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Orthokeratology

What is Orthokeratology?

Orthokeratology (also known as Ortho-K) is a clinical technique of corneal reshaping using specially designed rigid contact lenses. In modern Ortho-K, lenses are usually worn only during sleep and are removed first thing in the morning. During the night the contact lenses gently reshape the front surface of the eye, correcting the refractive error and allowing clear vision through all waking hours without the need for spectacles or contact lenses.

Am I suitable for Ortho-K?

At the moment we are able to correct low to moderate degrees of myopia (short-sightedness) with Ortho-K. If you know your prescription, this translates to a maximum of about 4.00 to 5.00 dioptres of myopia. The correction is achieved by applying gentle pressure to the centre of the cornea (the clear window of the eye) to flatten it slightly. This reduces the optical power of the cornea, thus correcting myopia.

Ortho-K lenses for myopia may correct about half of your astigmatism, but this varies from patient to patient. Some practitioners, particularly in Europe, are experimenting with relatively complex lens designs to correct astigmatism.

New lens designs for the correction of hyperopia (long-sightedness) are being developed here in Australia and also in the USA. These lenses aim to gently steepen the cornea, increasing corneal optical power and thus correcting hyperopia.

There are currently no Ortho-K lens designs specifically to help people who require glasses mainly for reading. This condition is known as presbyopia and affects everyone over the age of 45 years.

Apart from the refractive status of your eye, there are many other factors that may influence your suitability for overnight Ortho-K lens wear. In general, this procedure is only suitable for people with good ocular (and general) health and relatively low prescriptions. Patients must have the dexterity to handle the lenses for insertion and removal, and must closely follow practitioner instructions on lens wearing schedule and lens care procedures, to ensure safe lens wear.

Is the Ortho-K treatment permanent?

No, the effect of overnight Ortho-K lenses on corneal shape is temporary and wears off over a few days if the lenses are not worn. To maintain the optical effect, lenses must be re-inserted and worn every night (or in some cases, every 2nd or 3rd night).

How to Insert & Remove OrthoK Lenses

Safety & hygiene

  • Thoroughly wash hands and fingers with an antibacterial based hand wash
  • Dry hands with a lint free towel
  • Remove lenses while sitting at a table with a lint free cloth
  • Avoid bathrooms as they contain more germs than any other room in the house
  • Inspect lenses for scratches, chips or cracks as these can provide surfaces for bacteria to grow

Always wash and rinse your hands thoroughly and dry them with a lint-free towel/tissue before handling contact lenses. All traces of soap, perfumes, hair spray, creams and lotions should be removed from your hands and around your eyes.

Insertion

Step 1. Remove lenses from the cleaning solution case and rinse with saline. If using hydrogen peroxide solution a minimum soaking time of 6 hours is required for the acid to neutralise to saline.

Step 2. Place 1-2 drops of a lubricating eye drop and fill the back of the lens. Place the lens on your index finger and insert directly onto the centre (coloured part) of your eye in a face-down position, parallel to the floor. To save confusion, it’s a good idea to always insert the right lens first.

Step 3. If you happen to drop your lens, use saline solution to rinse. DO NOT USE TAP WATER.3 Place the lens in the palm of your hand and rinse thoroughly for 5 seconds.

Step 4. Dry and wipe out your lens case with a tissue. Leave the case lid off to air dry face down.4

NORMAL occurrences on insertion: Occasionally a lens may become dislodged within your eye. This may be uncomfortable but will not do any harm.

  • Look in a mirror to establish where the lens has moved to.
  • Move your eyes in the direction away from where the lens is located – for example, if the lens in your right eye is on the white of your eye nearest to your nose, move your eyes to the right and gently nudge the lens with your eyelids
  • Avoid directly pushing the lens into place as this can damage the surface of your eye

ABNORMAL occurrences on insertion: If on insertion you experience stinging, burning or pain, remove the lens, rinse and re-insert. If pain persists once the lenses have been removed, or if the lens feels as though it is stuck to the eye, contact your optometrist immediately.

Removal

Suction Removal. Using your middle fingers, open the eyelids wider than the lens diameter. With the suction tool between your index finger and thumb, align the suction cup so it is positioned in front of and parallel to the lens. When the suction cup touches the lens, apply pressure gently to adhere the lens to the cup and remove the lens from your eye. After removal from the eye, carefully slide the lens sideways off the suction tool and it will come off easily.

There are other ways to remove rigid lenses however these techniques cause flexure of the lens and may decrease its effectiveness overtime. 

How to Clean & Store Your Rigid Contact Lenses

An effective cleaning process is vital to ensure comfortable, hygienic and infection-free contact lens wear. With correct cleaning, contact lenses will feel better on your eyes, allow better eye health and vision, and dramatically reduce the risk of infection. Always clean your lenses after wear, and NEVER RINSE OR STORE YOUR LENSES IN TAP WATER.3 The acanthamoeba microorganism is plentiful in tap water and can cause a severe, painful and sight-threatening infection.

Peroxide cleaner (AO Sept with Hydraglyde)

  • To clean, disinfect and condition: Fill the case up to the line, place your lenses in the correct cage-holder, then submerge the case and screw closed. Over the course of a 6 hour period the catalyst in the case converts the disinfecting hydrogen peroxide solution into water and oxygen gas. The solution also includes Hydraglyde, an ingredient which improves the wettability of your contact lenses.

This cleaning solution requires no rubbing step, which decreases the risk of accidental breakage. The lenses do not need to be rinsed after the clean, as the solution neutralises to sterile water. The case can be left to air dry when not in use and should be replaced with each new bottle of solution. Take care when transporting the case as sometimes the small gas-release hole can leak the solution. Do not remove the lenses from the case before 6 hours, as the un-neutralised hydrogen peroxide in your eyes will sting painfully. If this occurs, rinse thoroughly with water and contact your optometrist if the pain persists or your vision is affected.

Multipurpose solutions (Menicare and Boston Simplus)

  • To clean: Place a few drops of rigid contact lens solution on the palm and the lens, then rub with your finger-pad for at least 10 seconds on each side. The back surface (concave) is best cleaned by moving your thumb across the surface. This step removes material that deposits on the lens during wear.
  • To disinfect and condition: Place the lens in fresh solution in your lens case, ensuring the lens is completely submerged. This step kills microbes on your lenses and prepares the surface of your lens to stay wet throughout wear, increasing comfort. Store your lenses in this solution for at least 4 hours for the cleaning process to be complete.

Whilst RGP lenses are strong, with incorrect technique or too much force they can break, so take care during the cleaning step.

Regular protein removal (Progent)

  • To use: Place the lenses into the Progent case lens holders. Open vial A and B by twisting the cap and pour the contents into the Progent case. Replace the lid and tighten. Leave the lenses in the solution for 30 minutes, then remove and rinse thoroughly with saline.

An intensive cleaner like Menicon Progent cleans and maintains the wettability of your lenses. After rinsing the lenses, they can be worn following this protein clean or can be disinfected using your normal routine.