Deep Anterior Lamellar Keratoplasty - Techniques SHERAZ DAYA MD FACP FACS FRCS(Ed) FRCOphth
Financial Disclosure Company 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
Primo No Nocere DALK Why? 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
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 Clear Graft survival 110% 100% 90% 80% 70% 60% 50% 40% year 1 year 2 year 3 year 4 year 5 keratoconus herpetic therapeutic/tectonic
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.
Stromal injection of Air Air accumulates and cleaves PDL Courtesy Luigi Fontana, MD Removal of anterior stroma Perforate remaining stroma Courtesy Luigi Fontana, MD Courtesy Luigi Fontana, MD Courtesy Luigi Fontana, MD
Injection of Viscoelastic Removal of residual stroma Courtesy Luigi Fontana, MD Courtesy Luigi Fontana, MD Exposure of Descemet s /PDL Courtesy Luigi Fontana, MD
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 Melles Determination 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
Eyes (%) DALK on Hydrops 100 80 60 40 20 0 Best spectacle corrected visual acuity (BSCVA) 100 100 75 75 75 6/12 or better 6/24-6/12 25 25 Worse than 6/24 12.5 0 0 0 0 0 0 0 1m 3m 6m 12m Last visit Follow up (months)
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!!!