Physiology & Mechanisms of a Detached Retina

The retina is a small piece of tissue within the eye. The physiology of the retina is a component of clear, normal vision. Various illnesses, injuries and natural factors can cause a retina to become detached. Symptoms of a detached retina, which involve some degree of impaired vision, constitute a medical emergency. A detached retina that is not treated quickly can result in permanent loss of vision.

Physiology

• The retina is a thin, transparent and light-sensitive tissue located in the back of the eye. The cornea and the lens of the eye send light to the retina, which in turn sends visual information through the optic nerve to the brain, where the information is processed. MedicineNet.com compares the retina to the film in a camera; however the retina can record multiple images. The central part of the retina is called the macula, and the light receptors in the in the retina are cells called rods and cones.

Detachment

• A detached retina is a retina that has become disconnected from the other tissue of the eye. According to MedicineNet.com, two-thirds of the inside of the eye is filled with a clear vitreous gel. If this gel for some reason becomes disconnected from the retina it can cause the retina to tear. A torn retina can allow the vitreous gel to collect in front of the retina and cause it to fully detach.

Factors

• According to Medline Plus, a retina can tear on its own without any external cause or injury. Trauma to the head or eye, complications of cataract surgery, "a family history of retinal detachment" and other eye disorders can cause retinal detachment, according to the National Eye Institute. Diabetes and severe myopia, or nearsightedness, may also cause a retina to become detached. Retinal detachment typically happens in only one eye; however, if the retina detaches from one eye the retina of the other eye may become detached later on.

Symptoms

• Symptoms of a detached retina include bright flashing lights in the peripheral vision, blurred vision, partial blindness, and "floaters" in the visual field. The vitreous gel of the eye pulling on or bumping the retina causes the flashing lights associated with a detached retina. "Floaters," which may appear as spots floating in the visual field are caused by condensed vitreous gel. Another symptom of a detached retina resembles a shadow over part of the visual field. The presence of such a shadow is cause for an immediate visit to an eye doctor.

Considerations

• According to Medline Plus, most cases of retinal detachment require surgery soon after symptoms appear. A detached retina can happen to people of all ages. According to the National Eye Institute, detached retinas are most common among Caucasian males over the age of 40.