Paediatric Conditions
Amblyopia (lazy eye).
Reduced vision in one or both eyes as a result of poor eye alignment (strabismus/squint), the poor focus of the eye (refractive error), and/or occlusion of one eye (often ptosis or cataract) in childhood. These conditions lead to the visual information reaching the brain not being equal between the eyes during the years of visual development in the brain.
During these critical years, reversing the causes and equalising the clarity and use of the eyes can reverse amblyopia. Permanent vision loss results if treatment is not initiated in childhood. Treatment usually involves glasses for the refractive error and/or surgically removing the occlusion if present. Rehabilitation to improve vision may also involve patching or penalising drops at home to improve vision asymmetry.
Early detection improves outcomes, and in NSW, there is a screening program, “Statewide Eyesight Preschooler Screening” (StEPS) which examines the vision of all four year old children in the state. https://www.health.nsw.gov.au/kidsfamilies/MCFhealth/Pages/steps.aspx Family history is also important, and early review with a dilated eye examination is recommended.
https://eyewiki.aao.org/Amblyopia
Refractive Error (hypermetropia and anisometropia)
When a child is born, their eyes are still small (short), measured by the distance from the front of the eye to the back. This means children are born long-sighted (hypermetropia), and as their eye gets elongates, the focus number (dioptre) gets less and closer to zero. If the focus is too high for their age (eye too short) or a significant difference between the two eyes (anisometropia), this can lead to amblyopia and strabismus. The child will need glasses for the difference between the eyes or the gap of their focus compared to where the focus number should be or the full focus number if there is strabismus to help align the eyes. The glasses’ focus number changes as the eye grow, and new glasses are prescribed often once a year.
For accurate prescribing of glasses, cycloplegic refraction must occur, which involves a set of dilating drops in the clinic. These drops also stop the eye from changing its focus to measure the child’s true refractive error.
Refractive Error (Myopia)
As explained under refractive error, a child’s eye at birth should be short to grow into normal focus as an adult. If the child is born with a longer than average eye (often still short but not as short) or grows longer faster than average or both, the child can become short-sighted (myopic/nearsighted). The elongation of the eye can be measured by the focus changes with their glasses or, more accurately but interferometry. Interferometry is a machine that can measure the distance from front to back of the eye without touching it in micrometres.
Again, for accurate prescribing of glasses, cycloplegic refraction must occur, which involves a set of dilating drops in the clinic. These drops also stop the eye from changing its focus to measure the child’s true refractive error.
As the eye can only grow further, myopia is progressive. We now know lifestyle and genetics are very important. Early review if there is a family history is recommended, and an increase in natural light exposure, especially before myopia occurs, has been extensively documented in the research literature. Reduction of near work has also been recommended to help slow progression down. There are now various interventions to reduce progression, and at the forefront is the use of novel designs glasses and low dose atropine drops.
Population data reveals myopia rates have risen worldwide, and with this, it is also occurring in younger children leading to high myopia. High myopia is of concern for its associated eye diseases as an adult, including permanent vision loss.
https://eyewiki.aao.org/Myopia
More information is in my research section as it is the title of my PhD, “ Myopia progression in Children”, and ongoing research.
Strabismus (squint).
Strabismus is poor eye alignment. It can be un-cosmetic and can lead to amblyopia. The cause for strabismus can be restrictive, a palsy (where the nerve does not innervate the muscle to move the eye) or more commonly in children due to poor control of alignment from the brain, but the eye can move in every direction normally. In the last cause, the eye can be turned in (Esotropia) or out (Exotropia) with respect to the other eye and may be present at birth or develop later in childhood. Often glasses can help the alignment, and some patients benefit from surgery. Prisms in the glasses can be used in the older population, especially for small deviations; however, they are not generally recommended for children.
https://eyewiki.aao.org/Esotropia
https://eyewiki.aao.org/Exotropia
Strabismus Surgery
Strabismus surgery is done under a general anaesthetic as a day surgery where the patient goes home the same day. While under anaesthetic, the muscles around the eyes are moved to assist alignment. This may be done with patching and glasses to achieve the best visual and cosmetic results.
The most common strabismic surgeries in children are to correct horizontal deviation: esotropia or exotropia. This surgery involves moving two muscles, either two in one eye or one muscle in each eye. There are rare but significant risks with this surgery, including the need for more surgeries for alignment in the future and potential complications including vision loss and slipped or lost muscle, meaning the eye cannot move well in a direction, and more surgery is required.
https://eyewiki.aao.org/Strabismus_Surgery,_Horizontal
https://eyewiki.org/Strabismus_Surgery_Complications
Watery Eye
A common cause for a watery eye from birth is nasolacrimal duct obstruction. A blockage causes this in the drainage of tears and mucous produced by the tear gland and conjunctival surface. This results in a watery/sticky eye usually present in the first 2-4 weeks of life. A large portion of these cases improves with time, a majority resolving by 12 months. There is also a chance that the blockage can self-resolve after 12 months. If the case does not resolve in the first 12 months, a procedure can unblock the system. A metal probe is passed through the system while the child is under a general anaesthetic. If the duct is narrow, it can then be intubated with a silicon tube that stays insitu and removed in clinic rooms two months later.
https://eyewiki.org/Nasolacrimal_Duct_Obstruction,_Congenital
Chalazion
The eyelid contains Meibomian glands that produce oil to mix in with the tears, helping hydrate the eye. The opening of the glands is along the lid margin next to the eyelashes. These glands can become blocked (at any age). The blockage leads to oil build-up higher up from the opening, creating a lump known as a chalazion. Initially, as the oil escapes the gland, it causes a foreign body reaction that looks much like an infection. The conservative treatment is hot compresses, lid hygiene with wipes and omega-three fatty acids (fish oil) tablets or flaxseed powder in food to help make the oil less thick. If the lump is large and not self-resolving, an incision and curette can be performed to remove it. Surgery is conducted under a general anaesthetic at a hospital in children.
Paediatric Cataracts
Paediatric cataracts are an opacity to the intraocular lens of the eye. They can be congenital (from birth) or acquired (some common causes are trauma, medicines, inflammation), unilateral or bilateral. The cataract must be visually significant to require surgical removal. Paediatric cataract surgery requires longer surgery and significant long term postoperative care compared to adult cataracts. Postoperative care includes amblyopia management, glasses to correct the refractive error after surgery and monitoring for new ocular diseases associated with surgery, such as glaucoma.
Some paediatric cataracts are associated with systemic disease. Initial diagnosis involved a screen for some of the more common diseases. They can also be hereditary, so examining the family can be helpful.
https://eyewiki.org/Cataracts_in_Children,_Congenital_and_Acquired