What is Optical coherence tomography angiography or OCT-A?
Optical coherence tomography angiography, or OCT-A is a non-invasive 3D imaging technique used to document the vasculature and avascular structures within the layers of the retina.
The OCT-A technique is similar to Optical coherence tomography, although it differs as the OCT-A scan has the ability to capture thousands of sequential cross- sectional horizontal and vertical scans in moments. The OCT-A scans measure the volumetric movement of blood flow within the retina and choroid. Blood flow from the retina’s superficial vessels as well as the deeper vasculature structure is imaged, alongside the choroidal vasculature flow.
The choroid is the layer that lies beneath the retina and it brings blood flow/oxygen to the retina. Earlier imaging systems were not able to visualize the choroid as it was too deep in the eye. The OCT-A scanner can now image the choroidal vessels to better predict if there is a concern for the choroidal vessels to penetrate into the retina due to pathology such as macular degeneration and macular telangiectasia.
OCT-A scans produce 3D and enface images that can be visualized for an even deeper view into the retina to seek out future possible problematic neovascular membranes that other diagnostic tests cannot yet detect. Retina Associates of Greater Philadelphia has the most advanced technology with eye tracking capabilities. The eye tracking feature has retinal recognition technology. The system can identify each patient’s retina with incredible accuracy to guarantee all comparison measurements are obtained within one micron with optimized clarity in every scan. This clarity safeguards that no subtle changes are overlooked as well as ensures treatment options for each patient are planned with precision.
Some of the possible retinal disorders the retinal specialists may be able to better diagnose and treat utilizing the OCT-A are:
- Branch retinal vein occlusion (BRVO)
- Central retinal vein occlusion (CRVO)
- Central serous retinopathy (CSR)
- Diabetic retinopathy
- Macular degeneration (AMD)
- Macular telangiectasia
What can I expect during an OCT-A test?
An OCT-A test is done in the office. After the eyes are dilated, the patient will be positioned in front of the camera with their chin resting in the chin rest. The patient will be asked to follow a fixation light either inside or outside of the scanner. The scan utilizes a safe, infrared light and most often blinking is allowed. The machine does not touch the eye and the test is completed in minutes.