Digital Retinal Imaging
Digital Imaging can assist in the early detection of ocular problems including central retinal diseases, central detachments, holes, thinning, optic nerve disease, pre-cancerous lesions, macular degeneration, hypertensive retinopathy and diabetic retinopathy.
This type of testing also allows us to store these images to compare with the results of future tests, so that a complete ocular health history can be generated. This will allow us to see minute changes that we may not have been able to identify without these tests.
We strongly recommend that ALL of our adult patients receive this test. It is especially important for those patients who have a personal or family history of high blood pressure, diabetes, retinal problems, headaches, floaters, flashing light streaks, a strong prescription for glasses, diminishing vision, macular degeneration, cataracts or are taking certain medications.
Optical Coherence Tomography (OCT)
OCT is a non-invasive, high-resolution technology used to image the retina, the multi-layered sensory tissue lining the back of the eye. OCT scans produce real-time cross-sectional images of the retinal layers and it is revolutionizing the early detection and treatment of eye conditions such as age-related macular degeneration, diabetic macular edema, epiretinal membranes, and macular holes.
Similar to CT scans of internal organs, OCT uses the optical backscattering of light rays to rapidly scan the eye and describe a pixel representation of the anatomic layers within the retina. Each of these ten important layers can be differentiated and their thickness can be measured. OCT produces extremely high resolution images – 10 times greater than MRI or ultrasound. No radiation or x-rays are used and the scan is quick and painless.
OCT is also useful for the detection and management of glaucoma: a progressive disease of the optic nerve. The OCT will scan the nerve fibre layer of the optic nerve allowing for more accurate measurements and analysis of change over time. This data will help your Optometrist determine when treatment of glaucoma is necessary and, if you are already on treatment, whether your prescribed treatment is adequately controlling the disease. This test will most likely need to be repeated on a regular basis.
During a routine eye exam, some eye doctors may want to determine through visual field testing the full horizontal and vertical range of what you are able to see peripherally. This is commonly referred to as “side vision.” Visual field tests assess the potential presence of blind spots (scotomas), which could indicate eye diseases.
Many eye and brain disorders can cause visual field abnormalities. For example, optic nerve damage caused by glaucoma creates a very specific visual field defect. Other vision problems associated with blind spots developing within the visual field include: optic nerve damage (optic neuropathy) from disease or toxic exposure or damage to the light-sensitive inner lining of the eye (retina).
Various forms of automated perimetry measure your responses to the presence of objects in different areas of your field of view. While your head is still, you will be asked to stare (fixate) on a source of light straight ahead. A series of random lights of different intensities are flashed in your peripheral field of vision. You then press a button to indicate your response, when you perceive the computer-generated light appears in your field of view. If you are unable to see the objects in an appropriate portion of your field of view, then you may have a blind spot indicating vision loss.
Pachymetry is an ultrasonic measurement of an individual’s corneal thickness. This is a useful auxillary test to help your Optometrist determine your risk of developing glaucoma. It is also used to determine one’s candidacy for laser corrective surgery and to monitor corneal disease.