A squint (also called strabismus, or a turn in the eye) refers to any ocular misalignment - that is, when both eyes are not looking in the same directions. The deviating eye can either turn inwards (esotropia), outwards (exotropia), upwards (hypertropia) or downwards (hypotropia). A squint can be intermittently occurring or constant. A squint can either be in 1 eye or alternate between the eyes. 2-4% of the population have a squint.
Management of a squint commonly involves glasses and patching, but exercises (Orthoptic therapy) or surgery are sometimes required. The most important factor for a good outcome is early detection. If your baby has a wandering eye that persists beyond 3 months of age, or any child develops a squint after this age they should be fully assessed by an Ophthalmologist as soon as possible.
Refractive error is a focusing problem whereby someone is long-sighted, short-sighted or astigmatic. It is caused by the length of the eye being too long (myopia), short (hypermetropia), or slightly irregular in shape (astigmatism). It is corrected by wearing glasses. It is normal for children to be long-sighted and this doesn’t require glasses. If a child is excessively long-sighted, has a squint or has symptoms of eyestrain then glasses are often indicated.
Amblyopia (or lazy vision) occurs when the brain is not delivered a clear image from the eye during childhood. Instead the brain is delivered a blurry, double or poor image and therefore ignores it. Over time the ignored eye becomes lazy and can’t work even if visual conditions improve. Common causes of a suboptimal image are a squint, a difference in focus between the eyes or something that blocks the image altogether such as a cataract.
Amblyopia can be treated up until the age of about 8 years of age. Glasses are often prescribed to improve the quality of the blurry image as much as possible. A patch over the strong eye is used to force the brain to “wake up” the lazy eye. The duration of the treatment largely depends on how lazy the eye has become and how responsive the lazy eye is to treatment. Generally, the younger that patching is introduced the better the visual outcome.
Up to 20% of the newborn population have watery, sticky eyes. Normally, the eye produces tears to wash and lubricate the ocular surface and these flow down the tear duct and into the nose. When a baby’s eyes are excessively watery and/or sticky it is usually due to a delay in opening of the tear duct. It is estimated that 80% of babies affected will spontaneously improve once the tear duct finishes developing within the first 6-12 months of life. If it fails to spontaneously improve, a probing of the tear duct under general anaesthetic by a qualified Ophthalmologist is usually successful in curing this problem.
If the watery eye is accompanied by redness or a lump under the inner opening of the eye then you should take your baby to your general practitioner as soon as possible.
Watery eyes can also be caused by allergies in an older paediatric population. Accompanying signs are itchiness, photophobia (light sensitivity) and rubbing of the eyes. Relieving measures include washing the eyes with cold water, cold compresses to the eyelids and artificial tears (can be bought over-the-counter). Prescription eye drops can be used when symptoms are severe and do not settle with conservative measures.
Chalazion (cyst of the eyelid):
A chalazion is a blockage of one of the glands of the eyelid. It can appear as a lump on or near the eyelid margin. Sometimes a secondary infection can develop and antibiotics are required. Usually with heat and gentle massage applied to the area they resolve without further treatment. If they are very large, persisting or infected, an operation under general anaesthesia may be necessary to drain the cyst.
Reading Difficulties/ Dyslexia:
Reading is defined as the ability to extract meaning from print and involves co-operation between the visual and language centres in the brain. Dyslexia is essentially difficulty with reading that is not explainable by a lack of educational opportunities or support. Research has shown that people with dyslexia experience a variety of language based problems that stem from altered brain function. Speech therapy is therefore often a crucial component in the treatment of dyslexia. Sometimes children may also have a visual problem in addition to their reading problems but it is not a causal relationship. The incidence of visual problems in dyslexics is the same as the general population. If there is a diagnosable vision problem, Ophthalmologists’ can improve the clarity of visual input to the brain but the complex function of interpreting these images will not change. Referral to an educational psychologist is indicated for remedial treatment which is language based. Vision training, tinted lenses, “training” glasses which relax the eye’s focus and “neurological re-organisation” training remain scientifically unproven and therefore cannot be recommended.