1. EYE BANKING AND KERATOPLASTY
BY DR. ANITA
PG 2nd year
DEPT. OF OPHTHALMOLOGY

2. EYE BANKING
EYE BANK
An Eye Bank is a non-profit community organization which deals with the collection, storage, distribution of cornea for the purpose of corneal grafting, research & supply of the other eye tissues for the other purposes.
A medical director, an eye bank manager, eye bank technicians and grief counselors manage the day- to-day affairs of an eye bank.

3. The functions of eye banks are:
Educate the public about eye donation and eye banking
Carrying out eye donations.
Preserving, processing and evaluating the donor corneas
carrying out serological tests of eye donor’s blood sample.
Distributing donor corneas to corneal surgeons according to waiting list.
Initiating Hospital Cornea Retrieval Programme in neighbouring hospitals.

4. LEGAL ASPECTS OF ORGAN DONATION
Under the Transplantation of Human Organ Act, 1994
The qualification of doctors permitted to perform enucleation (surgical eye removal) has been reduced from MS (Ophth.) to MBBS.
Eye donation in India is always decided by the donor’s surviving relatives and not by the actual donor,
Enucleation doctors always have to legally obtain a written consent from the relatives of the deceased before they actually remove the eyes.

5. WHAT IS EYE DONATION? Eyes should be donated within 6-8 hrs. of death.
Total removal time is about minutes.
Nobody is charged for making eye donation.
The only cost to encounter is one local telephone call.

6. STEPS OF EYE DONATION Donor selection Tissue retrieval
Corneal examination
Tissue transportation
Storage of corneal tissue
Distribution

7. WHO CAN DONATE EYES? Any gender can donate eyes
All religions endorse the practice of eye donation
Willing donation of one’s own eye during life
Eyes from medico legal post mortem cases
Eyes from unclaimed bodies
A good donor cornea
Healthy cornea
Removal of cornea soon after death(within 6 hrs)

8. DONOR SELECTION
1. AGE : no influence of age on transplant outcome Lower limit: 2 yrs to myopic shift after keratoplasty

9. Medical history review
Eye banks must have consistent policies for the examination and documentation of donor’s available
medical records,
medical history
cause of death
medications
laboratory reports

10. Serology testing
Preparation of donor
povidone iodine 1-5 % for 1-2 min +
Good stream of balanced saline

11. Legal consent taken from next of kin
Consented donor meets medical and social history screening criteria
Physical assessment reveals no contraindication to donation
Acquisition of donor tissue can be carried out

12. Contraindication for the use of donor tissue for keratoplasty
Death of unknown cause
Death from central nervous system disease of unestablished diagnosis
Creutzfelt-Jacob disease or a risk factor
Subacute sclerosing panencephalitis
Progressive multifocal leukoencephalopathy
Congenital rubella
Reyes syndrome
Active viral hepatitis

13. WHO CAN’T DONATE EYES …

14. Active leukemias
Active disseminated lymphomas
High risk for HIV infection
Hepatis B surface antigen positive
HTLV-1 or HTLV-2 infection
Hepatitis C seroposive donors
Retinoblastoma, malignant tumor of the anterior ocular segment
Active ocular inflammation
Congenital or acquired disorders of the eye
Prior intraocular surgery or anterior segment surgery

15. TISSUE RETRIVAL
enucleation by in- situ corneo-scleral i.e. surgical removal of the whole eye excision( globe is retained in the orbit)

16. CORNEAL EVALUATION Examination of the corneas in situ
A simple penlight examination:
Epithelial defects (drying, erosion, sloughing)
Corneal edema with associated haze
Abnormal corneal shape
Blood or cloudiness in the anterior chamber
Corneal scars or infiltrates, arcus senilis, and any sign of conjunctivitis or discharge.

17. The slit-lamp examination
Low power & higher power
Whole eyes can be examined within the container used for the retrival
Excised cornea: from the bottom of the storage vial
Cornea should be allowed to reach the room temperture

18. Methods of endothelial evaluation
Specular microscopy: Mostly used by eye banks using hypothermic storage of corneo-scleral buttons.
Other methods:
Phase contrast microscopy
Transmitted light microscopy
Critical density: cells/mm3
Functional cell density: cells/mm3

20. Storage methods Short term method Moist chamber technique:
Whole globe is preserved at 40 C temp. with saline humidification for upto 48 hours.
Simple, cheap, easily transportable, and requires minimum manipulation

21. Intermediate term method
Mc-Kaufman(MK) medium: can preserve cornea upto 4 days at 40C temp.
Chondroitin sulphate enriched media
dexol medium
Lysol medium
Optisol medium: it contain dextran and chondroitin sulphate which enhances corneal dehydration during storage and the cornea can be preserved for 14 days.

