Retrobulbar needle and methods of use

A method of performing an injection into the orbital fat of a patient, the method comprising:

• providing a needle and a cannula, the cannula having a distal end, the needle having a sharpened distal end and a lumen extending proximally from said sharpened distal end, the needle positioned and longitudinally movable within the cannula between a distal position at which the needle sharpened distal end is distal of the cannula distal end, and a proximal position at which the needle sharpened distal end is proximal of the cannula distal end;
• moving the needle into the distal position;
• inserting the needle and the cannula into the orbital fat;
• moving the needle into the proximal position;
• and
• injecting a fluid through the distal end of the needle lumen, through the distal end of the cannula, and into the orbital fat;
• wherein providing a needle and a cannula comprises providing a syringe including
• a cylindrical barrel having a proximal end, a distal end, an interior wall, and an open interior space between the proximal and distal ends;
• a plunger assembly including
• a plunger stem having a proximal end and a distal end, and
• a piston attached to the plunger stem distal end, the piston forming a fluid seal with the barrel interior wall;
• wherein the cannula is attached to the barrel, the cannula including a longitudinally extending lumen, a proximal portion, and a distal portion having a flexibility greater than the cannula proximal portion, the distal portion comprising the cannula distal end;
• and
• a needle assembly including said needle, the needle including
• a longitudinally extending shaft having a proximal end, said sharpened distal end, and said lumen extending proximally from the needle shaft sharpened distal end, and
• a proximal body mounted to the needle shaft proximal end, the proximal body sealing the proximal end of the needle shaft lumen, the proximal body positioned proximal of the piston.