An ophthalmoscopy is a test that examines the back part of the eye, called the fundus. The fundus includes the retina, which contains the nerve cells that sense light and images. It also includes nerves, blood vessels and connective tissue. This test usually occurs as part of a standard eye exam, and it uses bright light and special instruments to look through the pupil to the back of the eye. An ophthalmoscopy usually is performed by an optometrist or an ophthalmologist in his or her office.
Some of the problems that can be found during an ophthalmoscopy are macular degeneration, glaucoma and retinal detachment. It can also be used if patients show signs and symptoms of health issues that affect blood vessels, such as high blood pressure or diabetes. In a normal outcome of an ophthalmoscopy, the fundus, including the retina, appears normal and healthy.
There are two commonly used types of ophthalmoscopy. The first type is called a direct ophthalmoscopy. In this type, the patient sits in a dark room, and his or her eyes might be dilated using eye drops, but dilation isn't required. The doctor will shine a bright light into the patient's eyes and look at the back of the eye through an ophthalmoscope, a tool that is about as large as a small flashlight and has several lenses are able to magnify the view up to 15 times. Each eye is checked separately, and the entire test takes three to five minutes.
The second type is called an indirect ophthalmoscopy, with provides a wider view of the fundus, with more detail, and takes about five to 10 minutes. For this test, the patient either lies down or sits tilting backward, and his or her eyes have to be dilated. The doctor will hold the patient's eye open, will shine an intensely bright light into the patient's eye from a headlamp the doctor is wearing and will look at the fundus using a handheld lens. The doctor might use a dull instrument to press through the skin and put pressure on different areas of the eye in order to bring parts of the fundus, such as the edges, into view. The doctor also might ask the patient to look in various directions.
Ophthalmoscopy should not be painful; if it is painful, the patient should tell the doctor immediately. The procedure can be unpleasant, though. The lights that are used are very bright and can cause discomfort during the test. Many patients see spots or other shapes called after-images from the bright lights as well, especially because of the more intense light used for an indirect ophthalmoscopy.
In addition, the pressure used on the eye with the indirect test may be uncomfortable for some patients. If eye drops are used, they might sting for a moment or two. The patient typically will be sensitive to light and have trouble focusing for a while after the test.
