Myopia most commonly originates from the elongation of the eyeball. Excessive elongation of the eyeball increases the risks of permanent vision loss due to cataract, glaucoma and macular changes.
Traditional means of vision correction like glasses, contact lenses and refractive surgery, relieve the symptoms of blurry vision by only helping you to see better. However, these options do not slow or halt the excessive elongation of the eyeball.
There are now options available to slow down/halt the abnormal eyeball elongation thereby slowing down the progression of myopia. By reducing the abnormal elongation, the risks of possible vision loss can be reduced.
In saying that, monitoring your child's myopia progression should rightfully be done with axial length (eyeball length) instead of just the glasses prescription.
Babies are born with an eyeball length of approximately 16-17mm. The average length of a mature eye (12-15 years of age) is 23.8mm. The growth of an eyeball beyond the normal length results in myopia. The elongation not only cause blurry vision, it also results in the increased risk of vision impairment when older.
A 2016 study showed that, 39% of people with with high myopia (larger than -6.00D) developed visual impairment by the age of 75. The following table shows the risk of developing visual impairment in relationship to eyeball length.
Myopia is a multifactorial disease and the exact cause is still unknown. The risk factors of Myopia are the following:
Having parents with myopia is a big risk factor for a child to develop myopia. (2)(3) East Asian children having higher incidence of myopia compared to European Caucasian children. (3) Identical twins are found to have more similar prescriptions and eye length than non identical twins. Heritability of eyeball length is higher than 90%. (4)
Children who develop myopia have a lack of outdoor time and lack of exposure to natural lighting. (5)(6) Eyeball elongation and childhood myopia were associated with high population density and smaller homes (7)
Excessive near tasks ie. reading and portable devices. (3)(8)
© Perth Myopia Clinic