9 Criteria For A Good LASIK Candidate
By Brian S. Boxer Wachler, MD
A successful LASIK procedure is determined largely by whether you meet certain patient criteria and if laser eye surgery is right for you.
LASIK and PRK outcomes are almost always favorable; however, not everyone is a good candidate for vision correction surgery.
The following laser eye surgery checklist is a good start to help you determine if LASIK or PRK is right for you.
1. Your Eyes Must Be Healthy
If you have any condition that can affect how your eyes respond to surgery or heal afterwards, you must wait until that condition is resolved. Examples are severe dry eye syndrome, conjunctivitis(pink eye), infection and any type of eye injury.
If you have persistent dry eyes, where you do not produce enough tears to keep your eyes lubricated and healthy, LASIK surgery may aggravate this condition. Common symptoms of dry eyes include burning or stinging, a gritty sensation in the eye, reduced tolerance to wind, intermittent blurry vision, and even excessive tears in some cases. If you have some of these symptoms, be sure to discuss them with your doctor prior to surgery.
Your eye doctor can determine if you have dry eyes during your preoperative exam and usually can successfully treat the condition so you can then proceed with laser eye surgery. Possible treatments include artificial tears, punctal plugs, medicated eye drops, flaxseed or fish oil supplements, or a combination of these approaches.
Cataracts that interfere with your vision and uncontrolled glaucoma also will typically prevent you from being a candidate for LASIK or PRK procedures.
2. Your Cornea Must Have Sufficient Thickness
Most refractive procedures improve visual acuity by reshaping the front surface of the eye (cornea). Performing laser eye surgery on a cornea that is too thin or has a surface that is extremely irregular and misshapen (for example, if you suffer from keratoconus) could compromise results and impair your vision.
If you've been told in the past that you couldn't have LASIK because your corneas are too thin, recent advances may mean you're now an acceptable candidate for laser vision correction. For example, using a femtosecond laser instead of a microkeratome may enable your surgeon to make a thinner corneal flap and thereby preserve more underlying corneal tissue for laser treatment.
And, if you're still not a good candidate for LASIK or PRK despite new technologies and techniques, another type of refractive surgery, such as implantable lenses (phakic IOLs), may be an option.
3. Your Pupils Must Not Be Overly Large
If your pupils are naturally large, you could be at increased risk of side effects such as halos, glares and starbursts in low light, especially when driving at night.
4. Your Prescription Must Be Within Certain Limits
If your prescription is very high — whether due to nearsightedness, farsightedness or astigmatism— your eye surgeon may advise you against the LASIK procedure.
Resu.
9 Criteria For A Good LASIK CandidateBy Brian S. Boxer Wachler, .docx
1. 9 Criteria For A Good LASIK Candidate
By Brian S. Boxer Wachler, MD
A successful LASIK procedure is determined largely by whether
you meet certain patient criteria and if laser eye surgery is right
for you.
LASIK and PRK outcomes are almost always favorable;
however, not everyone is a good candidate for vision correction
surgery.
The following laser eye surgery checklist is a good start to help
you determine if LASIK or PRK is right for you.
1. Your Eyes Must Be Healthy
If you have any condition that can affect how your eyes respond
to surgery or heal afterwards, you must wait until that condition
is resolved. Examples are severe dry eye
syndrome, conjunctivitis(pink eye), infection and any type
of eye injury.
If you have persistent dry eyes, where you do not produce
enough tears to keep your eyes lubricated and healthy, LASIK
surgery may aggravate this condition. Common symptoms of dry
eyes include burning or stinging, a gritty sensation in the eye,
reduced tolerance to wind, intermittent blurry vision, and even
excessive tears in some cases. If you have some of these
symptoms, be sure to discuss them with your doctor prior to
surgery.
Your eye doctor can determine if you have dry eyes during your
preoperative exam and usually can successfully treat the
condition so you can then proceed with laser eye surgery.
Possible treatments include artificial tears, punctal plugs,
medicated eye drops, flaxseed or fish oil supplements, or a
combination of these approaches.
Cataracts that interfere with your vision and
uncontrolled glaucoma also will typically prevent you from
being a candidate for LASIK or PRK procedures.
2. Your Cornea Must Have Sufficient Thickness
2. Most refractive procedures improve visual acuity by reshaping
the front surface of the eye (cornea). Performing laser eye
surgery on a cornea that is too thin or has a surface that is
extremely irregular and misshapen (for example, if you suffer
from keratoconus) could compromise results and impair your
vision.
