Assessment of Choriocapillaris Flow Prior to Nascent Geographic Atrophy Development Using Optical Coherence...

Area of Science:

• Ophthalmology
• Medical Imaging
• Cardiovascular Science

Background:

• Age-related macular degeneration (AMD) is a leading cause of vision loss.
• Geographic atrophy (GA) is an advanced form of AMD characterized by photoreceptor and retinal pigment epithelium loss.
• Early detection of GA precursors is crucial for timely intervention.

Purpose of the Study:

• To investigate the association between choriocapillaris (CC) blood flow and the development of nascent geographic atrophy (nGA).
• To evaluate the predictive capability of CC flow deficits for future nGA development using optical coherence tomography angiography (OCTA).

Main Methods:

• A prospective, longitudinal study included 62 participants with bilateral large drusen but no late AMD or nGA at baseline.
• Swept-source OCTA imaging was performed at 6-month intervals.
• Choriocapillaris flow deficit percentage (CC FD%) and drusen volume were analyzed globally and locally (superpixels) prior to nGA development.

Main Results:

• Of 105 eyes, 15 developed nGA.
• No significant difference in global CC FD% was found between eyes that developed nGA and those that did not.
• Local CC FD% was significantly higher in areas that subsequently developed nGA (P < 0.001).
• A model using CC FD% predicted nGA foci better than drusen volume alone (P ≤ 0.040).

Conclusions:

• Significant local impairments in CC blood flow can be detected before nGA development.
• These findings enhance understanding of the pathophysiology of atrophy in AMD.
• Local CC flow deficit is a potential early biomarker for nGA development.