Published in Expert Review of Ophthalmology, a peer-reviewed study demonstrates that Novai’s Detection of Apoptosing Retinal Cells (DARC) imaging technology may help identify where macular atrophy (MA) will progress in patients with age-related macular degeneration (AMD). Baseline DARC measurements showed a stronger association with future atrophy expansion than three standard optical coherence tomography biomarkers.
Age-related macular degeneration is a leading cause of blindness and irreversible vision loss worldwide. In advanced dry-AMD, known as geographic atrophy or macular atrophy, patients experience the progressive loss of retinal cells responsible for central vision. Historically, clinicians have relied on conventional structural imaging to monitor these changes. Yet, standard imaging often fails to show structural damage until long after retinal cells have already become stressed and begun to die. This has limited the ability to identify patients at greatest risk of vision loss.
Evaluating DARC Against Standard OCT Biomarkers
The retrospective exploratory analysis evaluated 7 eyes from the Phase 2a DARC clinical trial (ISRCTN10751859) using longitudinal imaging over a mean follow-up period of 48.4 months. Investigators utilized an angular plot method around the center of existing macular atrophy lesions to map both the extent and directional growth of the disease over time.
Researchers compared baseline DARC activity against three established optical coherence tomography (OCT) markers: ellipsoid zone (EZ) loss, the difference between the ellipsoid zone and the retinal pigment epithelium (EZ-RPE difference), and hyperreflective foci (HRF) density. Statistical evaluations revealed that baseline DARC measurements correlated significantly stronger with subsequent directional macular atrophy growth than EZ loss (P = .0191), EZ-RPE difference (P = .0267), and HRF density (P = .0252).
DARC signals were also observed beyond the visible boundaries of existing atrophy margins. This distribution aligns with the underlying mechanism of action: detecting active cellular stress and apoptosis in photoreceptors prior to structural damage appearing on conventional OCT. The study also noted methodological limitations with existing markers; for instance, HRF density could not be quantified at baseline in 3 eyes because atrophy was not yet present, whereas DARC measurements were available at baseline.
In Plain English: The Clinical Takeaway
- Spotting Cell Stress Early: DARC technology uses a fluorescently labeled probe to identify stressed and dying retinal cells before structural loss becomes apparent on standard eye scans.
- Better Prediction: In a small study of 7 eyes, these early warning signals predicted which direction eye damage would spread better than three traditional imaging markers.
- Clinical Trial Value: Better early tracking tools could help pharmaceutical researchers test new dry-AMD treatments by identifying patients most likely to benefit.
Novai’s DARC technology merges a fluorescently labeled Annexin A5 probe with advanced digital image processing, AI-powered algorithms, and data science. This combination allows clinicians to quantify the number and spatial distribution of stressed, sick, and apoptotic cells in the retina. By illuminating disease activity at an earlier biological stage, the technology provides a window into active tissue degeneration.
Professor Maria Francesca Cordeiro, founder and CEO of Novai, emphasized the clinical relevance of these findings for expanding treatment options:
A major unmet need in geographic atrophy is successfully met by the discovery that DARC can offer an earlier glimpse into active disease, including the specific locations where that disease activity takes place. DARC can pinpoint ongoing cellular activity prior to the onset of permanent structural damage, presenting a valuable opportunity to spot patients facing the highest risk of progression and central vision loss while intervention remains feasible.
With prospective validation currently underway through the DAB clinical trial (ISRCTN22122298), researchers aim to confirm these findings in larger cohorts. Improved disease activity markers are needed to refine patient stratification in clinical trials, support timely therapeutic intervention, and monitor biological responses as new treatments emerge.
| Biomarker Evaluated | Comparison Metric | Statistical Significance vs. DARC |
|---|---|---|
| Ellipsoid Zone (EZ) Loss | Directional MA Growth | P = .0191 |
| EZ-Retinal Pigment Epithelium Difference | Directional MA Growth | P = .0267 |
| Hyperreflective Foci (HRF) Density | Directional MA Growth | P = .0252 |
Contraindications & When to Consult a Doctor
While DARC imaging represents an advanced investigational approach for assessing retinal cellular stress, it remains an exploratory tool evaluated primarily within clinical trial settings such as the Phase 2a trial and the ongoing DAB study. It is not currently a standalone diagnostic test for routine outpatient screening.
References
- Expert Review of Ophthalmology: Predicting directional macular atrophy progression using angular plot analysis of DARC, EZ loss, EZ-RPE difference, and HRF density.
- Phase 2a DARC Clinical Trial Registry: ISRCTN10751859.
- DAB Clinical Trial Registry: ISRCTN22122298.
Always consult a licensed ophthalmologist or healthcare professional for individualized medical advice, diagnosis, and treatment options regarding retinal diseases.