If you've been told in the past that you couldn't have LASIK
because your corneas are too thin, recent advances may mean
you're now an acceptable candidate for laser vision correction.
For example, using a femtosecond laser instead of
a microkeratome may enable your surgeon to make a thinner
corneal flap and thereby preserve more underlying corneal
tissue for laser treatment.
And, if you're still not a good candidate for LASIK or PRK
despite new technologies and techniques, another type
of refractive surgery, such as implantable lenses (phakic IOLs),
may be an option.
3. Your Pupils Must Not Be Overly Large
If your pupils are naturally large, you could be at increased risk
of side effects such as halos, glares and starbursts in low light,
especially when driving at night.
4. Your Prescription Must Be Within Certain Limits
If your prescription is very high — whether due
to nearsightedness, farsightedness or astigmatism— your eye
surgeon may advise you against the LASIK procedure.
Results of LASIK surgery for the treatment of very high
refractive errors are less predictable and may not be worth the
cost and potential risks.
In addition, very high amounts of myopia, for example, could
require removal of too much corneal tissue and put you at
increased risk of vision complications.
If you have a severe refractive error, another type of vision
correction surgery may be a better option, such as phakic IOL
implantable lenses or refractive lens exchange.
5. You Must Be Over A Certain Age
3. Certain procedures require you to be 18; others, 21. Patients
younger than these ages can be treated as an exception at the
discretion of the LASIK surgeon with permission from the
patient's parent(s) or guardian.
Generally there is no upper age limit to laser eye surgery.
However, it is important to note that once you hit your 40s, you
may still need reading glassesto correct near vision due to a
normal, age-related condition called presbyopia.
Of course, your surgeon may also consider you a candidate
for surgical correction of presbyopia such
as monovision LASIK, which can improve your near vision
without reading glasses or bifocals.
Keep in mind that women are more at risk for dry eyes after
menopause, and men have a greater risk for dry eyes later in life
as well. As noted above, a dry eye condition should be treated
before LASIK surgery.
6. You Must Have Stable Vision For At Least A Year
Teenagers and many young adults often experience changes in
their contact lens prescription andeyeglass prescription from
year to year. It's important for refractive errors to be stable for
at least 12 months before undergoing LASIK or other refractive
surgery.
Usually it is nearsightedness that gradually becomes worse, but
there may be other changes as well.
Younger people are not good candidates until their eyes have
"settled down" into one prescription. Your eye care
practitioner can tell you whether your prescription is stable.
7. You Must Be In Good Health
Contraindications to laser eye surgery may include certain
uncontrolled degenerative conditions or uncontrolled
autoimmune diseases such as Sjogren's syndrome, rheumatoid
arthritis, type 1 diabetes and AIDS. People with HIV who have
good immune cell counts may be candidates for LASIK.
Basically, if your body has any trouble with healing, you will
have a higher risk of an unsatisfactory LASIK surgery outcome.
Opinions vary among LASIK surgeons regarding which diseases
4. are automatic disqualifiers and which ones might pose
acceptable risks in certain cases.
Also, certain medications can increase risks associated with
laser eye surgery. For example, immunosuppressants may
interfere with post-operative healing, and some medications
such as isotretinoin (Accutane) may increase the chance and/or
severity of dry eye syndrome.
8. If You Are Pregnant, You Should Delay Surgery
The LASIK procedure is not suitable if you are pregnant or
nursing. Hormonal changes can alter the shape of your cornea,
leading to temporary changes in your vision.
Surgery should not be performed until your hormones and
vision have returned to normal after pregnancy. This could take
a few months.
Pregnant women often have dry eyes, which is another reason
you may need to postpone LASIK until a few months after
pregnancy. Also, some medications that would normally be used
before or after surgery to promote healing (such as antibiotics
and steroids) may be risky for your baby, whether unborn or
nursing.
9. Do You Have Realistic Expectations?
While the vast majority of LASIK surgery results are excellent,
you should be fully aware of the possible side effects, risks and
potential LASIK complications before you choose to undergo
the procedure.
An experienced LASIK surgeon will advise you whether you are
a good candidate for laser eye surgery, or if another type of
refractive surgery may be more appropriate.
It's important to tell your surgeon all pertinent information
relating to your health and medical history to ensure you
achieve the best possible results.
Additional Resources
· For a personalized evaluation, take our free two-minute online
LASIK screening.
· To find an eye care practitioner in your area who specializes
in LASIK eye surgery, visit our LASIK Surgeon Directory.
