AUG 11, 2010
This experimental study investigates the feasibility of pneumatic dissection in separating Descemet's membrane and endothelium from the overlying stroma.
A 30-G needle connected to a 10-cc, air-filled syringe is inserted bevel up into the peripheral cornea approximately 1 mm from the limbus and advanced in a tangential direction immediately beneath the endothelium for approximately 2 mm. Air is injected into donor tissue from the endothelial side to detach Descemet's membrane, with the resulting "bubble" expanded as far as possible into the periphery. A silicone weight is then attached to the scleral ring to prevent the cornea from floating after immersion into the tissue culture medium and possibly dehydrating the "bubble." The prepared tissue is stored in tissue culture medium for seven days.
Complete detachment of Descemet's membrane was achieved in 95 percent of cases. In 12 cases this was achieved with a single injection of air, while seven required repeat injections. An adequate size of graft tissue (average, 8.11 mm) was obtained without manual manipulation, and endothelial cell loss after seven days of tissue storage was low (4.44 percent). During injection the air was frequently seen to leak from the limbal area. Persistent injection, however, ensured complete dissection.