Evaluation of agreement in macular vascular density measured by different protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm.

Abstract

To evaluate the agreement in the macular vascular density (MVD) measured by two protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm. Cross-sectional observational study. Healthy volunteers between the age group of 19 and 39 years were recruited. Topcon DRI OCT Triton plus (Topcon Corporation, Tokyo, Japan) was used to acquire the fovea-centered optical coherence tomography angiography (OCTA) image using two protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm. MVD was measured by the manufacturer software in the superficial capillary plexus slab in five regions: central, superior, nasal, inferior, and temporal subfields of early treatment diabetic retinopathy study grid in each protocol. The study included 79 eyes of 40 healthy volunteers. The difference in the mean MVD between two protocols was 3.84% in right eye and 4.2% in left eye in central subfield, 0.93% in right eye and 1.13% in left eye in superior subfield, 0.06% in right eye and 1.45% in left eye in nasal subfield, 1.65% in right eye and 0.7% in left eye in inferior subfield, 0.4% in right eye and 0.54% in left eye in temporal subfield. The measurements were significantly higher in 6 mm × 6 mm in central subfield in both the eyes and in nasal field in the left eye. Whereas, the measurements were significantly higher in 4.5 mm × 4.5 mm in superior and inferior subfield in both the eyes and in temporal subfield in the left eye. The protocols should not be used interchangeably and it is necessary to include recommendation of the field of view to measure MVD while standardizing OCTA reporting.