PMC6889425_01
PMC6889425_02
Schematic diagram with surgical view describing AHM pneumatic dissection technique showing the needle tip visualization in cross-sectional diagram view, microscopic diagram view, and actual surgical screen capture
40942_2019_191_Fig1_HTML.jpg
PMC6889425_02_40942_2019_191_Fig1_HTML.jpg
Fig1
It is critical at this point to visualize the tip of the needle behind the lens to confirm entrance into the vitreous cavity before any air injection (Fig. 1).
The needle tip is rotated 90  with retraction parallel to the pars plana
40942_2019_191_Fig2_HTML.jpg
PMC6889425_02_40942_2019_191_Fig2_HTML.jpg
Fig2
After visualizing the needle tip behind the lens, the needle is rotated 90  parallel to the limbus and gently retracted until mild resistance from the bent needle reaching the pars-plana is felt (Fig. 2).
Pneumatic dissection anterior to the AHM
40942_2019_191_Fig3_HTML.jpg
PMC6889425_02_40942_2019_191_Fig3_HTML.jpg
Fig3
Filtered air is then injected under direct microscopic visualization (Fig. 3) (Additional file 1: Video 1).