b. Operative Procedures.
(1) Discussion, or needling of lens. The capsule is incised and the lens
substance is broken up. The aqueous humor exerts a solvent action on the exposed
lens tissue, thus a clear opening for the passage of light is obtained. The principal use
for needling is in cases of cataract due to trauma and in cataract surgery performed on
(2) Iridectomy. A sector of the iris is removed as a preliminary step in
extraction of the cataract (lens extraction).
(3) Lens extraction, intracapsular. The entire lens within the capsule is
removed intact through a corneoscleral incision (see figure 1-4).
Figure 1-4. Intracapsular lens extraction.
(4) Lens extraction, extracapsular. The anterior capsule is cut, and the lens
substance is delivered through the opening in the capsule. The posterior lens capsule