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