Refractive lens exchange 2017

Cataract Surgery
Dr B Farpour
Geneva 2017
www.visionlaser.ch
PRELEX
Presbyopic Refractive Lens Exchange
Geneva refractive public education lectures
Courtesy of AAO
presentation support

Refractive Lens Exchange
• Light rays enter the eye through
the clear cornea, pupil and lens.
• These light rays are focused
directly onto the retina, the light-
sensitive tissue lining the back of
the eye.
• The retina converts light rays into
impulses, sent through the optic
nerve to your brain, where they
are recognized as images.
• 70% of the eye's focusing power
comes from the cornea and 30%
from the lens.
2
How the eye works
Eye anatomy

Refractive Lens Exchange 3
How the eye works

Refractive errors
• Inability to see clearly is often caused by refractive error.
• Four types of refractive error:
 Myopia (nearsightedness)
 Hyperopia (farsightedness)
 Astigmatism
 Presbyopia
4

• In myopia (nearsightedness),
there is too much optical
power in the eye.
 The distance between the
cornea and the retina may be
too long or the power of the
cornea and the lens may be
too strong.
• Light rays focus in front of the
retina instead of on it.
• Close objects will look clear,
but distant objects will appear
blurred.
5
Refractive errors: myopia
Myopia, or nearsightedness

• In hyperopia (farsightedness),
there is too little optical power.
 The distance between the
cornea and the retina may be
too short.
• Light rays are focused behind
the retina instead of on it.
• In adults (but not children),
distant objects will look clear,
but close objects will appear
blurred.
6
Refractive errors: hyperopia
Hyperopia, or farsightedness

• In astigmatism, the cornea is
curved unevenly — shaped
more like a football than a
basketball.
• Light passing through the
uneven cornea is focused in
two or more locations.
• Distant and close objects may
appear blurry.
7
Refractive errors: astigmatism
Astigmatism occurs when light passes
through an uneven cornea.

• Presbyopia is a normal
condition in which your eyes
gradually lose the ability to
focus on things up close.
• When we are young, the lens
in our eyes is flexible and is
able to change focus easily
between near and far objects,
like an autofocus on a camera.
• At around age 40, this
flexibility naturally begins to
gradually decrease, making it
more difficult to see objects up
close.
8
Refractive errors: presbyopia

• Refractive surgery is a group of outpatient surgical procedures used to
alter how your eye focuses light rays on the retina, thereby improving
vision and reducing dependence on glasses and contact lenses.
• In most cases, refractive surgery affects the shape of your cornea to
redirect how light is focused onto the retina. Popular procedures
include LASIK, LASEK and PRK.
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What is refractive surgery?
Refractive
surgery
procedure on
the cornea

What is refractive surgery?
• Most refractive surgery is performed on the cornea and affects only
the front of your eye, while the rest of your eye will change naturally
as you age.
• In some cases, refractive surgery procedures don’t reshape the
cornea; instead, the eye’s natural lens is either replaced or
enhanced by an implantable lens that helps correct vision.
10

• A non-laser procedure where
the natural, non-cataractous,
lens of the eye is removed and
replaced with an artificial,
intraocular lens (IOL).
• The cornea is not reshaped.
• Used to treat moderate to high
degrees of nearsightedness
(myopia), farsightedness
(hyperopia) and patients who
are not LASIK candidates.
11
What is refractive lens exchange (RLE)?
Typical intraocular lenses (IOLs) used
in the refractive lens exchange (RLE)
procedure

What is an IOL?

Multifocal IOLs

Accommodative IOLs

How is the RLE procedure performed?
• The IOL is implanted in a surgical procedure and performed on an
outpatient basis under local or topical anesthesia.
 The RLE procedure takes approximately 15 to 20 minutes.
 The procedure is exactly the same as routine cataract surgery.
15

• In addition to a complete
preoperative eye exam, these
measurements are performed to
give the surgeon the necessary
information to calculate the
necessary power of the IOL:
 Keratometry: measurement of the
form and curvature of the cornea
 Retinal exam
 A-scan: The axial length of the eye
from the cornea to the retina
 The depth of the anterior chamber
16
A phoropter is used to measure
refractive errors.

• After the eye is numbed with
topical or local anesthesia, one
to three small incisions are
made close to the edge of the
cornea.
• After the procedure, these
incisions are usually “self-
sealing,” requiring no stitches.
17
A small incision is made close to the
edge of the cornea prior to removing
the natural lens and inserting the IOL.

• A tiny, high-frequency ultrasound
instrument is inserted into the eye
to break up the center of the
eye’s natural, crystalline lens.
• The lens is then gently vacuumed
out through this same instrument.
18
The eye’s natural lens is suctioned out
through an incision.

• An IOL is folded and inserted
through the same incision that was
made to extract the natural lens.
• The IOL is then unfolded and
placed into the "capsular bag" that
originally surrounded the natural
lens.
19
IOL in the eye

Considerations for the RLE procedure
• RLE may be recommended for patients who have cataracts starting
to form.
• RLE may be recommended for patients with thin corneas who are
otherwise not candidates for the LASIK procedure.
• RLE may be recommended for patients with unusually high
refractive error.
20

Considerations against the RLE procedure
• Patients with significant ocular disease of any type
• Patients with a history of retinal detachment
• Patients with any reason for increased risk of infection
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Risks and possible side effects of RLE surgery
• Overcorrection or undercorrection (with a possible need for
retreatment)
• Infection
• Increased floaters or retinal detachment
• Corneal swelling
• Swelling or edema of macula
• Dislocation of implant
• Loss of vision (rare)
22

Is refractive surgery right for you?
• Advanced surgical procedures, including refractive lens exchange,
are creating more opportunities for people who want to be less
dependent on glasses or contacts.
• Surgery may not entirely eliminate your need for corrective lenses.
Glasses or contacts may still be needed for activities such as fine or
detailed work, reading and perhaps night driving.
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Is refractive surgery right for you?
• A large part of the success of any refractive surgery depends on
your understanding of the procedure and your expectations.
• Since refractive surgery is an elective procedure, you have the
opportunity and responsibility to become fully informed about its
risks and benefits.
• Your ophthalmologist will explain the specific technique, its benefits,
as well as possible risks and side effects associated with your case.
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• With the help of your ophthalmologist,
it’s ultimately your responsibility to
weigh the risks and side effects of a
procedure with the benefits it has to
offer.
• If you decide refractive surgery is right
for you, you may join millions of
people who have reduced their
dependence on glasses or contacts.
25
Discuss options and questions with your ophthalmologist

Refractive lens exchange 2017

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