Myopia is the sciectific term for "short/near-sightedness. The science of studying why we develop myopia has been practiced for many years resulting in many different theories over the years. These have included RGP lenses, giving under-powered spectacles and discouraging reading. All of these theories have since been discredited, however.
The study of myopia progression has recently become much more urgent with the incidence of the condition increasing all around the world. In singapore for instance the propotionof myopic people is between 70 and 90%! Here in Europe the figures, although lower are certainly inccreasing. In the last 50 years the prevelance has increased from 25 to 40%.
The reasons why we develop myopia are still unclear, however, great strides have been made in the last few years. Genetics are involved, the latest research shows us that if you have one parent with myopia then you are at risk by a factor of four, if you have two myopic parents then you risk increases to nine times. As you can see family history is not the whole story and the current concensus is that time outdoors and UV light seem to have a great affect. The focus of peripheral light light into the eye also seems to be a factor.
Time outdoors can be spent reading or even playing computer games and the protective effect holds. Wecurrently do not know why this helps but we do know that the effect disappears once a child becomes myopic. The most credible theories are that the level of ambient light is generally higher outdoors, the focal points are not contained within four walls and Vitamin D deficiency also plays a roll. The only substantative study at the time of writing suggests that a minimum of two hours a day spent outdoors doing any activity is beneficial.
Some medications aimed at the control of progrssive myopia have been available for some time in the form of atropine and are very effective, however, being derived from the deadly nightshade plant the drugs have significant side affects including systemic toxicity and deat, therefore many companies are busily trying to develop a safer alternative. Until the other methods of myopia control should be considered.
The study of the light focus by the off-centre areas of the eyes lenses came about after anecdotacl evidence of OrthoK halting the myopia progression of patients successfully fitted with this refractive treatment. (for more information on OrthoK click here). The evidence shows that this peripheral refraction in a myopic eye is not accuratley focused on the retina and as such promotes retinal growth in an attempt to rectify the defocus. The result of which is myopic progression. If you could re-focus this peripheral light them you remove the eyes stimulus to grow and, therefore, stop or slow the rate of myopic change. This theory has been the mainstay of common optometric traetment for some time now and the most effective mothods we have avaiable in the UK are Ortokeratology (OrthoK) or soft contact lens multifocals.
If you have any questions regarding the information in this page please contact us at the practice either by email, phone or in person we would be happy to help.