Optical Coherence Tomography Angiography in Glaucoma Care

ABSTRACT

Purpose: To provide the reader with information on the principal techniques of optical coherence tomography angiography (OCTA); the current literature on OCTA reproducibility; its applications to glaucoma detection and monitoring of progression; and the role of OCTA in the assessment of the vascular component in glaucoma pathogenesis.Methods: A literature review of the pertinent publications for the OCTA in relation to the development, techniques, and its use in glaucoma was carried out.Results: Rapid improvements in optical coherence tomography (OCT) technology have allowed for enhancement of both image resolution and scanning speed, and the development of vascular assessment modality. OCTA is the non-invasive in vivo imaging of the vasculature located within the retina and optic nerve head area. The principle of OCTA is to use the variations in OCT signals caused by moving particles as the contrast mechanism for imaging of flow. Several algorithms which aim to maximize the contrast signal and minimize the noise have been developed including the phase-based techniques, intensity-based techniques (e.g., split-spectrum amplitude decorrelation angiography (SSADA)), and complex-based techniques (e.g., optical microangiography (OMAG)). With its reliable technique, high image resolution, and current availability, OCTA has been widely used in the assessment of posterior segment diseases including glaucoma in which ocular perfusion dysfunction has been proposed as a pathophysiological mechanism.Conclusion: OCTA may enhance our knowledge of glaucoma pathogenesis and offer an improvement in our ability to detect glaucomatous change.

Keywords:

• Glaucoma
• optical coherence tomography angiography
• glaucoma imaging
• ocular perfusion
• optical coherence tomography

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

The writing of this manuscript was supported in part by Research to Prevent Blindness (Unrestricted Grant), the NIH-NEI EY002162- Core Grant for Vision Research, and That Man May See, Inc.