the eye blog
EYE CARE INFO & UPDATES
Here at Eyecare Concepts, a family optometry practice with a focus on children's vision, I test a lot of kids' eyes. Kids of all ages and from different family backgrounds. Many children come in for their routine eye checkups and have normal eyesight and healthy eyes, which is always great to see. Some children’s cases are more challenging, but it’s very satisfying and professionally rewarding when I'm able to help them and enhance their lives with better vision.
Lazy eye is a condition that most parents have heard of and are often concerned about. Sometimes the term ‘lazy eye’ gets confused with a turned eye or crossed eye. In optometry speak, lazy eye is called amblyopia, while a turned eye is called strabismus. They are often related, but quite different conditions. A lazy eye is usually a healthy eye but the eye and the brain are not working together properly. The visual processing system and nerve pathway associated with this eye is under-developed, from the brain becoming accustomed to 'ignoring' this eye in favour of the stronger eye. Without proper neural stimulation, the suppressed eye falls behind the good eye in eye-to-brain development.
The majority of cases of lazy eyes in Australian children are associated with long-sightedness (hyperopia). Some children are born highly long-sighted in one or both of their eyes. A long-sighted eye is an eye that is physically shorter in length than normal, or has a lens that is too powerful, so that light entering the eye is focused behind the retina instead of on it. Most children are mildly long-sighted when young, that is perfectly normal, but when an eye is significantly long-sighted (usually +4.00 or above) the eye is unable to fully compensate for this and the result is blurred vision both in the distance and up close. Normal development of the visual system is hindered by blurred vision from the affected eye/s. A lazy eye can also result if a child has one eye that is significantly more short-sighted (myopic) than the other, or has a high degree of astigmatism (uneven eye surface shape).
It is important to diagnose lazy eye in a child from an early age. Amblyopia occurs in around 2-3 in every 100 children, so it's not a rare condition. Some children have mild forms of amblyopia, and some have more severe forms. If a lazy eye is not detected, corrected or treated before age 8, permanently reduced vision in the affected eye can result and which will affect the child for the rest of his or her life. Lazy eyes are usually not treatable, or are extremely difficult to treat, in adulthood. Loss of vision in one eye means the child has impaired stereo (3D) vision and depth perception, and can affect potential future career ambitions as an adult, as some professions require good vision from both eyes.
One tell-tale sign that your child may have a lazy eye is a turned eye (strabismus). An eye that is highly long-sighted will have a greater tendency to turn inwards toward the nose (termed esotropia), especially when the child is tired. Some children may have an eye that turns outwards (termed exotropia). An inward-turning strabismus is more common in Caucasian children, while an outward eye turn is more common in kids from Asian backgrounds. If you suspect your child may have a eye that turns or wanders, whether it affects one eye or both eyes, turns inwards or outwards, and even if it happens only occasionally, you should have your child examined by an eye care practitioner — an optometrist or an ophthalmologist — as soon as possible.
With some infants and toddlers their eyes may give the appearance of being turned or crossed but are in fact straight. This is an optical illusion called pseudostrabismus caused by facial features and eyelids that are not yet fully developed. As trained professionals, we can differentiate between a true strabismus and a pseudostrabismus. We suggest seeking a professional opinion if you have any concerns at all about your child's eyes.
Our recommendation is that all parents should bring their children to an optometrist for their first eye test by the age of 3, even if they show no signs or symptoms and seem to be perfectly fine. Young children do not realise anything is wrong with their sight, they are not aware of what blurred vision is, and can appear to be functioning perfectly, especially when a problem affects only one eye. Often it's only at their first eye test that significant issues are discovered.
Children will usually have a basic vision screening test by their maternity nurse when they reach 3.5 years of age. This test is called the Melbourne Initial Screening Test (MIST). While these tests are helpful they are not always reliable and are not a substitute for a proper comprehensive eye examination. We believe all kids should be tested by an optometrist even if they have passed their screening test, for a more in-depth assessment of their eyesight, visual functions and eye health.
In our children's clinic we have special instruments and sophisticated eye measuring equipment to test young children, and objective tests that do not require any responses from the child if they are too young to read letters, identify symbols or give reliable responses. We also use dilating eye drops to more thoroughly assess your child's eyes and focusing. The presence of a lazy eye, turned eye, long-sightedness, short-sightedness and astigmatism can be detected. Where a lazy eye is found we can diagnose the cause of it and implement a treatment plan to gradually build up the vision in this eye and to make both eyes work together as a team. This usually involves glasses (sometimes contact lenses), eye patching or eye drops, and vision therapy. With timely and appropriate treatment the visual outcome for a child with a lazy eye is usually very good.
As an eye care professional, to see a child's face light up and smile when given glasses for the first time and being able to see better is always such a delight. And I'm reminded of what a privilege it is to have the opportunity, and to be entrusted with this responsibility, of looking after young children's eyes and enhancing their lives through eye care.
FAMILY & CHILDREN'S OPTOMETRIST — KEW, BALWYN, BALWYN NORTH
Philip Cheng - B.Optom (Melb) Ocular Therapeutics (GCOT). Optometrist at Eyecare Concepts Kew East, Melbourne. An experienced eye care & contact lens practitioner with expertise in myopia control & orthokeratology.