Digital diagnostic imaging assists our optometrists in early detection of eye health problems including macular degeneration, retinopathy caused from diabetes and high blood pressure, optic nerve diseases like glaucoma, and much more.
Your retina is like the film of a camera; it captures light rays, processing them into light impulses through millions of tiny nerves, and then sends these light impulses to the optic nerve. Retinal photos allow us to capture an image of your retina at your examination so a complete ocular health history can be kept on file. Your photos can then be compared year-to-year to establish if there is any relative change in your eye health between visits. This will allow our optometrists to see very subtle changes that they may not have been otherwise able to detect. We strongly recommend that all of our adult patients have retinal photos taken at every visit. It is especially important for those patients who have a personal or family history of macular degeneration, glaucoma, high blood pressure, diabetes, retinal problems, floaters, or poor vision.
A visual field test is a test of your side or peripheral vision. This test is often done for patients who have a family history or are at risk of having glaucoma or certain health concerns like history of stroke or multiple sclerosis, for example. Less often we will also conduct the test for those with macular degeneration or for those who are being tested for their driver’s licence, for example. The test requires you to push a button every time you see flashes of light in your side vision, regardless of how bright they are. The test is looking to measure the dimmest light you can possibly see in different areas of your peripheral or side vision. A visual field test is often done annually for those who are glaucoma suspects or who have glaucoma, however your doctor will recommend a frequency of testing which is appropriate for you. Visual field test reliability largely relies on the patient’s responses and performance. OHIP covers visual field tests for those under age 20 or over 65, and for those patients who otherwise are covered under OHIP for their eye examinations.
Optical Coherence Tomography (OCT) is used to help in the detection of vision threatening conditions like glaucoma and macular degeneration. The OCT takes a detailed cross-sectional high definition image of your retinal tissue, giving a more detailed picture of your eye health beyond what we can see in a routine eye examination. It's like looking at a slice of a layered cake: your optometrist can see the "icing" or top layer of the retina through their examination techniques but the OCT shows the layers underneath. For example, while retinal photos capture a surface shot of the back of the eye the OCT reveals in-depth images of the eyes’ internal structures. Many eye conditions in early stages can start out symptom-free; the OCT detects these early changes in eye health. Your optometrist will recommend an OCT based on your eye examination findings, your family history of eye disease or simply as a baseline scan. The scan only takes a few seconds; you simply look into the machine and the scan is performed. We may need to use eye drops to make your pupils larger to take the scan. An OCT is often done in conjunction with a visual field test as in the case of glaucoma testing. After the OCT your optometrist will interpret the results along with your other examination findings.
Your optometrist will check for changes in eye health that need to be monitored carefully or that need to be referred to a specialist for treatment. Please ask your optometrist if you wonder why a procedure is recommended for you.