The pressure in the eye (intraocular pressure, often abbreviated to IOP) can vary during the day. Typically (but not always), measurements are higher in the early morning. Therefore, measuring the pressure only once might not be enough to decide on the diagnosis or best treatment for your child. If the IOP is border-line or if the glaucoma is suspected of progressing we will need to measure the pressure every 2 hours during the day; this is called phasing.
The IOP is checked by using an instrument called a Goldman tonometer, which is attached to a slit lamp microscope. A small probe is gently moved onto the surface of the eye and the pressure that the cornea pushes back onto the tonometer is measured.
No, your child will not feel any pain as we put anaesthetic drops into the eyes before we check the IOP, which numb the eye (take away the feeling).
We measure the pressure every two hours starting from 8am until 4pm.
We will ask you to come back to the ward at specific times but you and your child do not have to stay on the ward in between measurements.
At the end of the day the consultant will review your child’s measurements and will explain the results to you and your child.
We usually do the phasing on a Wednesday and you will need to stay for the whole day. If you are unable to on 020 7566 2595, giving us your child’s name and hospital number.
Review date: September 2022