Children’s vision continues to develop until they are around 7 or 8 years old. This period is known as the critical period of visual development, and any interruption to normal visual development during this time can result in amblyopia, also known as a lazy eye.
Amblyopia is a condition of poor vision in one or both eyes, where the vision fails to develop normally. It is however treatable if caught early enough.
The most common causes of amblyopia are refractive, i.e. the need for glasses, or strabismic, which results from a misalignment of the eyes. There can be no obvious sign that a child has amblyopia, particularly if they do not have a squint too, and therefore it is important that children get their eyes checked by an orthoptist and a paediatric ophthalmologist during this period.
When a child is seen at Clinica London, they will first see the orthoptist who will assess their child’s vision. Assessing vision when a child is verbal is done using pictures and letters, much like when adults have their eyes tested. For non-verbal children, the orthoptist will use bright lights and toys to assess visual behaviour and will show preferential looking pictures and gratings, to see if the child looks towards these. The orthoptist will perform tests to look at the alignment of the eyes, and how well they can use their eyes together. The orthoptist may then put some eye drops in which will dilate the child’s pupils and temporarily stop them from focussing. This will allow the paediatric ophthalmologist to perform a glasses test and allow them to look inside to check the health of the eyes.
The first step in amblyopia therapy is always to prescribe the required glasses, and allow 4 months of full-time adaptation to the glasses. If after those 4 months there remains poor vision in one eye, then the orthoptist will suggest the use of either patches or eye drops to improve the vision. Amblyopia therapy works by penalising the better-seeing eye, so an eye patch would be worn on the ‘good’, essentially forcing the bad eye to work harder. Eye drops that are used for amblyopia treatment are stronger than those given for undertaking the glasses test, and only need to be used twice a week, also only going into the better-seeing eye.
During amblyopia therapy, children will be monitored closely by the orthoptist who will adjust any treatment regimens according to how well the vision is improving every 2 months. With good compliance with treatment, the vision in the amblyopic eye can improve to see as well as the better eye.
We at Clinica London are very fortunate to have four specialist Orthoptists, so there is always someone available every week for your child. We all work closely with the consultant ophthalmologists, in particular Ms Naz Raoof, the Paediatric and Neuro-Ophthalmologist