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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 !!!