What is Orthokeratology?

Orthokeratology Defined

Orthokeratology (OrthoK) is the optometric practice of using rigid contact lenses to alter the shape of the cornea while you sleep, so that a myopic (nearsighted) eye will have temporary improved optics during waking hours.

More recently, OrthoK has been linked to the reduction of axial length growth in children and is now a means of treating at-risk children from developing higher levels of myopia.

How Does the Process Orthokeratology Work?

The orthokeratology process involves wearing specific types of rigid contact lenses throughout the night while you sleep, which reshape your eye for better vision while you’re awake.

OrthoK is used specifically for patients with myopia, which is an optical condition in which light focuses in front of the fovea in the back of the eye, instead of focusing directly on the fovea for perfect focus. 

Since most of the focusing of light by the eye occurs at the cornea (the clear dome over the iris – which is the color portion of your eye), altering the cornea’s shape can alter focus. So, by flattening the cornea with OrthoK, the point of focus can be pushed back to the fovea by properly fitting lenses that flatten the cornea. This is a similar concept to the process of reshaping the cornea through laser refractive eye surgeries.

The nighttime lens flattens the cornea by essentially pressing down on the center to make it flatter while making the peripheral cornea steeper. The fluid properties of the cornea shift while you sleep, and the cornea remains “flattened” for a while after you wake up, until the dynamics of the cornea return to their “normal” situation. 

It is kind of like wearing a belt that is too tight at night to make your waist thinner tomorrow. The belt would leave an impression in your skin that will go away as time goes on, but it has its limits too. 

A belt can’t be fit so tight as to make a 40 inch waist a 30 inch waist without potential complications. And so it goes with OrthoK – the level of safely fitting contacts has its limits on how much can be done, so OrthoK is not intended for higher levels (lens sphere power over -6.00 D) of myopia.

Long-Term Concerns with Orthokeratology

There has always been a concern that if you continue to wear these lenses that reshape the eye every day during your growing years, it may alter the eye altogether. 

Observation over time has revealed that instead of being a problematic effect on the growing eye, the associated long term effect has proven beneficial by being linked to the decrease in axial length of the eye and reduction in overall progression of myopia.

Be aware that not all eye doctors partake in orthokeratology, as it is an artistic science. Altering your cornea to determine its long term shape should only be done with caution and by doctors trained and comfortable in its use and benefits.

What Makes Orthokeratology Contact Lenses Different?

OrthoK contacts are far more rigid than the common soft disposable contacts that are meant to fit to and take the shape of your eye.

Instead, it’s intended that your eyes take the shape of the lens. They are specifically designed to reshape the cornea of the eye at night to shift the focal point back to the fovea and, therefore, decrease the need for glasses or contacts during the day. 

Fitting a soft contact involves making sure that a patient has a contact lens that is not too tight or too loose. The lens has to be fit perfectly everywhere for comfortable and safe wear. Also, fitting soft contacts is safe especially if you follow the major rule of not sleeping in your contacts.

OrthoK lenses are pretty much the opposite of soft contact lenses. They are rigid lenses that fit closer in some areas and loose in others and are designed to be worn at night while you are sleeping.

Orthokeratology Pros and Cons

Risks of OrthoK 

• Cost and time necessary for proper fitting of the lenses
• Reduced physical comfort during adaptation
• Management and caring for OrthoK lenses
• Improper fit
• Infection and irritation potentially leading to more severe eye conditions

If an orthokeratology lens fits improperly throughout the night or does not fit appropriately in the first place, instead of having a day of clear vision without contacts, a patient may experience a day where neither contacts or glasses will improve their vision. Now, this would be temporary, but a problem nonetheless.

The biggest health risks of OrthoK include the risk of infection, dry eyes, and irritation that may lead to greater complications such as photophobia, red eye, pain, ulcers, and vision loss. These complications are also associated with all forms of contact lens wear.

Advantages of OrthoK 

There are two main benefits to OrthoK.

1. Seeing during the day without glasses or contacts
2. Potential management to myopic progression in a developing child

Orthokeratology Cost

On average, you could expect OrthoK to cost about $1000-1500 per eye. This is not the exact cost, but this is a good estimate of what to expect for a fit. 

Make sure your doctor explains all of the costs before you begin treatment. The exact cost will depend on how many different lenses you will have to purchase and how many sessions are needed to achieve the necessary corneal change and good daytime vision. 

Basically, the higher your prescription, the more lenses, the more sessions, and the higher the overall cost.

Should I Consider Orthokeratology Treatments?

Orthokeratogy is not for all patients and has not been embraced by all doctors. If you are considering OrthoK, do your research on the topic and talk to your doctor to see if you are a good candidate.

If your doctor is equipped to fit orthokeratology contact lenses and you understand the process, OrthoK would be worth considering. You will have to be willing to accept the costs and journey for the potential reward, but if so, OrthoK is considered a safe form of vision correction and myopia management.