Glaucoma readings in the pandemic era: Are facial masks an obstacle to a correct intraocular pressure measurement?
It is currently recommended in the UK to wear a mask to prevent the spread of the coronavirus. Whilst this is vital for patient and optometry staff safety, it has led to several changes in the approach to a patient’s examination.
We have encountered cases of doubtful raised intraocular pressures (IOP) using the Goldmann applanation tonometry technique. A common factor noticed in these cases was the type of facial mask the patients presented with.
If the patient is wearing a respiratory protective FFP3 mask – a rigid type of mask, this may press on the eye during the taking of eye pressure.
This will result in an increase in actual eye pressure and thus lead to a higher reading using the tonometer.
Goldmann applanation tonometry is one of the most commonly used techniques for IOP measurement used in a hospital setting and also in our optometric practice.
A correct measurement also requires a proper observer’s technique. One further vital step is to ensure that the head of the tonometer is perpendicular to the eye. This is to guarantee that there is a correct positioning of this device to the patient’s eye and consequently an accurate result of the IOP.
A bulkier mask can tilt the head of the measurement device. This subsequently will lead to an overestimation of the IOP reading, which can have a significant impact on the patient’s management.
Therefor it is important to take notice of the type of mask the patient wears and how this may affect the measurement of the IOP (eye pressure).