endothelium normal corneal...
TRANSCRIPT
6/21/2012
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A Single pass Microkeratome preparation of Ultra-Thin DSAEK
Grafts in the Eye Bank
Eric Abdullayev MD,MBA,CEBT
Director of Clinical Development and Research
International Sight Restoration Eye Bank
Tampa , Florida USA Eye Bank Association of America
2012 Annual Meeting
June 20-23, 2012, Hollywood FL, USA
Financial Disclosure
I have no any financial interest in any of the techniques or products
discussed
Endothelium
• Extremely thin
• Innermost layer of cornea
• Pumps excess fluid out of the stroma
• Essential in keeping the cornea clear
• Once cells destroyed by disease or trauma, they are lost forever
Normal Corneal Endothelium
• Primary function of the endothelium is to maintain the health and transparency of the corneal stroma
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Endothelial Corneal Disease
Normal corneal endothelium Diseased corneal endothelium-Fuch’s
dystrophy
Fuch’s Distrophy
Normal endothelial cells –
Density 3200
GUTTATA – cells loss Not suitable for EK or PKP
Severe Polymegathism
or large cells
( post cataract sx complication)
Normal endothelial cells –
Density 3200
Large cells-cells count 1350
Not suitable for EK or PKP
Endothelial Corneal Disease Clinical Evaluation
Clinical Evaluation
Blurred Vision
Fluctuating Vision
Halos around lights
Photophobia
Foreign body sensations
Contact lens intolerance
• Clinical Signs
• Stromal edema
• Increased thickness
• Loss of transparency
• Decreased visual acuity
• Epithelial edema
• Epithelial edema
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The Traditional Transplant Procedure or Full Thickness Cornea Transplant
1.White arrow shows opaque,
damaged cornea
2.Round shaped portion
of damaged cornea
removed
3. A donor button of clear cornea
is replaced 4. The donor cornea is sutured
into place
The Traditional Transplant Procedure or Full Thickness Cornea Transplant
DSAEK procedure DSAEK Benefits
• The eye is left much stronger and more resistant to
injury
• There is minimal change in refractive error because
the patient's cornea is essentially intact
• Suture-related problems can be eliminated
• Visual recovery is significantly faster and better
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DSAEK procedure
Host(recipient) 550 (range:480-650) µ
Lenticule(donor) + 150 (50-250) µ
Cornea after DSEK = 700 (530-900) µ
Too thick of tissue will lead to poor pump function
INTERNATIONAL SIGHT RESTORATIOB EYE BANK TAMPA FL USA
FDA- registered
AHCA- registered
EBAA- accredited
-Number donor corneas suitable for DSAEK- 50
- Donor age-between 19 and 79 - Average endothelial cell density before precut - 3155/mm² - Central stromal thickness prior precut ≈ 493µ
Backlight Microscopy Specular Microscopy
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Backlight Microscopy Back Light Microscopy (Direct) - Normal Cornea
Back Light Microscopy (Direct) - Epithelial Sloughing
25x 25x
40x 25x
Back Light Microscopy (Distant or Artificial “Red Reflex” )
FOLDS
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Back Light Microscopy (Direct) Endothelial Stress Striae
40x
Endothelial stress striae
Back Light Microscopy (Direct)
Arcus
Arcus
Back Light Microscopy - Artificial “Red Reflex” Surgical Scars ( cataract surgery)
Materials and Methods Donor corneas preservation
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ISO 5 Class Sterile Room with
Ophthalmic Microscope Ophthalmic Microscope
Center of donor cornea identified and marked
Ophthalmic Microscope Tissue mounted on chamber and centered
Ophthalmic Microscope Epithelium removed during processing
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Corneal Pachymetry
(Pachymeter- MMD AP2000)
Measuring Range : 45µ and up
Corneal Pachymetry (Pachymeter- MMD AP2000)
• Waveform
measuring the ultra-thin DSAEK
flap at 56 micron; flap was created by single pass method
Single Pass Ultra-Thin Graft Preparation
Increasing stromal resistance by
raising pressure in the anterior chamber
Standard pressure up to 90 mmHg Our approach-
pressure > to 90 mmHg for several seconds
Graft Preparation Cut Slowly – 6 seconds pass
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Physiology of the cut RESULTS - 50 - donor corneas were prepared using
pressurized single pass cut:
*No complication were observed
- 78.4µ - Average central stromal thickness ≈ (thinnest graft was 50 and thickest 100 microns)
- 3132/mm² -Average endothelial cell density -
- 9.76 mm - Cap size
RESULTS
• 63µ • 74µ
MICROKERATOME POST-RESECTION
TISSUE EVALUATION FORM
ISR EK# OD 2011-0333-OD
ISR EK# OS n/a
If cornea(s) to be processed are from source other than ISR, document source eye bank and source tissue #’s:
Eye Bank: n/a Tissue imported by ISR: Y N
Tissue # OS: n/a Tissue # OD: n/a
SPECULAR MICROSCOPY
Cell count prior to resection: 3004 /mm² Cell count post- resection: 2934 /mm²
Normal Endothelium Normal Endothelium
Notes:none Notes: none
Performed by: E.Abdullayev MD,MBA,CEBT Performed by: E.Abdullayev MD,MBA,CEBT Date: 09/19/2011
Date: 09/16/2011 POST-RESECTION CELL DENSITY EVALUATION: Pass Fail
SLIT LAMP/BACKLIGHT MICROSCOPY: POST RESECTION
EPITHELIUM: Removed during processing Notable defects: none
ANTERIOR STROMA: Clear
Centered, Adhered, and aligned with orientation mark (s)
Notable defects: none
POSTERIOR STROMA (Graft):
Clear, no visible decrease in clarity
Uniform cut, no irregularities or chatter noticed in cut
Uneven cut; Notes: none
DESCEMET’S MEMBRANE:
Intact, no folds or defects Folds (rate): few several mild moderate
central peripheral diffuse
ENDOTHELIUM:
Intact, no stress striae or defects Stress striae (rate): few several mild moderate
central peripheral diffuse
No significant increase in degree of folds or stress striae Notes: none
MEASUREMENTS: BED DIAMETER: 10 mm BED THICKNESS (post-resection actual): 72 µ CAP DIAMETER: 10 mm
FINAL GRAFT EVALUATION POST-RESECTION: ACCEPTABLE Tissue doesn’t meet acceptance criteria for EK ALK
IF NOT ACCEPTABLE, SPECIFY REASON: n/a
Evaluated by: MD CEBT: E.Abdullayev MD,MBA,CEBT Evaluated by Medical Director (optional, as needed):
Date: 09/19/2011 Date:
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RESULTS
49 corneas transplanted
RESULTS Complications
Graft Failure – 1
Interface Haze -3
Conclusion
• Our method for single pass microkeratome ultra-thin graft preparation is a safe technique and can be performed in eye-banks with no increased risk of perforation.
• Use of standard Moria equipment eliminates the needs for this procedure-fee increase.
• The prepared ultra-thin graft survives long distance international shipping. Foreign patients can also benefit from this advanced procedure.
Thank you !!!