keratoplasty, partial corneal transplantation, presentation

1. Lamellar Keratoplasty
MODERATOR- DR SUNDEEP
PRESENTER- DR AKSHAY NAYAK

2. DEFINITION
 The replacement of diseased cornea with autologus or heterologus cornea
is called as keratoplasty. In most of the cases the donor cornea is taken
from a deceased person.
 Either full thickness of the cornea or a part of it may be transplanted.

3. Introduction
 For over hundred years Penetrating keratoplasty has been the standard care for corneal
diseases
 PK involves replacing a full thickness of diseased recipient’s cornea with that of a healthy
donor cornea secured into place with 32,16 or 12 sutures
 Claesson et al studied 520 grafts, at 2 years after PK showed a visual acuity of upto
20/40 (6/12)

4. Layers Thick
ness(
um)
Composition
Epithelium 50 Stratified Squamous Epithelium
Bowman’s
Membrane
8-14 Compact layer of unorganised
collagen fibres Stroma
Stroma 500 Orderly arrangement of collagen
lamellae with keratocytes
Descemet’s
Membrane
10-12 Consists of basement membrane
materials
Endothelium 5 single layer of simple squamous
epithelium

5. Types of keratoplasty
Based on the thickness of the cornea transplanted, keratoplasty can be
divided as:
 Penetrating keratoplasty- involved full thickness of the cornea.
 Lamellar keratoplasty- involves transplantation of a part.
 Anterior lamellar : SALK, MALK, DALK, TALK
 Posterior lamellar : DLEK, DMEK, DSAEK,DSEK

6. . LAMELLAR
KERATOPLAST
Y
Anterior
lamellar
Superficial
ALK(SALK)
Mid
ALK(MALK)
Deep
ALK(DALK)
Posterior
lamellar
Deep Lamellar
Endothelial
Keratoplasty(D
LEK)
Descemet’s
stripping
Automated endo
thelium
keratoplasty
DSAEK

8. Donor tissue
 Removed as early as possible (6-12 hours of death).
 Corneas from infants (2 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

11. 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.

12. Contraindications for donation of
corneal tissue
Absolute
 Rabies
 HIV, viral hepatitis, syphilis and active malaria.
 Septicaemia
 Prior high-risk behavior for HIV and hepatitis.
 infectious diseases of the CNS.
 Creutzfeldt-Jacob disease
Relative
 Most hematological malignancies.
 Ocular disease such as inflammation and malignancies (e.g. retinoblastoma) and corneal
refractive surgery.
 Death of unknown cause.
 Congenital rubella, tuberculosis

13. Why there is
need for an
alternative to
PK?????

14. Because
 PKP induced astigmatism in range of 3 to 7 diopters
 Decline in endothelial cell count leading to graft failure
 Allograft rejection and endothelial decompensation were the major concerns
 Postoperative discomforts and wound healing time more
 Wound strength in lamellar graft superior
 Non penetrating surgery, it reduces the risk of intraocular complications like glaucoma,
cataract, CME,RD, endophthalmitis
 Graft quality , endothelium count should be good in cases of PK compared to LK

15. LAMELLAR KERATOPLASTY
 Involves a partial thickness of the cornea that is transplanted only on the
diseased portion.
 Less invasive procedure but involves finer surgical skill and more refined
instrumentation.

16. History
 In 1824 Reisinger performed the first animal graft and coined the term
‘Keratoplasty’.
 The first successful lamellar keratoplasty was performed by Arthur Von
Hippel at the end of 19th century.
 Jose Barraquer was the first to perform posterior lamellar keratoplasty in
1950

17. Anterior Lamellar Keratoplasty (ALK)
 Removal and replacement of deformed or diseased anterior corneal
tissue ( epithelium, Bowman’s layer, and stroma)
 Sparing the host Descemet’s membrane and endothelium

19. Indications
 Indicated in corneas that have a healthy endothelium
1.Optical ALK is useful in
 Anterior stromal scars after infectious keratitis or trauma
 Complications after refractive surgery
 Dystrophies like epithelial and stromal dystrophy
 Salzmann nodular degenerations, spheroidal degeneration etc
 Post inflammatory:Trachomatous kerartopathy,healed superficial keratitis

20. Indications (contd…)
2. Tectonic ALK is useful in
 Peripheral non inflammatory thinning
 Terrien’s marginal degeneration
 Pellucid marginal degeneration
 Peripheral ulcerative autoimmune keratitis - Mooren’s ulcer.
 Descematocoele
3. Combined indications include
 Keratoconus
 Pellucid marginal degeneration
 Iatrogenic keratoectasia after Refractive surgeries
 4.therapeutic
Infective keratitis limited to anterior corneal layers

21. Surgical Planning
(Surgeon to ask themselves)
 Is the Endothelium Normal?
 What level does the pathology extend?
 Will leaving minimal posterior stroma affect visual outcome?

