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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 !!!