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eyebank-190216141356.pptx eye banking eye
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- 2. What is anEye Bank ?
- 3. It is anon profit community organization which deals with the collection , storage , & distribution of cornea for the purpose of corneal grafting , research & supply of the other eye tissues for the other purposes.
- 4. THREE TIER ORGANIZATION An integrated systeminvolving a three- tier community eye banking pyramid based on the infrastructure and manpower at all levels . The three tiers proposed were eye donation centres, eye bank and eye bank training centres.
- 5. EBTC (EYE BANKTRAINING CENTRE) The top tier comprises of 5 Eye banking training centers (EBTC) responsible for 1. Tissue harvesting, processing & distribution. 2. Creating public awareness. 3. Training and skill up-gradation of eye banking personnel.
- 6. EYE BANKS Middletier would comprise of a strong network of 45 Eye Banks(EB) • cater to a population of 20 million each. • would be closely linked with 2,000 Eye Donation Centers- EDC (ratio of 1: 50 suggested)
- 7. EYE DONATION CENTERS •Publicity of the volantary donation • Registration • Arrangement for the collection of the eye after death • Processing , packing , & transportation of collected eye to attached eye bank • would cater to a population ranging from 50,000 to 100,000.
- 8. FUNCTIONS OF EYEBANK
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- 10. TISSUE RETRIEVAL Contraindications: Systemic: •AIDS • Rabies • Active viral hepatitis • Creutzfeldt-Jakob disease • SSPE • Death from unknown causes • Congenital Rubella • Active septicemia • High risk behavioral features • Leukemia (blast form) • Lymphoma/ lymphosarcoma Ocular: • Intrinsic eye diseases Retinoblastoma Active conjunctivitis , iritis , uveitis , vitreitis, retinitis Congenital abnormalities (keratoconus) Central opacities, pterygeum • Prior refractive procedures (radial keratotomy scar, lamellar inserts)
- 11. STEPS OF EYEDONATION 1. Donor selection 2. Tissue retrieval 3. Corneal examination 4. Tissue transportation 5. Storage of corneal tissue 6. Distribution
- 12. DONOR SELECTION 1) AGEOF DONOR: no influence of age on transplant outcome. Older age : usage rate declines Lower limit : 2 yrs to prevent myopic shift after keratoplasty
- 13. 2) MEDICAL HISTORYREVIEW • Eye banks must have consistent policies for the examination and documentation of donor's available • medical records, • medical history • cause of death • Medications • laboratory reports
- 14. TISSUE RETRIVAL enucleation i.e. surgicalby in -situ removal of the whole eye corneo-scleral excision (globe is retained In the orbit)
- 15. 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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- 18. EVALUATION OF THEDONOR TISSUE Gross examinations: Whole globe: eyes with excessive stromal hydration should be discarded unless specular microscopy can be done for endothelial 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. 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
- 21. STORAGE OF DONORTISSUE storage Short term 2-3days Moist chamber (24hrs),M- K medium Intermedi ate 7-10days K-sol, Dexol, Optisol, Optisol GS Long term 30days Organ culture medium,MEM Very long term 1year Cryopreservation
- 22. METHODS OF CORNEAL PRESERVATI0N 1.Short-term storage methods 2. Intermediate-term storage 3. Long term storage
- 23. EYE BANK -PRESERVATION MEDIA • Short Term (48hrs) - Moist Chamber • Intermediate Term (4 days) - McCarey - Kaufman medium – 4 days K - Sol medium - 7 days Dexsol medium - 10 days Optisol medium - 14 days • Long term storage - Organ Culture – 35 days Cryopreservation - 1 year
- 24. SHORT TERM STORAGEMETHODS 1. Moist chamber storage: • Storage of the whole globe for short period of time at 4 degree • It is a closed container with cotton gauze moistened with sterile saline • Container is never completely filled with liquid
- 25. Advantages of moistchamber storage 1.simplicity 2. needs little expertise & manipulation 3.inexpensive Disadvantages 1.storage time limited to 48 hrs 2. endothelium remains in contact with aqueous.
