There are already a few sub-Tenon’s cannula available for use . The features and benefits of this cannula over other cannulae are:
- It is curved (radius of curvature 14 mm) in such a way that, when it is pushed into the sub-Tenon’s space it will remain in the sub-Tenon’s space. This will avoid damage the optic nerve ocular muscles, and the blood vessels.
- The curved portion is 27 mm long. When the cannula is inserted at 5 mm from the from limbus,it will be about 5 mm away from the optic nerve. Even in relation to the smallest eye ball, the tip will be 5mm away from the optic nerve and will not damage it. In longer eye balls, the tip will be behind the equator so that it will not produce messy chemosis.
The straight position which is tangential to the curved position indicates the point at which the penetration should stop. This enables the surgeons to know when to stop the penetration into the sub-Tenon’s space.
This cannula is easy to use and will avoid complications which can be anticipated from other sub-Tenon’s cannulae.