Myopia, commonly called short-sightedness ("sight set too short") makes it difficult to see distant objects clearly. It is a very common condition. Myopia's onset is typically in the mid-teens and less frequently later in the twenties. There is considerable debate about whether myopia is inherited or whether it is exacerbated by excessive close work.
The prevalence of myopia has increased significantly over the past few decades, especially in certain population groups of East Asia. As a result, considerable efforts and research has been conducted into how myopia occurs and how the progression of myopia can be halted or at least slowed. Current evidence supports a number of treatment methods for reducing the progression of myopia - these are reviewed below.
Atropine eye drops
Recent studies such as the Atropine in the Treatment of Myopia (ATOM) project provide strong evidence to support the use of low concentration atropine eyedrops to retard the progression of myopia. Atropine is a prescription-only medication, the main effects of which are usual to dilate the pupil and relax the eye's focusing (accommodation) system.
The most recent studies into atropine and myopia control show that atropine in low concentrations can significantly slow the progression of myopia without the usual side effects of pupil dilation and reduced functioning at near. It is believed that this effect is not due to the blocking of accommodation, but rather atropine's effect on the receptors responsible for controlling the length of the eye.
Orthokeratology, also known as ortho-K, is a non-surgical process involving the wear of rigid contact lenses while sleeping. These lenses change the shape of the cornea, the clear tissue at the front of the eye. On awakening, distance vision is clear without the need to wear glasses or contact lenses during the day. The effect of wearing ortho-K lenses remains so long as the lenses are worn overnight, but the therapy is completely reversible.
Orthokeratology has increased in popularity over the past few decades, especially since a steady stream of evidence that indicates as well as correcting myopia in the short term, this therapy also slows the progression of myopia in the longer term. For more on the processes involved in orthokeratology fitting and treatment, click here.
Soft multifocal contact lenses
Multifocal contact lenses are usually prescribed for patients with age-related decreased ability to focus on close objects. But recently they have also been used as another option to reduce the progression of myopia. Like orthokeratology, these lenses inadvertently blur the image that falls on the peripheral retina. This does nothing to compromise central vision and is not usually noticeable to the wearer, but also appears to slow the progression of myopia.