Wednesday, December 29, 2010

PHACOEMULSIFICATION

It is presently the most popular method of
extracapsular cataract extraction. It differs from the
conventional ECCE and manual SICS as follows:
1. Corneoscleral incision required is very small (3
mm). Therefore, sutureless surgery is possible
with self-sealing scleral tunnel or clear corneal
incision made with a 3 mm keratome.
2. Continuous curvilinear capsulorrhexis (CCC) of
4-6 mm is preferred over other methods of anterior
capsulotomy (Fig. 8.20A).
3. Hydrodissection i.e., separation of capsule from
the cortex by injecting fluid exactly between the
two (Fig. 8.20B) is must for phacoemulsification
in SICS. This procedure facilitates nucleus
rotation and manipulation during phacoemulsification.
Some surgeons also perform hydrodelineation
(Fig. 8.20C).

4. Nucleus is emulsified and aspirated by
phacoemulsifier. Phacoemulsifier basically acts
through a hollow 1-mm titanium needle which
vibrates by piezoelectric crystal in its longitudinal
axis at an ultrasonic speed of 40000 times a
second and thus emulsifies the nucleus. Many
different techniques are being used to accomplish
phacoemulsification. A few common names are
‘chip and flip technique’, ‘divide and conquer
technique’ (Figs. 8.20 D&E) ‘stop and chop’ and
‘phaco chop technique’.
5. Remaining cortical lens matter is aspirated with
the help of an irrigation-aspiration technique

6.IOL implantation. A posterior chamber IOL is
implanted in the capsular bag after filling the bag with
viscoelastic substance (Figs. 8.19N, O & P) Foldable IOL is

most ideal with phacoemulsification technique.
7. Removal of viscoelastic material is done
thoroughly from the anterior chamber and capsular
bag with the help of two-way irrigation aspiration
cannula.
8. Wound closure.The anterior chamber is deepened
with balanced salt solution / Ringer's lactate solution
injected through side port entry. This leads to self
sealing of the sclero-corneal tunnel incision due to
valve effect. Rarely a single infinity suture may be
required to seal the wound. The conjunctival flap is
reposited back and is anchored with the help of wet
field cautery (Fig. 8.19Q).



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