5. Back to top ⤴
Home » LASIK & Vision Surgery » LASIK Criteria
About the Author: Brian Boxer Wachler, MD, is an
ophthalmologist and refractive surgeon at the Boxer Wachler
Vision Institute in Beverly Hills, Calif. He has pioneered
treatments for keratoconus, participated in many FDA clinical
trials for new refractive surgery technologies and written
several books. He is a member of All About Vision's editorial
advisory board.
Aimee Surtenich also contributed to this article.
[Page updated September 2016] Retrieved from
http://www.allaboutvision.com/visionsurgery/lasik-criteria.htm
Part 3:
The following is an excerpt from “Perfect Vision is Helping and
Hurting Navy” (Cloud, 2006):
Colin Carroll, a 21-year-old midshipman from Olney, Md., put
anesthetic drops in his eyes and lay down under the laser as
Capt. Kerry Hunt, a Navy doctor, and two assistants prepared to
begin. "We're locking the laser on now," Captain Hunt told him.
Midshipman Carroll had originally hoped to enter flight school
but discovered not only that his eyes were not good enough, but
also that he was prone to kidney stones, ruling him out of
aviation entirely. He said he was "resigned" to entering the
Marine Corps or becoming an officer on a surface ship, neither
an assignment requiring perfect vision.
But he decided to get the surgery anyway.
By 10:49, both eyes were done, though extremely bloodshot,
and Mr. Carroll walked out wearing sunglasses, declaring he
could already see better.
6. The procedure used by the Navy, photorefractive keratectomy,
or PRK, is different from the one used on most civilians. That
approach, known as laser-in situ keratomileusis, or Lasik,
requires cutting a flap in the surface of the cornea and then
using a laser to reshape the cornea. But military doctors worry
that the flap could come loose during combat, especially in a
supersonic fighter.
So rather than slicing into the cornea covering, Navy doctors
grind it away. The approach requires a longer recovery as the
covering re-forms but leaves the eye more stable.
The Air Force also limits its pilots to PRK, but nonpilots can
get either procedure. Army personnel, including helicopter
pilots and other aviators, are allowed to get either procedure.
Use principles such as beneficence/nonmaleficence, and
concepts such as the benefit/risk ratio, and the features relevant
to Medical Indications (diagnosis, prognosis, treatment options,
goals of treatment, indicated and non indicated interventions) to
support an ethical answer to the question: Is it ethical to
perform corrective LASIK on military personnel?
References
Cloud, D.S. (June 30, 2006). Perfect visions is helping and
hurting Navy. The NY Times.
Retrieved from
http://www.nytimes.com/2006/06/20/us/20eye.html?_r=0
9/13/2016 LASIK eye surgery - Mayo Clinic
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7. surgery/basics/definition/prc-20019041?p=1 1/6
Tests and Procedures
LASIK eye surgery
Laser-assisted in-situ keratomileusis (LASIK) eye surgery is a
procedure that corrects certain
vision problems, reducing or eliminating the need for eyeglasses
or corrective lenses.
LASIK eye surgery is the most common type of refractive
surgery. Refractive surgery changes the
shape of the dome-shaped transparent tissue (cornea) at the
front of your eye.
The desired result of LASIK eye surgery is to bend (refract)
light rays to focus more precisely on
your retina rather than at some point beyond or short of your
retina.
The goal of LASIK eye surgery is to produce clearer, sharper
vision.
LASIK eye surgery may be an option for you if you have one of
these vision problems:
Nearsightedness (myopia). When your eyeball is slightly longer
than normal or when the
cornea curves too sharply, light rays focus in front of the retina
and blur distant vision. You can
see objects that are close more clearly, but not those that are far
away.
Farsightedness (hyperopia). When you have a shorter than
average eyeball or a cornea that
8. is too flat, light focuses behind the retina instead of on it. This
makes near vision and
sometimes distant vision blurry.
Astigmatism. When the cornea curves or flattens unevenly, the
result is astigmatism, which
disrupts focus of near and distant vision.
Your eye doctor will likely recommend that you try other ways
of correcting your vision, such as by
using glasses or contact lenses, before you turn to LASIK eye
surgery or another similar refractive
procedure.
As with any surgery, LASIK eye surgery carries risks,
including:
Undercorrections. If the laser removes too little tissue from
your eye, you won't get the clearer
vision results you were hoping for. Undercorrections are more
common for people who are
nearsighted.
You may need another refractive surgery (enhancement surgery)
within a year to remove more
tissue.
By Mayo Clinic Staff
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9. Overcorrections. It's also possible that the laser will remove too
much tissue from your eye.
Overcorrections may be more difficult to fix than
undercorrections.
