What is myopia?
Myopia is caused by elongation of the axial length of the eye. This causes light rays to focus at a point in front of the retina for objects that are far, rather than directly on the retinal surface. This means distant objects are blurred. The greater the myopia, the nearer objects are before they become blurred. To explain, someone that has a prescription of -1.00 has a focal point of 1 meter, which means objects further than 1 meter become blurred the further away they are. For someone with a prescription of -3.00, their focal point is now only 33cm, meaning objects become blurred if they are further than 33cm away.
Below are some examples of relative sight to demonstrate the effects on vision of different levels of myopia compared to someone with no prescription, known as emmetropia.
Emmetrope: no prescription & 20/20 vision
Myope with -3.00
Myope with -6.00
The development of myopia in early childhood is particularly disturbing as it provides a longer time to become progressively worse, as myopia tends to increase on average by 0.50D per year until about 16. As myopia progresses, it typically means the eye continues to elongate, increasing a child’s risk of more serious vision problems in adulthood. For every 0.1mm increase in eye (axial) length, an increase of about 0.25D of myopia occurs.
FACT: The earlier the onset of myopia, the higher the rate of progression and the higher the final degree of myopia.
Significant Risks with Myopia
- The retina pulls away from the eye’s supportive tissue
- Can cause permanent vision loss
- Typically associated with aging, but tend to develop sooner in nearsighted eyes
- specifically the posterior subcapsular variety of cataract, which happens on the back surface fo the lens, can progress rapidly, and is often very detrimental to vision
- cataract surgery can remove the lens opacity, but again, myopes face increased risk of post-operative retinal detachments
- Due to higher pressure in the eye, which often has no presenting symptoms or pain, leading to insidious vision loss
- Damages the optic nerve with resultant peripheral vision loss in the early stages, and later on to central vision loss (irreversible and often referred to as tunnel vision)
- Myopes have a 2 to 3 times greater risk of developing Open-Angle Glaucoma
Myopic Maculopathy or Degeneration
- The most common complication of high myopia
- A slowly progressive and sight-threatening condition in which visual loss develops from atrophy of the retinal pigment epithelium and/or sub-retinal neovascularization
What causes myopia development and progression?
Genetics (a family history of myopia), individual characteristics (e.g. dopamine levels), and environment (e.g. lack of outdoor activity).
Why is early-onset myopia particularly concerning?
The earlier the onset, the higher the rate of progression, and the greater the degree of myopia in adulthood.
How is myopia diagnosed?
An optometrist or ophthalmologist can diagnose myopia in the course of a routine eye exam which includes visual acuity, retinoscopy, and subjective refraction.
What are the risks associated with myopia?
Myopia is associated with an increased risk of retinal detachment, cataracts, glaucoma, and myopic maculopathy. All these conditions can lead to irreversible vision loss. In fact, in 2010, myopia was estimated to be the main cause of distance visual impairment worldwide – and it is ranked as the second most common cause of blindness globally. By 2050 it is estimated that 50% of the world’s population will be nearsighted or myopic, that means 5 billion people globally will be affected.
How is myopia treated?
Current treatment consists of glasses, atropine, rigid contact lenses (Ortho-K), D.I.M.S. spectacle lens technology, bifocal/multifocal spectacles in some cases of binocular or accommodative dysfunction and peripheral defocus modifying contact lenses (soft contact lenses). It is the latter type of correction that we will be discussing here due to its convenience, safety, and high rate of success at retarding the progression of myopia.
MiSight by Coopervision: 1st Daily Disposable Lens to Treat Myopia
Daily disposables offer ease of care (no cleaning/disinfecting solutions required) and reduced risk of infection (younger children are found to actually have a lower rate of infection than teens, and the overall rate of eye infection in children waring daily disposable soft lenses is 1 case in 12,000 years of wear.
- MiSight 1 day – the first soft contact lens treatment proven to slow the progression of myopia in children by 59%.
- Glasses can help the child see clearly but has little or no effect on slowing down the progression of Myopia.
- Treatment lenses such as MiSight 1 day is proven to significantly reduce the rate of myopia progression in children as young as 8 years, or younger as per the discretion of the eye care professional
- 85% of children say MiSight 1 – day lenses are easy to insert
- 100% of children found MiSight 1 – day lenses are easy to remove
- 90% of children said they preferred wearing their MiSight 1-day contact lenses over wearing their spectacles
- 98% reported seeing well while playing outdoors
- 41% of children had no clinically meaningful change
To determine your child’s risk of developing myopia and more advice on how to help further slow the progression, click here and take the short survey.
MiSight lenses, as mentioned earlier, are one of several options for treating childhood myopia. To learn the status of your child’s eye health and vision, and the potential best options for treatment, please call Dr. Sciberras office to book your child’s first or annual eye exam. Regular eye examinations for young children are important to identify and treat myopia early. This may help to reduce the final prescription and the potential risk for future eye health issues. Every dioptre helps, and the younger we start, the better.