a review of use of AMT in ocular diseases. i sincerely thank all the authors of various articles that helped me with this information and also for the images, videos borrowed. no financial interests.

1. AMNIOTIC MEMBRANE
IN OPHTHALMOLOGY
Dr. Keerti Wali
Fellow, Cornea Phaco and Refractive surgery
M M Joshi Eye Institute

2. AMNIOTIC
MEMBRANE
Amniotic membrane is the
innermost layer of the fetal
membranes
• It is semi-transparent and 0.02–0.05
mm thick.
• AM has neither blood vessels nor a
direct blood supply.

3. LAYERS OF AM

4. Single layer, cuboidal with
microvilli

5. • first used for therapeutic purposes by Davis in
1910 for skin transplantation
• first application in ophthalmology was
described by de Rotth in an attempt to
reconstruct the ocular surface in patients with
symblepharon(1940)
• the modern ophthalmic usage of AM really
blossomed as a result of the work of Tseng and
his team (Kim and Tseng 1995)

7. PROPERTIES OF AM
• SEMI TRANSPARENT
• LACK OF IMMUNOGENECITY
• PROMOTES EPITHELISATION
• ANTI INFLAMMATORY
• ANTI FIBROGENIC
• ANTI ANGIOGENESIS
• ANTI MICROBIAL

8. PROMOTES EPITHELISATION
• acts as an excellent substrate for the growth, migration and adhesion of epithelial
cells
• maintains a physiological moist microenvironment, reduce water loss and
promote wound healing.
• The basement membrane of AM closely resembles that of the conjunctiva and
cornea especially in relation to its collagen composition, thus serves as a substrate
on which epithelial cells of the ocular surface can easily grow.
• AM stimulates the epithelialization and differentiation of the epithelium, by the
production of EGF, HGF and KGF.
• reinforces the adhesion of basal epithelial cells
• prevents epithelial cell apoptosis
• The expression of these growth factors, as well as TGF, are preserved even after
storage of AM at -80 C

9. ANTI FIBROTIC
• Suppression of TGF b signalling along with reduced
expression of TGF b-1, b-2, and b-3 isoforms and TGF-
beta receptor II.
• This inhibits the proliferation of corneal, limbal and
conjunctival fibroblasts as well as the differentiation of
fibroblasts into myofibroblasts

10. ANTI INFLAMMATORY
• The anti-inflammatory impact of AM is driven by the
inhibition of the expression of proinflammatory
cytokines such as interleukin (IL)-1a, IL-2, IL-8, IL-10,
IFN-c, bFGF, tumour necrosis factor b and platelet
derived growth factors from the damaged ocular
surface).
• Moreover, in patients with persistent epithelial defects,
it has been demonstrated that inflammatory cells may
be trapped by the AM stroma where they undergo
apoptosis.

11. ANTI ANGIOGENIC
• Stimulates productionof potent anti-angiogenic
compounds including thrombospondin-1, endostatin
and tissue inhibitors of metalloproteases (TIMP-1, 2, 3
and 4)

12. ANTI MICROBIAL
• attributable to the presence of bactricidin, beta-lysin,
lysozyme, transferrin and 7-S immunoglobulins
• AM works as an effective physical barrier due to its
close adherence to the wound surface.

13. NON IMMUNOGENIC
• Initially it was believed that the surface of AM cells was
free of the major histocompatibility antigens
• Subsequently demonstrated a limited expression of
HLA class Ia (HLA-A, B, C, DR) and class Ib (HLA-E, G)
antigens by AM epithelial and mesenchymal cells.
• Nevertheless, grafting of cryopreserved AM does not
lead to immunological rejection.
• This feature of AM obviates the need for any
immunosuppressive treatment in AM transplantation.

15. ADVANTAGES
• relative easy availability of
placenta,
• easy preparation
• Immediate availability for
grafting.
• Risk of transmitting
communicable diseases.
DISADVANTAGES
• Maternal blood sampling at the time of
donation or, shortly after childbirth, but
<7 days at max.
• In the absence of PCR testing,
serological screening of the donor
should be repeated after 6 months:
window period
• Screening for HIV-1/2, hepatitis B and
C, and syphilis is mandatory

16. PROCUREMENT
• Preselected donors- informed
consent
• Donor screening
• LSCS delivery
• Thoroghly cleaned
• Transferred to lab within 2hours
• Peeling started at umblical cord
• Placental AM retrieved
• sterilised- antibiotic cocktail/
radiation
• Placed on carrier: nitrocellulose
paper, epi side up,
• cut into small pieces,
• preservation

17. METHODS OF PRESERVATION
cryopreservation
• glycerol (86%)
inDulbecco’s Modified
Eagle Medium (DMEM),
at 1:1 ratio.
• No morphological
changes, some
devitalization+
Lyophilisation[freezedrying]
• pieces ofAM are rapidly
frozen at-50 to -80C,
dried under high
vacuum. Water content
reduced to 5-10% by
sublimation
• sterilized using gamma-
irradiation
• Pretreatment with
saccharide
lyoprotectants reduces
cellular damage and
better protects its
biochemical stability
Airdrying
• kept at room
temperature under
biohazard hood and
exposed to air for 24
hours
• Sterilised by gamma
irradiation

18. BEFORE APPLICATION

19. Onlay patch: stromal side
up
Inlay graft: epi side up

20. INDICATIONS OF AMT IN
OCULAR SURGERY
Conjunctival surface
reconstruction
• Pterygium surgery
• Chemical burns
• Cicatrizing conjunctivitis
• Ocular surface
squamous neoplasia
(OSSN)
• Leaking blebs
• Conjunctivochalasis
Ocular surface
reconstruction
• Symblepharon
release
• Fornix formation
• Steven Johnson
syndrome
• Ocular cicatricial
phemphigoid
Oculoplasty
• Socket reconstruction
• Entropion correction
• Lid reconstructions
Glaucoma
• Trabeculectomy
Corneal surface
reconstruction
• PEDs
• Non-healing stromal
ulcers
• descemetocele
• Partial LSCD
• Total LSCD
• Shield ulcers
• Bullous keratopathy
• Band keratopathy
• Scleral melt
• Punctal patch for dry eye
• Substrate for ex-vivo
expansion of limbal stem
cells

21. COMPLICATIONS
• Hematoma formation under the membrane. The blood usually absorbs or may
need drainage, by making a small opening in the graft, if excessive.
• Premature degradation of the membrane and cheese wiring may need frequent
repeat transplantations.
• Residual subepithelial membrane may persist in some cases and inadvertently
opacify the visual axis.
• Post –AMT microbial infections-1.6%. [8% with fresh AM] Gram-positive
organisms- most frequent isolates. Gabler et al. reported a case of sterile
hypopyon after repeated AMT.
• Calcification occurs in about 12.8% of cases. White plaques have been attributed
to ciprofloxacin therapy

22. NEWER ADVANCES
A) AmnioClip, disassembled,
left: outer silicone ring, right:
inner steel ring;
B) AmnioClip, assembled
without AM, view from the
inner (ocular) side;
C) AmnioClip, assembled with
AM, view from the inner
(ocular) side,
D) mounting device, open
position allowing placement
of the rings and AM;
E) mounting device, closed
“mounting” position.