From Dye to Digital: Why OCTA is Replacing Invasive Imaging in Retinal Care

For decades, clinicians have relied on invasive dye-based methods to map the eye’s vascular system. Between the injections and long waiting times, traditional OCT is beginning to show signs of ageing. Now, Optical Coherence Tomography Angiography (OCTA) is changing what’s possible in everyday practice. TowardPi’s ultra-widefield OCTA systems, including the BMizar and Yalkaid, are setting new standards in imaging speed, accuracy and patient comfort.  Already proven across Asia and Europe, these high-performance systems have now arrived in the UK, offering hospitals and clinics a safer and more efficient alternative to traditional fluorescence angiography.

What is OCTA? 

OCTA uses motion contrast to visualise blood flow in retinal and choroidal vessels, all without the need for fluorescent dye. With ultra-widefield capability, TowardPi’s BMizar system captures up to 120° images in a 7–15-second scan, providing a detailed, panoramic view of both the anterior and posterior segments. Compared to traditional OCT, OCTA delivers a far more complete picture, enabling you to visualise all the vessels within the eye simultaneously.  This includes the superficial and deep capillary plexuses, as well as a detailed analysis of the foveal avascular zone (FAZ), metrics that can indicate early diabetic or ischemic changes before fundus signs appear. This broader view is not just faster; it enables better, more informed treatment decisions at a much earlier stage.

What are the key benefits of OCTA?

No invasive fluorescein injections

Traditional fluorescein angiography can take up to 45 minutes (between risk assessments, consent forms, finding staff, etc.), keeping patients waiting and requiring a trained medical practitioner. However, with OCTA, no injection is needed. A simple scan performed by an ophthalmic photographer captures everything in under 30 seconds.

• No waiting time – Immediate results for faster diagnosis
• No injection risk – Eliminates dye-related complications
• No medical practitioner required – Reduces staffing pressure and improves patient flow

Faster, clearer imaging

Speed is one of the most significant advantages of TowardPi’s OCTA technology.  The BMizar delivers a scan in approximately 10 seconds per eye, capturing widefield, high-resolution images that can reveal even subtle vascular changes. Powerful eye tracking technology compensates for blinks, allowing patients to blink naturally during imaging without disrupting results, helping improve both comfort and image consistency.

Advanced support for retinal conditions

From diabetic retinopathy to retinal vein occlusion, OCTA is transforming early detection and management pathways.

• Diabetic retinopathy: OCTA detects new vessel growth as it occurs, visualising when new capillaries break into the retina, without the need for dye. It can also quantify deep capillary plexus perfusion loss and subtle changes in FAZ circularity, both early biomarkers of DR.
• Vein occlusions: Areas of retinal ischemia are clearly visible as patches where blood vessels are absent. With ultra-widefield OCTA, clinicians can see the entire vascular network in one view, revealing global ischaemia in a single capture and avoiding the limitations of manual scoping or narrow-field systems. Ultra-widefield OCTA makes it possible to visualise peripheral non-perfusion and subtle microvascular loss that narrow-field systems may miss, offering earlier insight into disease progression and more accurate staging.

Swept-source OCTA additionally provides information about choroidal vascular health changes that may precede retinal microvascular findings in diabetic or ischemic eye disease.

Enhanced patient comfort and uptake

For patients, OCTA is a completely non-invasive experience. There’s no injection, no discomfort and no recovery period. The quick 10-second scan per eye means a shorter appointment and less stress, especially for anxious or needle-phobic patients. The ease of the process can encourage more people to attend regular screenings, ultimately improving long-term outcomes.

Simple for staff to use

TowardPi’s systems are designed with usability in mind. After a brief 5–10-minute training session, staff can operate the device confidently. This simplicity makes the technology ideal for both specialist retinal clinics and general ophthalmic settings, helping teams integrate OCTA into daily workflows without disruption.

OCTA vs OCT 

While traditional OCT remains a valuable diagnostic tool, it cannot match OCTA’s ability to visualise the retinal vasculature in real time, across a wider field and without invasive procedures. The BMizar’s ultra-widefield scan and high-speed performance mean clinicians can detect microvascular changes earlier and with greater accuracy, helping to shape faster, more targeted treatment plans. Here’s an example: A type 2 diabetic patient who was diagnosed with AMD in both eyes and BRVO (after PRP) in the left eye complained of more severe vision loss recently. Ultra-wide-field (UWF) colour fundus images revealed abnormal yellow and white lesions at the macula in both eyes ( see fig.1 below) and panretinal laser spots in his left eye. A small area of intraretinal haemorrhage was also noticed in the superior nasal quadrant of his left eye (see fig.2 below). FFA of the right eye showed fluorescent leakage at the macula, while OCT angiography revealed CNV in the leakage area. OCT image of the corresponding area revealed PVD, macular atrophy, and PED, indicating the existence of CNV (fig.1). FFA of the left eye showed a non-perfusion area in the superotemporal quadrant with several microaneurysms and severe fluorescent leakage at the macula. No peripheral information could be achieved with the limited field of view of FFA. In contrast, UWF full-range OCTA revealed clearly the details of non-perfusion areas, microvascular abnormalities in the SVC slab, and neovascularisation in the vitreous slab (fig.2 circle). Ultra-wide B scan showed how the neovascularisation grew into the vitreous (fig.2 arrow). https://www.main-line.co.uk/wp-content/uploads/unnamed-10.png

Figure 1

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Figure 2

Is OCTA the future of ophthalmology?

Across Asia and Europe, TowardPi’s OCTA systems have already become a fixture in leading hospitals and imaging centres. As adoption grows in the UK, more clinicians are discovering the practical benefits of dye-free, high-speed imaging for both staff and patients.  OCTA data is also increasingly used in AI-driven research to automate risk grading and identify early biomarkers, enhancing diagnostic accuracy and workflow efficiency. With systems like BMizar and YALkaid, retinal diagnostics are moving decisively from dye to digital.

Experience TowardPi OCTA in your own clinic

To see the difference firsthand, call us on 0121 458 6800 or reach out to our team via [email protected]  to book your in-clinic demonstration.  We’ll bring the system to you so you can explore how TowardPi OCTA performs in a real clinical setting, and how it can make a difference in the lives of your patients.  References used in this article: A Novel Exploration of the Choroidal Vortex Vein System: Incidence and Characteristics of Posterior Vortex Veins in Healthy Eyes Advances in Structural and Functional Retinal Imaging and Biomarkers for Early Detection of Diabetic Retinopathy