Page 48 - The Book Pi in eye

Rajesh Khanna, MD

Gaining an entry to leaving no mark:

What is so great about entering the eye? Any rookie with a knife
and some knowledge of eye anatomy can do this right? But here is the
catch, if one leaves the door open the bugs and thieves will come, and
what's in can go out. Therefore the opening should be as small and as
brief in duration as possible.
The proper construction of these entry wounds is an art. The
opening in Prelex is less than tenth of an inch and fashioned in such a
way to prevent the need for any stitches. The wound needs to provide
adequate entry for instruments and Pi, yet be able to self-seal. Swelling
the opening edges with water helps seal them quickly.

Breaking the Cataract- a true labor of Hercules

The lens is held in a bag. The natural crystalline lens has a diameter
of 12-14 mm whereas the diameter of the cornea is 11-12 mm (a
penny has a diameter of 19 mm). A few decades ago the lens was
removed with the bag a method termed intracapsular lens extraction.
The preferred method today is to open the bag, remove the lens and
leave the bag behind to provide a natural space to implant the
synthetic lens.
So we need a method to open the bag using a pointed instrument,
like a forcep. The lens can be broken down using ultrasound, with
pulsating pressure waves or laser. Ultrasound or pressure waves
emulsify the broken lens pieces so that they can be sucked or aspirate
out. This is a skillful tough task requiring precise control.

Artificial Lens - Synthetic but biocompatible PI

The most physiological place to implant the artificial lens is from
the place that we are moving, the natural lens. This means that we
implant it in the capsular bag. The testy grail of lens implant
technology has been to mimic the natural lens. Currently we are quite
close to meeting the goals. We can place the lens in the bag. The lens
does not cause any inflammatory reaction and can outlive the person.
We have two different types of lenses - multifocal &
accommodative. Multifocal lens are either refractive or diffractive. In
refractive lens there are alternative zones for distance and near.

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