PRK / LASIK ~ LASIK, PRK, laser vision correction, eye care, hyperopia - farsightedness, myopia - nearsightedness, astigmatism and excimer laser information.

RESULTS FOLLOWING PRK

Prospective candidates should understand that the following statistical information is designed to give them an estimation of the visual results that they can expect based upon what has been achieved in the past with PRK. Our goal is to have each patient achieve 20/40 vision or better, which is about "90%" of the eyechart. Patients with 20/40 vision or better are quite functional for virtually all normal activities and although they may need a very thin pair of glasses for night driving or detailed vision, they are overwhelmingly satisfied with their results. We call achieving 20/40 vision or better "the Happiness Zone". We can not guarantee that you will be 20/15 or 20/20 but you will be 20/HAPPY.

Refractive surgery is not perfect nor will it ever be, however, it provides each person with a level of freedom from corrective eyewear that makes it a real alternative for over 95% of patients. These charts are designed to give you an idea of what to expect for your degree of nearsightedness and astigmatism, but it remains impossible to predict or guarantee that every patient will achieve an ideal result. That means, even if 100% patients in the past have achieved 20/40 vision for a particular range of myopia, that does not mean that 100% of patients will in the future. The goal of PRK would be to get each candidate as close as possible to their vision in glasses or contact lenses. Most patients have vision unaided post-operatively within 2 to 3 lines of their best vision with glasses pre-operatively. It may require more than one procedure to further improve visual outcomes.

For the purposes of understanding what is the estimated statistical probability of outcome after PRK, we have divided myopia up into subgroups. We do not do PRK for myopia greater than 6.00 diopters any more . We have found that LASIK gives a better and more stable visual result for myopia greater than 6.00.

The myopia, or nearsighted subgroups are divided into:

Low (-1.00D to -3.00D)
Moderate (-3.10D to -6.00D)
Severe (-6.10 to -9.00D)
Extreme (-9.10 to -15.00)
Greater than -15.00D

To use the charts, look at your degree of astigmatism (second number of your prescription) to determine what to look at when viewing the appropriate chart. Look across the bottom row to find your approximate degree of myopia. The first bar indicates the percentage probability of achieving 20/20 vision or better without glasses. The second bar indicates the percentage probability of achieving 20/25 vision or better and the third bar indicates the percentage probability of achieving or 20/40 or better vision. The first four bar graphs estimate the percentage probability of achieving a particular visual outcome after a single PRK procedure.

As the degree of myopia increases, the visual and refractive predictability decreases with an increases need for retreatment (enhancement). Likewise, as the degree of cylinder increases, the visual and refractive predictability decreases with a increased need for retreatment (enhancement). Some degree of astigmatism is present in 3 out of every 4 of the patients we treat. We have grouped results into 1.00 diopter steps of cylinder (astigmatism) as outcomes vary with the amount of astigmatism required to correct. Although we treat 3.00 diopters and more of cylinder this represents the most severe 1% of the astigmatic population. We have also treated many dozens of patients with several diopters of astigmatism, but these may require more than one procedure. There are a number of important clinical issues to be aware of when treating higher levels of myopia and astigmatism. Many patients with very high degrees of myopia are unable to read the 20/20 line on an eyechart and would never be expected to read 20/20 post-operatively.

The 1 year retreatment or enhancement rates for the different levels of myopia with astigmatism less than 1.00 diopter are as follows:

0 to 3.00 2.3%
3.1 to 6.00 3.8%

The probability of losing or 1 to 2 lines of best corrected visual acuity is as follows:

0 to 3.00 .48%
3.1 to 6.00 .89%

For the purposes of understanding what is the estimated statistical probability of outcome after Hyperopic PRK, we have divided hyperopia up into subgroups.

0 to 2.0 Low
2.1 to 4.0 Moderate
4.1 to 6.0 High
> 6.0 Extreme

To use the charts, look across the bottom row to find your approximate degree of hyperopia. The first bar indicates the percentage probability of achieving 20/20 vision or better without glasses. The second bar indicates the percentage probability of achieving 20/25 vision or better, the third bar indicates the percentage probability of achieving or 20/30 or better , and the fourth bar indicates the percentage probability of achieving 20/40 or better.