Types of Myopia Control
There are four widely accepted types of myopia control treatments: Orthokeratology (OrthoK aka CRT), Atropine eye drops, Distance-Centre Multifocal Contact Lenses and in some cases Bifocal or Multifocal Eyeglasses. Optometrists throughout the country use methods based on patient age, prescription and need, sometimes combining methods for maximum impact. There is a lot of bad information out there, and recommendations are made for methods that actually may INCREASE myopia such as “undercorrection”, where the doctor provides a lower prescription than needed.
In several scientific studies specific types of contact and spectacle lenses have been shown to effectively control the progression of myopia. Ortho-K lenses, distance-center bifocal contact lenses, and bifocal spectacles are all methods with randomized, controlled peer-reviewed studies on their effectiveness in slowing down or preventing the progression of myopia. The myopia control specialist you choose will determine which methods are the best fit for your child based on prescription and lifestyle and monitor change over time with the goal of minimizing myopic “creep”.
Orthokeratology, also known as OrthoK or CRT is a method where medical devices similar to contact lenses are applied to the eye while asleep. The gentle pressure exerted on the cornea, or surface of the eye overnight results in the temporary “molding” of the outer layers, providing “lens like” effects for the user. The effects last all day, providing vision for users without wearing glasses or contact lenses during their waking hours. The effects are dramatic and free people from issues with glasses or regular contact lenses for sports, swimming and performing the activities they love to perform. Orthokeratology has many peer-reviewed, randomized and some longitudinal studies that show it is an effective method to reduce the progression of myopia and, in many cases, halt it altogether.
Distance Center Multifocal Soft Contact Lenses
Distance Centre Multifocal Soft Contact Lenses are worn precisely the same as regular soft contact lenses. An optical “trick” in the centre of the lens has been shown in several studies to slow down the progression of myopia. This method is rapidly gaining in popularity. At this writing there are only two brands of these lenses. Your eye care practitioner can help determine which brand might be best for you.
Atropine, available in eye drop or ointment form, has been found in several studies to reduce the progression of myopia. Applied once a day, atropine treatment is continued as long as myopia progression continues. It is not a cure, but it has shown to control myopia in many patients and in some cases may be used in conjunction with bifocal eyeglasses to enhance the myopia control effect. Pirenzepine is an analog of Atropine that has been shown effective but is not currently on the market. Dopamine has also been studied but use has been impractical.
Bifocal and Multifocal Spectacles
In some children with certain eye-muscle positioning known as Esophoria, studies have shown that wearing a different prescription for distance and near is helpful. This is usually achieved in Bifocal or Multifocal spectacle lenses. Bifocals have shown to be more effective in some studies and preference has been given for bifocals where the line is placed at the lower margin of the pupil of the eye. For those parents with children with the Esophoria who prefer not to have the children where contacts or use eyedrops or are too young this method has been shown to help in some studies.