- 26. INTERMEDIATE TERM STORAGE METHODS Tissuemedia preservation: Advantages: 1.provides a chemically defined & stable environment 2.helps support & enhances metabolic activities 3.reduces the stromal swelling 4.keeps the tissue under sterile condition till use 5.provides time for EB to serologically screen the donor for communicable diseases
- 27. INGREDIENTS : 1.Dextran 2.Chondroitin sulphate 3.Electrolytes 4.pHbuffer system 5.Antibiotics 6.Essential aminoacids 7.Antioxidants,ATP precursors 8.Insulin 9.EGF 10.ANTIPROTEASES & anticollagenases
- 28. Dextran • Keeps preservedcornea thin • Initially 5% of 5,00,000 mol wt dextran is used. • In newer media 1% of 40000mol.Wt is used. Chondroitin sulphate. • it is akin to naturally occuring GAG in cornea. • It is available from whale(type A),wine(typeB),shark(type c). • High mol.wt chondroitin sulphate maintains deturegence where as low mol.wt helps retain viability of endothelium • Also acts as an antioxidant
- 29. MC CAREY KAUFMANMEDIUM Components Tic 199 5% dextran Bicarbonate buffer Penicillin and streptomycin which was later substituted by gentamycin in con of 50-200 micro grams per ml
- 30. Modified MK medium •Waltman and plamberg • Substituted 0.025 M hepes buffer for bicarbonate buffer • phenol red as a pH indicator • Osmolarity 290 milli osm/kg • pH 7.4 • Storage period 4 days at 4 degree C.
- 32. SNAIL TRACKS, STRESSSTRIAE CARELESS The middle and lower illustrations show snail tracks at varying degrees of magnification. Careless folding of the corneal cap during removal causes snail tracks .
- 33. DISTRIBUTION OF CORNEA Distribution to only hospitals and ophthalmologists registered under HOTA Maintenance of waiting list Distribution record Feedback from the hospital receiving cornea
- 34. OTHER USES: DonatedSclera can be used for glaucoma , oculoplastic and retinal surgeries Human amniotic membrane can be used for ocular surface procedures Fair and equitable distribution of transplantable tissues to corneal surgeons acco to waiting list.
- 35. CORNEAL TRANSPLANTATION (Keratoplasty)
- 36. CORNEAL TRANSPLANTATION Cornealtransplantation refers to surgical replacement of a full-thickness or lamellar portion of the host cornea with that of a donor eye. Allograft/autograft Full-thickness( Penetrating)/ Partial thickness ( lamellar)
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- 38. TYPES OF KERATOPLASTY Optical – to improve vision Tectonic- to restore or preserve corneal integrity Therapeutic- to remove infected corneal tissue Cosmetic- to improve appearance
- 39. KERATOPLASTY : SCHEMATICDIAGRAM
- 40. INDICATIONS OF PENETRATING KERATOPLASTY(PK) Keratoconus Post- cataract surgery edema Corneal dystrophies and degenerations Mechanical or chemical trauma Microbial/postmicrobial keratitis Congenital opacity
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- 43. PREOPERATIVE EVALUATION Systemicevaluation A complete eye examination Examination of the ocular adnexa
- 44. SURGICAL TECHNIQUE Determinationof graft size Excision of donor cornea Excision of diseases host cornea Fixation of donor button Removal of viscoelastic substance
- 45. REMOVAL OF CORNEALBUTTON
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- 47. INTRAOPERATIVE COMPLICATIONS Damageto the lens and/or iris Irregular trephine Poor graft centration Excessive bleeding from the iris and wound edge Choroidal hemorrhage Iris incarceration in the wound Damage to the donor endothelium
- 48. POSTOPERATIVE CARE Topicalsteroids and antibiotics Mydriatic Oral antiviral Removal of suture Rigid contact lens for residual astigmatism
- 49. POST OPERATIVE COMPLICATIONS Infection Suture dehiscence Corneal allograft rejection ( epithelial/ stromal/ endothelial) Secondary glaucoma
- 50. PROGNOSTIC FACTORS Abnormalitiesof eyelid Tear film function Recurrent and progressive conjunctival Inflammation Stromal vascularisation Uveitis and anterior synechia Uncontrolled glaucoma
- 51. LAMELLAR KERATOPLASTY Lamellarkeratoplasty refers to replacement of only a portion of the corneal layers of the host cornea with the graft. Indications: -Opacification of superficial corneal stroma -Marginal thinning or infiltration -Localised thining / descematocele formation
- 52. TYPES OF LAMELLARKERATOPLASTY Superficial/ Deep anterior lamellar keratoplasty ( SALK/DALK) Descemet stripping automated endothelial keratoplasty (DSAEK) Descemet membrane Endothelial Keratoplasty (DMEK)
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- 54. TRIPLE PROCEDURE Cataractextraction Intraocular lens implantation Corneal transplantation
- 55. LEGAL ASPECTS ININDIA Under the Transplantation of Human Organs Act, 1994 (THOA) 1. The qualification of doctors permitted to perform enucleation (surgical eye removal) has been reduced from MS (Ophth.) to MBBS. 2. Eye donation in India is always decided by the donor’s surviving relatives and not by the actual donor. 3. Enucleating doctors always have to legally obtain a written consent from the relatives of the deceased before they actually remove the eyes.
- 56. Don't Burn orBury Your Eyes..... Help Others See Our Beautiful World Too!
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Editor's Notes
- #9 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.