Microcirculation without injected dye

Mapping blood flow in the smallest vessels.

Non-invasive imaging of blood flow within the retina and choroid without an injection of dye.

Method

Non-invasive

Injection

Not required

Information

Blood-flow mapping

Dr Sofia Zogana performs an OCT angiography examination

Eye examinations

OCT Angiography

What is OCTA?

A detailed view of blood flow, without intravenous dye.

OCT angiography records changes associated with blood flow in the small vessels of the retina and choroid.

It complements structural OCT and can provide information about vascular networks in selected conditions.

It is not a replacement for every form of angiography. A different examination may be required according to the clinical question.

i

No intravenous contrast injection is required. Image quality is affected by movement, steady fixation and any media opacity.

When it is used

A detailed view of the retinal microcirculation.

OCTA is selected when vascular information can answer a specific clinical question.

01 / MACULA

Central microcirculation

Macula

Assessment of vascular networks in conditions affecting central vision.

  • Neovascular age-related macular degeneration
  • Diabetic microvascular changes
  • Impaired macular perfusion
  • Retinal vascular occlusions

02 / FLOW

Selected indications

Vascular mapping

Complementary information for selected vascular conditions.

  • Retina
  • Choroid
  • Selected optic nerve conditions
  • Comparison with structural OCT

The process

Repeated scans without an injection of dye.

Image capture resembles conventional OCT but analyses differences associated with blood flow.

01

Positioning

The head is supported comfortably on the device.

02

Fixation

The gaze remains on a light target.

03

Flow scanning

The same area is scanned repeatedly to analyse changes.

04

Combined assessment

Findings are reviewed alongside OCT, fundus examination and other investigations.

Image limitations

Movement and unstable fixation may create artefacts, while very slow flow or leakage is not recorded in the same way.

Dr Sofia Zogana reviews OCTA imaging of the microcirculation

Personalised assessment

Clinical interpretation

Interpretation & limitations

Vascular mapping needs clinical context.

The doctor interprets the findings alongside structural OCT, fundus examination and the medical history.

01

Vascular network

Imaging of small vessels and the distribution of flow.

02

Without dye

Information is generated from repeated optical scans.

03

Complementary role

OCTA does not replace every other angiographic examination.

Artefacts and technical limitations can affect the image. Automated interpretation without ophthalmic assessment is not appropriate.

Frequently asked questions

Before your examination.

Concise answers about the process and preparation.

Is injected dye required?

No. OCTA does not require intravenous dye administration.

Is it the same as conventional OCT?

The process is similar, but OCTA analyses flow and complements structural OCT.

Does it replace every angiogram?

No. In some cases a different examination may be required according to the clinical question.

Vascular imaging

Is detailed mapping of the microcirculation required?

OCTA provides non-invasive vascular imaging without injected dye.

Medical information notice

This content is provided for general information and does not replace an ophthalmic examination, diagnosis or personalised medical advice.