This document provides information on penetrating keratoplasty (PKP), which involves replacing the full thickness of diseased corneal tissue with donor corneal tissue. It discusses the types of PKP including optical, therapeutic, and tectonic. The common indications for PKP include corneal scarring, infections, dystrophies, and thinning. Preoperative evaluation and obtaining a suitable donor corneal tissue is important. The surgical procedure involves trephination of the donor and host corneas followed by suturing the donor graft. Postoperative complications can include rejection, infections, glaucoma and astigmatism. Long term graft survival depends on the preoperative diagnosis and condition.

1. PENETRATING
KERATOPLASTY
DR NIKITA JAISWAL

2. GLOSSARY
• INTRODUCTION
• TYPES
• INDICATIONS
• DONOR CORNEA & PRE OPERATIVE EVALUATION
• COMPLICATIONS

4. HISTORY
1905 by Eduard Zirm

5. INTRODUCTION
• Penetrating keratoplasty
(PKP).
• This comprises of replacing full
thickness host corneal tissue
with a full thickness donor
corneal tissue.

6. OPTICAL
THERAPE
UTIC
TECTONIC
COSMETIC
TYPE
S
OBTAINING A CLEAR VISUAL
AXIS FOR VISUAL
REHABILITATION
TO ELIMINATE CORNEAL
INFECTION
TO PROVIDE
SUPPORT
IMPROVE APPEARNANCE OF
EYES WITH A WHITISH
CORNEAL SCAR

7. INDICATIONS
OPTICAL
• Pseudophakic/aphakia
• Stromal corneal dystrophies
• Primary corneal endotheliopathies
• Corneal ectasias & thinning.
• Congenital corneal opacity
• Acquired corneal scars
• Non infectious ulcerative keratitis.

8. THERAPEUTIC
• NON HEALING INFECTIOUS
KERATITIS
• INFECTIOUS KERATITIS
WITH PERFORATION
• POST CHEMICAL INJURY

9. TECTONIC
• RECONSTRUCTION OF OCULAR
SURFACE
• TO STRENGTHEN THE CORNEA IN
CASE OF CORNEAL MELTS
• CORNEAL THINNING.

10. PREOPERATIVE EVALUATION

11. OCULAR EVALUATION
• Ocular history
• Visual acuity
• Detailed examination:
Underlying pathology
IOP
Vascularization
Tear film status
Presence of cataract
Need for IOL exchange
B-scan

12. SURGICAL TECHNIQUE
• PREOPERATIVE EVALUATION
• SURGICAL PROCEDURE
• SUTURING TECHNIQUE

13. PREOPERATIVE PREPARATION
• ANTI INFECTIVE AGENTS:PRE OP ANTIBIOTICS
TREATMENT OF BLEPHARITIS
5% POVIDINE IODINE SOLUTION
 IOP CONTROL: PRE-OP MANNITOL
HONAN’S BALLOON COMPRESSION AT 30 MM HG
GOOD LID EXTRA OCULAR AKINESIA.
 ANESTHESIA : PERIBULBAR ANESTHETIA WITH OR WITHOUT LID
BLOCK
GENERAL ANAESTHESIA FOR PAEDIATRIC CASES
APPREHENSIVE PATIENTS
MENTAL IMPAIRMENT
 PUPIL DILATATION: PUPIL CONSTRICTION WITH 2% PILOCARPINE
PUPIL DILATATION WITH MYDRIATICS WHEN CATARACT
SURGERY IS PLANNED

14. SURGICAL PROCEDURE
• TREPHINIZATION
• GRAFT SIZING
• HIGHLIGHTS OF TRIPLE PROCEDURE

15. TREPHINATION
• DONOR TREPHINATION
• HOST TREPHINATION

16. DONOR TREPHINATION
• Trephination of the donor button should
preferably be performed from the epithelial
side using an artificial anterior chamber
with a large central opening
• Punching the donor from the endothelial
side results in an undercut at the level of
Descemet’s membrane with convergent cut
angles

