The DALK (Deep Anterior Lamellar Keratoplasty) using the Anwar big-bubble technique creates a dissection plane at the level of:
- A Bowman's layer, leaving all stroma with donor
- B Mid-stroma, leaving posterior stroma and Descemet's intact
- C Pre-Descemet's layer (Dua's layer) using pneumatic dissection, leaving recipient Descemet's and endothelium intact ✓
- D Sub-Bowman's layer, preserving recipient epithelium
Explanation
The Anwar 'big-bubble' technique in DALK involves injecting air through a 27G needle into the deep corneal stroma to pneumatically dissect the stroma from Descemet's membrane, creating a large space (Type 1 big bubble at pre-Descemet's plane, i.e., Dua's layer). This allows near-total stromal removal while preserving the recipient's Descemet's membrane and healthy endothelium — the primary advantage over penetrating keratoplasty (PKP). DALK eliminates the risk of endothelial rejection and reduces immune-mediated graft failure. It is ideal for keratoconus, stromal scars with intact endothelium, and macular/granular corneal dystrophies.
Reference: Khurana Comprehensive Ophthalmology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.