Welcome to question of the day #390

Eyetools question of the day #390 

I work as an eye specialist in community practice. Last week I inserted a rigid contact lens into a patient’s eye and within 30 seconds she collapsed onto the floor. I called the paramedics and she was resuscitated and is now recovered. What happened?

This sounds like vasovagal syncope. It’s happened to me twice in community practice.

The first was a large male adult who collapsed during contact tonometry and the second was another large adult (my brother) who collapsed when I inserted a rigid contact lens during my training year in an eye hospital.

Syncope is the transient, temporary loss of consciousness and posture. Vasovagal syncope is a reaction centered around the fight-or-flight response which occurs when patients experience a perceived or actual danger or threat, especially when it involves discomfort.

The vagus nerve is over-stimulated and causes the peripheral blood vessels (hands, arms, legs, and toes) to dilate which lowers the blood pressure, and the heart slows down. There is a reduction in blood pumped to the brain causing less oxygen in the brain and fainting occurs. People with vasovagal syncope usually collapse to the floor. In an eye care setting this is not usually a big fall as the patient is usually seated.

It can occur with pupil dilation, contact lens insertion, contact tonometry, gonioscopy, punctal plug insertion or removal, and foreign body removal

After the faint the patient may have a pale complexion, exhibit jerky abnormal body movements (similar to a fit) have a slow, weak pulse, and dilated pupils

In my experience, once the person has collapsed they recover consciousness in less than a minute. It’s best to sit with the patient while they are unconscious and at the same time call for help.

While the patient is unconscious check for breathing. If there is a problem with breathing use any resuscitation techniques you know or call someone who knows them.

Once the patient is conscious leave them lying down for at least 15 minutes. Loosen any tight clothing with the patient’s permission.

If the cause is obvious, for example, contact lens insertion there is no need to call a medical practitioner but do make clear notes in the records.

Vasovagal syncope doesn’t happen very often. Perhaps once or twice in a career but it’s could to be aware of it and have a reasonable idea of what to do should it happen.