Download MBBS (Bachelor of Medicine, Bachelor of Surgery) Ophthalmology PPT 3 Eye Banking Lecture Notes
EYE BANKING
Department of Ophthalmology
Learning Objectives
At the end of the class, students shall be able to
? Understand the importance and need of eye banking
? Have basic knowledge of structure and functions of
eye banks
? Understand the various surgical procedures for
corneal transplantation
History
? 1903: E. Zirm(Czechoslovakia) performed 1st
successful human corneal transplantation.
? 1935: V P Filatov (Russia): Father of
keratoplasty and modern eye banking.
? 1944: Dr. R. Townley Paton established the first
eye bank in New York City.
? 1945: The first eye bank in India was started in
Regional Institute of Ophthalmology, Chennai.
? 1960 : 1st successful corneal transplantation in
India by Dr. Dhanda (Indore).
? 1974: McKarey and Kaufman developed M-
K medium which allowed the excised
corneo-scleral rim to be preserved for
up to 4 days at 4?C.
? 1985: Kaufman et al. presented K-Sol as a
storage method viable for up to 10 days.
? 1989: Eye Bank Association of India was formed.
WhydowenedanEyeBank?
Infectious keratititis
Injuries
? Open globe injuries
? Chemical injuries
Can be devastating
Need early intervention
What is an Eye Bank ?
Eye Bank is a non profit organization
which deals with the collection, storage
and distribution of the donor cornea for
the purpose of corneal grafting, research
and supply of eye tissues to other eye
banks for ophthalmic purposes.
Structure of Eye Bank
? Medical section : Medical Director ( A qualified
Corneal Surgeon), Trained technicians
? Administrative Section: Eye Donation Counsellor /
Social Worker / Health Educator / Clerk
Functions of the Administrative Section
The administrative section is responsible for
- Public awareness programmes
- Liaison with government, local voluntary and
other health care agencies
- Fund raising
Functions of the Medical Section
Medical section deals with the entire technical
operation of the eye bank:
-Tissue harvesting, evaluation, preservation and
distribution
(maintaining medical quality of highest standard).
Functions of the Eye Bank
Networking of eye banks under the umbrella of a national
organisation ( e.g. Eye Bank Association of India) allows
-Public education programmes
- Institution of newer eye banking procedures
- Training programmes and
development of uniform medical standards
Eye Banking System
Eye Banking System
Eye 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 programs on eye donation.
? Co-ordinate with donor families and hospitals to motivate eye
donation/Hospital Cornea Retrieval Programs ? (HCRP)
? To harvest corneal tissue
? To process, preserve and evaluate the col ected tissue
? To distribute tissue in an equitable manner for Keratoplasty
? To ensure safe transportation of tissue
Eye Bank Training Centre (EBTC)
? Al of the eye bank functions plus training for al levels of personnel in
eye banking and research.
Equipments
EQUIPMENTS
EBTC
EB
EDC
Slit lamp
Required
Required
Not required
Refrigerators
Required
Required
Preferable
Serology
Required
Required
Not required
Specular
Required
Required if
Not required
microscope
col ection is
200/yr
Instruments for
Required
Required
Required
corneal excision
Autoclave
Required
Required
Should have
access
Laminar flow
Required
Required
Required
hood
How It Works ?
Recovery or
retrieval
Cornea
Processing
Distribution
Deceased family cal s Eye Bank
Grief counselor motivates
and obtains consent
Retrieval/ Recovery of
tissue
Tissue Retrieval
? Contraindications:
Systemic:
Ocular:
? AIDS
? Intrinsic eye diseases
? Rabies
? Retinoblastoma
? Active viral hepatitis
? Active
? Creutzfeldt-Jakob disease
conjuctivitis,iritis,uveitis,
? SSPE
vitritis,retinitis
? Reye's syndrome
? Congenital abnormalities
? Death from unknown causes
(keratoconus)
? Congenital Rubel a
? Central
? Active septicemia
opacities,pterygium
? Leukemia (blast form)
? Prior refractive
? Lymphoma/lymphosarcoma
procedures (radial
keratotomy)
Preliminary preparations
? Obtain legal permission.
? Go through the donor's medical records for any
contraindications.
