OK – Orthokeratology – Myopia control
What is ORTHOKERATOLOGY? (Also known as Ortho-K)
It is a non-surgical procedure using specially designed contact lenses to gently reshape the curvature of the eye to improve vision.
Some benefits of Ortho-K are:
– Vision improvement while you sleep
– Reversible/low risk
Children who, with their parents, wish to significantly slow or stop their progression of myopia would benefit from Ortho-K. There is continuing research on the control of myopia (nearsightedness) in children by the use of Ortho-K and results are very promising.
Individuals who need an optical correction, but wish to be free of lenses and glasses during the day while maintaining clear and comfortable vision, will benefit from Ortho-K.
Who is suitable for this treatment?
Orthokeratology is perfectly suited for anybody who wants clear natural vision all day, every day but have the following conditions:
- Mild to moderate myopia (-0.75 to –5.00D), and more.
- Mild hyperopes, up to +3.00D
- Suitable Presbiope – mono vision corrections
- Active individuals or those with occupational demands that are not suited to disposable contact lenses
- Lose their contacts easily, or suffer from allergies from some contact lenses
- Considered refractive surgery because of the freedom it provides, but are worried about the risks
- Have difficulty with dry eyes from air conditioning, computer use or dusty environments
- Find soft contact lenses do not fulfill the comfort demands their lifestyle places on their eyes
Increasing myopia is becoming an epidemic. In some Asian countries, up to 80% of adults have Myopia. Recent findings on the ability of Ortho-K lens wear to slow the progression of myopia means that the lens modality could become a major technique for the control of myopic progression.
How does Orthokeratology work?
Orthokeratology lenses are customized contact lens molds. They are worn each night and removed each morning. The molding that occurs overnight allows for clear vision at all distances during the day without glasses or daytime contact lenses. The lenses are comfortable and do not interfere with sleep. They last approximately a year and are worn as long as myopia progression is considered a risk or until freedom from daytime lens correction is no longer desired.
What results can you expect from Ortho-K?
Eye care practitioners usually aim for 20/20 vision after Ortho-K and corneal refractive therapy. There are times some patients still need glasses, but with less prescription.
Once your eyes reach the desired prescription, you will need to wear lenses when you sleep or during part of the day to maintain your prescription. Discontinuing lens wear altogether allows your corneas to gradually regress to their original shape or close to it.
Is it a new concept?
Reshaping the cornea with contact lenses to improve vision, otherwise known as Ortho-K, was first introduced to contact lens practitioners by George Jessen in 1962. The initial flurry into orthokeratology was hindered by poor technology and understanding of the criteria needed to successfully and predictably correct myopia.
With these changes, over about 50 years, there has been an upsurge in interest in the technique among contact lens specialists, researchers and academics that has resulted in a better and safe lens material and predictable correction of myopia.
An exponential increase in the publications on this technique and more funding for research from governments and industry bodies started the birth of Orthokeratology in 1992 and was given an FDA approval in 2002.
Are there any side effects?
The biggest side effect of controlling myopia with Ortho-K lenses is actually a benefit, namely there are no lenses to be worn during the day, during which time vision remains clear.
You might experience glare and halos that will be reduced with time, but may never completely go away. As with LASIK, patients with large pupils are especially susceptible to this.
The greatest potential adverse risk for any contact lens patient is infection. Patient’s compliance is an utmost importance. If you properly care for your eyes as instructed, the risk of infection or adverse effects are very low. Parents are recommended to supervise young children in the insertion, removal and care of their lenses.
Contact lenses also can be used to treat presbyopia, although many people may take time to adjust to them.
There are two types of contact lenses that can be worn to correct for presbyopia: Bifocal / Multifocal, and monovision.
Bifocal contact lenses work in much the same way as bifocal eyeglasses. The bottom portion of the contact lens corrects for near vision, while the top portion corrects for other refractive errors. Specially manufactured lenses keep the contacts from rotating on the eye.
Multifocal Contact Lenses is more commonly used and have a gradual focus change from near to distance. Two types are available – Center Near, or Center Distance, for different needs and circumstances, as advised by your eye care practitioner.
Monovision contact lenses use one contact lens to correct for near vision and the other contact to correct for distance vision if needed. Monovision works by training the brain to use one eye for distance vision and the other eye for near vision. It usually takes a while for patients to adjust to monovision contact lenses, but many patients adapt very quickly.
Because presbyopia continues to get worse as we age, the right magnification lenses needed will change over time.
As your natural lenses increase in rigidity, your need for stronger corrections do increase with the years, and you will typically need to update your reading correction every 12-18 or 18-24 months.
Sport & eye injuries
The facts on sports related eye injuries:
• Approximately 40,000 sports eye injuries occur every year, many resulting in permanent vision loss.
• Injuries range from abrasions of the cornea to bruises of the eyelids to internal eye injuries, such as retinal detachments and internal bleeding. Some of these lead to vision loss and permanent blindness.
