This document discusses corneal transplantation, including definitions, types (penetrating keratoplasty and lamellar keratoplasty), indications, donor evaluation and storage, contraindications, surgical techniques, and postoperative care and complications. It provides details on penetrating keratoplasty, including that it is the most common type and its main indications are diseases involving all corneal layers. It also summarizes anterior and posterior lamellar keratoplasty.

1. Dr. Atul Kumar Anand
Senior Resident
AIIMS Patna

2. Definition: It is an operation in which the
patient's diseased cornea is replaced by
the donor's healthy clear cornea.
Types:
1. Penetrating keratoplasty (full-thickness
grafting)
2. Lamellar keratoplasty (partial-thickness
grafting) -anterior or posterior lamellar

3. Indications
 Optical ,i.e., to improve vision - corneal
opacity, bullous keratopathy, corneal
dystrophies, advanced keratoconus.
 Therapeutic, i.e., to replace inflamed cornea
not responding to conventional therapy
 Tectonic graft, i.e., to restore integrity of
eyeball in eyes with severe structural changes
such as severe thinning with descemetocele.
 Cosmetic, i.e., to improve the appearance of
the eye.

4.  removed as early as possible (12–24 hours of
death).
 Corneas from infants (3 years and under) are
rarely used -surgical, refractive and rejection
problems.
 It should be stored under sterile conditions.
 Evaluation –medical history review and donor
blood screening to exclude contraindications,
and microscopic examination of the cornea
including endothelial cell count determination

5. Short-term storage (up to 2 days) -The
whole globe is preserved at 40C in a moist
chamber.
Intermediate storage (up to 2 weeks) -
McCarey-Kaufman (MK) medium and
various chondroitin sulfate enriched media
such as optisol medium used.
Long-term storage (up to 35 days) -It is
done by organ culture method.

6.  Death of unknown cause.
 Certain systemic infections such as HIV, viral
hepatitis, syphilis, congenital rubella,
tuberculosis, septicemia and active malaria.
 Prior high-risk behavior for HIV and hepatitis.
 infectious diseases of the CNS.
 Receipt of a transplanted organ.
 Most hematological malignancies.
 Ocular disease such as inflammation and
malignancies (e.g. retinoblastoma) and
corneal refractive surgery.

7.  Severe stromal vascularization, extreme
thinning at the proposed host-graft junction
and active corneal inflammation.
 Abnormalities of the eyelids (blepharitis,
ectropion, entropion and trichiasis).
 Recurrent or progressive forms of
conjunctival inflammation.
 Tear film dysfunction.
 Anterior synechiae.
 Uncontrolled glaucoma.
 Uveitis.

8. most commonly performed corneal
transplantation procedure.
INDICATIONS INCLUDE:
Disease involving all layers of the cornea.
Specific common indications: keratoconus,
pseudophakic bullous keratopathy, Fuchs
endothelial and other dystrophies.

9.  Determination of graft size:
- by trial placement of trephines with different
diameters or by measurement with a caliper.
- An ideal size is 7.5 mm.
- grafts smaller than this may give rise to high
astigmatism.
- Grafts of diameter 8.5 mm or more are prone
to postoperative anterior synechiae formation,
vascularization and increased intraocular
pressure.

10. Excision of donor corneal button -The
donor corneal button should be trephined
0.25 mm larger than the recipient, taking
care not to damage the endothelium.

11. Excision of recipient corneal button -
care should be taken, not to damage the
iris and lens.

12. Suturing of corneal graft into the host bed
is done with either continuous or interrupted
10-0 nylon sutures.

13.  Topical steroids are used to decrease the risk of
immunological graft rejection.
 Other immunosuppressant –azathioprine,
cyclosporin may be rarely used in high-risk for
prevention of rejection.
 Mydriatics - if uveitis persists.
 Monitoring of IOP is performed during the early
postoperative period.
 Removal of sutures when the graft-host junction
has healed. This is usually after 12–18 months.
 Rigid contact lenses -to optimize visual acuity in
eyes with astigmatism.

14.  Early complications: persistent epithelial
defects, irritation by protruding sutures,
wound leak, flat anterior chamber, iris
prolapse, uveitis, elevation of intraocular
pressure, microbial keratitis and
endophthalmitis .
 Late: astigmatism, recurrence of initial
disease process, late wound separation,
retro-corneal membrane formation, glaucoma
and cystoid macular oedema.

15. This involves partial thickness excision of
the corneal epithelium and stroma.
endothelium and part of the deep stroma
are left behind.
Indications:
 Opacification of the superficial one-third of the corneal
stroma.
 Marginal corneal thinning or infiltration as in recurrent
pterygium, marginal degeneration.
 Localized thinning or descemetocele formation.

16.  Opaque corneal tissue is removed almost to the level
of Descemet membrane.
 decreased risk of rejection because the endothelium, a
major target for rejection, is not transplanted.
Indications:
 Disease involving the anterior 95% of corneal
thickness with a normal endothelium and absence of
breaks or scars in Descemet membrane .
 Chronic inflammatory disease such as atopic
keratoconjunctivitis which carries an increased risk of
graft rejection.

17.  It involves removal only of diseased
endothelium along with Descemet membrane,
through a corneoscleral or corneal incision.
 Folded donor tissue is introduced through the
same small (about 5 mm) incision.
Indications:
 include endothelial disease such as
pseudophakic bullous keratopathy.