Cataract surgery today is typically performed using a microincisional procedure. To the patient, this means minimal discomfort during or after surgery, a more speedy recovery of vision, and reduced risk of induced astigmatism. This means less dependence on glasses afterwards. The major steps of cataract surgery are detailed below using a microincision procedure, phacoemulsification (ultrasonic cataract removal), and a foldable lens implant. This type of procedure is considered state-of-the-art for cataract surgery today. The procedure demonstrates basic principles only.
The most commonly used cataract incision is about 3 millimeters in size – just about one-eighth of an inch! Because of the careful construction of this incision, and its small size, the incision is generally self-sealing. This translates to a “no-stitch” type operation.
The surgeon then creates an opening in the capsule, which is a micro-thin membrane surrounding the cataract. This procedure, called capsulorhexus, requires extraordinary precision since the capsule is only about four-thousandths of a millimeter thick. This membrane is actually thinner than a red blood cell and the surgeon must delicately remove the capsule while manipulating instruments within the anterior chamber – a space only 3 millimeters deep.
Phacoemulsification is the aspect of the procedure in which ultrasonic vibrations are used to break the cataract into smaller fragments. These fragments are then aspirated from the eye using the same instrumentation.
The surgeon may elect to create grooves in the cataract, and subsequently break the cataract into smaller pieces using the phacoemulsification tip and a second instrument passed through a smaller “side-port” incision. The “phaco” aspect of the procedure is used to remove the denser central nucleus of the cataract.
Once the denser central nucleus of the cataract has been removed, the softer peripheral cortex of the cataract is removed using an irrigation/aspiration handpiece. The posterior or back side, of the lens capsule is left intact to help support the intraocular lens (IOL) implant. The intraocular lens is often folded and passed through the tiny incision where it is opened (implanted) inside the “capsular bag”. The lens is being inserted via an “injector”. This is an instrument designed to help keep the incision size small while allowing implantation of a 6 millimeter lens through a 3 millimeter (or even smaller) incision.
The IOL is implanted within the “capsular bag” where it is neatly centered. The springy “arms” of the IOL, known as haptics, hold the lens implant within the capsular bag. The IOL does not generally require sutures to remain in good position. This position is the same as that of the natural lens (cataract) of the eye and, therefore, is generally tolerated best and provides the most optimal visual results. At this stage, the cataract operation with IOL implantation is complete.