22. SALK
 should be used when the anterior 30--50% of the cornea is affected with
pathology and is to be replaced with a similar amount of donor tissue.
The main indications are superficial scars resulting
 from healed infections, including trachoma, trauma (post-laser or
accidental),
 superficial corneal dystrophies and degenerations,
 or persistent epithelial defects

23. Surgical Techniques
1)DIRECT DISSECTION- Partial thickness(60-80%) trephination
 Corneal stromal dissection with crescent
 Partial thickness donor
 Suture
 Disadvantage – Unreliable depth of dissection
Irregular Host Bed
Interface haze

24. Melles Technique(closed dissection)
 To visualize the depth of lamellar dissection –
 Exchange aqueous with air- Create Air Endothelium interface – Act as convex mirror
 Specialised spatula –stromal pocket—inject visco—stroma over visco excised
 A black band is visualized in front of dissecting instrument, which represent twice the residual
stroma
 Trephination
 A full-thickness donor button stripped off its DM is sutured in place.
 Good visual results have been reported with this technique.
 There is about a 14% chance of DM perforation.

25. ANWAR Big Bubble Technique

26. Surgical technique Anwar ‘BUBBLE’
TECHNIQUE
 The technique involves trephining the anterior host corneal surface with a Hessburg-
Barron suction trephine to a depth of about 400 µm
 25-gauge disposable needle inserted into the corneal stroma,
 Air is then injected to create a big bubble (Anwar’s technique) that will detach the deep
stromal layers from the Descemet’s membrane.
 lamellar dissection and removal of the anterior stromal disk by crescent knife

27.  Using a 30° superblade/15° lance tip, a small oblique incision is made in the corneal
stromal surface, releasing air and collapsing the big bubble.
 The space between the Descemet’s membrane and the detached deep stroma is then
filled with viscoelastic.
 Utilizing a divide-and-conquer technique with corneal microscissors, the remaining deep
corneal stroma is excised to expose the smooth surface of the Descemet’s membrane

28.  The donor cornea is then trephined with a Hessburg-Barron trephine, followed by
staining of the endothelium with trypan blue.
 Descemet’s membrane and the donor endothelium are then removed using dry cellulose
sponges and forceps.
 The donor cornea devoid of Descemet’s membrane and endothelium is then placed
within the host corneal bed and sutured in place with 16 interrupted 10-0 nylon sutures.

30. Viscoelastic Dissection Technique –
 Viscoelastics, namely sodium hyaluronate, were forced into a previously
made stromal pocket using a 25-gauge blunt cannula to create a visco-
bubble.
 This technique detaches the deeper stromal layer from the Descemet’s
membrane, and the detached stroma is then excised to expose the
Descemet’s membrane.

31. Hydrodelamination Technique-
 A partial trephination and a lamellar keratectomy are carried out at a
suitable depth.
 A small cut/depression is created in the deeper stroma. A 27-gauge needle
attached to a syringe is inserted at the bottom of the depression, and
saline is injected into the stromal bed, which whitens and swells.
 A fine spatula is then inserted through a small incision in the
delaminated tissue and moved fan like in different direction to loosen the
residual stroma which is then dissected to reach the Descemet’s
membrane.
 A 5-mm DM area in front of the pupil is exposed.