Vision returning to pre-surgery vision. Over time, your eyes
may slowly return to the level of
vision you had before surgery. This may happen due to certain
conditions, such as abnormal
wound healing, hormonal imbalances or pregnancy.
Visual loss or changes. Rarely, you may experience loss of
vision due to surgical
complications. Some people also may not see as sharply or
clearly as previously.
Astigmatism. Astigmatism can be caused by uneven tissue
removal. It may require additional
surgery, glasses or contact lenses.
Glare, halos and double vision. After surgery you may have
difficulty seeing at night. You
might notice glare, halos around bright lights or double vision.
Even when a good visual result is measured under standard
testing conditions, your vision in
dim light (such as at dusk or in fog) may be reduced to a greater
degree after the surgery than
before the surgery.
Dry eyes. LASIK causes a temporary decrease in tear
production. For the first six months or so
after your surgery, your eyes may feel unusually dry as they
heal. Dry eyes can reduce the
quality of your vision.
Your eye doctor might recommend that you use eyedrops during
this time. If you experience
severe dry eyes, you could opt for another procedure to get
special plugs put in your tear ducts
10. to prevent your tears from draining away from the surface of
your eyes.
Flap problems. Folding back or removing the flap from the front
of your eye during surgery can
cause complications, including infections, excess tears and
inflammation.
The outermost corneal tissue layer (epithelium) may grow
abnormally underneath the flap
during the healing process.
Conditions that increase risks
Certain health conditions can increase the risks associated with
LASIK surgery or make the
outcome less predictable. Doctors may not recommend laser
surgery for you if you have certain
conditions.
These conditions include:
Autoimmune disorders, such as rheumatoid arthritis
Immunodeficiency conditions caused by immunosuppressive
medications or HIV
Persistent dry eyes
Unstable vision due to medications, hormonal changes,
pregnancy, breast-feeding or age
Several eye conditions, such as keratoconus, keratitis, uveitis,
herpes simplex affecting the eye
area, glaucoma, cataracts, eye injuries or lid disorders
LASIK may not be advisable if you:
11. 9/13/2016 LASIK eye surgery - Mayo Clinic
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Have fairly good overall vision
Have very large pupils or thin corneas
Have a job that may be affected if you have the procedure
Have age-related eye changes that cause you to have less clear
vision (presbyopia)
Participate in contact sports that may be associated with blows
to the face
If you're considering LASIK eye surgery, talk to your doctor
about your questions and concerns. He
or she can explain how the surgery might benefit you and help
put the risks in perspective. Your
doctor will discuss with you whether you're a candidate for the
procedure.
To prepare for LASIK eye surgery:
Stop wearing your contact lenses. If you wear contact lenses,
you'll need to switch to glasses
full time for at least a few weeks before your surgery.
Contact lenses can distort the shape of your cornea, which could
lead to inaccurate
measurements and a poor surgical outcome. Your doctor will
provide specific guidelines
depending on your situation and how long you've been a contact
lens wearer.
Skip the eye makeup. Don't use eye makeup, cream, perfumes or
lotions on the day before
and the day of your surgery.
Your doctor may also instruct you to clean your eyelashes daily
12. or more often in the days
leading up to surgery, to remove debris and minimize your risk
of infection.
Arrange for a ride home. You'll need to have someone drive you
to and from your place of
surgery. Immediately after surgery, you might still feel the
effects of medicine given to you
before surgery, and your vision may be blurry.
Know what surgery may cost you. LASIK eye surgery is usually
considered elective surgery,
so most insurance companies won't cover the cost of the
surgery. Be prepared to pay out of
pocket for your expenses.
LASIK eye surgery is performed using a laser programmed to
remove a defined amount of tissue
from your cornea. With each pulse of the laser beam, a tiny
amount of corneal tissue is removed.
The laser allows your eye surgeon to flatten the curve of your
cornea or make it steeper. Often,
LASIK is performed on both eyes on the same day.
Before surgery
Before surgery, your doctor will discuss the risks and benefits
of LASIK surgery, your expectations,
what to expect before and after surgery, and answer any
questions you may have.
During a pre-surgical eye exam, your eye doctor takes a detailed
medical and surgical history and
conducts a comprehensive eye examination.
In the eye examination, your doctor will evaluate your vision
13. and look for signs of eye infections,
inflammation, dry eyes, large eye pupils, high eye pressure or
other eye conditions.
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Your doctor will also measure your cornea, noting the shape,
contour, thickness and any
irregularities.
