Download MBBS Ophthalmology PPT 3 Eye Banking Lecture Notes

EYE BANKING

Department of Ophthalmology

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Learning Objectives

At the end of the class, students shall be able to

? Understand the importance and need of eye banking

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? Have basic knowledge of structure and functions of

eye banks

? Understand the various surgical procedures for

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corneal transplantation
History

? 1903: E. Zirm(Czechoslovakia) performed 1st

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successful human corneal transplantation.

? 1935: V P Filatov (Russia): Father of

keratoplasty and modern eye banking.

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? 1944: Dr. R. Townley Paton established the first

eye bank in New York City.

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? 1945: The first eye bank in India was started in

Regional Institute of Ophthalmology, Chennai.

? 1960 : 1st successful corneal transplantation in

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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.

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? 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.

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WhydowenedanEyeBank?



Infectious keratititis

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Injuries

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? Open globe injuries
? Chemical injuries

Can be devastating
Need early intervention

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What is an Eye Bank ?

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Eye Bank is a non profit organization

which deals with the collection, storage

and distribution of the donor cornea for

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the purpose of corneal grafting, research

and supply of eye tissues to other eye

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banks for ophthalmic purposes.

Structure of Eye Bank

? Medical section : Medical Director ( A qualified

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Corneal Surgeon), Trained technicians

? Administrative Section: Eye Donation Counsellor /

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Social Worker / Health Educator / Clerk
Functions of the Administrative Section

The administrative section is responsible for

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- Public awareness programmes

- Liaison with government, local voluntary and

other health care agencies

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- Fund raising

Functions of the Medical Section

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Medical section deals with the entire technical

operation of the eye bank:

-Tissue harvesting, evaluation, preservation and

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distribution

(maintaining medical quality of highest standard).

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Functions of the Eye Bank

Networking of eye banks under the umbrella of a national

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organisation ( e.g. Eye Bank Association of India) allows
-Public education programmes
- Institution of newer eye banking procedures
- Training programmes and

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development of uniform medical standards

Eye Banking System
Eye Banking System

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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

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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)

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? 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

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donation/Hospital Cornea Retrieval Programs ? (HCRP)

? To harvest corneal tissue
? To process, preserve and evaluate the col ected tissue

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? 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

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eye banking and research.


Equipments

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EQUIPMENTS

EBTC

EB

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EDC

Slit lamp

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Required

Required

Not required

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Refrigerators

Required

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Required

Preferable

Serology

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Required

Required

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Not required

Specular

Required

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Required if

Not required

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microscope

col ection is

200/yr

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Instruments for

Required

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Required

Required

corneal excision

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Autoclave

Required

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Required

Should have

access

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Laminar flow

Required

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Required

Required

hood

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How It Works ?

Recovery or

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retrieval

Cornea

Processing

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Distribution

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Deceased family cal s Eye Bank

Grief counselor motivates

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and obtains consent

Retrieval/ Recovery of

tissue

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Tissue Retrieval

? Contraindications:

Systemic:

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Ocular:

? AIDS

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? Intrinsic eye diseases

? Rabies

? Retinoblastoma

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? Active viral hepatitis

? Active

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? Creutzfeldt-Jakob disease

conjuctivitis,iritis,uveitis,

? SSPE

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vitritis,retinitis

? Reye's syndrome

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? Congenital abnormalities

? Death from unknown causes

(keratoconus)

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? Congenital Rubel a

? Central

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? Active septicemia

opacities,pterygium

? Leukemia (blast form)

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? Prior refractive

? Lymphoma/lymphosarcoma

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procedures (radial

keratotomy)

Preliminary preparations

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? Obtain legal permission.
? Go through the donor's medical records for any

contraindications.

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? Wash hands and be prepared with aseptic dressing.
? Identify the donor.
? Collection of postmortem blood:10ml
? Femoral vein

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? Subclavian vein
? Heart
? Jugular vein

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Enucleation

Corneo-scleral button excision

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Serological testing

? HIV

? HBV

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? HCV

? Syphilis

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Evaluation of donor tissue

? Gross examination
? Whole globe: eyes with excessive stromal

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hydration should be discarded unless specular

microscopy can be done for endothelial cell

count.

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? Corneoscleral button:
Colour of the tissue storage media is to be
noted to rule out contamination.

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Evaluation of donor tissue

? Slit Lamp Biomicroscopic examination

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Endothelial cell count

AGE

Average

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Endothelial cell

count

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10-19

2,900-3,500

20-29

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2,600-3,400

Critical cell density:

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30-39

2,400-3,200

300-500 cells/mm2

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40-49

2,300-3,100

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Functional cell density:

50-59

2,100-2,900

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1500-2200 cells/mm2

60-69

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2,000-2,800

70-79

1,800-2,600

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80-89

1,500-2,300

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* 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*

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? 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).

