Treatment
There is currently no effective medical
treatment for cataract. Treatment is by the
surgical removal of the opacified lens. One
of two surgical techniques may be used:
1. Extracapsular cataract extraction
(ECCE)
Cornea
Anterior chamber Lens 2-3 mm incision
at corneal/scleral
junction
Aspirate
Ciliary body Capsule
(posterior segment
marked ^^m )s
preserved in this
procedure)
Phacoemulsifier/
aspirator
Figure 1. Phacoemuisification using an uitrasonic needle.
2. Intracapsuler cataract extraction
(ICCE).
Extracapsular cataract extraction
The affected cortex and nucleus are
removed through an incision made in the
anterior capsule, either whole or, as is now
more common, in fragments following
phacoemuisification and aspiration.
Phacoemuisification is the mechanical
breaking up (emulsification) of the lens by
a hollow needle vibrating at around 40000
cycles per second, coupled with the simultaneous
irrigation and aspiration of the
emulsified particles from the anterior
chamber through the needle tip (Brunner
and Suddarth, 1982) {Figure 1).
More recently, phacoemuisification has
been achieved by the use of laser technology
(Dodick et al, 1993) which offers
more precision than ultrasonic phacoemuisification;
lasers also allow for a
much smaller incision into the eye,
thereby minimising the effect on nearby
non-target tissues. In this procedure the
capsule is preserved.
Following the removal of the cataract
lens, a synthetic lens can be implanted,
usually into the posterior chamber. This
effectively restores sight in most people
but leaves them without the ability to
focus. Spectacles are therefore still
required.