32. Microkeratome Technique –
 The advantage of this technique over other lamellar techniques is the
relative ease of surgery and the low incidence of interface scarring and
irregular astigmatism.
 The automated microkeratome is used to cut the donor lenticule, as well
as the corneal disc in the recipient eye.
 The thickness of the cut can be adjusted in relation to the depth of the
lesion, by choosing the proper plate size (up to 450 μm).
 This technique has advantage of a smooth central host bed and a
consistent and controlled bed diameter

33. Big Bubble Technique Combined with
Zigzag Femtosecond Laser Incisions--
 The use of a femtosecond laser for the dissection of anterior lamella in
anterior keratoplasty was first described by Suwan et al in and latter by
Price et al Farid in 2009.
 The technique combines the advantages of secure zigzag femtosecond
laser wound construction with the aim to reduce the amount of
postoperative astigmatism combined with the high-quality interface
obtained with the big bubble technique

34. Clinical Outcomes over various
techniques
 The techniques of dissection as well as surgeon's experience are main
factors in determining the rate of true Descemet’s membrane
(DM)exposure
 Sarnicola et al* found the highest rate (60%) with Anwar's big-bubble
technique.
 Supplemented with viscoelastic dissection at the same session in the case
of unsuccessful air injection, this rate increased to as high as 77%
 Viscodissection technique was the second most successful technique in
baring the DM, with a rate of 58%, followed by the hydrodelamination (7%)

35. Complications Intraoperative
 Microperforation – Sudden softening eye and excursion of fluid or air
into the interface.
 Occurrence 39% expert hand
 Manage – Air in AC- Continue dissection peripheral to perforation.
Leaving Air bubble with supine position of patient
 Macroperforation –
Convert PKP
 Pupillary Block Glaucoma-
due to air bubble left in AC
Avoided by Pupil dilation if air left
Periodically examination eye in hour immediately after surgery

36.  Graft host malapposition/edge irregularity
Due to improper sizing of tissues
 Interface debris
Fibers, bleeding

37. COMPLICATION POSTOPERATIVE
 Double AC
Cause- Micro perforation, Entrapped Visco at interface
Manage- Accelerated intracameral Air/ SF6 and drain interface fluid
 Persistent epithelial defects
Suture related,ocular surface diseases,wound/edge problems
 Infections
Suture related, lid adnexal abnormalities,poor hygiene,steroid
use,reactivation of herpectic infections

38.  Graft vascularization
In cases of trachomatous keratopathy,chemical burns and SJ syndrome
 Epithelial, Subepithelial or stromal rejection
Epithelium – Line of oedema
Subepithelial- Subepithelial infiltrate
Stromal –Oedema

39. Advantages of ALK
 less chances of postoperative inflammation as well as secondary glaucoma.
 No risk of endothelial graft rejection.
 No need for long term steroid prophylaxis
 Rapid functional recovery of vision.
 Very good best corrected visual acuity (BCVA)
 very low astigmatism.
 No significant endothelial cell loss.
 Penetrating Keratoplasty can be done if recurrences occur or Descemet's membrane
perforation occurs intraoperatively.
 The criteria for quality of donor tissue are not very stringent

40. Endothelial keratoplasty
 DLEK
 DSEK
 DMEK

41. Endothelial Keratoplasty (EK)
 Purpose To remove the diseased recipient endothelium and replace with
healthy donor corneal endothelium.
 In 1998,Dr.Gerritt Melles et al first described this technique involved large
limbal incision and deep manual lamellar corneal dissection .
 Dr. Mark Terry modified by small incision 5mm rename the Procedure
“Deep Lamellar Endothelial Keratoplasty (DLEK)”
 Next Evolution by Melles was the substitution of the patient dissection with
Descement’s stripping and “Descement’s stripping Endo Keratoplasty (DSEK)”
coined

42. Why there is need
for EK ,an
alternative to
PKP?????

43. DLEK/DSEK/DMEK vs PKP
 EK procedure preserves the normal corneal topography to allow faster visual recovery
 Astigmatism after DLEK surgery was 1.63 ±0.97D* ,
 In contrast, after standard PKP surgery was between 4.00 and 6.00D
 After DLEK surgery and in DSEK 18-35% endothelial cell loss from preoperative donor
counts.After 5 years its was 54%.
 After PKP, the cell count has been at 6months- 34% cell loss from preoperative donor
counts and 69% at 5 years.
 Less immunological rejection rates than PK.PK>DSEK>DMEK
 Tectonically stable globe
 No suture related complication

44. Patients Selection
1. Endothelial Diseases
2. Fuch’s endothelial dystrophy
3. Pseudophakic bullous keratopathy
4. Aphakic bullous keratopathy
5. Iridocorneal endothelial syndrome