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? Extreme polymegathism or pleomorphism.
? Presence of significant guttata.
? Presence of many non-hexagonal or abnormally shaped

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cells.

? Presence of inflammatory cells, bacteria, or debris on

endothelial surface.

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? Numerous vacuolated cells.

*Standards of Eye banking in India 2009;NPCB;Director General of Health & Family Welfare, Govt. of India

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Storage of donor tissue

Storage

Short term

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Intermediate

Long term

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2-3days

Very long term

7-10days

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30days

Moist chamber

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Organ culture

1year

(24hrs)

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K-sol,

medium,

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Cryopreservation

M-K medium

Dexsol,Optisol,

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MEM

Optisol GS

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Preservation of cornea

? Moist chamber storage
? Storage of whole globe

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? 4C
? 24 hours
? Advantage: Simple
? Disadvantage:
Corneal stromal edema.

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Preservation of cornea

? Tissue Media

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Cornea storage Storage time

o Dextran

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Media

(days)

o Chondroitin sulphate

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MK

4

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o Electrolytes

o pH buffer system

K-SOL

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7

o Antibiotics

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CSM

7

o Essential amino acids

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o Antioxidants,ATP precursors

DEXSOL

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10

o Insulin

OPTISOL

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14

o Epidermal growth factor

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PROCELL

14

o Antiprotease,anticoagulants

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M-K medium:
? Described by Mc-Carey & Kauffman.
? Mixture of tissue culture medium (TC-199) and Dextran

(5%,40,000 MW)

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? Buffer: HEPES (N hydroxyethyl- piperazine-N-ethane

Sulphonic acid)

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? Antibiotics:Penicillin,Gentamicin,Polymyxin
? Storage period- 96hrs.
K-Sol:
? Purified chondroitin sulphate in tissue culture medium

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(TC 199).

? Storage:7-10days in 40 C.

Preservation of cornea

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? Long term Organ Culture storage system
? MEM media(minimum essential media)
? Developed by Harry Eagle.
? 34 degree C

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? Incubated at room temperature in nutrient medium
? Storage period : 30 days
? Advantage: Enables HLA matching

? Very long time preservation:

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? Cryopreservation
? 1year
CORNEAL TRANSPLANTATION

Cornea as transplant

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? Immune privilege of cornea
? Absence of blood and lymphatic channel in the graft and

its bed

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? Absence of MHC class I APCs in the graft
? Reduced expression of MHC coded alloantigen on graft

cells

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? Immunosupressive microenvironment of aqueous humor.
? Anterior chamber associated immune deviation.
Corneal Transplantation

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? Corneal transplantation refers to surgical replacement of a

full-thickness or lamellar portion of the host cornea with
that of a donor eye.

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? Allograft/autograft

? Full-thickness( Penetrating)/ Partial thickness ( lamellar)

Corneal Transplantation :Schematic

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Types of Keratoplasty

? Optical ? to improve vision

? Tectonic- to restore or preserve corneal integrity

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? Therapeutic- to remove infected corneal tissue

? Cosmetic- to improve appearance

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Keratoplasty : Schematic Diagram
Indications of Penetrating Keratoplasty(

PK)

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? Keratoconus

? Post- cataract surgery edema

? Corneal dystrophies and degenerations

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? Mechanical or chemical trauma

? Microbial/postmicrobial keratitis

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? Congenital opacity

Lamellar keratoplasty

? Lamellar keratoplasty refers to replacement of only a portion

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of the corneal layers of the host cornea with the graft.

? Indications:

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-Opacification of superficial corneal stroma

-Marginal thinning or infiltration
-Localised thinning / descemetocele formation
Types of Lamellar Keratoplasty

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? Superficial/ Deep anterior lamellar keratoplasty
( SALK/DALK)
? Descemet stripping automated endothelial

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keratoplasty (DSAEK)

? Descemet membrane endothelial keratoplasty

(DMEK)

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LEGAL ASPECTS IN INDIA

? Under the Transplantation of Human Organs Act, 1994

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(THOA)

1. The qualification of doctors permitted to perform

enucleation (surgical eye removal) has been reduced

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from MS (Ophth.) to MBBS.

2. Eye donation in India is always decided by the

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donor's surviving relatives and not by the actual

donor.

3. Enucleating doctors always have to legally obtain a

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written consent from the relatives of the deceased

before they actually remove the eyes.