Your eye doctor also evaluates which areas of your cornea need
reshaping. Your eye doctor uses
tests to measure the shape and contour of your cornea and
determine the precise amount of tissue
to remove from your cornea.
Doctors generally use wavefront-guided technology to evaluate
your eye in detail before LASIK
surgery. In this test, a scanner creates a highly detailed chart,
similar to a topographical map, of
your eye. Theoretically, the more detailed the measurements,
the more accurate your eye doctor
can be in removing corneal tissue.
During surgery
LASIK eye surgery is usually completed in 30 minutes or less.
During the procedure, you lie on
your back in a reclining chair. You may be given medicine to
help you relax. After numbing drops
are placed in your eye, your doctor uses an instrument to hold
14. your eyelids open.
A suction ring placed on your eye just before cutting the corneal
flap may cause a feeling of
pressure, and your vision may dim a little.
Your eye surgeon uses a small blade or cutting laser to cut a
hinged flap about the size of a
contact lens away from the front of your eye. Folding back the
flap allows your doctor to access the
part of your cornea to be reshaped.
Using a laser, your eye surgeon then reshapes specific parts of
your cornea. After reshaping is
complete, the flap is folded back into place and usually heals
without stitches.
During the surgery, you'll be asked to focus on a point of light.
Staring at this light helps you keep
your eye fixed while the laser reshapes your cornea.
You may detect a distinct odor as the laser removes your
corneal tissue. Some people describe
smelling an odor similar to that of burning hair.
If you need LASIK surgery in both eyes, doctors will generally
conduct the procedure on the same
day.
After surgery
Immediately after surgery, your eye may itch, burn and be
watery. You'll probably have blurred
vision. You generally will experience little pain, and you'll
usually recover your vision quickly.
15. You may be given pain medication or eyedrops to keep you
comfortable for several hours after the
procedure. Your eye doctor might also ask you to wear a shield
over your eye at night until your
eye heals.
You'll be able to see after surgery, but your vision won't be
clear right away. It takes about two to
three months after your surgery before your eye heals and your
vision stabilizes. Your chances for
improved vision are based, in part, on how good your vision
was before surgery.
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You'll have a follow-up appointment with your eye doctor one
to two days after surgery for your
doctor to see how your eye is healing and check for any
complications.
Plan for other follow-up appointments during the first six
months after surgery as your doctor
recommends.
It may be a few weeks before you can start to use cosmetics
around your eyes again. You might
also have to wait several weeks before resuming strenuous
contact sports, swimming or using hot
16. tubs.
Follow your doctor's recommendations about how soon you can
resume your normal activities.
Refractive surgery often offers improved vision without the
hassle of glasses or contact lenses. In
general, you have a very good chance of achieving 20/25 vision
or better after refractive surgery.
More than 8 out of 10 people who've undergone refractive
surgery no longer need to use their
glasses or contact lenses for the majority of their activities.
Your results depend on your specific refractive error and other
factors. People with a low grade of
nearsightedness tend to have the most success with refractive
surgery. People with a high degree
of nearsightedness or farsightedness along with astigmatism
have less predictable results.
Many people have positive results and report high satisfaction
after LASIK surgery. However, long-
term results often aren't available, as many people are
sufficiently satisfied after surgery. They
don't feel a need for repeat examination, and they become lost
to follow-up. Also, the LASIK
procedure has evolved over time, and the procedure done today
17. is different from the procedure
done a few years ago.
Feb. 25, 2014
References
1. Bower KS. Laser refractive surgery.
http://www.uptodate.com/home. Accessed July 15, 2013.
2. LASIK — Laser eye surgery. American Academy of
Ophthalmology. http://www.geteyesmart.org/eyesmart/glasses-
contacts-lasik/lasik.cfm. Accessed July 15, 2013.
3. Bastawrous A. Laser refractive eye surgery. British Medical
Journal. 2011;342:d2345.
4. Yanoff M, ed., et al. Ophthalmology. 3rd ed. Edinburgh,
U.K.: Mosby Elsevier; 2009. https://www.clinicalkey.com.
Accessed July 15, 2013.
5. When is LASIK not for me? U.S. Food and Drug
Administration.
http://www.fda.gov/MedicalDevices/ProductsandMedicalProced
ures/SurgeryandSurgeryandL/LASIK/ucm061366.htm.
Accessed July 15, 2013.
6. What should I expect before, during, and after surgery? U.S.
Food and Drug Administration.
http://www.fda.gov/MedicalDevices/ProductsandMedicalProced
ures/SurgeryandLifeSupport/LASIK/ucm061270.htm.
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for Medical Education and Research.