Comparison of choriocapillaris perfusion between swept-source optical coherence tomography angiography and spectral-domain optical coherence tomography angiography in five different choriocapillaris slabs in patients with intermediate age-related macular degeneration

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Diseases

Background:

• Intermediate age-related macular degeneration (iAMD) affects the macula, potentially impacting vision.
• Choriocapillaris (CC) perfusion is crucial for retinal health and is often assessed using optical coherence tomography angiography (OCTA).
• Different OCTA technologies, such as swept-source (SS-OCTA) and spectral-domain (SD-OCTA), may yield varying results.

Purpose of the Study:

• To compare choriocapillaris (CC) perfusion analysis between SS-OCTA and SD-OCTA.
• To investigate the impact of different CC slab depths on perfusion measurements.
• To evaluate the effect of OCTA averaging on quantitative results in iAMD patients.

Main Methods:

• Cross-sectional study involving 23 eyes from 20 patients with iAMD.
• Acquisition of OCTA scans using SS-OCTA and SD-OCTA (non-averaged V1 and averaged V4).
• Calculation of flow deficit parameters (percentage, size, area, number) across five distinct CC slabs.

Main Results:

• Significant differences in CC flow deficits were observed when comparing SS-OCTA vs. SD-OCTA V1 and SD-OCTA V1 vs. V4.
• Fewer significant differences were found between SS-OCTA and SD-OCTA V4, except for specific slabs.
• Flow deficit percentages varied significantly between different CC slabs within the same OCTA device.

Conclusions:

• The quantification of CC flow deficits is influenced by the specific CC slab, the OCTA technology employed, and volume averaging in SD-OCTA.
• Direct comparisons of quantitative OCTA data across different studies, instruments, or averaging methods are challenging due to these significant impacts.
• Standardization of OCTA acquisition and analysis protocols is essential for reliable interpretation of CC perfusion in iAMD.