The Collaborative International Dictionary
Capsulotomy \Cap`su*lot"o*my\, n. [Capsule + Gr. ? to cut.] (Surg.) The incision of a capsule, esp. of that of the crystalline lens, as in a cataract operation.
n. (context surgery English) incision into a capsule, especially into the lens of the eye when removing cataracts
Capsulotomy is a type of eye surgery in which an incision is made into the capsule of the crystalline lens of the eye. In modern cataract operations, the lens capsule is usually not removed. The most common forms of cataract surgery remove nearly all of the crystalline lens but do not remove the crystalline lens capsule (the outer “bag” layer of the crystalline lens). The crystalline lens capsule is retained and used to contain and position the intraocular lens implant (IOL).
Months or years after the cataract operation, the lens capsule can become opaque in about 30% of eyes.
Before the advent of laser surgery, a tiny knife called a cystotome was used to cut a hole in the center of lens capsule, thus providing a clear path for light to reach the retina. This procedure thus reduces the opacity of the lens of the eye. This method has been replaced by YAG laser capsulotomy.