Cutting edge technology has expanded the number of patients who benefit from laser vision correction. Nonetheless, there are certain limits to how large of an eyeglass prescription can be corrected with refractive surgery. The prescription that is in your corrective lens makes up for the irregularities in your human eye. These irregularities are called refractive errors and they include myopia (or near-sightedness), astigmatism and hyperopia (or far-sightedness). The measurement of this refractive error is called a refraction, and it is one of the many measurements that we will take during your doctor’s visit. If this refractive error is too high, then yes indeed, your eyes may be too bad for LASIK. But at Lucent Vision we offer the most comprehensive options for vision correction. If LASIK is not an option, we may be able to offer you a different procedure that safely corrects your vision and changes your life.
What prescription is too high for LASIK?
According to the stipulations set forth by the Food and Drug Administration (FDA), the laser device used by most LASIK surgeons can treat:
- Myopia up to -12 diopters with or without astigmatism up to 6 diopters
- Hyperopia up to +6 diopters with or without astigmatism up to 5 diopters
If your glasses or contact lens prescription falls out of this range, then you may not be a good candidate for the LASIK prescription.
What do refractive errors and diopters have to do with being a LASIK candidate?
With LASIK (a.k.a. laser in situ keratomileusis) we are able to alter the corneal tissue of the human eye to allow light rays to properly focus onto the retina. When light rays are not properly focused onto the retina due to an abnormality or imperfection in the shape of the eye we call this problem a refractive error. In the field of ophthalmology, the degree of visual impairment is usually measured in diopters. Good LASIK candidates will typically fall within a particular range of refractive errors. Refractive errors can be translated into an eyeglasses prescription that may be necessary for a person to have normal vision.
What are the requirements for LASIK eye surgery?
In order to safely improve your visual perception with LASIK eye surgery there are certain basic requirements that need to be met. These requirements include:
- You must be older than 18 years of age.
- A stable prescription that has not changed by more than a 0.5 diopters in the previous year.
- You must not be in the midst of a pregnancy, nor should you still be breastfeeding. A previous article in our series detailed how changes in female hormones play a role in vision stability.
- Vision prescriptions must fall within the FDA approved limits for LASIK.
- A healthy corneal topography and adequate corneal thickness to undergo LASIK. These measurements would be taken on the day of your LASIK consultation.
- You must not have any active eye diseases such as infection, keratoconus, or scarring from previous eye injury.
Are there other vision correction options if I’m not a candidate for LASIK?
Yes there are other vision correction options available if you are not a candidate for LASIK. These other options include SMILE (Small Incision Lenticule Extraction), PRK (Photorefractive Keratectomy), EVO ICL implantation, and RLE (Refractive Lens Exchange). SMILE and PRK are other forms of laser vision correction that may preserve more healthy corneal tissue. The EVO ICL procedure involves the placement of a permanent contact lens inside of the eye between the pupil and the natural lens. The EVO ICL procedure, recently FDA approved in the United States, is particularly well-suited to patients who have severe nearsightedness and too little tissue for laser assisted procedures. With the RLE procedure the dysfunctional natural lens is replace with an artificial lens that corrects refractive errors. This elective procedure is particularly well-suited for patients beyond the age of 40 who are suffering from presbyopia, or difficulty with seeing nearby objects such as reading books up close. Patients who undergo RLE are usually do not need to wear glasses for the majority of their daily activities. Finding the right solution for you involves an experienced staff that will understand your vision demands and your particular eye anatomy before problem solving to choose the appropriate treatment.
FAQ’s About Can Your Eyes Be Too Bad For LASIK
What vision conditions might make someone ineligible for LASIK?
We typically reserve LASIK for patients who are not suffering from other eye diseases such as diplopia (or double vision), cataracts, glaucoma, or active ocular inflammation. Your medical history may also play a role with how healthy your eyes are for LASIK. There are certain conditions affecting the body which can also affect the eyes and make LASIK a higher risk procedure. Some of these illnesses include Human Immunodeficiency Virus (HIV), Rheumatoid Arthritis, Lupus, and other disorders of the immune system. Give a short 50-100 word answer
Can LASIK treat extremely high prescriptions for nearsightedness or farsightedness?
Although LASIK can treat extremely high prescriptions for nearsightedness or farsightedness, it may be less predictable for these prescriptions. For this reason we offer alternative options that may be safer and more effective for your particular vision profile.