45. SURGICAL PROCEDURE LARGE
INCISION TECHNIQUE(DLEK)
 A scleral access incision is placed at superior limbal region of size 9.0
mm
 SCLERO CORNEAL LAMELLAR POCKET IS MADE USING A CRESCENT
BLADE
 STRAIGHT DEVERS DISSECTOR IS THEN USED TO EXTEND THE POCKET
TO MID PUPILLARY REGION OF THE CORNEA
 THEN A CURVED DEVERS DISSECTOR EXTENDS THE POCKET
COMPLETELY TO THE LIMBUS FOR 360 DEGREES, CREATING A TOTAL
AREA OF DEEP LAMELLAR POCKET

46.  THE RESECTION OF THE POSTERIOR RECIPIENT TISSUE IS DONE WITH
AN INTRASTROMAL TREPHINE (TERRY TREPHINE)
 ONCE THE BLADE IS IN POSITION IN THE POCKET, IT IS ROTATED
ALONG THE ARC OF 9.0 MM SCLERAL INCISION
 RESECTION OF THE RECIPIENTS DISK IS COMPLETED USING CINDY
SCISSORS
 ONCE THE POSTERIOR RECEIPIENT DISK HAS BEEN CUT 360 DEGREES,
THE TISSUE IS REMOVED FROM THE EYE

47. DONOR TISSUE PREPARATION
 THE DONOR CORNEOSCLERAL FLAP IS PLACED ON AN ARTIFICIAL ANTERIOR
CHAMBER WHICH IS COATED WITH HELON ON THE ENDOTHELIAL SIDE ARTIFICIAL
ANTERIOR CHAMBER HEALON ON THE ENDOTHELIUM
 THE DONOR TISSUE IS THEN CAPPED ONTO PLACE AND TREPHINATION IS CARRIED
OUT TO ABOUT 60% DEPTH
 LAMELLAR DISSECTION IS COMPLETED USING CRESCENT KNIFE THE DONOR
POSTERIOR DISC IS THEN PLACED ON A OUSLEY SPATULA
 THE DONOR DISC IS THEN SLOWLY INSERTED USING OUSLEY SPATULA
 THE SPATULA IS THEN GENTLY REMOVED FROM THE EYE LEAVING THE DONOR
TISSUE BEHIND SUPPORTED BY AIR BUBBLE IN ANTERIOR CHAMBER
 10-0 NYLON IS THEN USED TO CLOSE THE SCLERAL WOUND AND PREVENT THE
ESCAPE OF DONOR TISSUE
 A REVERSE SINSKEY HOOK IS THEN USED FOR ENDOTHELIAL SIDE POSITIONING
APPEARANCE AT THE END OF SURGERY

49. Descemet’s Membrane Stripping
Automated Endothelial Keratoplasty
(DSAEK)
 DSAEK It is a method of posterior lamellar keratoplasty in which the
recipient bed is prepared by stripping off the recipient’s Descemet's
membrane.
 Technique was popularized by Gerrit Melles in 1999

50. Indications of DSAEK
 Fuchs endothelial dystrophy (most common)
 Pseudophakic/ Aphakic bullous keratopathy
 Post PK endothelial graft rejection
 Iridocorneal endothelial syndromes (ICE)
 After glaucoma filtration surgeries
 Eyes with anterior chamber IOL

51. SURGICAL TECHNIQUE
 RECIPIENT’S CORNEA WOUND CONSTRUCTION THROUGH A 3-5 MM
SCLERO CORNEAL TUNNEL
 WITH HEALON FILLING THE ANTERIOR CHAMBER DESCEMETORHEXIS
AND REMOVAL OF DESCEMET’S MEMBRANE AS A SINGLE DISK IS
CARRIED OUT USING DEXATOME
 DESCEMETORHEXIS IS BEGUN IN THE DISTAL POINT FROM THE
ANTERIOR CHAMBER ENTRY SITE AND CONTINUED IN CLOCKWISE
FASHION.
 THE PERIPHERAL STROMA IS MADE ROUGH USING THE DSAEK
SCRUBBER TO ENHANCE DONOR DISK ATTACHMENT TO RECIPIENT
CORNEA

