
• Brain or circulatory death• From any source: hospitals, Coronial, hospices, rest homes,
funeral directors, community
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Organ donation: heart, liver, kidneys, lungs, pancreas - ~100 per year
Tissue donation: skin, heart valves, bone - many 100’s per year
Eye donation: corneas, sclera - many 1000’s per year
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Age: 10 – 85 yearsTime: within 24 hours
Generally suitable:• Cancers• Heart disease, respiratory disease• Bacterial infection / septicaemia• Diabetes, arthritis• Vision problems or common eye disorders eg. cataract, glaucoma, retinopathy
Medical contraindications:• Death of unknown cause• Infectious disease: - Hepatitis B,C, HIV, meningitis• Systemic viral infection• CNS diseases, progressive dementia• Leukaemia, lymphoma• Previous corneal disease or surgery, laser surgery• Various congenital disorders• Lifestyle risk factors
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2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Australia Coroner Family Funeral Director Hospice Multi-organ
Multi-tissue Other Private Hospital Public Hospital USA
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13.6
36.1
30.1
11.7
8.5
0
10
20
30
40
50
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70
80
90
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Ageexclusion
Timeexclusion
Medicalexclusion
Yes consent
No consent45
2
5
11
29
3
81
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2019
Australia Coroner Funeral Director Hospice
Multi-organ Multi-tissue Public Hospital USA
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Suitable donors identified: by medical staff, transplant coordinatorsOR referral from families
Next-of kin contacted: - information provided about donation- possibility raised, no coercion- if consent given, process explained
Retrieval: - careful surgical procedure in hospital, mortuary, funeral home- donor treated with dignity & respect- no delay to funeral arrangements- no visible difference, viewing can occur
Driver’s licence is indication of wish only -important to discuss wishes with family/whanau
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• Acquisition after any death• 50 - 75% people suitable• Donation anywhere• Normal appearance • Plenty of time• No delay to funeral arrangements• Informed consent• Medical history interview – family, GP• Follow-up of outcome - memento
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• Donor characteristics• Technical & storage details• Serology/microbiology tests• Allocation & distribution
Eye Bank:
180
• Recipient details• Ophthalmic history• Surgical & graft procedure• Post-operative outcome
Recipient:45
Follow-Up: • Graft condition & survival• Visual acuity• Other ophthalmic procedures
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NZNEB Trust10 ophthalmologists & 2 optometrists
Clinical DirectorDr David Pendergrast
Scientific DirectorProf Charles McGhee
ManagerLouise Moffatt
CoordinatorHelen Twohill
Technical OfficerNigel Brookes
Scientific AdvisorProf Trevor Sherwin
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The University of Auckland, Department of Ophthalmology and should not be reproduced without written permission.