Electroretinography
What is electroretinography?
Electroretinography is an eye test used to detect abnormal function of the retina (the light-detecting portion of the eye). During the test, an electrode is placed on the cornea (at the front of the eye) to measure the electrical responses to light of the cells that sense light in the retina at the back of the eye. These cells are called the rods and cones.
What is the difference between electroretinography and an ERG?
None. An electroretinography is an ERG.
How is an ERG done?
The person assumes a comfortable position (lying down or sitting up). Anesthetic drops are placed in the eyes, causing them to become numb. The eyelids are then propped open and an electrode is placed on each eye.
What do the electrodes do?
The electrodes measure the electrical activity of the retina in response to light. The information that comes from each electrode is transmitted to a monitor where it is displayed as two types of waves, labeled the A waves and B waves.
How are eletroretinography readings made?
Readings during eletroretinography are usually taken first in normal room light. The lights are then dimmed for 20 minutes and readings are again taken while a white light is shined into the eyes. The final readings are taken as a bright flash is directed toward the eyes.
Why is an ERG done?
An ERG is useful in evaluating both inherited (hereditary) and acquired disorders of the retina. An ERG can also be useful in determining if retinal surgery might be useful.
What is normal a normal outcome for an ERG?
A normal ERG shows a normal A- and B-wave pattern with appropriate increases in electrical activity with increased light intensities.
What does an abnormal ERG mean?
Decreased electroretinography values may indicate abnormal function of the retina as occurs with conditions such as arteriosclerosis (hardening of the arteries) involving the eye vessels, giant cell arteritis with eye involvement, metabolic diseases called mucopolysaccharidoses, detachment of the retina, siderosis(excess iron), and vitamin A deficiency.
Does the test hurt?
The test is painless. However, the electrode that rests on the eye may feel a little like an eyelash has lodged in the eye.
What are the risks of an ERG?
There are no risks specifically associated with an ERG.
How long does the ERG take?
The ERG takes about an hour.
How about after the test?
One should not rub the eyes for an hour after an ERG (or any test in which the cornea has been anesthestized), lest one injure the cornea.
How to Order | Price
List | Refill Orders |
Order Tracking
Home |
About Us | Contact
Us | FAQ
Buy cheap canadian prescriptions from a Canadian Internet Pharmacy leader.
cheap online pharmacy canadian pharmacy prescription drugs online discount medicine pharmacies
online mail order prescription medication canadian online pharmacy search for online drugs
canada pharmacies discount canadian medication drugstore Plavix Fosamax Lipitor Celebrex
Actonel Flomax Glucophage Premarin Prevacid Evista .
|
