There are some diagnostic imaging devices available that go even further than a comprehensive eye exam to help optometrists to judge the overall health of your eyes. These advanced technologies help eye doctors detect problems before they become untreatable.
Digital Mapping – Corneal Topography
The cornea, the outer structure of the eye, is normally responsible for some 70 percent of the eye’s refractive power, so the shape of the cornea is critical in determining the quality and clarity of your vision. Corneal topography is a non-invasive medical imaging technique for mapping the surface curvature of the cornea, the outer structure of the eye, using a grid of thousands of data points covering the entire cornea. The procedure takes only seconds and is completely painless.
Digital mapping can assist in the diagnosis and treatment of a number of diseases, including keratoconus or pellucid marginal degeneration. This technology is also important for planning refractive surgery such as LASIK and evaluating its results or it can be used to assess the fit of contact lenses for astigmatism or orthokeratology.
Digital Retinal Imaging (OPTOMAP)
Digital retinal imaging captures an instantaneous digital scan of the retina to reveal important information about the health of the back of your eye, the retina. Confirming the health of the retina, optic nerve and other retinal structures is vital and is used as a baseline to track any changes in your eyes. Retinal images are stored electronically and will give your eye doctor a permanent record of the condition of your retina that can be compared year after year.
Many eye conditions, like glaucoma, diabetic retinopathy and macular degeneration, are diagnosed by detecting changes in your retina over time.
Optical Coherence Tomography (OCT Scan)
An Optical Coherence Tomography Scan (OCT scan) is the latest advancement in imaging technology. It’s similar to ultrasound but this diagnostic method uses light rather than sound waves to achieve higher resolution pictures of the structural layers of the back of the eye. An OCT scan can see areas behind the eye than can’t be seen with the naked eye. It is non-invasive, painless and can be performed in about ten minutes.
Similar to a CT scan of the brain, this technique uses a scanning laser to analyze the layers of the retina and optic nerve for any signs of disease. It works using a light without harmful radiation and is important for early diagnosis of glaucoma, macular degeneration and diabetic retinal disease.
Visual Field Test
A visual field test measures the range of your peripheral or “side” vision to see if you have any blind spots, loss of peripheral vision or visual field abnormalities. It’s a straightforward and painless test that can take from 2 to ten minutes.
A visual field test is performed on one eye at a time. One eye is covered and you place your chin on the chin rest. You must keep your gaze fixed on a central point of light while lights are flashed in your periphery. When you see a light, you press a button. The flashing lights vary in brightness and intensity throughout the test to determine the threshold of what you see and will be compared to other people in your age group. This test can create a computerized map of your visual field to screen for diseases or deficiencies like glaucoma, tumours or side effects from medications.
