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Dr.Puskar Ghosh
Final year PGT
BMC
EYE BANKING
DEFINITION:
• An "Eye Bank" is a not for profit community organisation governed by a Board of Directors or Trustees constituted by community representatives.
• Where safe quality donor eyes are procured,processed and distributed for therapeutic use and research.
CORNEA AS TRANSPLANT:• Imune privilage of cornea: Absence of blood and lymphatic channel in the graft and
its bed Absence of MHC class II APCs in the graft Reduced expression of MHC coded alloantigen on graft
cells,replaced with minor peptides Expression of T-cell deleating legand on
endotheleum→apoptosis of killer T cells. Immunosupressive microenvironment of aqueous humor. Anterior chamber associated immune deviation.
MAGNITUDE OF THE PROBLEMCorneal blindness is a major form of visual deprivation in developing countries. A high percentage of these individuals can be visually rehabilitated by corneal transplantation, a procedure that has very high rate of success among organ transplants.
• trachoma,
• corneal ulceration,
• xerophthalmia,
• ophthalmia neonatarum,
• traditional eye medicines,
• onchocerciasis,
• leprosy, and
• ocular trauma
THE SCENARIO IN INDIA*Year Tissue retrieved transplantation2000 18,641 4381
2008 34520 9509
• Trend is increasing.• Target: annual tissue retrieval 200,000/year
annual transplantation 100,000/year.• ˃ 50% of tissue retrieval : Tamilnadu, Gujarat,Maharashtra, Andhra Pradesh, Karnataka• West bengal- Collection-1688 Utilization-489
*JIMSA July - September 2010 Vol. 23 No. 3
Eye Banking SystemEye Donation Center (EDC)• affiliated to a registered eye bank
(1) public and professional awareness about eye donation
(2) co-ordinate with donor families and hospitals to motivate eye donation
(3) to harvest corneal tissue and collect blood for serology
(4) to ensure safe transportation of tissue to the parent eye bank.
Eye Bank (EB):• Provide a round-the-clock public response system over the telephone and conduct public
awareness programmes on eye donation.
• Co-ordinate with donor families and hospitals to motivate eye donation/Hospital Cornea Retrieval Pgramme – (HCRP)
• To harvest corneal tissue
• To process, preserve and evaluate the collected tissue
• To distribute tissue in an equitable manner for Keratoplasty
• To ensure safe transportation of tissue
Eye Bank Training Centre (EBTC)• All of the eye bank functions plus training for all levels of personnel in eye banking and
research.
STRUCTURE AND FUNCTION:• Relative autonomous,voluntary community based and
networked set up.
• Located either in large hospital set up or central neutral non profit organizations.
MANPOWER EYE BANK TRAINING CENTER
EYE BANK EYE DONATION CENTER
Board of diorectors Yes Yes No
Medical director Yes Yes No
Executive director Yes Yes No
Eye bank manager Yes Yes Yes
Eye bank technicians Yes Yes Yes
Eye donation councelor
Yes Yes No
Administrative secretary
Yes Yes no
Telephone operators Yes Yes No
Registered medical practitioners to
eneucleate round the clock
Yes Yes yes
EQUIPMENTS:EQUIPMENTS EBTC EB EDC
Slit lamp Required Required Not required
Refrigerators Required Required Preferable
Serology Required Required Not required
Specular microscope Required Required if collection is ˃ 200/yr
Not required
Instruments for corneal exision
Required Required Required
Autoclave Required Required Should have access
Laminar flow hood Required Required Required
Recovery or retrieval
CorneaProcessing
Distribution
How It Works ?
