ORTHOKERATOLOGY

Orthokeratology

Ortho-K

What is Orthokeratology?

Ortho-K refers to the method of correcting vision by temporarily reshaping the cornea by wearing specialty gas permeable rigid contact lenses at night while sleeping as demonstrated by Image 1. This process is similar to a refractive surgery in the fact that it allows you to visually function without contacts or eyewear throughout the daytime hours. However, the biggest difference is that vision improvements with Ortho-K are reversible (just stop wearing the shaping contacts) while surgical options are not.

Who is a good candidate for Ortho-K?

Most commonly Ortho-K is used to correct low to moderate amounts of nearsightedness (myopia). It can also be done to correct low amounts of astigmatism and hyperopia. It is used as an alternative to glasses, daytime contact lenses, and refractive surgery. Refractive surgery is limited to individuals 18 and older, and is not offered to individuals until refractive error has stabilized (which in some individuals isn't until their mid-20s). Thus, Ortho-K is a good alternative for these patients or for patients that want the benefit of refractive surgery (no more glasses or daytime contacts) but aren't ready for LASIK or PRK.

Who is not a good candidate for Ortho-K?

Patients with a high amounts of nearsightedness (>6D), farsightedness (>2D), or astigmatism (>1.5D) are poor candidates. Additionally, Ortho-K is contraindicated in patients with 1) keratoconus/corneal ectasia, 2) ocular herpes, 3) extremely dry eye, 4) corneal dystrophies/disorders, 5) anterior chamber infection/inflammation or 6) pregnancy.

What are the risks and complications?

There are many possible risks and complications with ortho-K, just like there are many risks and complications with wearing any contact lens. The risk of infection while wearing Orthokeratology or soft contact lenses is very rare, however, there is a slight risk of infection caused by Acanthamoeba (found in tap water). Under no circumstances should an individual rinse his/her shaping lenses with tap water. Serious infection from Acanthamoeba can result in corneal scarring, a permanent reduction of vision, and/or possibly a need for a corneal transplant. Another complication you may experience is a superficial abrasion to the cornea, which can occur if debris gets trapped between the eye and the lens if the lens is not cleaned properly, if the disinfectant is not rinsed from the lens, or if you sleep with your eyes slightly open. These are rare and temporary, and can occur with either soft contact lens wear or Ortho-K.

There are a few risks and complications that are unique to Ortho-K. First of all, due to the rigidity of the shaping lenses, they may feel scratchy and irritating if they are worn during waking hours. After-all they are designed for closed-eye wear. With time, this scratchiness will usually lessen. However, it is advised to minimize your use of the shaping lenses during waking hours, unless you need them.

Secondly, some patients experience halos or flare around lights at night, which usually becomes less noticeable within a few weeks. If it does not subside, it is recommended to redesign the lenses to create a larger treatment area. However, in some cases, these haloes may not completely disappear.

Third of all, during the first week of treatment, reshaping may be incomplete and you may experience some blurred vision. If necessary, your doctor may provide a series of disposable soft lenses to be used until you feel your vision is comfortable. In most cases, the initial Orthokeratology shaping lens will achieve optimal vision, however, occasionally over or under treatment may occur. New shaping lenses may need to be ordered to correct this problem. Additionally, regression of treatment may occur at some point, which may require a redesigning of the lenses to again achieve optimal vision.

Finally, it is impossible to list every conceivable complication that could occur with wearing Orthokeratology lenses, but this treatment is a safe and viable option that can provide life-changing results.

Image 1

Image 2

Image 3

How does it work?

Ortho-K is like orthodontics for your eyes and the treatment lenses are often compared to dental braces. These lenses induce constant pressure on the flat meridian and variable pressure on the steep meridian causing a push-pull situation that results in central flattening and peripheral steepening as demonstrated by image 2. The flattening effect changes the way that light is focused within the eye leading to a sharp image placed directly on the retina. Additionally, the corneal reshaping causes a peripheral myopic defocus that is instrumental in controlling the progression of myopia, which makes it an excellent tool not just to correct nearsightedness, but prevent it. Click to read more about Myopia Control. The corneal reshaping effects are monitored closely using corneal topography (basically mapping of the cornea) as shown in image 3.

What are the benefits?