Digital Retinal Imaging
Digital Retinal Images help the doctors at Midtown Optometry evaluate your eye health, screening for diseases such as diabetes, glaucoma and macular degeneration
Checking the eye pressure is an important yearly evaluation to screen for glaucoma.
What is Digital Retinal Imaging?
With the advent of digital photography, the optometrists and eye care specialists can use digital retinal cameras to produce amazing views of the inside of the eye.
Digital retinal imaging, DRI for short, is the act of taking a digital photograph of the inside of the eye including the retina, optic nerve, macula and blood vessels. This image is used to screen for eye diseases and can be used to compare to images taken in future examinations.
If a condition or disease is found, our doctors will repeat the test using a higher resolution for a higher quality test, called fundus photography. Routine digital retinal imaging is usually performed at a lower resolution for screening purposes and this serves as a baseline test.
Routine Vision Screening vs Comprehensive Medical Eye Examinations
Most routine examinations include a part of the examination where drops are use to dilate the pupil of the eye. With the pupil dilated, your doctor can look into your eye to look for signs of certain eye diseases, and to get a general idea of your overall eye health. However, it is difficult to see the entire retina and sometimes, due to a patient’s naturally small pupils or their level of cooperation, it is difficult for the optometrists and ophthalmologists to visualize everything he or she needs to see.
Digital retinal imaging provides a different way of viewing the retina that sometimes gives the doctor clues about certain eye conditions. Some of these subtle changes can be better seen by digital retinal imaging. Depending on the type of instrument used, digital retinal imaging provides a better view of the retinal periphery.
Does this test mean you don't have to have your eyes dilated, you may ask. No. Physically looking into the eye is still invaluable. However, using digital retinal imaging provides different types of information. Combining both allows the eye doctor to make a better health assessment.
Who Needs DRI Most?
Midtown Optometry’s doctors are more likely to recommend DRI if you suffer from the following diseases or conditions:
Diabetes: Diabetes damages the blood vessels in your retina. Over time, diabetes will cause the loss of sight if it is not treated and managed properly.
Macular degeneration: The central part of your retina (known as the macula) naturally deteriorates with age, leading to have blurry vision and difficulty shifting the focus of your vision. When that happens, you may be considered legally blind even though you may still have peripheral vision. There are two kinds of macular degeneration: wet and dry. Wet macular degeneration is caused by abnormal blood vessel growth under the retina and often leads to rapid vision loss. Retinal imaging is very important in finding and treating this type of macular degeneration.
Glaucoma: Glaucoma damages your optic nerve and may cause vision loss. It typically happens when fluid builds up in the front of your eye. It can cause blindness but it normally progresses slowly and can be treated with special eye drops to lower the pressure caused by the fluid.
Retinal Toxicity: Certain pharmaceuticals, such as the arthritis drug hydroxychloroquine (Plaquenil) can damage your retina.
Our doctors may also recommend digital retinal imaging if your vision is getting worse without any clear causes.
How Does DRI Work?
Before the test, your doctor may dilate your eyes with special drops to widen your pupils if they are naturally very small. It takes about 20 minutes for your eyes to be ready for the examination.
During the test, you place your chin and forehead on a support to keep your head steady. Your doctor will instruct you to open your eyes as wide as possible and stare straight ahead at an object while a laser scans your eyes. The images are uploaded to a computer so your doctor can look at them.
If the test show that you might have wet macular degeneration, your doctor will then perform a fluorescein angiogram. For this test, she’ll place an IV needle in a vein in your arm and inject a dye, which will travel through your bloodstream and eventually reach your eyes. When this dye enters your eye, it highlights the blood vessels so pictures can be taken.
The regular test takes 5 minutes. The fluorescein angiogram takes about 30 minutes.
What Happens After the Test?
If you’ve had your eyes dilated, your vision will be blurry for around 4 hours. Your eyes will also be very sensitive to sunlight, too. During this 4 hour period, you will need to wear sunglasses to protect your eyes, and should not attempt to drive.
If fluorescein dye was used, do not put soft contact lenses in your eyes for at least 4 hours so they don’t get stained by the dye.
The images from the test should be ready immediately and normally your doctor will talk to you about them before you leave.
What Are the Benefits and Drawbacks?
Retinal imaging allows eye doctors to see signs of eye diseases that they couldn’t see before. The test itself is painless and the results are easy for doctors to interpret. Your doctor can store the images on a computer and compare them with other scans.
Retinal imaging has its limitations. It can’t detect a disease where the retina is bleeding. It also may not see problems on the outer edges of your retina.
Retinal imaging may be covered by your medical insurance (not your vision insurance) or Medicare. It depends on the terms of your insurance policy, as well as the reason you are having the test done.