The Risks of Lasik

By:  L. Fleming Fallon Jr., MD,

    All of these surgical procedures carry risks, the most
serious being corneal scarring, corneal rupture, infection,
cataracts, and loss of vision.    In addition, a study published in
March 2001 warned that mountain climbers who have had LASIK
surgery should be aware of possible changes in their vision at
high altitudes.  The lack of oxygen at high altitudes causes
temporary changes in the thickness of the cornea.

    Since refractive eye surgery doesn't guarantee 20/20 vision,
it is important to have realistic expectations before choosing
this treatment.  In a 10-year study conducted by the National Eye
Institute between 1983 and 1993, over 50% of people with radial
keratotomy gained 20/20 vision, and 85% passed a driving test
(requiring 20/40 vision) after surgery, without glasses or contact
lenses.  Even if a person gains near-perfect vision, however,
there are potentially irritating side effects, such as
postoperative pain, poor night vision, variation in visual acuity,
light sensitivity and glare, and optical distortion.  Refractive
eye surgeries are considered elective procedures and are rarely
covered by insurance plans.

    Myopia treatments under research include corneal implants and
permanent surgically placed contact lenses.

Alternative treatments

    Some eye care professionals recommend treatments to help
improve circulation, reduce eye strain, and relax the eye muscles.
It is possible that by combining exercises with changes in
behavior, the progression of myopia may be slowed or prevented.

    Alternative treatments include:  visual therapy (also
referred to as vision training or eye exercises), discontinuing
close work, reducing eye strain (taking a rest break during
periods of prolonged near vision tasks), and wearing bifocals to
decrease the need to accommodate when doing close-up work.

Prognosis

    Glasses and contact lenses can (but not always) correct a
person's vision to 20/20.  Refractive surgery can make permanent
improvements for the right candidates.

    While the genetic factors that influence the transmission and
severity of myopia cannot be changed, some environmental factors
can be modified.  They include reducing close work, reading and
working in good light, taking frequent breaks when working at a
computer or microscope for long periods of time, maintaining good
nutrition, and practicing visual therapy (when recommended).

    Health care team roles Ophthalmologists and optometrists
diagnose myopia.  Both may prescribe corrective lenses (glasses or
contact lenses).  Ophthalmologists perform surgery to correct
myopia.  Various individuals can fill prescriptions
for corrective lenses.    This is governed by individual state
laws.

    Prevention Eye strain can be prevented by using sufficient
light for reading and close work, and by wearing corrective lenses
as prescribed. Those with corrective lenses should have regular
eye examinations to see if their prescription has changed or if
any other problems have developed.  This is particularly important
for people with high (degenerative) myopia who are at a greater
risk of developing retinal detachment, retinal degeneration,
glaucoma, or other problems.

--------------

KEY TERMS

---------------

Accommodation - The ability of the lens to change its focus from
    distant to near objects.  It is achieved through the
    action of the ciliary muscles that change the shape of the
    lens.

Cornea - The outer, transparent tissue that covers the front of
    the eye.  The cornea is part of the eye's focusing system.

Diopter (D) - A unit of measure for describing refractive power.

Laser-assisted in-situ keratomileusis (LASIK) - A procedure that
    uses a cutting tool and a laser to modify the cornea and
    correct moderate to high levels of myopia.

Lens - The transparent, elastic, curved structure behind the iris
    (colored part of the eye) that helps focus light on the
    retina.

Ophthalmologist - A medical doctor (MD or DO) who specializes in
    the diagnosis and medical and surgical treatment of eye
    diseases and disorders.

Optic nerve - A bundle of nerve fibers that carries visual
    messages in the form of electrical signals to the brain.

Optometrist - Doctors of optometry are primary health care
    professionals who examine, diagnose, treat, and manage
    diseases and disorders of the visual system, the eye, and
    associated structures, as well as diagnose related
    systemic conditions.  They prescribe glasses, contact
    lenses, low vision rehabilitation, vision therapy and
    medications, as well as perform certain surgical
    procedures.

Orthokeratology - A method of reshaping the cornea using a contact
    lens.  It is not considered a permanent method to reduce
    myopia.

Peripheral vision - The ability to see objects and movement to the
    side, outside of the direct line of vision.

Photorefractive keratectomy (PRK) - A procedure that uses an
    excimer laser to make modifications to the cornea and
    permanently correct myopia.  As of 2001, two lasers have
    been approved by the FDA for this purpose.

Radial keratotomy (RK) - A surgical procedure involving the use of
    a diamond- tipped blade to make several spoke-like slits
    in the peripheral (nonviewing) portion of the cornea to
    improve the focus of the eye and correct myopia by
    flattening the cornea.

Refraction - The bending of light rays as they pass from one
    medium through another.  Used to describe the action of
    the cornea and lens on light rays as they enter they eye.
    Also used to describe the determination and measurement of
    the eye's focusing system by an optometrist or
    ophthalmologist.

Refractive eye surgery - A general term for surgical procedures
    that can improve or correct refractive errors by
    permanently changing the shape of the cornea.

Retina - The light-sensitive membrane that lines the back of the
    eye.  The retinal cells process and send visual signals to
    the brain through the optic nerve.

Visual acuity - The ability to distinguish details and shapes of
    objects.