OCT Eye Scan: What to Expect and What It Can Detect

If you have had a comprehensive eye exam at Trendsetter Eyewear, you have had an OCT scan. If you have not, you should know what you are missing — because OCT is the most significant advance in eye care technology in the past 30 years, and it detects conditions that can cause permanent vision loss before you have any idea something is wrong.

OCT detects glaucoma damage up to 5 years before it causes measurable vision loss — making it the most important screening tool in modern optometry. Your annual eye exam with OCT is not a formality; it is the earliest warning system available for the conditions most likely to steal your sight.

Optical Coherence Tomography (OCT) is a non-invasive imaging technology that uses light waves to produce detailed, cross-sectional images of the retina, optic nerve, and macula. Think of it as an ultrasound for the eye — but instead of sound waves, it uses near-infrared light, and instead of a blurry image, it produces a high-resolution cross-section that shows individual tissue layers.

OCT was developed in the early 1990s and has become the standard of care for diagnosing and monitoring a range of serious eye conditions. It is now included in every comprehensive eye exam at Trendsetter Eyewear.

Glaucoma is the leading cause of irreversible blindness worldwide. It damages the optic nerve, typically through elevated intraocular pressure, and causes progressive peripheral vision loss that is often not noticed until significant damage has occurred.

OCT measures the thickness of the retinal nerve fiber layer (RNFL) — the layer of nerve fibers that carries visual information from the retina to the optic nerve. Thinning of the RNFL is one of the earliest detectable signs of glaucoma, often appearing years before visual field loss is measurable on standard perimetry.

This means OCT can detect glaucoma at a stage when treatment can prevent vision loss — not after it has already occurred.

Age-related macular degeneration (AMD) is the leading cause of vision loss in adults over 50. It affects the macula — the central portion of the retina responsible for sharp, detailed vision.

OCT can detect the earliest structural changes of AMD, including drusen (deposits beneath the retinal pigment epithelium) and the fluid accumulation that characterizes wet AMD. Early detection allows treatment to begin before central vision is affected.

Diabetes affects the blood vessels of the retina, causing leakage, swelling, and eventually new vessel growth that can lead to severe vision loss. OCT detects diabetic macular edema — swelling of the central retina — with a sensitivity that far exceeds clinical examination alone.

A thin layer of fibrous tissue that grows on the surface of the macula, causing distortion and blurred central vision. OCT visualizes epiretinal membranes clearly and allows monitoring of their progression.

A small break in the macula that causes a central scotoma (blind spot). OCT is the definitive diagnostic tool for macular holes and is used to guide surgical planning.

Abnormal adhesion between the vitreous gel and the macula that can cause distortion and vision loss. OCT shows the vitreoretinal interface in detail, allowing assessment of traction and its effects on the macula.

No special preparation is required for a standard OCT scan. If dilation is planned as part of your comprehensive exam, the OCT is typically performed before dilation, as dilation can affect image quality in some instruments.

You will be seated in front of the OCT instrument and asked to rest your chin on a chin rest and your forehead against a forehead bar. You will be asked to look at a fixation target — typically a small light or cross — inside the instrument.

The scan itself takes approximately 5–10 seconds per eye. You will see a brief flash of light. The instrument does not touch your eye. There is no discomfort.

Results are available immediately. Dr. Payne will review the OCT images with you during your exam, explaining what the images show and whether any findings require follow-up or monitoring.

Both OCT and fundus photography (retinal photography) are used in comprehensive eye exams, but they provide different information:

At Trendsetter Eyewear, we use OCT as part of every comprehensive exam because it provides information that fundus photography alone cannot.

Is OCT covered by insurance? OCT is typically covered as part of a comprehensive eye exam under vision insurance plans. If OCT is performed for a specific medical indication (monitoring glaucoma, diabetic retinopathy), it may be covered under medical insurance. Call us to discuss your specific plan.

Does OCT require dilation? Standard OCT does not require dilation. Some OCT instruments have a wide-field capability that benefits from dilation, but the standard macular and optic nerve scans are performed without drops.

How often should I have an OCT scan? For most patients, annual OCT as part of a comprehensive exam is appropriate. Patients with glaucoma, AMD, diabetes, or other conditions affecting the retina may need more frequent monitoring.

Can OCT detect cataracts? OCT is primarily used for retinal and optic nerve imaging. Cataracts are assessed during the slit-lamp examination portion of the comprehensive exam.

OCT retinal imaging is included in every comprehensive eye exam at Trendsetter Eyewear. Dr. Cynthia Payne has over 30 years of experience interpreting OCT findings and managing the conditions it detects.

Contact us online or call (702) 479-5222. We are located at 1225 S Fort Apache Rd #145, Summerlin, Las Vegas.

Related reading:

• Comprehensive eye exams at Trendsetter — everything included in your annual visit
• How often should you get an eye exam? — recommended frequency by age
• Eye exam without insurance in Las Vegas — cost and payment options
• Optometrist in Summerlin, Las Vegas — about our practice