• Prevention is the most effective treatment. About 90 % of sports related eye injuries are preventable if the right protective eyewear is worn.
• For young athletes, baseball and basketball account for the largest number of injuries.
• Most sports related eye injuries are due to ocular contact with the ball.
• Little league pitches may throw the ball up to 70 mph: fast enough to break bones and do serious damage to the eye.
• Most protective eyewear, including goggles, face shields and guards, should be made of polycarbonate plastic and recommended specifically for your sport to provide the best protection.
• Regular street glasses, contacts and industrial safety eyewear do not offer enough protection for sport.
• Many celebrity athletes agree that eye protection is important and use protective eyewear themselves.
• There’s no evidence that wearing eye protection hampers athletic performance. In fact many famous athletes have excelled in their respective sports while wearing protective eyewear, such as NBA All –Star Kareem Abdul-Jabbar and NFL Hall of Famer Eric Dickerson.
• Some high risk sports include basketball, baseball, hockey, football, lacrosse, racquetball and soccer
• Baseball accounts for the largest number of eye injuries in children ages 5-14, at about 21%, while basketball is responsible for 32 % of eye injuries in 15 – 24 year olds. Racquet sports account for 29 % of sports related eye injuries in 24 – 64 year olds.
• In baseball, most eye injuries are due to ocular contact with the ball. Batters are the most common victims; however pitchers and fielders can also be injured.
• In basketball most eye injuries are due to eyes being poked by fingers and elbows. This contact can’t be prevented, but you can prevent the serious eye injuries they cause by wearing protective eyewear.
• In Canada, ocular trauma decreased by 90% after certified protective eyewear and headgear was made mandatory in organized amateur hockey.
• NFL facemasks are specially contoured according to the position in which they fit on the face to prevent eye injuries.
• Paintball has become a popular sport worldwide, but has been associated with devastating eye injuries, including blindness.
• In 1993, the Dixie Youth Baseball team mandated the use of polycarbonate face shields for all runners and batters. The coaches of the Dixie Youth Baseball Team, which includes little league players in the South and Southwest, agree the safety shields have NOT hindered the performance of the players when batting or catching. Since the rule was enforced, no significant eye or face injuries have occurred while wearing the protective gear.
Tips to help prevent Sports Related Eye Injuries
• Parents must insist that their children wear appropriate eye protection during sports activities and wear eye protection themselves when playing sports to set a positive example.
• Adults and children participating in high-risk sports should always wear appropriate sport-specific protective eyewear.
• Protective eyewear lenses should be made of polycarbonate material, a material ten times more impact resistant than other plastics. It can withstand the force of a .22 caliber bullet. Polycarbonate material offers the best protection against many sports-related eye injuries.
• Do not wear contact lenses, ordinary street wear glasses or industrial safety eyewear as a substitute for protective eyewear. Contact lenses, ordinary glasses and industrial safety eyewear offer no protection against eye injuries in sports activities.
• Make sure your sports protection eyewear fits properly. Your eyewear can be properly fitted by your eye MD (Ophthalmologist)
• Wear sports protective eyewear every time you play! Please make sure your kids do too.
• If you do sustain an eye injury, don’t try to treat it yourself. Go to your local emergency room or call your Ophthalmologist immediately.
Safety Tips for Adults and Children with Good Vision in Only One Eye or History of Eye Injury.
• Functionally one-eyed athletes (those who’s best corrected visual acuity is worse than 20/40 in the poorer seeing eye) or those who have had previous surgery should never participate in boxing or full contact martial arts.
• For sports in which a facemask or helmet with eye protector is required, functionally one-eyed athletes should also wear sports goggles with polycarbonate lenses to ensure adequate protection. The helmet must fit properly and have a chinstrap.
• For more information on manufactures that offer eye protection, please visit the Protective Eyewear Certification Council at www.protecteyes.org
• All athletes should wear protective eyewear, but not just any eyewear. Use protection specifically designed for the sport.
• Baseball—Polycarbonate or wire face guard attached to helmet; sports goggles with polycarbonate lenses on the field.
• Basketball—sports goggles with polycarbonate lenses.
• Field Hockey—Full face mask for the goalie; sports goggles with polycarbonate lenses/wire mesh goggles on the field.
• Football—polycarbonate eye shield attached to helmet with wire face mask.
• Ice Hockey—helmet with full face protection.
• Men’s lacrosse—helmet with full face protection.
• Women’s lacrosse—Full face protection or sports goggles with polycarbonate lenses/wire mesh goggles.
• Paintball—full face protection.
• Racquet sports—sports goggles with polycarbonate lenses.
• Skiing—high impact resistant eye protector.
• There is no satisfactory eye protection for boxing.
• For sports with no standard, eyewear certified for racquet sports are suggested.
Today’s athlete has a number of eye protectors available, and the best part is that protective eyewear does not hinder performance in any way. When properly fitted, appropriate eye protection can reduce the risk of eye injuries by 90%. Ask your Ophthalmologist to help you select the eyewear you need to play hard and play safe.