the presentation is of keratoprosthesis which will be of usee for post graduate students in ophtalmology

1. KERATOPROSTHESIS OR
PPROSTHETIC CORNEA
DR. GAURI N. BANKAR
ASSISTANT PROFESSOR
DEPT. OF OPHTHALMOLOGY
RURAL MEDICAL COLLEGE
PIMS, LONI

2. INTRODUCTION
 Keratoprothesis or Prosthetic cornea is the last
resort for the bilateral end stage corneal blindness.
 Eyes are high risk for conventional keratoplasty.
 Repeated keratoplasties have failed. ( Indication)
 Choice of Kpro depends upon the etiology,
anatomy of ocular surface, and tear film status.
 The keratoprosthesis are categorized in Type-1
and Type–2 Kpro based on the type of eye in which
they are used.

3. HISTORY

4. KERATOPROSTHESIS DESIGN
 It is similar to IOL consisting
of optic and haptic .
 The optic is the central pat
responsible for viewing. It is
cylinder made of PAMMA.
 The central part is clear
window
 The type of prosthesis
depends upon the design of
the haptic.
 The biological properties
are also considered,

5. TYPES OF PROSTHESIS
 Biocompatible – usually PAMMA skirt with the corneal
graft as in Boston type 1 & 2 K pro.
 Biointegrated – as in the Delcon mesh that forms the
skirt around the PAMMA optic in the Pintussi Kpro.
 Biological-- tooth or bone that forms the autologus
biological tissue that supports the optical cylinder in
the Osteo –odonto K pro and Osteo K pro.
 The supporting cover tissue adds to the Kpro complex
 BCL in K1 pro; Skin in K2 pro; Buccal mucosa in osteo
and odonto kerato prosthesis and Pintucci K pro

6. SELECTION OF KERRATOPROSTHESIS
 K1 Boston Type – in eyes with normal lid blink, and
tear film without under immunological etiology.
 Type 2 Kpro in eyes which are severely dry and
have keratinized ocular surface with underlying
immunological disorder associated with lid
abnormalities
 Osteoodonto -
 Choosing correct type of Kpro for the patient is
important.

7. BOSTON KERATOPROSTHESIS
 Boston Keratoprosthesis is the innovation and
design of professor Claes H. Dohlman
 FDA approval in 1992
 Types- 1 and Type – 2
 Made from polymethyl methacrylae (PAMMA)
 Most commonly used Type – 1

8. BOSTON TYPE – I
KERATOPROSTHESIS

9. BOSTON TYPE -2
KERATOPROSTHESIS
 The type 2 of device is of similar design with an
added anterior cylinder that protrudes through a
permanently closed eye lid and is used in end stage
dry eye.
 Back plates holes are important to allow the
nutrients to reach the graft

10. INDICATIONS
 Kpros are performed for bilateral corneal blindness
not amneable to conventional penetrating
keratoplasty.
 Pre-requisite –
1. Two failed grafts with poor prognosis for further
grafting
2. Vision less than 20/400 in the affected eye
3. Minimum vision of light perception
4. Lower than optimal vision in the opposite eye.

11. GOOD
PROGNOSIS
GUARDED
PROGNOSIS
VERY GUARDED
PROGNOSIS
Multiple failed
grafts
Paediatric
corneal
Conditions
Immune Conditions
Aniridia; Chemical Injuries Steven Jonson Syndrome
Herpetic Kerratitis; Ocular Cicatrical
Pempigoid
Silicone filled
eyes.
Severe chemical injuries
conjunctival scarring and
lid abnormalities
INDICATIONS FOR K1 PRO
Based on Prognosis

12. ADVANTAGES CONTRAINDICATIONS
 Long term (many
years) stability and
safety.
 It has excellent optics
 Provides excellent
vision if rest of the eye
is not damaged
 Unilateral vision loss
 End stage glaucoma or
uncontrolled
glaucoma
 Posterior segment
pathology
 Presence of
functioning K pro n
the fellow eye.

13. INDICATIONS FOR K2 PRO
 The choice based on long term anatomical and
functional outcome.
 In case of severe end stage disease the prosthesis of
choice is Modified osteo odonto keratoprosthesis
(MOOKP).
 Indications are –
1. Stevenson Jhonson SyndromeS
2. Ocular Cicatrical Pempigoid
3. Severe chemical burns;
4. Severely keratinized surface.

