Deep Anterior Lamellar Keratoplasty- Techniques

SHERAZ DAYAMD FACP FACS FRCS(Ed) FRCOphth

Financial DisclosureCompany Code

1. Abbott Medical Optics Inc. S

2. Bausch + Lomb C,L

3. Carl Zeiss Meditec C

4. Clarvista C

5. Ellex L

6. Excellens C, O

7. LinCor Biosciences C

8. Medicem C

9. Nidek, Inc. C,L

10. Physiol L

11. PRN O

12. STAAR Surgical C

13. Strathspey Crown C

14. Scope Pharmaceuticals C

15. Rayner C

C = Consultant / Advisor

E = Employee

L = Lecture Fees

O = Equity Owner

P = Patents / Royalty

S = Grant Support

DALK – Why ?

“Primo No Nocere”

• SAFETY

• SURVIVAL – long term

• OTHER…

INDICATIONS: Lamellar Keratoplasty

“WHENEVER THE ENDOTHELIUM IS

NORMAL”

Anterior Lamellar Keratoplasty

Advantages

– Retains endothelium

– Reduces risk of long term corneal blindness

– Decreases hazards of PK

Disadvantages (previously cited)

– Poor Vision

Interface opacification

Regular and Irregular Astigmatism

– Technical skill

Perforation

PK can be HAZARDOUS !!!

PK – Hazards…

Expulsive Choroidal Haemorrhage 0.56*-1%

Rejection & Failure

Reduced survival of Regrafts

Glaucoma 19- 30%

Cataract

Endophthalmitis

PK – long term…

Do Lamellars Reject ?

Epithelial Rejection Sub-epithelial Rejection

DALK vs PK for Keratoconus

Visual (optical)

– Keratoconus

– Corneal Stromal dystrophies & degenerations

– Deep corneal scarring

Traumatic

post infective – HSV, HZV

other stromal scars

Tectonic – higher risk for PK– Corneal ectasia

( focal such as pellucid marginal degeneration, diffuse, or post full

thickness grafting)

– Corneal melt

(autoimmune, neurotrophic, or infectious)

– Traumatic corneal perforation

– Peripheral corneal thinning

Mooren’s ulcer

Terrien’s marginal degeneration

collagen disease and other autoimmune diseases

DALK - Post Perforation

Ocular surface disease

– Stevens Johnson Syndrome (SJS)

– Chemical or thermal injury

– Ectodermal dysplasia

– Corneal stromal scarring or thinning from ocular

surface disease

Ocular Surface Disease

Special situation

Prior experience– all PKs in time failed*

– LKs survived

GOAL: – Tectonic or

– improve clarity

* Ilari L, Daya SM: Long-term outcomes of keratolimbal allograft for the treatment of severe ocular surface disorders. Ophthalmology. 2002 Jul;109(7):1278-84

Corneal Melt in prev DALK

GRAFT SURVIVAL

by Diagnostic Category

Keratoconus 50 49 (98%)

Corneal Scarring 7 7 (100%)

HSV / HZV 21 20 (95.2%)

Ocular Surface Disease 15 8 (53.2%)

Tectonic (perforation) 8 5 (62.5%)

n

Graft survival

40%

50%

60%

70%

80%

90%

100%

110%

year 1 year 2 year 3 year 4 year 5

keratoconus

herpetic

therapeutic/tectonic

Clear

DALK – How ?

• Descemet’s– Big Bubble – Anwar

– Viscodissection

• Pre-Descemet’s– Optical Recognition – Melles

• Femtosecond Assisted

Ferrara ”Cheesewire”

Big Bubble – Mohamed Anwar*

• Anwar M, Teichmann KD Big-bubble technique to bare Descemet's membrane in anterior lamellar keratoplasty J Cataract Refract Surg. 2002 Mar;28(3):398-403 Big-bubble technique to bare Descemet's membrane in anterior lamellar keratoplasty.

Perforate remaining stroma

Courtesy Luigi Fontana, MD

Removal of anterior stroma

Courtesy Luigi Fontana, MD

Stromal injection of Air

Courtesy Luigi Fontana, MD

Air accumulates and cleaves PDL

Courtesy Luigi Fontana, MD

Injection of Viscoelastic

Courtesy Luigi Fontana, MD Courtesy Luigi Fontana, MD

Courtesy Luigi Fontana, MD

Exposure of Descemet’s /PDL

Removal of residual stroma

FSDALK – Recipient

Big Bubble

• Type 1– Separates PDL – thicker layer

– Central Bubble extends to 8.0mm

– Accompanying emphysema

• Type 2– At DM – very thin

– Peripheral bubble extends to outside 8.0mm zone

– Little or no stromal emphysema

When is Big Bubble Contraindicated ?

• Endothelial failure

• Scarring to DM / Pre-Descemet’s Layer (PDL)

• Previous Hydrops

• ? Large diameter DALK

• Avoidance of conversion to PK– Down’s Syndrome

– Paediatric Keratoplasty

– Keratoglobus

Manual DALK Dissection• GOALS

• DEEP as possible – Descemet’s level best…

• SMOOTH as possible

CORNEAL ANATOMY

• Posterior lamellae = less densely packed

DEEP ANTERIOR LAMELLAR KERATOPLASTY

MELLES – Pre-Descemet’s dissection*

Technique of Melles

-Limbal incision

- Air in AC

- Posterior dissection of whole cornea

- Viscoelastic to separate posterior lamellae

- Trephination

* Br J Ophthalmol 1999;83:327-333

Modified MellesDetermination of Graft Size

Partial thickness trephination

PARACENTESIS

OUTSIDE area of Dissection

AQUEOUS REPLACED WITH AIR

Air - Endothelium Interface

black band

Air - endothelium interface acts as a convex mirror

Black band = 2 X residual stromal depth

Achieve appropriate depth

wrinkles in Descemet’s

Deep dissection with a blunt spatula*

*Daya Lasik Spatula, (John Weiss Ltd. UK)

Removal with Curved Corneal Scissors

Descemet’s membrane exposed

Donor Descemet’s Membrane Stripped

Trypan Blue (Vision Blue)

Suturing the Graft

Graft Sutured

Post DALK on Hydrops

DALK on Hydrops

25

75 75

100 100

75

12.5

25

0 00 0 0 0 00

20

40

60

80

100

1m 3m 6m 12m Last visit

Eyes (

%)

Follow up (months)

Best spectacle corrected visual acuity (BSCVA)

6/12 or better

6/24-6/12

Worse than 6/24

Conclusions DALK – Endothelial preservation technique

• Safer option than PK

• Long term corneal survival

• Better outcomes

– Newer techniques

– Experience

• Always a good first option

– PK can always be performed later

• Excellent skill to acquire

Deep Anterior Lamellar Keratoplasty

WORTH CONSIDERING WHENEVER

THE ENDOTHELIUM IS NORMAL !!!