Phacoemulsification

Phacoemulsification - The Surgical removal of a cataractous lens.

The instrument used is called an "emulsifier", technically an ultrasonic handpiece. It is nothing but a high speed (ultrasonic) chisel.

Phacoemulsifiers are broadly of two types, depending on how suction occurs (generation of aspiration and vacuum);

1. Flow pumps (vacuum indirectly controlled) - The Peristaltic and the Scroll pumps.
2. Vacuum pumps (aspiration indirectly controlled) - The Venturi, Diaphragmatic and Rotary vane pumps.

Simply put, the instrument chisels the lens and aspirates (sucks) the debris created by the chiseling, thus removing the lens.

The Phacoemulsification Handpiece

The handpiece is made up of a titanium tip and a transducer. An electronically controlled alternating current is applied to the transducer which is converted to mechanical vibrations at ultrasonic frequencies. The vibrations are described by distance covered by the tip (stroke length) and frequency (in terms of to and fro movement over time).

The tip of the handpiece is usually straight, however some surgeons prefer a bent tip.

A sleeve covers the handpiece to prevent thermal damage to surrounding structures, especially the cornea.

Phacoemulsification

Phaco + emulsification (emulsification of the lens, phaco=lens)

It is acheived by:
1. Ultrasonic chiseling (as described above) or the Jackhammer effect.
2. Cavitation - a result of rapid movement of a solid in a liquid. The retraction of the tip during the backstroke of the tip creates vacuum resulting in bubbles. The implosion of the bubbles releases energy causing emulsification of the lens matter which is then aspirated.
3. Sound waves too are transmitted to the tip, releasing energy in the lens.