Diagnostic Testing of the Retina
Dilated Eye Exam:
Chances are if you are going into see an Ophthalmologist, especially a retina specialist, for anything that requires them looking into the back of your eye; they are going to conduct an eye exam with your eyes dilated. Dilation provides them with more light into the back of your eye and thus an overall better view of the retina or area at the back of the eye.
This test is simple and painless. After the dilating eye drops are placed in your eyes, it takes about 20-30 minutes for your pupils to fully dilate. After the pupils are full dilated, the effects can last a few to several hours; every body reacts differently. It’s recommended that you bring your sunglasses, as your eyes will be sensitive to light – and ask a friend to drive you home.
The eye doctor will be looking into the back of the eye with special magnifying lenses. Looking for abnormal retinal blood vessels, signs of poor circulation, scar tissue, and any swelling – signs that, if you have diabetes could mean retinal disease.
While one of the most basic of tests, this relatively easy, inexpensive tool can often be an important first line of defense in detecting early problems with the retina, while they are still preventable. Ideally, the Amsler grid should be placed in a location which can enable its daily use. It’s easy to remember to look at the grid, when it’s placed on the refrigerator or bathroom mirror.
The grid consist of a pater of vertical and horizontal lines with a dot in the center. You should test each eye separately, covering the other eye. Your glasses should be worn if they are normally needed for reading by holding or placing the grid about 18-inches from your face. You should look only at the center dot, and while doing this notice if whether all of the lines are present.
Look for any areas where the lines are wavy or distorted. Any areas where the grid is missing, wavy, distorted, and/or significantly different from your baseline, should be reported to your eye doctor immediately.
Optical Coherence Tomography (OCT):
An OCT is a quick and painless diagnostic test that delivers high quality images and important technical measurements of each distinct layer of the retina. Reviewed by the ophthalmologist during your visit; this information allows them to diagnose and provides treatment guidance for retinal diseases including age related macular degeneration, diabetic eye disease. The OCT also allows the doctor to evaluate and detect possible changes of the optic nerve caused by glaucoma.
The fundus is the inside, back surface of your eye, including the retina and blood vessels. The retina specialist might ask for fundus photos, which are very detailed pictures of the back of your eye, taken with a special camera. These photos will help detect problems with that part of the eye and also show any changes that might occur over time. While the flash from the camera can be bright, the test is not painful.
Fluorescein Angiography (FA):
Fluorescein Angiography (FA) is a diagnostic test in which a small amount of yellow, vegetable-based contrast (dye) is injected into a peripheral vein; usually in the arm or the hand. This dye travels through the blood vessels and lights up the retina’s detailed vascular network. A technician then takes a series of digital photographs of the eye using a special camera. These photographs help your ophthalmologist identify and locate any leaking blood vessels, determine the amount of leakage, and detect any other abnormalities in the eye. The results permit them to develop a specific treatment plan as well as track changes in eye disease over time.
Risks of Eye Angiography?
Oregon Trail eye uses a vegetable based contrast dye. The contrast used to perform an FA is generally safe and can be used on patients who have shellfish or iodine allergies as well as those who have previously experienced a negative reaction to contrast dye used in radiologic procedures. In very rare cases, a patient may experience an allergic reaction. Our staff will carefully monitor you throughout the test for any adverse reaction and provide appropriate treatment as necessary.
What to Expect
At Oregon Trail Eye Center, fluorescein angiography (FA) is performed in our office and usually takes about 30 minutes.
First, we will place drops in your eyes to dilate your pupils.
Then the fluorescein dye is injected into a vein, usually in your arm or hand.
It takes about 10-15 seconds for the dye to travel through your body to your eyes, and then the technician will digitally take the pictures using a specialized camera.
After the Fluorescein Angiography
Immediately after the test, objects may appear dark or tinted, but this goes away within a few minutes.
You should bring sunglasses to wear home as your eyes will be dilated.
We also recommend that you have someone drive you home after your exam.
Your urine may appear yellow, orange or green for a day or two after the test. This is normal and will clear up on its own.
In addition, your skin may look slightly yellow for a few hours but will also return to normal.