The Normal Retina
The eye is similar to a camera. Light enters through the front and is focused onto a film in the back. Images enters the eye through the cornea and then further focused by the lens onto the retina. The retina is a thin film that covers the back of the eye. It is responsible for organizing the visual input and then transmitting it to the brain via the optic nerve.
The tip of the optic nerve, seen inside the eye is called the optic disc. The major blood vessels to the retina (Central retinal artery and vein) come out of the optic disc and then branch out. These blood vessels are the main source of nutrients and oxygen to the retina, although a segment of the retina receives its nutrients from the layer below it (the choroid). The part of the retina responsible for a persons best and central vision is called the macula. In the very center of the macula is the fovea which is responsible for ones most fine central vision.
The macula is the part of the retina responsible for a person's best and central vision. In the very center of the macula is the fovea which is responsible for ones most fine central vision.
The macula may be damaged in many disorders including: Age-relted Macular Degeneration (AMD), Diabetic Retinopathy, Central Serous Retinopathy (CSR), Macular Pucker, Branch and Central Retinal Vein and Artery Occlusions. These topics are discussed under their sub-headings.
The vitreous is the clear gelly that fills the center of the eyeball. It is made of water and protein with the consistency of egg white. As we age, the protein structure breaks down and clumps of protein are seen as "floaters."
The vitreous may degenerate to the point where it separates from the eye wall. This is called a Posterior Vitreous Detachment (PVD). A PVD usually does not cause any problems. However, sometimes as the vitreous separates from the retina it may tug and cause a tear. This tugging on the retina causes flashes of light to be seen. Seeing flashes of light does not mean that one has a retinal tear, but it is a worrisome sign. If a retinal tear is detected early it can be treated with laser in the office. However, a tear may progress to retinal detachment at which point more extensive treatment is needed.
Whenever one sees a sudden onset of floater with or without flashes, an eye examination should be sought to rule out a retinal tear.