2. DONOR TISSUE : EVALUATION AND
PRESERVATION
• Evaluation of donor tissue:
• Biomedical examination of the whole globe, before processing the
tissue for media storage, is very important . The donor corneal tissue
is graded into excellent , very good, good, fair, and poor depending
upon the condition of the corneal epithelium, stroma, Descemet’s
membrane and endothelium
3. Table 1: Grading of donor cornea on slit-lamp biomicroscopic examination
Grade of donor corneal tissue
Parameter Grade I Grade II Grade III Grade IV Grade V
Epithelial defects
and haze
None Slight epithelial
haze
Obvious moderate
epithelial defects
Corneal stroma
cavity
Crystal clear Clear Slight cloudiness Moderate
cloudiness
Marked cloudiness
Arcus senilis None Slight Moderate
(<2.5mm)
Heavy(>2.5-4mm) Very heavy(>4mm)
Descemet’s
membrane No folds
Few shallow folds Numerous shallow
folds
Numerous deep
folds
Marked deep folds
Endothelium No defect No defect Few vacuolated
cells
Moderate guttate Marked guttate
4. • Specular microscopy should be done for endothelial cell count and
morphology
• Microbial evaluation by culture from the conjunctival swab from
deceased is ideal
• Serological screening for HIV, hepatitis B, hepatitis C and syphilis
should be done from the blood collected from the deceased
5. METHODS OF CORNEAL PRESERVATION
1. Short-term storage(24 hrs to 96 hrs ) methods include:
• Moist chamber method: the whole globe can be preserved in a moist chamber at
4°C in a refrigerator upto 24 hours
• McCarey Kaufman medium: it is of pink colour and comprises of: Tissue culture-
199, 5%, Dextran-40, HEPES buffer and gentamycin 0.1mg/ml.
• Donor corneoscleral rim can be preserved in the M-K mediu up to 96 hours. It is
the most commonly used method in India and world over . Corneoscleral rim can
be excised in situ from the cadaver or can be prepare in the laboratory from the
enucleated eyeball, and is immediately stored in the storage medium
6. 2. Intermediate-term storage (up to 2 weeks):
• Optisol GS . It comprises of 2.5% chondroitin sulphate, 1% dextran, ascorbic acid,
vitamin B12, ATP precursors, and the antibiotics gentamycin and streptomycin
• Other media are Cornisol, Eusol and Life-GE medium
3. Long-term storage (up to months to years):
• Glycerine preservation can be done for 3-4 weeks
• Organ culture method at 30°C to 37°C is useful for preservation up to 35 days
• Cryoperservation of corneal button at -70°C can be done up to 1 year
7. PROCESSING KIT CLEANING AND DISINFECTION OF DONOR EYE
REMOVAL OF CORNEOSCLERAL RIM
FROM WHOLE GLOBE
TRANSFER OF DONOR BUTTON TO
PRESERVATIVE MEDIA
8. EYE BANKING
• An eye bank is a non-profit organization with an aim to acquire and provide
donated human eye tissue for corneal transplantation procedures in addition to
providing vital tissue for research and education.
• It also stores and preserves human corneal tissue for future use.
• The eye bank also holds the responsibilities of ensuring the safety and efficacy of
donor corneas together with fair and equitable distribution of transplantable
corneas.
• All these services are provided in an environment of stringent quality assurance
standards with focus not merely on the quantity of tissue provided but also on
the quality of tissue and quality of service offered.
9. • The process of corneal transplantation begins with corneal donation. The
selection of donor corneal tissue is influenced by the potential for transmission of
disease to the recipient and also by the quality or potential efficacy of the tissue.
• Standards and guidelines for donor selection were initially developed by the Eye
Banking Association of America who produced their first set of Medical Standards
in 1980.
• A rigorous review process has ensured that these Medical Standards continue to
evolve as new knowledge and insight develops
10. 1. Death of unknown cause
2. Death from central nervous system disease of unestablished diagnosis
3. Creutzfelt-Jacob disease or a risk factor
4. Subacute sclerosing panencephalitis
5. Progressive multifocal leukoencephalopathy
6. Congenital rubella
7. Reyes syndrome
8. Active viral encephalitis or encephalitis of unknown origin
9. Active septicemia (bacteremia, fungemia, viremia)
10. Active bacterial or fungal endocarditis
11. Active viral hepatitis
12. Rabies
CONTRAINDICATIONS FOR THE USE OF DONOR
TISSUE FOR KERATOPLASTY
11. 13. Active leukaemia's
14. Active disseminated lymphomas (Hodgkin's disease, Malignant non-Hodgkins lymphoma, Burkitt’s
lymphoma, Mycosis fungoides, Multiple myeloma, Macroglobulinemia, Heavy Chain disease)
15. High risk for HIV infection
16. Hepatitis B surface antigen positive donors
17. HTLV-I or HTLV-II infection
18. Hepatitis C seropositive donors
19. HIV seropositive donors
20. HIV or high risk for HIV infection
21. Retinoblastoma, malignant tumours of the anterior ocular segment
22. Active ocular or intraocular inflammation
23. Congenital or acquired disorders of the eye which would preclude a successful outcome for the intended
use
24. Prior intraocular surgery or anterior segment surgery (Refractive corneal procedures, Laser photoablation
surgery)
25. Behavioural and or social issues, i.e. homosexual or other high risk sexual behavior within the last five
years, intravenous drug use for non medical reasons within the last five years, exposure to infectious disease
within the last year by contact with an open wound, needle stick, or mucous membrane or tattooing or
piercing within the last 12 months using shared instruments
13. VISION 2020
• VISION 2020: The right to sight is the common agenda launched by
the World Health Organization and a task force of International
Nongovernmental Organizations to combat this gigantic problem.
• VISION 2020 was officially launched by the WHO in 1999.
• VISION 2020 was launched by the Government of India in 2001.
14. • Goal : The aim of VISION 2020 is to eliminate avoidable blindness
worldwide by the year 2020
• The five conditions for global action were:
• Cataract
• Refractive errors/low vision
• Trachoma
• Onchocerciasis
• Vitamin A deficiency related and other causes of childhood blindness.
15. • Objectives:
• To raise the profile among key stake holders of the causes
of avoidable blindness and of the solutions that will help
eliminate the problem.
• Identify and secure the necessary resources around the
world in order to provide an increased level of activity in
prevention and treatment programs.
• Facilitate the planning, development and implementation
of three elements of the VISION 2020 strategic plan by
national programs
16. NATIONAL PROGRAM FOR CONTROL OF
BLINDENSS (NPCB)
• National Program for Control of Blindness (NPCB) was launched with the goal of
reducing the prevalence of blindness from 1.4 percent to 0.3 percent of
population
• The overall objectives of the NPCB launched in 1976 were:
• Provision of comprehensive eye care facilities at the primary, secondary and
tertiary levels of health care.
• Substantial reduction in the prevalence of eye diseases..
17. • The major component activities planned included:
• Intensification of education efforts on eye health care through mass communication
media and extension education methods.
• Extension of eye care facilities through units, to restore sight and to relieve eye
ailments, by adopting an eye camp approach .
• Establishment of permanent facilities for eye health care as an integral part of the
general health services at peripheral, intermediate and central levels.