? Wash hands and be prepared with aseptic dressing.
? Identify the donor.
? Collection of postmortem blood:10ml
? Femoral vein
? Subclavian vein
? Heart
? Jugular vein
Enucleation
Corneo-scleral button excision
Serological testing
? HIV
? HBV
? HCV
? Syphilis
Evaluation of donor tissue
? Gross examination
? 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 to rule out contamination.
Evaluation of donor tissue
? Slit Lamp Biomicroscopic examination
Endothelial cell count
AGE
Average
Endothelial cell
count
10-19
2,900-3,500
20-29
2,600-3,400
Critical cell density:
30-39
2,400-3,200
300-500 cells/mm2
40-49
2,300-3,100
Functional cell density:
50-59
2,100-2,900
1500-2200 cells/mm2
60-69
2,000-2,800
70-79
1,800-2,600
80-89
1,500-2,300
* Philips C, Laing R, Yee R. Specular Microscopy. In: Krachmer JH, Mannis MJ, Hol and 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
Storage of donor tissue
Storage
Short term
Intermediate
Long term
2-3days
Very long term
7-10days
30days
Moist chamber
Organ culture
1year
(24hrs)
K-sol,
medium,
Cryopreservation
M-K medium
Dexsol,Optisol,
MEM
Optisol GS
Preservation of cornea
? Moist chamber storage
? Storage of whole globe
? 4C
? 24 hours
? Advantage: Simple
? Disadvantage:
Corneal stromal edema.
Preservation of cornea
? Tissue Media
Cornea storage Storage time
o Dextran
Media
(days)
o Chondroitin sulphate
MK
4
o Electrolytes
o pH buffer system
K-SOL
7
o Antibiotics
CSM
7
o Essential amino acids
o Antioxidants,ATP precursors
DEXSOL
10
o Insulin
OPTISOL
14
o Epidermal growth factor
PROCELL
14
o Antiprotease,anticoagulants
M-K medium:
? Described by Mc-Carey & Kauffman.
? Mixture of tissue culture medium (TC-199) and Dextran
(5%,40,000 MW)
? Buffer: HEPES (N hydroxyethyl- piperazine-N-ethane
Sulphonic acid)
? Antibiotics:Penicillin,Gentamicin,Polymyxin
? Storage period- 96hrs.
K-Sol:
? Purified chondroitin sulphate in tissue culture medium
(TC 199).
? Storage:7-10days in 40 C.
Preservation of cornea
? Long term Organ Culture storage system
? MEM media(minimum essential media)
? Developed by Harry Eagle.
? 34 degree C
? Incubated at room temperature in nutrient medium
? Storage period : 30 days
? Advantage: Enables HLA matching
? Very long time preservation:
? Cryopreservation
? 1year
CORNEAL TRANSPLANTATION
Cornea as transplant
? Immune privilege of cornea
? Absence of blood and lymphatic channel in the graft and
its bed
? Absence of MHC class I APCs in the graft
? Reduced expression of MHC coded alloantigen on graft
cells
? Immunosupressive microenvironment of aqueous humor.
? Anterior chamber associated immune deviation.
Corneal Transplantation
? Corneal transplantation 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)
Corneal Transplantation :Schematic
Types of Keratoplasty
? Optical ? to improve vision
? Tectonic- to restore or preserve corneal integrity
? Therapeutic- to remove infected corneal tissue
? Cosmetic- to improve appearance
Keratoplasty : Schematic Diagram
Indications of Penetrating Keratoplasty(
PK)
? Keratoconus
? Post- cataract surgery edema
? Corneal dystrophies and degenerations
? Mechanical or chemical trauma
? Microbial/postmicrobial keratitis
? Congenital opacity
Lamellar keratoplasty
? Lamellar keratoplasty 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 thinning / descemetocele formation
Types of Lamellar Keratoplasty
? Superficial/ Deep anterior lamellar keratoplasty
( SALK/DALK)
? Descemet stripping automated endothelial
keratoplasty (DSAEK)
? Descemet membrane endothelial keratoplasty
(DMEK)
LEGAL ASPECTS IN INDIA
? 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.
This post was last modified on 07 April 2022