Paediatric Myopia
Paediatric Myopia (Near-sightedness in Children)
Paediatric myopia, commonly known as near-sightedness in children, is a refractive error in which the eye grows too long from front to back.
This causes light to focus in front of the retina rather than directly on it, resulting in blurry distance vision while near vision remains clear.
Paediatric myopia has become a global public health concern, with prevalence rates rising significantly over the past two decades.
Causes and risk factors
The exact cause of myopia is a combination of genetic and environmental factors:
Genetics
A child with one myopic parent is at a higher risk of developing myopia. If both parents are myopic, the risk increases significantly.
Lack of outdoor time
Studies show that children who spend less time outdoors are more likely to develop myopia. Natural sunlight is believed to stimulate the release of dopamine in the retina, which helps regulate eye growth.
Prolonged near work
Excessive time spent on activities close to the face, such as reading, using smartphones, or playing on tablets, increases the risk of myopia onset and progression.
Age of onset
Children who develop myopia at a younger age (e.g., 6–8 years old) are at a higher risk of progressing to “High Myopia” later in life.
Signs and symptoms
Children often do not realise their vision is abnormal. Parents and educators should watch for the following signs:
- Squinting to see distant objects (e.g., the whiteboard at school).
- Sitting unusually close to the television or holding screens close to the face
- Frequent eye rubbing or blinking
- Complaints of headaches or tired eyes
- Declining academic performance or lack of interest in sports
Why myopia control matters (Complications)
Myopia is not just an inconvenience that requires glasses. If a child’s myopia progresses to:
High myopia (typically defined as -6.00 diopters or worse) significantly increases the risk of severe eye diseases in adulthood, including:
- Myopic macular degeneration (MMD): Damage to the central retina, leading to irreversible vision loss.
- Retinal detachment: The stretching of the eyeball thins the retina, making it prone to tearing.
- Glaucoma: Increased pressure in the eye that can damage the optic nerve.
Diagnosis
A paediatric optometrist or ophthalmologist can diagnose myopia through a comprehensive eye exam, which typically includes:
- Visual acuity test: Reading letters or symbols on an eye chart.
- Refraction assessment: Using a phoropter to determine the exact lens prescription needed.
- Cycloplegic exam: Administering eye drops to paralyse the focusing muscle of the eye temporarily. This helps prevent the child from over-focusing and provides an accurate measurement of their refractive error.
- Axial Length Measurement: Measuring the physical length of the eyeball (front to back) to track progression over time.
Treatment and Management (Myopia Control)
Historically, children were only given standard glasses to *correct* blurry vision. Today, the standard of care includes therapies designed to *slow the progression* of the condition.
1. Optical Interventions
Orthokeratology (Ortho-K): Rigid gas-permeable contact lenses worn overnight to temporarily reshape the cornea. This provides clear vision during the day without glasses and has been shown to slow eye growth.
Multifocal/Dual-focus soft contact lenses: Specially designed daily disposable contact lenses (e.g., MiSight) that correct distance vision while simultaneously signalling the eye to stop growing longer.
Myopia control spectacle lenses: Advanced glasses lenses featuring Defocus Incorporated Multiple Segments (DIMS) or Highly Aspherical Lenslet Targets (HALT) technology. These glasses are specifically designed to slow the progression of myopia, unlike standard single-vision glasses.
2. Pharmacological Interventions
Low-Dose Atropine Eye Drops:
Each night at bedtime, a small drop (usually between 0.01% and 0.05% concentration) is placed in the eyes. Atropine has been proven highly effective in slowing myopia progression with minimal side effects.
3. Prevention and lifestyle recommendations
Parents can play an active role in preventing the onset of myopia or slowing its progression by enforcing healthy visual habits:
4. The 20-20-20 rule
For every 20 minutes of near work or screen time, the child should look at something 20 feet away for at least 20 seconds to relax the eye muscles.
5. Increase outdoor time:
Encourage at least 2 hours of outdoor play per day.
6. Limit screen time:
Restrict recreational screen time, especially on small devices like smartphones.
7. Maintain Proper Working Distance:
Ensure the child holds books and screens at least an elbow’s length away (the “Harmon distance”).
8. Adequate Lighting:
Ensure the child’s study area is well-lit to reduce eye strain.
Key message for parents
Paediatric myopia is a progressive condition that requires proactive management. By combining regular comprehensive eye exams, modern myopia control treatments, and healthy lifestyle changes, parents and eye care professionals can protect a child’s long-term visual health and significantly reduce the risk of severe eye diseases in the future.