Retinal imaging and scans
Optometrists and ophthalmologists have several forms of retinal imaging at their disposal. Each plays a slightly different role in maintaining the health of your retina — the thin layer of tissue in the back of your eye that is essential for good vision.
What can a retinal screening detect?
Some forms of retinal exam are better at detecting certain diseases than others. Your eye doctor will decide which test(s) to perform depending on any risk factors and/or symptoms you may have.
In addition to monitoring the overall health of your eyes, a retinal exam can be used to detect the early signs of some conditions, including:
Diabetic retinopathy (a complication of diabetes)
Hypertensive retinopathy (a complication of high blood pressure)
Cancers of the eye
Digital retinal imaging
If you’ve had an eye exam recently, there’s a good chance you’ve seen a digital retinal scan machine. This quick and affordable form of retinal screening is becoming a staple in eye doctors’ offices across the United States.
These retinal imaging devices use special technology to photograph an ultra-wide view of the inside of your eye in a single image. Included in the image are a detailed view of the retina, optic nerve and retinal blood vessels, all of which can show signs underlying eye conditions. The process is quick and painless, and doesn’t have any side effects.
In the past, an eye doctor would need to use special eye drops to dilate (enlarge) your pupils to get a wider view of the back of your eye.
In many cases, digital retinal imaging lets you bypass pupil dilation.
While dilation is still a common procedure, digital retina screenings offer an alternative without the extreme light sensitivity and blurry vision that can follow pupil dilation for several hours. They also offer a wider field of view — about four to five times that provided by standard viewing instruments that require a dilated pupil.
One of the most common retinal screening devices is Optos’ optomap, which offers a 200-degree view of the retina.
Some eye care professionals bundle digital retinal imaging into the overall fee for a comprehensive eye exam, but it’s more likely to be billed separately. In our nationwide eye exam cost survey, we found that eye doctors charged an average of $33 for a digital retinal test.
Other forms of retinal exams
There are many ways an eye doctor can examine your retina. While basic digital imaging is used for the everyday patient, other retinal tests are more specialized for diagnosing and monitoring specific eye conditions.
These tests are usually performed by an ophthalmologist, or more specifically, a retinal specialist. They may include:
Ocular ultrasound. Ultrasounds use “silent” sound waves to get a real-time view of the inside of your eye. They can be particularly useful when there is bleeding inside the eye, which can make it difficult for an eye doctor to spot the signs of retinal detachment, retinal tears or other retinal conditions. Two different scans — an “A-scan” and “B-scan” — can be used to get different information about the retina and other tissues inside the eye.
Fundus photographs. Fundus photos are similar to digital retinal images, but they usually require pupil dilation beforehand. They also capture a smaller amount of surface area inside the eye. The images are usually used to compare the progression of an eye disorder over time.
Fluorescein angiography. This is a test that involves injecting dye into the bloodstream then taking pictures of the inner eye. It is usually used to monitor the retinal effects of diabetes, hypertension or macular degeneration. Be careful not to confuse a fluorescein angiography with a fluorescein stain test, which is a way of detecting a scratched cornea or other issues on the front surface of the eye.
Schedule an appointment with your eye doctor
Having an eye doctor regularly examine your retinas, either with a digital imaging device or during a comprehensive eye exam with pupil dilation, ensures any retinal conditions are diagnosed and treated as early as possible.
Contact your eye doctor for more information about which retinal screening options are available for you.
Page updated October 2020