22. Anatomy of cornea
The cornea is the refractive surface of the eye and constitutes up to 1/6 of the entire eyeball.
It has 5 layers:
The epithelium
Bowman’s layer
The stroma
Descemet’s membrane
endothelium

23. Anatomy of cornea

24. KERATOPLASTY INTRODUCTION
Keratoplasty is the corneal transplant procedure in which diseased host corneal tissue is excised and replaced with healthy donor cornea.
Either full thickness of the cornea or a part of it may be transplanted.
Objectives:
Establish clear corneal visual axis
Minimize refractive error
Provide tectonic support
Alleviate pain
Eliminate infection

25. Indication Optical: to improve visual acuity Corneal scars
Corneal dystrophy/degenerations
Congenital corneal opacities
Keratoconus

27. Indication Tectonic and reconstructive
Restoration of altered corneal structure
corneal perforations/thinning
Therapeutic
Tissue substitution for corneal diseases
Non healing corneal ulcer(infectious keratitis)
Cosmetic
To improve the appearance of eye

29. Types of keratoplasty
Penetrating keratoplasty: full thickness replacement of entire cornea
Lamellar keratoplasty: partial thickness replacement of only part of the cornea
superficial lamellar keratoplasty
Deep lamellar endothelial keratoplasty
Endothelial keartoplaty: a variation in which only the endothelium layer is replaced
Type of surgery chosen according to cornea’s condition

31. Penetrating keratoplasty
Full thickness replacement of diseased tissue with healthy donor cornea
Indications:
Pathology involving whole cornea
Full thickness scars
Perforation of cornea
Herpetic scars
Vascularized scars
keratoconus

32. Penetrating keratoplasty (PK)
Surgical indication for PK:
Optical: a healthy, clear donor cornea is used to replace an opaque, cloudy, or distorted cornea in an attempt to improve vision
Pseudophakic bullous keratopathy
Keratoconus
Regraft secondary to allograft rejection
Regraft unrelated to allograft rejection
Keratoglobus
Degeneretions
Dystrophies
Scars
Aphakic bullous keratopathy
Congenital opacities
Chemical injuries

34. Tectonic:
Descemetocele
Corneal stromal thinning
Corneal perforation
Therapeutic : infection may be due to bacteria, virus, parasite,or other cause
Cosmetic : to improve appearance of the patient

35. Procedure for PK PREOPERATIVE PREPARATION ANESTHESIA
SURGICAL PREPARATION
TREPHINATION OF DONOR CORNEA
TREPHINATION OF RECIPIENT CORNEA
SUTURING OF DONOR CORNEA
POSTOPERTIVE TREATMENT

36. Preoperative evaluation
Ocular history
Visual acuity
Detailed examination: underlying pathology
IOP
Vascularization
Tear film status
Presence of cataract
Need for IOL exchange
B-Scan

37. Donor tissue preparation
The donor cornea is trephined from endothelial or epithelial surface. For epithelial surface trephination, an artificial anterior chamber is required.
2 types of trephines are- suctionless trephines and suction trephines.
A cutting block and artificial anterior chamber may also be used for corneal disc preparation.
Graft size: 7.5 mm

38. Trephination of donor cornea
Endothelial punch system
Hessberg barron vaccum trephine: less AC collapse & distortion
Sharper, deeper& more perpendicular cut

39. Hanna trephine laser trephine
Donor cornea encased within an artificial chamber
Corneal trephination from epithelial surface
Femtosecond excimer laser
No mechanical distortion
Perpendicular congruent edges

40. Trephination of recipient cornea

41. Recipient dissection

43. Suturing of donor cornea
Placement of donor cornea on recipient
Anterior chamber filled with viscoelastics
Donor cornea brought into field of microscope with a graft holder
Suturing of recipient cornea with 10-0 nylon suture -
- place 4 cardinal suture first at 900 interval
- first suture at 12 o’clock, 2nd at 6 o’clock followed at
3 o’clock and 9 o’clock

44. Postoperative management
Topical steroids : To decrese the risk of immunological graft reaction.
Immunosuppressants :azathioprine,ciclosprin may be used in high risk for prevention of rejection.
Mydriatics: if uveitis persist.
Monitoring of IOP is performed during the early postoperative period.
Removal of sutures when the graft-host junction has healed.
Rigid contact lenses- to optimize visual acuity in eyes with astigmatism

45. 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 endopthalmitis.
Late : astigmatism, recurrence of intial disease process, late wound separation, retro-corneal membrane formation, glaucoma and cystoid macular oedema

