Smaller Optic Discs Show Higher Macular Flow Density: An Optical Coherence Tomography Angiography Study

Area of Science:

• Ophthalmology
• Medical Imaging
• Retinal Vascular Diseases

Background:

• Macular flow density (FD) and foveal avascular zone (FAZ) are key indicators of retinal health.
• Optic disc size, quantified by Bruch's membrane opening area (BMOA), is a variable that may influence these parameters.
• Understanding these relationships is crucial for establishing normative data in optical coherence tomography angiography (OCT-A).

Purpose of the Study:

• To investigate the correlation between macular FD, FAZ characteristics, and optic disc size (BMOA).
• To evaluate differences in FD and FAZ parameters across different optic disc size cohorts.

Main Methods:

• Retrospective analysis of 151 healthy eyes using OCT-A.
• Rank correlation coefficients were computed to assess associations between FD and BMOA.
• FD and FAZ parameters were compared among three optic disc size groups.

Main Results:

• A significant negative correlation was found between FD in several macular subsectors and BMOA.
• Eyes with smaller optic discs showed significantly higher FD in both superficial capillary plexus (SCP) and deep capillary plexus (DCP) compared to larger discs.
• No significant differences were observed for foveal FD, FAZ area, or FAZ perimeter across disc size groups.

Conclusions:

• Optic disc size is a relevant variable for normative OCT-A data.
• Smaller optic discs are associated with higher macular FD in both SCP and DCP.
• FAZ parameters appear to be independent of optic disc size (BMOA).