Optical Coherence Tomography (Retina Imaging) Diagnostic Imaging

Optical coherence tomography (OCT) is a noninvasive imaging test that uses light waves to create detailed cross‑section pictures of the retina, the light‑sensitive tissue at the back of the eye.

Optical Coherence Tomography (Retina Imaging) procedure illustration

Overview

Optical coherence tomography (OCT) is a noninvasive imaging test that uses light waves to create detailed cross‑section pictures of the retina, the light‑sensitive tissue at the back of the eye. It shows the layers of the retina and measures their thickness. Clinicians use OCT to help detect, diagnose, and monitor many retinal conditions. It helps track changes over time and evaluate how well treatments are working.

Overview Preparation Clinical Info Recovery FAQ References

Also known as: OCT, Retinal OCT, Macular OCT, OCT scan

Recovery
Same day
Return to Work
Same day

Preparation & Next Steps

Everything you need to know before and after your procedure

Before Care

  • Bring a photo ID, insurance card, and a list of your current eye drops and medicines
  • Plan a little extra time in case your pupils are dilated for the exam
  • Bring sunglasses; bright lights and dilation can increase glare
  • Ask the clinic whether contact lenses should be removed for the scan
  • Avoid heavy eye makeup that could interfere with the camera alignment
  • Have recent eye test records or prior OCT reports available if you have them
  • Let staff know about medication or drop sensitivities, especially to dilating drops
  • Consider arranging a ride if you prefer not to drive with dilated pupils

After Care

  • Expect possible light sensitivity and blurry near vision for a few hours if dilated
  • Use sunglasses outdoors until brightness and glare improve
  • Review the results summary and images with your eye care team or in your portal
  • Follow the monitoring plan your clinic outlines for future scans or visits
  • Report new or worsening vision changes to your clinic
  • Keep copies of your OCT reports or download them from the patient portal
  • If images were repeated due to blinking or motion, this is common and not harmful
  • Ask how OCT findings relate to any treatments you are receiving

Clinical Information

Important medical details about this procedure

Indications

  • Age‑related macular degeneration (AMD)
  • Diabetic retinopathy and diabetic macular edema
  • Macular hole or epiretinal membrane
  • Central serous chorioretinopathy
  • Retinal vein occlusion
  • Vitreomacular traction
  • Evaluation of retinal detachment or fluid
  • Glaucoma optic nerve and retinal nerve fiber layer assessment

Alternatives

  • Dilated eye exam with slit‑lamp and indirect ophthalmoscopy
  • Color fundus photography (retinal photos)
  • Fluorescein angiography
  • Indocyanine green angiography
  • Ocular ultrasound (B‑scan) when media are cloudy
  • Visual field testing for glaucoma monitoring

Risks

  • Temporary light sensitivity or blurry vision if pupils are dilated
  • Discomfort from bright lights during imaging
  • Rare irritation or allergy to dilation drops
  • Motion or blinking can reduce image quality and may require repeat scans
  • Privacy risks if images are shared on unsecured devices

Contraindications

  • Known allergy or sensitivity to pupil dilation drops when dilation is planned
  • Risk of acute angle‑closure with dilation in people with narrow angles
  • Inability to fixate or sit still long enough for imaging
  • Active eye infection where clinic protocols limit imaging

Recovery Timeline

What to expect during your recovery

Most people resume normal activities right away. If pupils were dilated, light sensitivity and blurry near vision can last several hours.

Typical Range

Same day

Return to Work

Same day

Recovery Milestones

Day 0

Resume normal daily activities after the scan

Day 0–1

Use sunglasses and limit detailed close work if dilation causes blur or glare

Day 0–1

Review results and any next steps with the clinic

Frequently Asked Questions

Common questions and expert answers about this procedure

What is OCT and how does it work?

OCT uses light waves to take cross‑section pictures of the retina. It is noncontact and does not use radiation.

Does OCT hurt?

No. You place your chin on a rest and look at a target light. Bright lights may be briefly uncomfortable, but the test is painless.

Will my eyes be dilated for OCT?

Some clinics dilate pupils to improve image quality, especially with small pupils or cataracts. Many scans are possible without dilation.

How long does the test take?

The scan itself usually takes a few minutes. With check‑in and possible dilation, the visit may take longer.

How is OCT different from a retinal photo?

Retinal photos show surface images. OCT shows detailed cross‑sections of the retina and measures layer thickness.

Is OCT safe during pregnancy?

OCT uses light, not X‑rays or dye. Safety questions about dilation drops should be discussed with the clinic.

How often is OCT repeated?

Frequency varies by condition. It is often repeated to monitor disease changes and treatment response.

When will I get results?

Images are available immediately, and many clinicians review them with you the same day.