18. HOST TREPHINATION
• Horizontal positioning of limbal plane is
indispensable
• Flieringa ring is only necessary in aphakic
eyes
• The higher the intraocular pressure
(iatrogenic!) the more divergent are the
cut angles to be expected

19. Combination of donor trephined from the
endothelial side (convergent cut angle) and mechanically
trephined recipient (divergent cut angle) results
in a triangular-shaped tissue deficit at the level of
Descemet’s membrane which has to be compensated
by suture tension resulting in central flattening

20. • graft size has to be judged by the microsurgeon
individually in every single case
before recipient trephination to achieve the
best compromise between immunologic
purposes and optical quality
ς donor trephination from the endothelial
side results in a smaller donor button than
trephine size and convergent cut angles
(“undercut”)
ς recipient trephination results in larger
openings than trephine size and divergent
cut angles
ς this discrepancy makes a donor “oversize”
of ≥0.25 mm necessary
ς same size grafts are feasible
if the donor is
created by means of an artificial
anterior
chamber from the epithelial
side
ς
undersizing the graft for simultaneous

22. Hessburg-Barron suction trephine.
A Recipient trephine with cross-hairs for
centration;
B Donor trephination is performed from the
endothelial
side

23. GRAFT
• A good optical performance
requires a larger graft, whereas a low rate of
immunologic graft reactions tends to be seen
with smaller grafts.

24. TRIPLE PROCEDURE
• Comprises of grafting+extraction of cataract+IOL
implantation.
• PEARL:
• Cataract should be removed regardless of the stage as
later it will progress & then it can cause damage to the
corneal endothelium.
• Vitreous can be removed with vannazs or wide bore
canula.(host –graft junction should be free of vitreous)
• IOL insertion-routine insertion if not then the lens can be
sutured to the iris or to the sclera.

25. MEDIUM FOR CORNEAL PRESERVATION
• Short term storage
• Intermediate storage
• Long term storage

26. SHORT TERM STORAGE
Method:
• Moist chamber method:
when globe is preserved
at 4’c with saline
humidification for upto 48
hrs.
Endothelial viability
depends on:
• Enucleation within 6 hours of
death.
• Cool enviornment
maintainence until enucleation
• Maintaining 4’C
• Careful slit lamp examination

27. INTERMEDIATE TERM STORAGE
TERM
STORAGE
McCAREY- KAUFMAN
Chondroitin
sulfate
enriched
dexol medium
Optisol medium

28. McCAREY –KAUFMAN MEDIUM
ORIGINAL
• TC199
• 5% Dextran
• Bicarbonate buffer
• Penicillin&streptomycin(100uni
t/ml) later substituted by
gentamycin in conc of 50-
200µg/mi
MODIFIED
• Added phenol red as a pH
indicator
• Osmolarity -290mOsm/kg
• pH is 7.4
• k/as modified MK medium
• Cornea can be stored at 4’C
upto 4 days

29. LONG TERM STORAGE
ORGAN CULTURE
• DONOR CORNEA UPTO 35
DAYS
• NO REMARKABLE LOSS OF
ENDOTHELIAL CELLS .
CRYOPRESERVATION
• ONLY TRUE
PRESERVATION
• CAPELLA & KAUFMAN
• Corneoscleral rim—in a series of soln
of dimethyl sulfoxide(DMSO)
upto 7.5%.---placed for 10mins—
upto -80’C & subsequently stored at -
160’C indefinitely.

