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Eye banking
An eye bank is a nonprofit organization that retrieves, processes, stores and distributes donor corneal tissue for transplantation. Corneal blindness is a major problem in developing countries that can often be addressed through corneal transplantation, which has a high success rate. In India, the number of corneal transplants has been increasing but still does not meet the need, with over 50% of tissue coming from a few states. Eye banks are responsible for properly evaluating donor tissue through testing, examination and microscopy before distributing it to ensure safe and effective transplantation. Tissue is stored short or long-term in special nutrient media depending on preservation needs.
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Eye banking
- 1. Dr.Puskar Ghosh Final yearPGT BMC EYE BANKING
- 2. DEFINITION: • An "EyeBank" 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.
- 3. 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.
- 4. MAGNITUDE OF THEPROBLEM Corneal 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
- 5. THE SCENARIO ININDIA* Year Tissue retrieved transplantation 2000 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
- 7. Eye Banking System EyeDonation 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.
- 8. 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
- 9. EQUIPMENTS: EQUIPMENTS EBTC EBEDC 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
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- 12. Retrieval/ Recovery oftissue Deceased family calls Eye Bank Grief counselor motivates and obtains consent
- 13. 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)
- 14. PRELIMINARY PREPARATIONS • Obtainlegal 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
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- 17. SEROLOGICAL TESTING • HIV •HBV • HCV • HTLV I&II • Syphilis
- 18. EVALUATION OF THEDONOR 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.
- 19. EVALUATION OF DONORTISSUE • Biomicroscopic examination:
- 20. EPITHELEUM: • Location,extent,depth • Abrasion,laceration,FB •microcystic changes, • dry area • Haze, • exposure, • sloughing
- 21. BOWMAN’S LAYER • Anydefect • Corneal laceration by focusing a hairline slit Reforms at deeper level-defect is apparent,minimal Does’nt reforms- Bowman’s membrane involved
- 22. STROMA • Hairline slit15-20 degrees • See the epitheleal and endotheleal reflexes Converge centrally,diverge peripherally-no significant edema Nearly parallel or diverge centrally- edema
- 23. ARCUS SENILIS • Evidentwithin central 8mm of the cornea
- 24. DESCEMET’S MEMBRANE • The severityof the folds- width of the folds and the amount of endothelial area that they obscure from view.
- 25. ENDOTHELiUM • Seen byspecular reflection,high magnification • Uniformity • Size • Shape • Integrity. • Presense of guttata,vacuolated cells
- 26. EVALUATION OF DONORTISSUE • SPECULAR MICROSCOPY: Examine in room temperature 1hr is allowed in room temperature Within 1hr of recovery-examine without refrigeration Warming cooling cycle-3times
- 27. EVALUATION OF DONORTISSUE Corneal Endotheleum:
- 28. ENDOTHELIAL CELL COUNT* AGEAverage 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.
- 29. EXCLUSION CRITERIA FORPENETRATING 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
- 30. Parameters Clarity Epitheleal defects Epitheleal edema Scars Foreignbodies Stromal edema Opaque infiltrate Keratic precipitate Arcus senilis Folds Guttata Jaundice Endotheleal cell count CORNEAL VIABILITY
- 31. Rate criteria 1 (excellent)1. No epithelial defects 2. Crystal clear stroma 3. No arcus senilis 4. No folds in descemet’s membrane 5. Endotheleum-no defects 2 (very good) 1. Slight epitheal haze/defects 2. Clear stroma 3. Very slight arcus 4. Few folds in descemet 5. Endotheleum-no defects 3 (good) 1. Moderate epi. Defects 2. Moderate stromal cloudyness 3. Arcus < 2.5mm 4. Numerous but shallow folds 5. Few vacuolated cells in endotheleum 4 (fair) 1. Epitheleal defects ˃ 60% 2. Mod to heavy stromal cloudiness 3. Numerous deep descemet’s folds 4. Arcus ˃ 2.5mm 5. Low endotheleal cell density Poor 1. Central epitheleal defects 2. Heavy stromal cloudyness 3. Marked folds 4. Marked endotheleal cellular defects
- 32. STORAGE OF DONORTISSUE storage Short term 2-3days Moist chamber (24hrs),M-K medium Intermediate 7-10days K- sol,Dexol,Optisol,Optisol GS Long term 30days Organ culture medium,MEM Very long term 1year Cryopreservation
- 33. PRESERVATION OF CORNEA •Moist chamber storage Storage of whole globe 4◦C 24 hours • Advantage:simple • Disadvantage:Corneal stromal edema.
- 34. PRESERVATION OF CORNEA •Tissue Media o Dextran o Chondroitin sulphate o Electrolytes o pH buffer system o Antibiotics o Essential amino acids o Antioxidants,ATP precursors o Insulin o Epidermal growth factor o Antiprotease,anticoagulants Cornea storage Media Storage time (days) MK 4 K-SOL 7 CSM 7 DEXSOL 10 OPTISOL 14 PROCELL 14
- 35. M-K medium: • Describedby 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.
- 36. CONSTITUENTS DEXOL OPTISOL Basemedium 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
- 37. 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 Concentration Defined 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
- 39. AGE FOR EYEDONATION 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
- 40. INFORMATIONS •It is onlyone phone call away •Call the nearest eye bank or 1919 or 1053 or 104
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Editor's Notes
- #11 Eye banking services basically involves three steps. First is the recovery or retrieval of corneas from the deceased. Then these corneas are processed and examined. In the last step processed cornea, those are found to be suitable for transplantation are distributed as per requirement of in house cornea surgeons, or to other centers.
- #13 The collection team proceeds when the family of the deceased calls the eye bank or the collection center on their own. In other situation the family is motivated by the grief counselor or the organization for the consent.