Retrieval/ Recovery of tissue
Deceased family calls Eye Bank
Grief counselor motivates and obtains consent
TISSUE RETRIEVAL
• Contraindications:Systemic:• AIDS• Rabies• Active viral hepatitis• Creutzfeldt-Jakob disease• SSPE• Progressive multifocal
leukoenchephalopathy• Reye’s syndrome• Death from unknown causes• Congenital Rubella• Active septicemia• High risk behavioral features• Leukemia (blast form)• Lymphoma/lymphosarcoma
Ocular:• Intrinsic eye diseases Retinoblastoma Active
conjuctivitis,iritis,uveitis,vitreitis,retinitis
Congenital abnormalities (keratoconus)
Central opacities,pterygeum
• Prior refractive procedures (radial keratotomy scar,lamellar inserts)
PRELIMINARY PREPARATIONS
• Obtain legal permission.
• Go through the donor’s medical records for any contraindications.
• Wash hands and be prepared with aseptic dressing,draping etc.
• Identify the donor.
• Collection of postmortem blood:10ml Femoral vein Subclavian vein Heart Jugular vein
ENUCLEATION
CORNEOSCLERAL BUTTON EXCISION
SEROLOGICAL TESTING
• HIV• HBV• HCV• HTLV
I&II• Syphilis
EVALUATION OF THE DONOR TISSUE• Gross examinations: Whole globe:
eyes with excessive stromal hydration should be discarded unless specular microscopy can be done for endotheleal cell count.
Corneoscleral button:
colour of the tissue storage media is to be noted.Yellowish colour-acidic media-contamination.
EVALUATION OF DONOR TISSUE
• Biomicroscopic examination:
EPITHELEUM:• Location,extent,depth• Abrasion,laceration,FB• microcystic changes,• dry area• Haze,• exposure,• sloughing
BOWMAN’S LAYER• Any defect• Corneal laceration by
focusing a hairline slitReforms at deeper
level-defect is apparent,minimal
Does’nt reforms-Bowman’s membrane involved
STROMA• Hairline slit 15-20
degrees• See the epitheleal and
endotheleal reflexesConverge
centrally,diverge peripherally-no significant edema
Nearly parallel or diverge centrally-edema
ARCUS SENILIS• Evident within central
8mm of the cornea
DESCEMET’S MEMBRANE• The severity of the folds-
width of the folds and the amount of endothelial area that they obscure from view.
ENDOTHELiUM• Seen by specular reflection,high
magnification• Uniformity• Size• Shape• Integrity.• Presense of guttata,vacuolated
cells
EVALUATION OF DONOR TISSUE
• SPECULAR MICROSCOPY: Examine in room temperature 1hr is allowed in room
temperature Within 1hr of recovery-examine
without refrigeration Warming cooling cycle-3times
EVALUATION OF DONOR TISSUECorneal Endotheleum:
ENDOTHELIAL CELL COUNT*
AGE Average Endothelial cell count
10-19 2,900-3,500
20-29 2,600-3,400
30-39 2,400-3,200
40-49 2,300-3,100
50-59 2,100-2,900
60-69 2,000-2,800
70-79 1,800-2,600
80-89 1,500-2,300
Critical cell density:300-500 cells/mm2
Functional cell density: 1500-2200 cells/mm2
*Edelhauser HF. The balance between corneal transparency and edemathe Proctor Lecture. Invest Ophthalmol Vis Sci 2006 May;47(5):1754-67. Philips C, Laing R, Yee R. Specular Microscopy. In: Krachmer JH, Mannis MJ, Holland EJ (eds). Cornea, 2nd ed. Philadelphia: Elsevier Mosby, 2005:261-77.
EXCLUSION CRITERIA FOR PENETRATING KERATOPLASTY*
• Cell density less than 2000 cells per square millimeter. Corneas with cell density less than 2000 cells / sq. mm may be suitable for lamellar procedures.
• Extreme polymegathism or pleomorphism.
• Presence of significant guttata.
• Presence of many non-hexagonal or abnormally shaped cells.
• Presence of inflammatory cells, bacteria, or debris on endothelial surface.
• Numerous vacuolated cells.
