Objective:

Assess whether adaptive optics optical coherence tomography (AO-OCT) can track individual retinal ganglion cell (GC) soma loss over time in living human eyes.

Approach:

• Participants: Six healthy participants and two patients with glaucoma were followed.
• Imaging: Researchers repeatedly used AO-OCT to image the same retinal locations and track individual ganglion cell layer (GCL) somas. Healthy participants were imaged annually for up to three years; glaucoma patients were reimaged about two years after baseline.

Key Findings:

• Among 23,586 somas tracked in healthy participants, approximately 99.7% remained unchanged over three years; the average soma loss rate was 0.10% per year.
• One glaucoma patient had a soma loss rate of 0.26% per year within an arcuate defect, without detectable accompanying GCL thinning.
• The other glaucoma patient had a 31.6% annual soma loss rate, alongside approximately 13% annual GCL thinning at the same location.
• GC soma density and GCL thickness were strongly related in healthy eyes, but this association appeared weaker with more advanced glaucomatous damage.

Interpretation:

The authors report that AO-OCT can directly track individual GC soma loss and may support longitudinal monitoring of glaucoma suspects and assessment of therapies intended to protect retinal neurons.

Limitations:

• The cohort was small and included only two glaucoma patients.
• The study examined a limited number of retinal locations.
• Image analysis was labor-intensive; the authors noted that further automation is needed for routine use.
• The findings do not provide population-level estimates or establish immediate clinical applicability.

Conclusion:

The study demonstrates cellular-level tracking of retinal ganglion cell loss with AO-OCT, but larger studies and more automated analysis are needed.

Sources:

• Study published in Investigative Ophthalmology & Visual Science; source URL not provided