We are well tuned to the knowledge that a person complaining of flashes in their vision may have a rhegmatogenous retinal detachment following a posterior vitreous detachment. However, there are several other causes of flashes that don’t involve posterior vitreous detachment.
In my work as an expert witness I’ve seen optometrists disregard patients’ complaints of flashes because they haven’t found any signs of posterior vitreous or retinal detachment. Here, I deal with two other causes of flashes that I have experience of as a practitioner. I will leave migraine to another EyeTools Journal.
When I worked in my own community practice, a male aged around 30 presented with symptoms of seeing flashing in the top right hand corner of his vision for about months. He described it as like the filament of a light bulb. This was a vague symptom but very clearly described.
He was a moderate myope without any visual complaints or significant history. Visual field testing proved inconclusive. I referred him for further investigation by an ophthalmologist.
Around six months later, I was examining a female patient new to the practice. She told me that she had chosen me to examine her eyes because I’d examined her boyfriend about six months ago and the hospital staff had told her that I had done a good job in detecting his brain tumour.
After further discussion, I realised that her boyfriend was the patient with the bulb filament flashes. Brain tumours come in all shapes and sizes—and so do their symptoms. Some cause flashes (often referred to as aura), some don’t.
I’ve trawled through my medico-legal cases and found seven that involved choroidal melanoma. Two did not have any associated flashes or symptoms similar to flashes. Here are elements of the presenting symptoms for the other five:
‘…three lights in the comer of my eye when I close my eyes.’
‘…’gold leaf’ and ‘bright light’ images floating to the ground past the side of my left eye.’
‘…flickering in the side vision on my left hand side.’
‘…flickering and flashing lights in my left eye.’
‘For the last 5-6 weeks I’ve had pulsating images disturbing the lower part of my vision in the left eye.’
I can see why the optometrists considered that the symptoms were due to posterior vitreous detachment and possibly retinal detachment but once that diagnosis had been ruled out they all failed to take any further heed of these unusual symptoms.
Flashes that cannot be attributed to posterior vitreous detachment demand the raising of a red flag.