Amniotic Membrane Transplantation for Corneal Indications

                           Superficial corneal opacity
 
             Before AMT                                    After AMT

Overview:

Our strategy for corneal surface reconstruction includes amniotic membrane transplantation (AMT). There are two modes for clinical use of AMT; permanent graft or overlaid graft.

When used as a permanent graft, the aim of AMT is to fill in the corneal stromal defect.

When used as a overlaid graft, the aim of AMT is to reduce ocular surface inflammation to promote epithelial healing with minimal or no scarring.

  Indications for AMT as a                                 Indications for AMT as an      
     permanent graft:                                           overlaid graft:

Persistent Epithelial Defects

Corneal ulcers are serious and urgent clinical problems that can be complicated by microbial infections and threaten patient’s vision. Corneal ulcers can be caused by various insults (e.g., exogenously from chemical burns, infection, radiation, or surgeries, while endogenously from aging, diabetes mellitus, viral (herpes) infection, and autoimmune disorders) which have the common denominator - neurotrophic keratopathy. When all medical treatments fail and the ulceration persists, conventional surgical treatments include lamellar or full-thickness corneal transplantation (patch graft), tarsorrhaphy or conjunctival flap.

AMT offers the following advantages over corneal tissue use in the treatment of persistent epithelial defects: 

• avoidance of potential allograft rejection
• postoperative astigmatism of tectonic corneal grafts
• ease and convenience of use
• feasibility in the event of corneal tissue shortage
• preservation of a better aesthetic appearance
• Even if corneal transplantation is needed, its success is promoted if performed in an eye that received AMT to reduce inflammation

Click here for surigial instruction on AMT for the treatment of persistent corneal epithelial defects.

Descemetocele and Perforation

For deeper stromal ulcers down to descemetocele, multiple layers of amniotic membrane (AM) can be used to restore the normal corneal thickness. When there is frank perforation even up to 3 mm in diameter, AMT may be used to seal the ulcer with or without additional tissue adhesive.

Click here for surgical instruction on AMT for the treatment of descemetocele or click here for instruction on AMT for perforation.

Infectious Keratitis and Scleritis

Corneal ulcers due to bacterial, fungal or viral causes can be managed by AMT after controlling the infection with proper antimicrobial treatment. This procedure results in decreased melting and inflammation at the lesion site with re-epithelialization within 2-3 weeks. Also it decreases the recurrence of infection.

Bullous Keratopathy

Bullous keratopathy is a disorder caused by corneal endothelial decomposition due to degeneration (Fuch’s endothelial dystrophy), surgical trauma, intractable glaucoma, or previous corneal graft failure. For those who do not have a visual potential, relief of pain and recurrent erosion will rely on several surgical treatments including cauterization, anterior stromal puncture, excimer laser photoablation, and conjunctival flap. After epithelial debridement, AMT provides pain relief and healing in addition to creating a smooth corneal epithelial surface 1 month after the procedure, and no recurrent bullae formation.

Click here for surgical instruction on AMT for treating bullous keratopathy.

Band Keratopathy

Band keratopathy occurs in a number of corneal diseases characterized bchronic inflammation. Conventional treatments include chelation by EDTA and superficial keratectomy to remove superficial calcium deposit and corneal stromal tissue. AMT after this procedure has achieved a success rate of more than 90% in relieving patient’s pain, establishing a stable corneal epithelium, and in some eyes improved vision.

Click here for surgical instruction on AMT for treating band keratopathy.

Links to surgical instruction by corneal indication:

Indications for AM as a Permanent graft: (Click on the links below to view more)

Persistent Corneal Epithelial Defects and Ulcers

Descemetocele

Perforation

Painful Bullous Keratopathy

Band Keratopathy

Indications for AM as an Overlaid graft: (Click on the links below to view more)

Recurrent Corneal Erosion
Acute Chemical/Thermal Burns
Acute Stevens Johns Syndrome with or without Toxic Epidermal Necrolysis
High-risk Corneal Grafts (to reduce complications)
Excimer Laser Ablation (PRK/PTK) (to prevent haze)
Corneal Degeneration e.g. Salzmann’s Nodular Degeneration
Implantation of Keratoprosthesis
Limbal Stem Cell Deficiency

Click here to view standard surgical supplies

Click here to view standard post operative care

Videos edited by:
Scheffer C.G. Tseng, MD, PhD
Hosam Sheha, MD, PhD
Ahmad Kheirkhah, MD
Antonio Elizondo, MD
Victoria Casas, MD

If you have additional surgical questions after viewing this information, contact OSREF’s Research Director, Scheffer C.G. Tseng, MD, PhD, by e-mail at stseng@ocularsurface.com or by phone at 305-274-1299.

Note: This video is for peer discussion purposes and the creators are not participating in commercial promotion of any product.

Financial Interest Disclosure: Dr. Tseng and his family are more than 5% shareholders in TissueTech, Inc. and Bio-Tissue, Inc. which currently distributes AMNIOGRAFT® and PROKERA™

© 2007. Ocular Surface Research & Education Foundation. Content is protected under intellectual property laws and are licensed for non-commercial viewing only. Any distribution, copying transmission or alteration is prohibited. All rights reserved.