Choroidal imaging examines the vascular layer between the retina and sclera that supplies oxygen and nutrients to outer retinal structures. It is important in many macular and inflammatory conditions.
Methods
Enhanced depth OCT and swept-source OCT allow measurement of choroidal thickness and visualisation of larger vessels, while indocyanine green angiography shows choroidal blood flow. OCT angiography can also map choriocapillaris perfusion.
- Non-invasive OCT-based methods are commonly used in clinic
- Thickness varies with age, refractive status, and systemic factors
- Angiography highlights areas of hyper- or hypoperfusion
- Quantitative analysis can track changes over time
Clinical Role
Choroidal imaging is valuable in conditions such as central serous chorioretinopathy, polypoidal choroidal vasculopathy, high myopia, and uveitis. It helps clarify disease mechanisms and guide treatment.
- Altered thickness or vascular patterns may indicate active disease
- Monitoring can show response to therapies targeting choroidal circulation
- Findings contribute to differential diagnosis between similar macular disorders
- Interpretation must consider normal physiological variability