14. EXCLUSION CRITERIA FOR
KERATOPROSTHESIS
1. No PL
2. Advanced glaucoma &
retinal disease;
3. Unrealistic expectations
4. Unwilling patient or
unlikely to report for
regular follow up
5. Unwilling to accept
cosmetic outcome
6. Unwlling to come for
follow postoperative
care and restrictions
7. Dense amblyopia
Specific for
MOOKP
Specific for
Boston Type
Edentulous Absent eye
lids
Poor oral
Hygiene
Unfit for GA
< 18 years of
age

15. PREOPERATIVE EVALUATION
 Detailed history.
 Detailed examination
with B scan with axial
length measurement.
 PL and accurate PR
assessed.
 IOP by digital tonometry
 USG, anterior segment
OCT
 Counselling /Compliance
 Adequacy of blink is
confirmed.
 Schirmer’s I for tears.
 Patency of lacrimal
passages
 Patients for MOOKP
should have detailed
dental and mucosal
evaluation
 GA fitness

16. SURGICAL TECHNIQUE
 Decide type of K pro.
 8.5 mm backplate for
adult and 7.5 mm for
pediatric patient.
 Axial length specified
 Stand by Kpro should be
ready
 Recipient cornea
marked minimum 8.5
mm
 GA or LA
 Assemble the K pro
before trephing the
cornea.
 Good donor cornea
 Minimum donor graft
should be 8.5 mm It is
usually oversized by 0.5
mm
 Central 3 mm opening
in donor cornea is
trephined

17. SURGICAL PROCEDURE
 Optic placed on
adhesive strip upside
down.
 The donor graft is slid
down the stem of the
optic in to the slot using
wrench.
 The black plate is slid in
place. The assembly is
then locked with
titanium ring and
checked for snug fit.
 The recepient cornea is
trephined and removed
 The assembled Kpro is
then sutured like
kplasty
 BCL placed
 https://youtu.be/kyeBQ
CljkqY

18. SURGICAL PROCEDURE
 Assemble the k pro on
donor cornea
 Recipient cornea is
trephined.
 The donor corneal
button is sutured as in
keratoplasty witj16
interrupted sutures
buried.
 BCL placed on Kpro

19. POST OPERATIVE CARE
 Antibiotics 4th generation fluoroquinolones
QID. bid for many days
 Vancomycin 14mg/ml for 1 month or more
 Topical steroids
 Lubricants
 BCL to be changed once in 3 months apply
Povidine Iodine at the time of BCL change
 Follow up regular -- 3 months

20. POST OPERATIVE EXAMINATION
 Change in refraction
 Deposits on BCL
 Assessment of air
bubble
 Inspection of graft for
infiltration
 Irregularity of graft
 Presence of prosthetic
membrane
 Presence of loose
sutures
 IOP by digital tonometry
 Stain graft for any
epithelial defect
 Visual fields every 6
months
 ASOCT for graft thinning,
Prosthetic tissue loss,
Retroprosthetic
membrane and angle
details 6 monthly
 B scan every year

21. TOOTH FOR EYE
MAKES BLIND SEE
Dr. Gauri N. Bankar
Dept. of Ophthalmology
Rural Medical College
PIMS, Loni
MODIFIED OSTEO – ODONTO KERATOPROTHESIS

22. WHAT IS IT ?
 It is implanted plastic corneal lens.
 A plastic lens cemented in the
section of the decalcified tooth
that is then stitched in opening
cut in the total opaque cornea to
restore vision.
 In case of MOOKP instead of tooth
the bone from tibia is harvested
and is fashioned into an osteo
lamina in to optical cylinder is
fixed.

23. STRAMPELLI THE INVENTOR
 In order to maintain clear corneal window in such
heavily vascularized corneas various acrylic implanted
were tried but invariably they were rejected.
 Strampelli reasoned that if the acrylic implant is placed
in the root of the patient own tooth, it remain there
indefinitely.
 The acrylic implant along with patient’s tooth, bone
and soft tissue and the whole is placed in corneal
envelope.
 The tooth and bone would form autograft picture
frame and prevent the extrusion of the acrylic implant.

