Guidelines for Imaging the Choriocapillaris Using OCT Angiography.

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Imaging

Background:

• Choriocapillaris (CC) plays a crucial role in retinal health.
• Optical coherence tomography angiography (OCTA) is a key imaging modality for CC analysis.
• Standardized methods for CC quantification are needed.

Purpose of the Study:

• To provide guidance on appropriate quantification of choriocapillaris (CC) parameters using optical coherence tomography angiography (OCTA).
• To establish evidence-based recommendations for reliable CC imaging and measurement.
• To address the complexities of quantitative CC analysis in clinical research.

Main Methods:

• Review of existing literature on CC imaging and quantification.
• Analysis of author experiences with OCTA in retinal research.
• Evaluation of visualization and measurement validation criteria for CC parameters.

Main Results:

• Accurate CC visualization requires physiologically sound slabs and consistent imaging across scans.
• Validated CC quantification depends on physiologically meaningful parameters and appropriate binarization algorithms.
• Intercapillary distances (ICDs) measured by OCTA should align with histology and adaptive optics data.
• Optimization of thresholding methods, like Phansalkar, is crucial, with window radius related to average ICD.

Conclusions:

• Quantitative CC analysis with OCTA is complex and instrument-dependent.
• Researchers must tailor OCTA strategies to specific instruments, scan patterns, anatomy, and thresholding techniques.
• Achieving accurate and reliable CC measurements necessitates careful consideration of multiple factors.