EURETINA 2026: Predicting geographic atrophy progression with DARC

At the 26th EURETINA Congress in Vienna, Austria, Francesca Cordeiro, PhD, MD, FRCOphth, discussed a newly published paper evaluating Detection of Apoptosing Retinal Cells (DARC) in patients with geographic atrophy (GA). DARC highlights retinal cells that are stressed or undergoing apoptosis, a process Cordeiro described as cell suicide.

Predicting where atrophy will progress

According to Cordeiro, DARC identifies stressed photoreceptor cells that will eventually die. This activity predicts photoreceptor loss, visible on OCT as loss of the ellipsoid zone, as well as hyperreflective foci seen on fundus imaging.

The study followed a small group of patients for up to approximately 4 years. Each patient underwent DARC once at the start of follow-up and was then monitored with conventional imaging. Baseline DARC predicted both how fast GA would grow and in which direction.

Stratifying patients by risk

Cordeiro said this matters because only 2 GA treatments exist. Both are expensive and, apart from the US and Australia, have seen little use worldwide. Identifying which patients will benefit most could let clinicians treat before vision loss occurs, rather than having to “watch, wait and see.” Changes detected by conventional methods often appear only after vision loss has begun.

She outlined 3 groups:

• patients who should be treated;
• patients at risk of eventual vision loss, who need monitoring; and
• patients with little activity, who may need less intensive follow-up.

She said this personalised approach could also save health systems money.

Cordeiro distinguished DARC from AI analysis of OCT. AI applied to OCT scans shows structural loss, whereas DARC shows cellular activity before that loss occurs.

Applications in drug development

Some pharmaceutical companies already use DARC to enrich GA trial populations, Cordeiro said. Because DARC works at the single-cell level, performing it before treatment and again 1 to 2 months later can show whether a patient is responding. If the DARC signal does not fall, the treatment is likely not working. That allows developers to fail fast instead of waiting years for an answer.

Towards screening

DARC is currently given as an injection in the arm, but a nasal version is in development. Cordeiro said the nasal version could make testing available outside hospitals, at opticians, optometrists or wellness centres. Nearly 400 patients have received DARC to date, and she described it as “perfectly safe.”

Her team is also exploring DARC in diabetes, glaucoma, Parkinson disease, Alzheimer disease and multiple sclerosis. The aim is to identify these conditions earlier, before patients lose function.