Diagnostic & Technology
Fundus photographs are images of the back of the eye. Your doctor may take fundus photographs of your eye to make sure your optic nerve, vitreous (the gel that fills the eye), retina, macula (center of the retina) and blood vessels are healthy.
First, your pupils will be dilated with eye drops. Then you’ll look into the special fundus camera. You’ll see a series of bright flashes as the camera takes highly magnified and detailed images of your eye. The whole procedure is painless and takes only 5-10 minutes. The photographs may be compared to earlier images taken of your eyes or filed away for future comparison.
- Color Using a digital fundus camera, images of your eye are taken in color rather than black and white. This can provide your doctor with additional information and documentation of the retina’s appearance.
- Infrared (IR) Using infrared light instead of typical white light can provide more distinct images of certain portions of the eye. This can be particularly beneficial in patients with developed cataracts.
- Red-Free (RF) Red-free photographs filter out the red light and offer a high-contrast image of the vascular system of the eye.
- Autofluorescence (AF) Fundus autofluorescence allows for imaging of the retina and identification of retinal diseases that might not be readily apparent. It can determine metabolic changes within the deep retina that are not able to be seen during a routine examination. This approach can be especially helpful to analyze patients with vision loss of undetermined origins or those with a family history of hereditary retinal diseases.
Fluorescein angiography is a diagnostic test used to evaluate the retina and the retinal blood vessels with the help of a contrast dye (fluorescein). These pictures help doctors evaluate the retina and diagnose and track problems such as diabetic retinopathy, macular degeneration, abnormal blood vessel growth, retinal swelling, retinal detachment, cancer and retinal tumors.
First, the patient’s pupils are dilated with eye drops. Then a few photographs are taken with a special ophthalmic camera. Next, the contrast dye is injected, usually in the patient’s arm. The dye travels up to the eye within a few seconds and “lights up” the retinal blood vessels and retinal structures. This test only takes a few minutes to perform.
- Indocyanine Green Angiography (ICG) is another method for visualizing retinal circulation. In contrast to fluorescein angiography, ICG is of particular value in studying choroidal circulation while investigating retinal disease.
Optical Coherence Tomography
Optical coherence tomography (OCT) is an advanced technology used to produce cross-sectional images of the retina. These images can help with the detection and treatment of serious eye conditions such as macular holes, macular swelling and optic nerve damage.
OCT uses technology that is similar to CT scans of internal organs, using a scattering of light to rapidly scan the eye to create an accurate cross-section. Unlike other imaging techniques, OCT uses light to produce high resolution images, rather than sound or radiofrequency waves. Your doctor can evaluate and measure each layer of the retina through this image and compare it with normal, healthy images of the retina.
The OCT exam is performed in your doctor’s office, and usually requires dilation of the pupils for the best results.
B-scan is an advanced ocular ultrasound that produces cross-sectional images of the eye. This enables eye care professionals to accurately diagnose a wide range of eye conditions. B-scan utilizes a formulaic combination of sound wave absorption and reflection, angle of incidence and probe positioning to provide professionals and patients alike with accurate results.
B-scan uses advanced technology that allows images of the eye to be obtained from all patients, even those with eye conditions that typically obscure ocular ultrasound. Thanks to its accuracy, B-scan imaging allows eye care professionals to precisely determine the severity of the patient’s condition, ensuring that patients receive the care they need.
Perimetry/Visual Field Analysis
Perimetry, or visual field analysis, is another method of evaluating a patient’s visual function. This is a way to measure a person’s visual field, or exactly what amount of space that person can see when they hold a fixed gaze in a particular direction. There are several types of testing used for visual field analysis. Some of these are performed manually by a trained professional, and others are automated with the assistance of a computer. All of these methods can be effectively used to diagnose limitations within the visual field.