1. A good knife-needle must be carefully selected. We have already
concluded that the modified Hays knife-needle is the best model for
this purpose. The knife-needle must, of course, have a well sharpened
point and edge.
2. The character of the incision in the iris-membrane is of vital
importance. It should be a double incision. Guérin, Maunoir, DeWecker
and Galezowski recognized this. Guérin made a crucial incision,
Maunoir and DeWecker adopted the triangular flap, while Galezowski
advocated the T-shaped cut. Our choice is the V-shaped incision, which
is undoubtedly the only one that will cut through all the iritic fibers
in such a way as to give us the greatest retraction of the membrane.
3. Absolutely no pressure should be made in cutting with the
knife-needle. This must be recognized as the main secret of success,
whether you are incising a dense, felt-like iris-membrane, or a thin
filmy capsule. If this rule is observed all traction on the ciliary
body will be avoided.
4. The knife-needle should slide backward and forward through the
corneal puncture with a gentle sawing movement.
5. The corneal puncture and membrane counter-puncture should be far
enough apart to make the corneal puncture a good fulcrum for the
delicate leverage necessary in executing the iris incision.
6. The knife-needle should be so manipulated that no aqueous shall be
lost, as this accident may prevent the completion of the operation, and
may increase the tendency to iris hemorrhage by lowering the ocular
tension.
7. Every incision should be made a thoroughly clean cut, and all
tearing of the tissues should be avoided.
8. The most perfect artificial illumination should be secured, either
by an electric photophore or a condensing lens, as both iridotomy and
capsulotomy require constant and close inspection of the operative
field.