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1. KERATOPLASTY
- Dr. Narang

2. Keratoplasty/corneal grafting /
corneal transplantation
• 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. Donor tissue :
• 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. Methods of corneal preservation
• 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. Contraindications to ocular
tissue donation
• Death of unknown cause.
• Certain systemic infections such as HIV, viral hepatitis, syphilis,
congenital rubella, tuberculosis, septicaemia 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. Host factors may adversely affect
the prognosis:
• 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. Penetrating keratoplasty
• 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. Technique:
• Determination of graft size:
- by trial placement of trephines with different diameters or by
measurement with a calliper.
- 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.
- to facilitate watertight closure, minimize postoperative
flattening and reduce the possibility of postoperative
glaucoma.

11. • Excision of recipient corneal button - care should be taken,
not to damage the iris and lens.
- Recipient trephining can be performed freehand or with
suction trephine systems which stabilize the globe and ensure
that the angle of trephination is perpendicular to the surface.

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

13. Postoperative management:
• Topical steroids are used to decrease the risk of
immunological graft rejection.
• Other immunosuppressants –azathioprine, ciclosporin 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. Postoperative complications:
• 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. Superficial lamellar keratoplasty
• 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. Deep anterior lamellar keratoplasty
• 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. Descemetstripping endothelialkeratoplasty
• 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.