46. Lamellar keratoplasty
Similar to PK but only a part of thickness of cornea is grafted.
1.Superficial Lamellar keratoplasty
Partial thickness excision of the corneal epithelium and stroma.
Endothelium and part of the deep stroma are left behind.
INDICATIONS:
Superficial 1/3 stromal corneal opacity, granular dystrophy
Marginal corneal thinning or infiltration as in recurrent pterygium, marginal degeneration
Localised thinning or descemetocele formation

47. 2.Deep anterior lamellar keratoplasty
Opaque corneal tissue is removed almost to the level of Descemet membrane
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 keratoconjuctivitis.
During DALK, the surgeon injects air to lift off and separate the thin outside and thick middle layer of cornea and removal of ant. Corneal layer( leaving the endothelium and Descemet’s membrane behind)

48. Endothelial Keratoplasty
REPLACES ONLY THE INNERMOST LAYER OF THE CORNEA (ENDOTHELIUM) AND LEAVES THE OVERLYING HEALTHY CORNEAL TISSUE INTACT.
- THE SURGEON MAKES A TINY INCISION BY TREPHINE OR FEMTOSECOND LASER AND PLACES A THIN DISC OF DONOR TISSUE CONTAINING A HEALTHY
ENDOTHELIAL CELL LAYER ON THE BACK SURFACE OF THE CORNEA , AN AIR BUBBLE IS USED TO POSITION THE NEW ENDOTHELIAL LAYER INTO PLACE , THE SMALL INCISION IS SELF-SEALING AND TYPICALLY NO SUTURES ARE REQUIRED.

50. DESCEMENT STRIPPING ENDOTHELIAL KERATOPLASY(DSEK)
This technique combine stripping off endothelium and Descemet membrane, through a corneo-scleral or corneal incision.
INDICATIONS:
Pseudophakic bullous keratopathy

51. DSEK
THIS TECHNIQUE COMBINES STRIPPING OFF THE DYSFUNCTIONAL ENDOTHELIUM FROM THE HOST CORNEA WITH MICRODISSECTION OF THE DONOR TISSUE.
- IN THIS TYPE PATIENT'S ENDOTHELIUM IS REPLACED WITH A TRANSPLANTED DISC OF POSTERIOR STROMA/DESCEMET'S MEMBRANE/ENDOTHELIUM.
- SURGEON REMOVES THE ENDOTHELIUM ( ONE CELL THICK) AND THE DESCEMET MEMBRANE JUST ABOVE IT. THEN HE REPLACES THEM WITH A DONATED
ENDOTHELIUM AND DESCEMET MEMBRANE STILL ATTACHED TO THE STROMA .
-THIS REDUCES OCULAR SURFACE COMPLICATIONS GENERALLY COMPARED TO PENETRATING KERATOPLASTY.

52. DSEK surgical techinque

55. a) DLEK, b)DSEK

56. DESCEMENT’S MEMBRANE ENDOTHELIAL KERATOPLATY (DMEK)
DMEK is further variation on ( DSEK), in which immune- mediated rejection is reduced by transplanting bare endothelium and Descemet’s membrane without stroma.
Donor tissue thin and fragile, so difficult procedure but healing is quicker.

57. Before injecting DMEK tissue into anterior chamber
Descemetorhexis with no loose tags of Descemet membrane or stroma
Patent inferior peripheral iridotomy
Main incision widened to accommodate the Straiko injector and form a watertight seal
Evacuation of all viscoelastic from the anterior chamber and the injector
Pupil smaller than 3 mm, constricted

58. Complication of keratoplasty
Early complications-
Persistent epithelial defect(>2 weeks in duration): symptoms are as for corneal abrasion: pain- redness- tearing- sensitivity to light- blureed vision- may be a/w headache
Irritation by protruding sutures
Iris prolapse through operative wound
Keratitis or endophtalmitis- sight threatening complication
Uveitis
Flat anterior chamber
Elevated intraocular pressure

59. Graft rejection complications:
Late complications:
-Astigmatism
-Glaucoma
-Late wound separation and suture related problems
-Cystoid macular edema
Graft rejection complications:
Early graft rejection:
Occurs by the first operative day
There is a cloudy cornea
this is usually due to defective donor endothelium or trauma

61. Cont.
Late graft rejection
Sign of rejection eye pain, redness, photophobia, cloudy vision.
Occurs within the first 6 months or year
Red eye, corneal clouding+ uveitis, a/w decreased visual acuity
Rejection line
Usually due to immunological graft rejection

62. PROGNOSIS POOR PROGNOSIS IS NOTED IN PATIENTS WITH:
1-ADDITIONAL CORNEAL PROBLEMS SUCH AS VASCULARISATION OR PERIPHERAL THINNING.
2- ASSOCIATED OCULAR DISEASE SUCH AS HERPES, ACTIVE INFLAMMATION OR UNCONTROLLED GLAUCOMA.

63. POSTOPERATIVE CARE

65. THANK YOU