*Standards of Eye banking in India 2009;NPCB;Director General of Health & Family Welfare,Govt. of India
ParametersClarity
Epitheleal defects
Epitheleal edema
ScarsForeign bodiesStromal edema
Opaque infiltrateKeratic precipitate
Arcus senilisFolds
GuttataJaundice
Endotheleal cell count
CORNEAL VIABILITY
Rate criteria
1 (excellent) 1. No epithelial defects2. Crystal clear stroma3. No arcus senilis4. No folds in descemet’s membrane5. Endotheleum-no defects
2 (very good) 1. Slight epitheal haze/defects2. Clear stroma3. Very slight arcus4. Few folds in descemet5. Endotheleum-no defects
3 (good) 1. Moderate epi. Defects2. Moderate stromal cloudyness3. Arcus < 2.5mm4. Numerous but shallow folds5. Few vacuolated cells in endotheleum
4 (fair) 1. Epitheleal defects ˃ 60%2. Mod to heavy stromal cloudiness3. Numerous deep descemet’s folds4. Arcus ˃ 2.5mm5. Low endotheleal cell density
Poor 1. Central epitheleal defects2. Heavy stromal cloudyness3. Marked folds4. Marked endotheleal cellular defects
STORAGE OF DONOR TISSUE
storage
Short term2-3days
Moist chamber (24hrs),M-K
medium
Intermediate7-10days
K-sol,Dexol,Optisol,Optisol
GS
Long term30days
Organ culture medium,MEM
Very long term1year
Cryopreservation
PRESERVATION OF CORNEA• Moist chamber storage Storage of whole globe 4◦C 24 hours• Advantage:simple• Disadvantage:Corneal
stromal edema.
PRESERVATION OF CORNEA• Tissue Mediao Dextrano Chondroitin sulphateo Electrolyteso pH buffer systemo Antibioticso Essential amino acidso Antioxidants,ATP precursorso Insulino Epidermal growth factoro Antiprotease,anticoagulants
Cornea storage Media
Storage time (days)
MK 4
K-SOL 7
CSM 7
DEXSOL 10
OPTISOL 14
PROCELL 14
M-K medium:• Described by Mc Caray & Kauffman.
• Mixture of tissue culture medium (TC-199) and Dextran (5%,40,000 MW)
• Buffer:HEPES (N hydroxyethyle piperazine-N-ethane Sulphonic acid)
• Antibiotics:Penicilin,Gentamicine,Polymyxin
• Storage period-96hrs.
K-Sol:• Purified chondroitin sulphate in tissue culture medium (TC 199).
• Storage:7-10days in 40 C.
CONSTITUENTS DEXOL OPTISOL
Base medium MEM Hybride of Tc199 & MEM
Chondroitin Sulphate 1.35% 2.5%
Dextran 1% 1%
HEPES buffer Yes Yes
Gentamicine sulphate Yes Yes
Non essential amino acids 0.1mM 0.1mM
Sodium Bicarbonate Yes Yes
Sodium Pyruvate 1mM 1mM
Additional antioxidants Yes Yes
Other* No Yes
*ascorbic acid,Vit B12,ATP precursor
PRESERVATION OF CORNEA
• Long term Organ Culture storage system MEM media(minimum essential media) Developed by Hary Eagle. 34 degree C Incubated at room temp in nutrient medium Storage perid : 30 days Advantage:enables HLA matching
• Very long time preservation: Cryopreservation 1year
Constituents ConcentrationDefined fetal bovine serum 10%
Chondroitin sulphate 1.35%
L-Glutamine 2mM
Sodium Pyruvate 1mM
Non essential Amino acids 0.1mM
2-mercaptoethanol 0.44mM
Gentamicin sulphate 100mg/ml
AGE FOR EYE DONATION
No influence of age on transplant outcome.
Older age : usage rate declines due to low endotheleal count
Lower limit : 2 yrs to prevent myopic shift after keratoplasty
INFORMATIONS•It is only one phone call away•Call the nearest eye bank or 1919 or 1053 or 104
Thank you