One of the important steps in the procedure of cataract extraction with zonulolysis is the application of enzyme to the zonular fibers. Each surgeon uses a different instrument and a different technique for the application of chymotrypsin. This seems to suggest that the ideal instrument and technique has not yet been devised.
It is possible, I believe, to compile several stipulations to which a good cannula for the application of enzyme should correspond.
The cannula should not be a straight tube; by accident it may act as a javelin by piercing the delicate tissues inside the eye, because even small jerky movements at the plunger end may cause unfavorable results at the tip end of the cannula. A straight cannula which is partially flexed or bent, has identical disadvantages.
The enzyme stream should be kept from flowing from the cannula with too much force. In a straight cannula the downward
HILGERS JHC. Hook Cannula for the Application of ChymotrypsinA New Instrument. Arch Ophthalmol. 1961;66(3):341-342. doi:10.1001/archopht.1961.00960010343008