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Accommodative and Multifocal IOLs

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Accommodative and Multifocal IOLs Insert name/ Practice name/ Logo here if desired How the eye works Light rays enter the eye through the clear cornea, pupil and lens. – PowerPoint PPT presentation

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Title: Accommodative and Multifocal IOLs


1
Accommodative and Multifocal IOLs
Insert name/ Practice name/ Logo here if desired
2
How the eye works
  • 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.

3
Refractive errors
  • Inability to see clearly is often caused by
    refractive error.
  • Four types of refractive error
  • Myopia (nearsightedness)
  • Hyperopia (farsightedness)
  • Astigmatism
  • Presbyopia

4
Refractive errors myopia
  • 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.

Myopia, or nearsightedness
5
Refractive errors hyperopia
  • 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.

Hyperopia, or farsightedness
6
Refractive errors astigmatism
  • In astigmatism, the cornea is curved
    unevenlyshaped 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.

Astigmatism occurs when light passes through
football-shaped cornea and/or lens
7
Refractive errors presbyopia
  • Presbyopia is an age-related condition in which
    your eyes gradually lose the ability to see
    things up close, because the lens of the aging
    eye can no longer change shape.
  • 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 begins to
    gradually decrease, making it more difficult to
    see objects up close, unless the eye has
    nearsightedness.

8
What is accommodation?
  • The eyes lens, which provides your focusing
    power, has four primary functions
  • Transparency To provide a clear medium through
    which light rays from an object can reach your
    retina.
  • Optical To focus a sharp image of an object on
    the retina.
  • Anatomic To create a functional barrier between
    the anterior and posterior segments of the eye.
  • Accommodation To vary the eyes refractive
    power, thus providing clear images of objects
    over a wide range of distances.

9
What is refractive surgery?
  • 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, PRK and CK.

Refractive surgery procedure on the cornea
10
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
    dont reshape the cornea instead, the eyes
    natural lens is either replaced or enhanced by an
    implantable lens that helps correct vision.

11
What are accommodative intraocular lenses (IOLs)
and multifocal intraocular lenses (IOLs)?
  • An artificial lens that is surgically implanted
    in the eye, replacing the eyes natural lens.
  • Enables your eye to regain its focusing and
    refractive ability.
  • The cornea is not reshaped.
  • Used to treat nearsightedness (myopia),
    farsightedness (hyperopia) and the inability to
    focus at near with age (presbyopia).

12
What is an accommodative intraocular lens (IOL)?
  • The accommodative IOL is hinged to work in
    coordination with the eye muscles.
  • The design allows the accommodative lens to move
    forward as the eye focuses on near objects, and
    move backward as it focuses on distant objects.

A type of accommodative intraocular lens (IOL)
13
What is a multifocal IOL?
  • A multifocal lens has several rings of different
    powers built into the lens.
  • The part of the lens (ring) you look through will
    determine if you see clearly at a far, near or
    intermediate distance (this is sometimes called
    pseudo-accommodation).

A type of multifocal intraocular lens (IOL)
14
How is the IOL procedure performed?
  • The IOL is implanted in a surgical procedure,
    performed on an outpatient basis under local
    anesthesia and taking approximately 20-30
    minutes.

15
How is the IOL procedure performed?
  • In addition to a pre-operative eye exam,
    measurements of the eye are taken to give the
    surgeon the necessary information to perform the
    procedure. These measurements include
  • Refractive error measurement.
  • Pupil evaluation and size measurement.
  • Keratometry measurement of the form and
    curvature of the cornea.
  • A-scan Measurement of the axial length of the
    eye from the cornea to the retina.
  • Calculations to determine the correct power of
    lens (IOL) to use.

A phoropter is used to measure refractive errors
16
How is the IOL procedure performed?
  • 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.

Small incisions are made close to the edge of the
cornea for inserting the IOL
17
How is the IOL procedure performed?
  • A tiny, high-frequency ultrasound instrument is
    inserted into the eye to break up the center of
    the eyes natural, crystalline lens.
  • The natural lens is then gently vacuumed out
    through one of the incisions.

The eyes natural lens is suctioned out through
an incision
18
How is the IOL procedure performed?
  • An IOL is folded and inserted through the same
    incision that was used to extract the natural
    lens.
  • The IOL is then unfolded and placed into the
    "capsular bag" that originally surrounded the
    natural lens.

IOL in the eye
19
How is the IOL procedure performed?
  • Once the accommodative or multifocal IOL is
    implanted, your eye can focus on near,
    intermediate and far distances.

The IOL firmly in place
20
Considerations for the accommodative/multifocal
IOL procedure
  • May be an option for people with cataracts or
    people without cataracts who are presbyopic and
    want to reduce or eliminate their need for
    glasses.

21
Considerations against the accommodative/multifoca
l IOL procedure
  • The focusing ability of the lens may not be fully
    realized for six to eight weeks after the
    procedure.
  • Your eye must re-learn how to focus on objects at
    various distances in order to see clearly.

22
Risks and possible side effects of
accommodative/multifocal IOL surgery
  • Over-correction or under-correction (with a
    possible need for a re-treatment).
  • Infection.
  • Increased floaters or retinal detachment.
  • Dislocation of implant.
  • Loss of vision.

23
Is refractive surgery right for you?
  • Advanced surgical procedures, including
    accommodative and multifocal IOLs, 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/contacts may still be
    needed for activities such as fine or detailed
    work, reading and perhaps night driving.
  • If an accommodating or multifocal IOL is used,
    then reading as well as distance vision may be
    improved.

24
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.

25
Discuss options and questions with your
ophthalmologist
  • With the help of your ophthalmologist, its
    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.
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