What are orthokeratology (Ortho-K) lenses?
Do you wear minus-strength glasses? If so, have you ever thought what it would be like to spend a whole day without them or contact lenses and still see clearly?
Orthokeratology (Ortho-K) lenses are night lenses that are used during sleep. While you sleep, specially designed Ortho-K lenses temporarily shape the outermost layer of the eye, i.e. the cornea, so that when you remove the lenses in the morning, you can enjoy sharp vision throughout the day without the need for glasses or contact lenses.
As the change is temporary, it is important to wear the lenses every night. Otherwise the cornea will revert back to its original shape over time and you need to wear glasses or contact lenses again. Ortho-K lenses are custom-designed based on the size and shape of the customer’s cornea. They are like a tailor-made suit that accommodates all of the necessary special measurements of the outermost layer of the eye.
Who are Ortho-K lenses for?
The lenses are perfect for people who wish to enjoy their daily life without wearing glasses or contact lenses, provided that they follow the requirements to ensure smooth and consistent use of the overnight lenses. A proper cleaning routine and sufficient sleep are key. The lenses are suitable for all short-sighted people regardless of their age. Ortho-K lenses are particularly useful for young people aged 7-16, as short-sightedness develops quickly in that age and the use of corrective lenses helps to slow it down. The lenses are suitable for children from 7 years of age, provided that both the child and the parent are ready to follow the correct routine and understand its importance.
What do you need to know before using them?
In order to start using Ortho-K lenses, you need to undergo a comprehensive cornea exam and a tear film quality assessment. These tests are conducted in our Tallinn (Kaubamaja 4) and Tartu stores (Lõunakeskus). You are a suitable candidate for Ortho-K lenses if you have myopia of up to −4.00 D, have good tear film quality and healthy corneas. In order to ensure the best visual acuity and long-term comfortable wear, you need to undergo more follow-up checks than in the case of soft contact lenses. Ortho-K lenses may feel uncomfortable at first, because the cornea is very sensitive during the first instances of use. The material of these lenses is also thicker than that of soft contact lenses, which increases the feeling of a foreign body in the eye at first. Luckily, the eye will considerably adjust to the lenses within the first week, which makes wearing them much more comfortable. In order to achieve good visual acuity, you need to wear Ortho-K lenses while sleeping at least eight hours every night.
How are Ortho-K lenses prescribed?
1. During your first visit, the optometrist will cooperate with you to determine the required prescription. They check whether the eye’s parameters are suitable for using Ortho-K lenses. If so, the required data are collected to order custom-made Ortho-K lenses.
2. Lens orders are fulfilled within 2-3 weeks. Once the lenses have arrived, an appointment is scheduled. During the visit, you are taught how to apply and remove the lenses, undergo a suitability check and are provided information on rules of further use and cleaning the lenses.
3. The next mandatory visits take place as follows.
1st follow-up visit After the first night; morning and afternoon checks.
2nd follow-up visit After 3-5 nights; morning and afternoon checks.
3rd follow-up visit After 10-14 nights; morning and afternoon checks.
4th follow up visit After 3-4 weeks; morning and afternoon checks.
Further visits within one year are agreed with the optometrist.
Are Ortho-K lenses safe?
All contact lenses may increase the risk of infection, as they are placed directly on the surface of the eye. Ortho-K lenses entail an additional risk, because they are worn during sleep while your eyes are closed. They are more safe to wear during sleep than soft contact lenses.1–3 Per 10,000 patients, 7.7 cases of microbial keratitis have been found in adults and 13.9 cases in children below 12 years of age in the case of years-long wear. For night-time wear of silicone hydrogel lenses, i.e. soft lenses, the number of cases per 10,000 patients was 25.4 in the case of years-long wear.6 Wearing Ortho-K lenses is safe if proper lens care routine is followed. It is crucial to ensure that contact lenses, including Ortho-K lenses and all related accessories such as the container or the suction cups used for placement of the lenses, do not come into contact with tap water. In order to ensure good eye health, you need to attend follow-up optometrist visits at scheduled times.
Can Ortho-K lenses slow down the development of short-sightedness?
Correcting the short-sightedness in children and young people and thereby slowing down the development of myopia is close to our heart here in Pro Optika. We have included the option of correcting vision with Ortho-K lenses in our range of products and services in view of slowing down the progression of myopia. According to scientific studies, wearing Ortho-K lenses helps to curb the progression of myopia by up to 50%. Ortho-K lenses are as effective as the best myopia control glasses and soft contact lenses.4 They also come with the most extensive body of supporting scientific evidence, as these lenses have been studied for a long period of time.5 While all of the aforementioned options for controlling myopia offer two benefits, i.e. they correct blurry vision and slow down the progression of myopia, orthokeratology also offers good visual acuity during the day without the need to wear contact lenses or glasses.
Short-sightedness has become increasingly common among children. This is due to changes in our habits: we spend less time in natural daylight and increasingly more children spend long periods of time looking at near objects even before they start school. If myopia is left untreated in children aged 6-16 (when its progression is the quickest), it may cause long-term harmful effects on vision and eye health in adult life. In addition to use of specialist optical aids, controlling the development of myopia requires paying attention to maintaining healthy habits, such as limiting the time spent on near work after finishing school work, ensuring that the distance of close-up work is at least 20 cm from eyes and spending at least two hours outside in natural daylight every day.
1. Bullimore MA, Sinnott LT, Jones-Jordan LA. The risk of microbial keratitis with overnight corneal reshaping lenses. Optom Vis Sci 2013; 90:937-944.
2. Bullimore MA, Mirsayafov DS, Khurai AR, Kononov LB, Asatrian SP, Shmakov AN, Richdale K, Gorev VV. Pediatric Microbial Keratitis With Overnight Orthokeratology in Russia. Eye Contact Lens. 2021 Jul 1; 47(7): 420-425.
3. Stapleton F, Keay L, Edwards K, Naduvilath T, Dart JK, Brian G, Holden BA. The incidence of contact lens-related microbial keratitis in Australia. Ophthalmology. 2008 Oct;115(10):1655-62.
4. Brennan NA, Toubouti YM, Cheng X, Bullimore MA. Efficacy in myopia control. Prog Retin Eye Res. 2021 Jul;83:100923. (link)
5. Sun Y, Xu F, Zhang T, Liu M, Wang D, Chen Y, Liu Q. Orthokeratology to control myopia progression: a meta-analysis. PLoS One. 2015 Apr 9;10(4):e0124535. (link)
6. Lipson MJ. Long-term Clinical Outcomes for Overnight Corneal Reshaping in Children and Adults. Eye Cont Lens. 2008;34:94-99.