Articles
What is Orthokeratology?
Contact Lenses
11 August 2018
So What is this life changing procedure all about?
Simply speaking, this is a contact lens that you wear so you do not have to wear contact lenses — During your waking hours that is . Confused, well let me be more clear. This is a night time lens, worn overnight, it gently molds the shape of your cornea, causing it to flatten, thus changing the refractive state of your eyes. This flattening is similar to the flattening done with a laser in a procedure called Lasik.
Why would I want Ortho-K lenses?
(1) Well maybe you do or maybe you don’t. Lets see now, do you:-
(2)Like to swim?
(3) Play water Polo?
(4) Work in a profession where spectacles or contact lenses hinders your work. eg. Fire fighter, Scuba Diver?
(5) Feel that your Contact lenses are not comfortable after a few hours causing unsightly red eyes?
(6) Do you want to control or slow down your myopia (Short Sight) from increasing?
If you answered yes to any of the above, then yes, you may want to try Orthokeratology.
How does Orthokeratology work?
What changes in the eye occurs as myopia progresses?
Myopia Control.
Yes, I said myopia control. Many studies have demonstrated Orthokaratology or Ortho-K’s effectiveness in controlling or slowing myopic progression. Now from the above discussion above, we know what is the most common cause of myopic progression is. It is the increase in the Axial Length of the eye. Do studies in myopia control using ortho-k lenses in one eye while the other eye is fitted with a regular RGP lens show a greater increase in the eye fitted with a regular RGP lens when compared with the treated eye? Yes, Now we have evidence of Ortho-k’s effect on myopia control.
Why worry about myopic progression?
We know now that as the axial length of the eye increases, so does the myopia. This lengthening is stretching the eye. Just like a balloon, over stretching of the eyeball, will cause weakening of the layers of tissue that form the eyeball. This weakened eye is now at greater of developing some potentially blinding eye conditions such as Glaucoma, Cataract, Macular Degeneration, Retinal Detachment, etc. We must therefore prevent our eyes from weakening by controlling the progression of myopia.
What are the risks?
The greatest risk to any type of contact lens wear is infection. Some infections can be very serious, but fortunately, most can be treated with antibiotics or other medication. Infections are caused by pathogens that have been transferred to lenses by contaminated fingers, contact lens cases etc. To keep your lenses from contamination, make sure you follow closely your practitioner’s recommendation on cleaning and soaking solutions. Please follow each step carefully. Another concern are ill fitted lenses that may cause abrasions.
Make sure you follow your practitioner’s recommended return schedule for aftercare visits. This is extremely important as any concerns need to be ironed out early.
How are the lenses fitted?
Ortho-K lenses are fitted with the help of an instrument called a Topograph. After your medical and family history are taken, eyes are assessed to ensure suitability for ortho-k lenses, a topograph of each eye is taken (Fig A) They are a few ways to proceed from here. A trial lens can be used to trial fit the cornea, a drop of solution is place on the eye causing the tears under the lens to florescence when observed under ultra violet light. The thicker the tear layer under the lens the brighter the glow. This is then viewed through a slit lamp to judge the fit of the lens. Another method is to use software. The data from the topograph is down loaded onto the software the software will then automatically design the lens according to the shape of the cornea.Your experienced orthokeratologist will now tweek the design now to produce a lens that will provide you with all night comfort. As no two corneas are the same, no two lenses produced in this way are the same. This is a true custom made lens. This practice uses both methods.Your Lenses are ordered and you will be informed when they arrive. Your lens is placed on your cornea and you will be asked to wait for 30 minutes for the lens to settle down. The lens fit and prescription is assessed. if all systems go, we will teach you how to insert and remove the lenses safely, and how to maintain your lenses.
You will be instructed to return to the practice the very next morning after the first overnight wear. Your cornea will be checked carefully for any effects of overnight wear, your vision checked and your topograph taken. Your vision may not be perfect after the first night wear and will deteriorate at a faster rate. after a week or two, you should have clear vision that should last you through the day. Figure B is a topograph of an eye after the treatment and looks similar to that of a patient who had Lasik refractive sugery.
