1. Modified Instrumentation to Simplify “Big Bubble technique” for Deep Anterior Lamellar Keratoplasty (DALK)
Dr Rajesh Fogla DNB, FRCS, MMed
Senior Consultant, Corneal Surgeon
Apollo Hospitals, Hyderabad, INDIA
Financial Interest : No Financial Interest
The Fogla DALK instruments were developed by Storz (B&L) free of cost

2. Big Bubble Technique DALK
First described by Dr Mohammed Anwar
Technique uses forceful injection of air at 80% corneal depth using 27G needle connected to an air filled syringe
Air pressure results in separation of the Descemet Membrane (DM) from stroma.
Edge of DM separation is outlined with a dense white band
This allows replacement of pathological stroma with donor tissue devoid of DM.

3. Big Bubble Technique DALK
Original technique - Steep learning curve
Technique requires placement of sharp 27G needle at > 80% depth of cornea.
Superficial placement of needle tip results in stromal emphysema and lateral movement of air towards the limbus
Deeper placement of needle tip increases risk of perforation into the anterior chamber
Success rate of achieving Big Bubble is 65-80% even in hands of experienced surgeons

4. Modified Instruments for Big Bubble DALK Surgery

7. Deflating the Big Bubble using sharp 15 blade with cutting edge facing upwards
Using the Fogla Trifacet spatula the space in between the stroma and DM is entered, and the overlying stroma incised using No 15 blade to enlarge the opening

8. Using Fogla R & L Scissors, the overlying stroma is split into 4 quadrants
Using Fogla R & L Scissors, each quadrant of stromal tissue is excised carefully at the edge of corneal trephination

9. Note bare DM after excision of stromal tissue, Donor tissue is prepared by peeling off DM using fine tying forceps, Donor tissue is placed on the host bed and sutured using 10-0 Nylon suture
Post operative outcome is excellent following Big Bubble technique of DALK surgery
This technique also allows better utilization of donor tissues from the Eyebank

11. Modified Technique & Instrumentation
Instruments designed in 2006
Over 200 consecutive DALK procedures performed since then
Big Bubble achieved in > 95% cases
Microperforation occurred in 1.5% cases (3)
None of the cases converted to penetrating keratoplasty
Average uncorrected visual acuity 20/60, best spectacle corrected visual acuity of 20/25.

12. Conclusion
Modified Big Bubble technique of DALK surgery is easier to master with lower complication rates using the Fogla set of DALK instruments.
Surgeons will now be able to apply this surgical technique to a wide variety of corneal disorders with healthy endothelium requiring corneal transplantation surgery

13. Thank You www.corneaclinic.com