Wearing a patch for your appointment (diagnostic occlusion)

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Information for patients

What is this information about?

This information is about wearing a patch over your eye (diagnostic occlusion) before your appointment. We check your squint (strabismus) in this appointment to help us to decide what may be the best treatment for you.

This information explains:

• why you need to wear a patch before your appointment
• how wearing the patch helps us to decide on the best treatment for you
• what you need to do with the patch
• what happens in your appointment
• how you find out the results of the eye tests we will do in your appointment
• the minor side effects that you may get for a short time after wearing a patch.

Why do I have to wear a patch?

So that we can decide on the best treatment for your squint, we need as much information about it as possible.

We ask you to wear a patch over one eye for 1 hour before your eye tests as this helps us to get the information we need. Wearing a patch before your eye tests is called ‘diagnostic occlusion’.

What does wearing a patch do?

Wearing a patch for an hour stops your eyes from working together as a pair.

It means that we can:

• measure the largest amount by which the eyes drift
• find out more about what is causing your squint.

When we have this information, we use it to help us to make decisions about what treatment is best for you.

What do I need to do with the eye patch?

Your orthoptist (a specialist in diagnosing and managing problems with eye movement, vision, and how the eyes work together as a pair) will give you an eye patch.

• Keep it safe until your next appointment.
• Put the patch on one eye 1 hour before your next appointment.
  • It does not matter which eye you put the patch over.
  • Make sure it is fully stuck down on your face and there are no holes to peep through.

Do not remove the patch when you come to your next appointment. Your orthoptist needs to see you with the patch in place. They will remove it for you in your clinic appointment.

What happens in my clinic appointments?

Your Orthoptist will:

• give you a cover to hold over one eye while they remove the patch
• measure your squint using prisms (special lenses that bend light and change its direction).

Do I need to wear the patch after my orthoptist has finished taking measurements?

No. You do not need to wear the patch after the orthoptist has finished taking measurements.

How do I find out the results of the eye tests done at my appointment?

Your orthoptist will tell you if the tests and measurements showed that your squint has changed. This information may change the way in which your squint is managed. Your orthoptist will discuss these options with you.

Can wearing the patch and having the tests cause me any harm?

Wearing a patch for diagnostic occlusion and having the tests afterwards are not known to cause any harm.

• Sometimes the patch can cause skin irritation. If you have any known allergies to plasters or sticky tapes, please let your orthoptist know.
• If you have symptoms of double vision or eye strain, they may get worse for a short time after removing the patch.

Where can I find further information about squints?

For further information about squints and their treatments visit:

• NHS choices www.nhs.uk search for ‘squint’
• www.squintclinic.com

Who should I contact if I have any questions after I have read this information or have lost my patch before my appointment?