52. Graft insertion and positioning
 Forceps – charlie 2, goosey ,kelman
 Sheets glide – sheets intraocular lens
 Busin glide-reusable funnel glide
 Insertors/injectors- endosertor,endoglide,neusidl
 After graft is inserted—air BUBBLE—10-12 MINS
 Anterior chamber and wound is closed by 3 interrupted nylon sutures
 Donor disk is uniformly adherent to the patient’s cornea

53. DONOR PREPARATION
 MOUNTED ON AN ARTIFICIAL ANTERIOR CHAMBER
 MANUALLY OR SEMI AUTOMATED MICROKERATOME
 FEMTOSECOND LASERS

54. DSAEK

55. DSEK/DSAEK - disadvantages
 Steep learning curve
 Higher endothelial cell loss rate in initial post op period
 Graft dislocation
 Pupillary block
 Reports of graft dislocation in vitreous cavity in aphakics
 Interface haze limiting 20/20 vision
 More hyperopic shift compared to DMEK

56. DMEK(Descemet’s membrane
endothelial keratoplasty)
 Transplantation of isolated donor endothelium and Descemet’s
membrane.
 Steps – Isolation of donor DM and endothelium , recipient
descematorhexis followed by donor insertion and positioning
 Donor preparation :DM isolated by direct peeling(SCUBA) or by injection
of air to create a Big Bubble
 Donor tissue over 40 years of age is preferred
 Insertion – glass pipette or IOL catridge and injector, through 2.8mm
corneal incision—unwrapping--air fill

57. DMEK --advantages
 Reduction of interface haze
 Less incidence of graft dislocation
 Shorter visual recovery as total corneal thickness remains
same
 Larger donor surface provides more viable endothelial cells
 Less strong host graft apposition at interface allows easier
removal of failed/rejected donor lenticule
 No costly instruments for donor lenticule preparation

58. disadvantages
 Difficult and more traumatic manipulation of rolled
DM
 Higher endothelial cell loss rates with current
techniques

59. DMEK
 Not suitable for
1. Aphakics
2. Large iris defects
3. Previous pars plana vitrectomy

60. Surgical Outcomes
 Visual acuity-6/9 to 6/18 with DSEK
DMEK has faster and better visual recovery
DMEK – 6/9 or better vision
 Refractive results- mean hyperopic shift of 0.75 to 1.5D due to changes in
posterior corneal curvature and increase in thickness in DSEK
 DMEK– 0.25 to 0.50 D hyperopic shift
 Endothelial cell loss- at 6months- 18-35 % , 54% at 5years
 Graft survival-55-100% in various studies

61. Complications of EK
 Early post operative raised IOP
Pupillary block
Appositional angle closure
 Graft Detachment/Dislocation-The most common complication following DSAEK surgery
is dislocation of the graft due to difficulty in achieving air fill for required time or to
maintain a firm eye.
DMEK>DSEk
Management-scraping, venting incisions, air, supine position, rebubbling
 Epithelial down growth- donor epithelial entrapment

62.  Interface abnormalities- thickness irregularities due to manual dissection—
folds and wrinkles in EK, incomplete removal of visco
Haze due to proteoglycan deposition
 Infections
 Graft rejection- Lower in EK compared to PK, rejection PK>DSEK>DMEK
 Late endothelial graft Failure
 Steroid induced glaucoma

63. The future of keratoplasty
 Femtosecond Laser DSAEK •
 This laser is used to create flaps in LASIK and can be used to perform keratoplasty with
different shapes of stromal cut. •
 The laser uses an infrared wavelength (1053nm) to deliver closely spaced, 3 microns
spots that can be focused to a preset depth to photodisrupt the tissue within the corneal
stroma.
• Femtosecond laser is used to create a dissection plane on the donor cornea mounted on
artificial anterior chamber.
• Offers a potential advantage over microkeratome with regards to better sizing of the
posterior lenticule.
•Obtains a smooth surface and precise stromal cuts

64. SUTURELESS CORNEAL ADHESION
 Bioadhesive (Fibrin glue)
Kaufman et al successfully used fibrin glue in small series of lamellar
keratoplasty
 Photochemical keratodesmos is method of producing sutureless adhesion
by applying a photosensitizer to wound surfaces followed by low energy
laser irradiation.
Laser promotes cross linkage between collegen molecules to produce tight
seal without thermal damage.