4 Things to Know About OCT Tests

An OCT, or optical coherence tomographer, is a special instrument that is frequently used by eye doctors. This instrument allows a laser to perform a cross-section scan of the retina or optic nerve in the back of the eye. The precise measurements that are provided by this instrument allow better diagnosis, management, and treatment of many eye conditions. Some of the most common uses of an OCT are to monitor the progression of glaucoma, evaluate for swelling or inflammation in the back of the eyes, and to check for changes to the macula from conditions like macular degeneration. Some eye doctors will even perform an OCT as a screening procedure on all patients to more thoroughly evaluate eye health. An OCT is also often used to rule out any pathology as a cause of reduced vision or prior to any eye surgery.
 

How an OCT Works

The basic principle of an OCT is similar to an ultrasound, but instead of using sound waves, an OCT uses light waves to produce a cross-section of the tissue.

An OCT will use infrared light waves to scan the retina or optic nerve and can then produce an image based on the reflection of the light that the instrument detects.

To have an OCT, a patient is seated in front of the instrument and places his or her chin in a chinrest, and will look toward an illuminated target.

There is no pain, no contact, and no known risks associated with this procedure. In some individuals with epilepsy or similar light sensitivity conditions, it may be relatively contraindicated.
 

OCT for Glaucoma

One of the biggest uses of an OCT in eye care is to manage and monitor glaucoma changes.

Glaucoma causes damage to the optic nerve and the nerve fibers in the retina which are unable to be visualized in early or mild stages.

Monitoring change with only a visual field analysis requires damage to become so severe that the vision is impacted.

An OCT offers a way to precisely and accurately measure the size of the optic nerve, the thickness of the nerve fiber layer, and any potential changes to either down to the micron.
 

OCT for Retinal Swelling

The biggest cause of vision loss from conditions such as diabetic retinopathy and retinal vein occlusions is swelling in the retina.

If the retina swells or is inflamed, it can result in permanently damaged retinal tissue with associated vision loss.

An OCT can show a cross-section of the retina and display if there are any fluid-filled pockets of swelling in the retina.

This can also be used to monitor the progression of swelling as the retina is treated with injections or steroids.
 

OCT for Macular Degeneration

The number one cause of blindness in elderly patients is macular degeneration. This condition can be better monitored for progression by using an OCT.

Traditionally, macular degeneration was solely monitored by observing changes in the retina and was only treated when there was a hemorrhage or break in the blood vessels.

Now with OCT, it is possible for early changes to be detected and treated at an early interval and provide a better prognosis.

Our eye doctor at Local Eyes Optometry in New Braunfels, TX excels in the prescription of glasses, contact lenses and the diagnosis of a variety of eye diseases. Call our optometrist at (830) 627-9272 or schedule an eye exam appointment online if you would like to learn more about OCT tests. Our eye doctor, Dr. Marcus Page, provides the highest quality optometry services and eye exams in New Braunfels, Texas.