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High Correction With Lasik

Really bad eyesight presents difficult challenges for vision correction surgery.

Image of thick spectacles.  
Lasik laser eye surgery may not be best for very high correction. Alternatives should be considered.  

As a (very) general rule, patients with more than about 10.00 diopters of myopia (nearsighted, shortsighted) vision or more than around 3.00 diopters of hyperopia (farsighted, longsighted) vision are significantly less likely to achieve uncorrected vision after conventional or custom wavefront Lasik or Bladeless Lasik that is equal to their corrected vision before surgery. To determine your refractive error, read your prescription.

Patients with greater than about 6.00 diopters of needed correction are at a higher risk of corneal haze if PRK is selected. This elevated risk of corneal haze may be able to be reduced by the use of 500mg of vitamin C taken orally twice a day for one week before surgery and at least two weeks after surgery. Yes, plain old vitamin C. Another technique to reduce the probability of corneal haze is the application of Mitomycin C to the cornea during surgery. Mitomycin C is a strong medicine that is appropriate when needed, but probably should be avoided when possible.

LASEK and Epi-Lasik are techniques developed to provide ablation on the surface of the cornea as in PRK, but with a lower risk of corneal haze. Available studies are inconclusive if this is actually the situation. For the greatest margin of safety, patients needing greater than 6.00 diopters of correction may want to consider Lasik instead of PRK, LASEK, or Epi-Lasik. Lasik has a very low incidence of corneal haze with higher corrections.

Additionally, patients with astigmatism that is greater than half their sphere, or more than 2.00 diopters are less likely to achieve uncorrected vision after Lasik, PRK, LASEK, or Epi-Lasik that is equal to their corrected vision before surgery. All patients with refractive error beyond these guidelines can expect regression and would have a higher probability of a surgical enhancement.

Patients with very high refractive error may find lens-based refractive surgery a better option. P-IOLs appear to be most appropriate for patients with moderately-high to high refractive error. RLE may be appropriate for a patient with any amount of refractive error if that patient is fully presbyopic, or for patients who have accommodation with very high refractive error if the patient is willing to sacrifice accommodation. A significant limitation of both P-IOLs and RLE is that they may not be able to correct astigmatism.

These are guidelines that not every surgery will agree are accurate and there is room for disagreement on the issue. Also, an individual's circumstances may indicate that one procedure is significantly more safe than another regardless of these general guidelines. We are a patient advocacy primarily interested in patients avoiding problems or disappointing outcomes. There are most certainly refractive surgeons less conservative than our organization. It is also possible that due to the unique circumstances of the patient, a parameter not normally considered appropriate would be best. An individual's circumstances may indicate that one procedure is significantly more safe than another regardless of these general guidelines.

If your refractive error is so great that you cannot reasonably expect full correction with refractive surgery, you may consider having surgery with only partial correction. However you first need to consider your motivation for refractive surgery. If the motivation is to never wear glasses again, you already know that this is not probable. In this instance it would appear that you will not receive the outcome you want - not wearing corrective lenses.

You may want to ask your doctor to fit you with contacts or spectacles that will simulate your expected vision after surgery for partial correction. This will provide you with an indication of what life would be like after surgery. Wear these corrective lenses for at least a month before you decide if the expected visual acuity after surgery will meet your needs.

Discuss with your doctor if after surgery you will be able to wear contacts and/or glasses that will correct the remaining refractive error. It is unreasonable to expect that your vision after refractive surgery without corrective lenses will be better than your vision with corrective lenses before surgery.

Don't rush. You have only one set of eyes. If you have doubt that you will reach the goal that is the basis of your personal motivation, you should seriously consider deferring refractive surgery until you and your doctor can reasonably expect a completely satisfactory result.

The most you can expect from refractive surgery is the convenience of a reduced need for corrective lenses. To achieve that convenience, you must accept some risk. While there is risk in any surgery, the risk of surgery outside these general guidelines may be unacceptable for most patients.

Looking For Best Lasik Surgeon?

If you are ready to choose a doctor to be evaluated for conventional or custom wavefront Lasik, Bladeless Lasik, PRK, or any refractive surgery procedure, we recommend you consider a doctor who has been evaluated and certified by the USAEyes nonprofit organization. Locate a USAEyes Evaluated & Certified Lasik Doctor.

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