Flashes and Floaters
Flashes are often perceived as bright flashes of light in the peripheral vision. They are often noticed in the early evening. Patients may describe them looking like lightning flashes in the distance or a white arc of light in the peripheral vision of one eye.
Posterior Vitreous Detachment (PVD)
Floaters are often perceived as translucent grey shapes that move slowly in the visual field. Some patients describe floaters as appearing like little insects or a spider’s web in the vision. Flashes and floaters are often due to the vitreous jelly in the eye physically separating from the retina at the back of the eye. This is known as a Posterior Vitreous Detachment (PVD).
A PVD is a normal part of the ageing of the human eye, and typically occurs in people aged in their 50s. In younger people, the vitreous is a semi-solid gel like consistency. Through ageing it liquifies and eventually separates from the retina, resulting in the PVD. The flashes are from traction of the vitreous on the peripheral retinal photoreceptors.
A PVD can sometimes cause a tear or several tears in the retina. This is by mechanical traction pulling on the retina. Often this occurs in the periphery of the retina, and requires a thorough dilated retinal examination to detect. The picture to the right demonstrates a retinal tear (arrow) on ultrawide field imaging.
A retinal tear needs to be urgently assessed and treated. The main treatments are barrier retinal laser or freezing therapy (cryotherapy) to minimise the risk of a retinal detachment. Retinal laser can be performed in the rooms at Eye and Retina Specialists as an in-office procedure.
If not treated, fluid can enter through a retinal tear and underneath the retina, causing a retinal detachment. This can be seen sometimes as a black shadow moving across your vision that you cannot see through.
A retinal detachment is a serious surgical emergency, and can cause loss of vision (blindness), sometimes within a short time period. The image below demonstrates a large retinal detachment that resulted from an untreated retinal tear.