24. CONTRAINDICATIONS
 Absent Light Perception
 Edentulous Patient
 Age below 17 years
 Retinal Detachment
 Posterior Segment Pathologies
 Mentally Unstable Patient
 Un-availability of Long term follow – up
 Unreasonable visual and Cosmetic Expectations

25. PRE-OPERATIVE EVALUATION
 Same as K pro
 The patients for MOOKP should have detailed
dental and mucosal evaluation

26. SURGICAL TECHNIQUE
 It is performed in 2 stages over a period of 6-9
months
 Stage – I – in three steps
1. A – ICCE+ Anterior Vitrectomy + total iridectomy
2. B – Mucous membrane Grafting
3. C – Preparation of Osteodentalacrylic lamina (ODAL)
 Stage -- 2
Implantation of ODAL

27. STAGE – 1
 Preparaton of Ocular Surface –
Superficial Keratectomy & Pannus
Removal
 Intra Capsular Cataract Extraction
 Anterior Vitrectomy
 Total Iridectomy
 The total iridectomy and anterior
vitrectomy are done to reduce the
possibility of glaucoma and formation
of retro-prothestic membrane

28. STAGE – I B
BUCCAL MEMBRANE GRAFTING
 Done after 6 weeks
 Involves covering the ocular
surface with full thickness
buccal mucous membrane graft
 Corneal epithelium and
Bowman’s membrane are
removed
 Graft of 3-4 cms and covering
both fornices
 Mucous membrane supply the
blood supply to bone, lamina
and protects against the
microbial invasion.

29. STAGE - I - C
ODAL OSTEODENTALACRYLIC LAMINA
 Upper canine is chosen – single root
tooth
 The with surrounding alveolar bone is
extracted for preparation of lamina
 The lamina has bone on one side and
dentine on the other
 The alveolar dentine ligament must be
preserved.
 Neck is cleared of all gingival tissue.
 The dental pulp canal is opened and all
soft tissue removed
 The crown is cut off.

30. OPTICAL CYLINDER
 Dioptric Power of the optical cylinder is 50-60
diaptors in aphakic eye and varies with axila length
of globe.
 The length of the anterior part is 5.75 – 6 mm
 The posterior part length is 2.25-2.5 mm
 The overall length of cylinder is 8 – 8.25 mm

31. ODAL – Tooth Preparation
 Neck is cleared off all
the gingival tissue
 Dental pulp canal is
opened and all the
soft tissue removed
 The crown is cut off
 The cylinder is drilled
for the acrylic
prothesis

32. STAGE – I C
 ODAL is placed in the
subcutaneous pouch in the
orbitozygomatic area for 3
months to develop
vascularization and promote
growth of connective tissue.
 Spiral CT is done to rule out
resorption of lamina and
document laminar
measurements
 ODAL dissected from the pouch

33. STAGE - II
 Intactness of lamina is
confirmed
 The mucous membrane is
reflected from cornea
 A central hole is drilled as
posterior diameter of cylinder
 The cylinder is sutured
 The centration of the cylinder
is important and confirmed by
indirect ophthalmoscope and
macula and disc are central
with adjusting the suture

34. POST OPERATIVE CARE
 Systemic and local antibiotics
 Analgesics and anti-inflammatory drugs
 Systemic steroids and anti glaucoma drugs
 Visual Acuity, Digital tonometry, refraction
Optic nerve status and visual fields at each follow
up
 Health of mucous membrane, stability and
protrusion of the optical cylinder

35. COMPLICATIONS
Ocular Mucous
Membrane ODAL
Oral
Glaucoma MMG thinning Oral Fistula
Retroprosthetic
Membrane
MMG necrosis Damage to parotid
duct
Vitritis Expulsion of
cylinder
Damage to
adjacent tooth
Endophthalmitis Extrusion of
prosthesis
Mandibular
Fracture
Retinal
Detachment

36. Six
months
later
With Ocular
Prosthesis

37. GUIDELINES & PRACTICAL PEARLS
 To recommend only for bilateral corneal blindness.
 Not an alternative to PK.
 It is not for cosmesis or increasing field of vision.
 It is last resort
 Should strictly follow the contraindications
 Type 1 Kpro is not recommended for
immunological conditions
 Bilateral K pro is contraindicated

38. CONCLUSION
It is really a boon to those patients who are at
end stage of ocular surface disorders and
have lost hope.
It provides stable and superior long term
visual rehabilitation
It is extremely demanding and time
consuming procedure, the rewards are very
satisfying and make the effort worth while.
Dr. Prof. Giancarlo Falcinelli and Dr. Giovanni
Facinelli have operated 22 cases at Sankara
Netralaya.