30. SUTURING TECHNIQUES
• Suture material
• Suture technique (interrupted,
single running, double
running, combinations)
• Length of stitch
• Depth of stitch
• Angle of stitch towards graft-
host apposition
• Suture tension
• “Depth disparity”

31. Correct position of second cardinal
suture (arrow) is facilitated by orientation
tooth
(donor) and corresponding notch (host)

33. SURGICAL OUTCOMES
GROUP 1
• EXCELLENT
PROGNOSIS
>90%
KERATOCONUS
CENTRAL/PARACENTRAL
CORNEAL SCARS
STROMAL DYSTROPHY
GROUP 2
• VERY GOOD
PROGNOSIS
EXPECTED SUCCESS
RATE OF 80-90 %
APHAKIC/P’PHAKIC CORNEAL
ODEMA & BULLOUS
KERATOPATHY
INACTIVE HERPETIC KERATITIS
MACULAR STROMAL DYSTROPHY

34. GROUP 3
• FAIR PROGNOSIS-
SUCCESS RATE 50 TO
80%
Active microbial /herpetic keratitis
Mild chemical injury
Moderate keratoconjunctivitis sicca
GROUP 4
• POOR PROGNOSIS-
<50%
• Severe chemical injury
• Radiation injury
• Steven’s johnson syndrome
• Multiple failed grafts

35. COMPLICATIONS
INTRAOPERATIVE
• SCLERAL PERFORATION
• Trephination related
• Retained descement
membrane
• Endothelial damage
• Intraocular hemmorhage
• Vitreous loss
POSTOPERATIVE
• Wound leak
Persistent epithelial defect
Post op inflammation
Suture related
Raised IOP
Ant synechiae formation
LATE:
Post PK astigmatism
Graft rejection
Post pk glaucoma

37. GRAFT REJECTION
• Time : rarely within 1st month but it can be till 20 years
post PK
• These rejections takes 4 clinical forms
• EPITHELIAL REJECTION:in this immune response—
donor epithelium-lymphocytes causes elevated linear
epithelial ridge—centipetally
The rejection has been reported at the rate of 10% of
patients experiencing rejection
Usually seen in the post op period (1-13 months)

39. SUBEPITHELIAL REJECTION
• They may present as subepithelial infiltrates
• Alone they may cause no symptoms
• Lymphocytes direction is unknown
• Can be seen in broad,tangential light
• These leave no sequelae if treated
• But it may presage the more severe endothelial graft rejection
• STROMAL REJECTION:
• This is uncommon
• If present can present as neovascularization
• In very prolonged bouts the stroma can become necrotic

40. ENDOTHELIAL REJECTION
• THE MOST COMMON TYPE
• 8%-37%
• loss of significant NUMBER OF ENDOTHELIAL CELLS
LEADS TO GRAFT REJECTION
• inflammatory cells seen in anterior chamber.
• endothelium lost—stroma thickens—epithelium
odematous
• pts have--- photophobia,redness,irritation,halos around
light.

41. TREATMENT
• Frequent steroid instillation
• Dexamethasone 0.1%
• Prednisolone0.1%
• Periocular injection of
triamcinolone acetonide for
severe rejection or non
compliant patient.
• PREVENTION
• Early attention to loosening
sutures
• Use of
cyclosporine,tacrolimus,mycop
henolate.

42. o preservative-free topical steroids hourly for 24 hours are the mainstay of
therapy. the frequency is reduced gradually over several weeks. steroid
ointment can be used at bedtime as the regimen is tapered. high-risk
patients can be maintained on the highest tolerated topical dose (e.g.
prednisolone acetate 1% four times daily)
○ topical cycloplegia (e.g. homatropine 2% or atropine 1% OD or BD daily).
○ topical ciclosporin 0.05% to 2% may be of benefit, but the onset of action is
delayed.
○ systemic steroids oral prednisolone 1 mg/kg/day for 1–2 weeks with
subsequent tapering; if given within 8 days of onset IV methylprednisolone 500
mg daily for up to 3 days may be particularly effective, suppressing rejection
and reducing the risk of further episodes.
○ subconjunctival steroid injection (e.g. 0.5 ml of 4 mg/ml dexamethasone).

43. KERATOPROSTHESIS
Group 1
• With good blink rate
• Wet eye
• BOSTON Type 1 K Pro
Group 2
• Significant conjunctival
scarring
• Dry eye & exposure
• Alpha cor
keratoprosthesis

44. Thank you