What is OCT?
Optical Coherence Tomography (OCT) is a non-invasive imaging test that uses light waves to take cross-sectional pictures of your retina. This technology provides detailed images of the retina's layers, allowing doctors to measure thickness and identify abnormalities with remarkable precision.
How OCT Works
OCT technology is similar to ultrasound, but uses light instead of sound waves. It creates detailed cross-sectional images by measuring the echo time delay and intensity of light reflected from different retinal layers.
Light Source
Uses near-infrared light that's safe for the eye
High Resolution
Provides images with 1-15 micrometer resolution
Real-time Imaging
Captures thousands of images in seconds
Common Conditions Diagnosed
- Age-related macular degeneration
- Diabetic retinopathy and macular edema
- Macular holes and epiretinal membranes
- Retinal detachment
- Central serous chorioretinopathy
- Glaucoma optic nerve damage
- Retinal vein/artery occlusions
- Inherited retinal diseases
Early Detection
OCT can detect retinal changes before they become visible to the naked eye, enabling earlier treatment and better outcomes.
What to Expect
Before the Test
- No special preparation required
- Pupil dilation may be used for better images
- Inform staff of any eye medications
- Test is completely painless
During the Test
- Sit comfortably at the OCT machine
- Rest your chin and forehead on supports
- Look at a fixation target
- Machine takes images automatically (2-10 minutes)
- May need to hold still briefly during scans
After the Test
- Results available immediately
- No recovery time needed
- Normal activities can be resumed
- If dilated, vision may be blurry for hours
Types of OCT Scans
Macular OCT
Detailed images of central retina and macula
Optic Nerve OCT
Measures optic nerve thickness for glaucoma
OCT Angiography
Shows blood flow without contrast injection
Wide-field OCT
Captures larger retinal areas in single scan
Advantages of OCT
Non-invasive
- No injections required
- No contact with the eye
- Completely painless
- Safe for repeated testing
High Precision
- Micrometer-level resolution
- Quantitative measurements
- Reproducible results
- Objective documentation
Clinical Value
- Early disease detection
- Treatment monitoring
- Progression tracking
- Guides therapeutic decisions
Understanding Your OCT Results
Normal Results
- Smooth, intact retinal layers
- Normal retinal thickness measurements
- No fluid accumulation
- Healthy optic nerve appearance
- Clear visualization of all retinal structures
Abnormal Findings
- Retinal thickening or thinning
- Fluid between retinal layers
- Breaks or holes in retinal tissue
- Scar tissue or membranes
- Changes in retinal blood vessels
Follow-up Testing
OCT is often repeated during follow-up visits to monitor treatment response and disease progression. Comparison with previous scans helps track changes over time.
Test Limitations
Image Quality Factors
- Cataracts may reduce image clarity
- Excessive eye movement affects results
- Severe vitreous hemorrhage blocks visualization
- Very dry eyes may impact image quality
Complementary Tests
- May need fluorescein angiography for blood vessels
- Clinical examination remains essential
- Other imaging may be required
- Visual field testing for functional assessment
Frequently Asked Questions
Is OCT safe?
OCT is completely safe and non-invasive. It uses low-power light that doesn't harm your eyes and can be repeated as often as needed for monitoring.
How long does the test take?
The actual OCT scan takes 2-10 minutes per eye. Additional time may be needed for pupil dilation if required for your specific condition.
Will I need to prepare for the test?
No special preparation is needed. However, if your pupils need to be dilated, you may want to bring sunglasses and arrange for someone to drive you home.
How often will I need OCT testing?
The frequency depends on your condition and treatment. Some patients need monthly OCT monitoring during active treatment, while others may need it annually.
Questions About OCT Testing?
Our team will explain your OCT results and how they guide your treatment plan.
Schedule an Appointment