Is there a limit to how much astigmatism LASIK can correct?
Astigmatism is an asymmetry in the contours of the human cornea, and it is a refractive error that can usually be corrected by wearing glasses or contact lenses. There is indeed a limit to the amount of astigmatism correction that can be achieved with LASIK. For myopic (near-sighted) patients this limit is 6 diopters, and for hyperopic (far-sighted) patients this limit is 5 diopters. Nonetheless, these are technical limits. In the real world, most eye doctors will choose a different procedure or combination procedures if you have such a high amount of astigmatism. At such high levels of astigmatism the LASIK procedure is less predictable, and you will be less likely to hit 2020 vision.
What eye health issues can disqualify someone from getting LASIK?
If you have a diagnosis of keratoconus from your eye doctor, then you may be disqualified from having a laser eye surgery. This eye disease involves a thinning and weakening of the central cornea which may be genetic in nature. It can usually be diagnosed with corneal imaging (i.e. corneal topography) done by a doctor of optometry or a doctor of ophthalmology. If you have a history of severe dry eye syndrome, autoimmune disease, uncontrolled diabetes, glaucoma, or cataracts then there may be a higher risk of complications. If you suffer from any of these eye health issues, you should have a thorough discussion with your eye doctor to better understand the risks associated with laser surgery.
Can LASIK be performed if my corneas are too thin?
Thin corneas along with a large eyeglasses prescription may prevent you from being a good candidate for LASIK. But there are other factors involving the cornea that need to be taken into consideration. If you have thin corneas in addition to a normal corneal curvature and prescription glasses with a smaller correction, you may still be a good candidate. The ratio of the correction needed to the amount of cornea available is very important. By the same token, not everyone with a normal or thick cornea is a good candidate for LASIK. Good candidates tend to have a symmetric corneal shape, regardless of how thin or thick the cornea may be.
Does severe dry eye prevent LASIK surgery?
Severe dry eye can indeed prevent LASIK surgery, especially if it is uncontrolled. Over the last several years there have been major advances in the field of ophthalmology that my improve dry eye symptoms. We now have available a prescription drug may reduce inflammation and increase tear production in patients suffering from dry eye. Although new treatments may improve the signs and symptoms of dry eye, it may still be something that jeopardizes your candidacy for LASIK. Dry eyes may slow down the healing process after LASIK. Even in the most healthy eyes LASIK may be associated with a temporary decrease in the tear production system. For this reason, make sure you ask your surgeon about dry eye disease and its risks.
Are there alternatives to LASIK for people with bad vision?
For people who are not good candidates for LASIK, alternatives include Photorefractive Keratectomy (PRK), Small Incision Lenticule Extraction (SMILE), EVO ICL implantation, Refractive Lens Exchange, and Premium Cataract surgery. We offer a comprehensive suite of vision correction procedures that can be matched to each individuals eye health and vision demands.
How does age affect whether my vision is too bad for LASIK?
When patients are above the age of 45 they typically experience age related changes of the lens inside of the eye. These changes lead to a problem called presbyopia, which causes difficulty with seeing objects close to the eye (e.g. being able to read up close). The LASIK procedure is generally not the best procedure for this age group unless a blended vision treatment is chosen. An alternative procedure to consider would be Refractive Lens Exchange. The other major age related change in the eye is a cataract, which in an opacification of the natural lens inside of the eye. This opacification of the natural lens causes a reduction of visual acuity as the lens has become cloudy. For these patients, the best treatment may be a cataract surgery with implantation of an intraocular lens, rather than LASIK.
Can prior eye surgeries make LASIK not an option?
A previous history of corneal transplantation, retinal surgery, or glaucoma surgery could potentially result in an eye that no longer qualifies for LASIK. In addition, if you have had LASIK previously in the past, then there may not be enough corneal tissue to proceed with a second laser eye surgery.
What tests determine if my eyes are too bad for LASIK?
At your LASIK consultation you will have your vision measured along with receiving a topography, tomography, and OCT of your cornea. With these tests your eye doctor will be able to determine the thickness of your cornea as well as its symmetry. In addition, a wavefront aberrometry will be performed to determine how light rays are treated by your whole vision system. Based on the profile that we build of your eyes and your visual demands, a customized treatment plan will be created by your eye surgeon.
source https://lucentvision2020.com/lasik/can-your-eyes-be-too-bad-to-for-lasik/
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