Optimization of the scan pattern in OCTA images in healthy subjects

Author: RAMKAILASH GUJAR (Italy)

Co-authors: Marco Lupidi, Rosa Dolz Marco, Jay Chhablani, Daniela Fruttini, Carlo Cagini

Purpose

The aim of the present study was to assess the optimal scan pattern on Spectralis HRA-OCT2 device measuring macular microvasculature perfusion in healthy subjects

Setting/Venue

This was an observational, cross-sectional study involving healthy eyes and conducted at the Eye Clinic of the S. Maria Della Misericordia Hospital (Perugia, Italy).

Methods

Consecutive healthy subjects were imaged within the same visit using the SPECTRALIS OCT-A Module (Heidelberg Engineering, Heidelberg, Germany) using different scanning protocols (10ºX10º- 512 ART 7[P1], 10ºX10º-256 ART 5[P2], 10ºX10º-512 ART 5[P3],15ºX10º-256 ART 5[P4]) centered in the macular area. Vessel perfusion density (VPD) and vessel length density (VLD) of the superficial capillary plexuses were computed using ImageJ software (National Institutes of Health) to evaluate potential differences between diverse scanning patterns. A qualitative grading of the foveal avascular zone and of image quality was performed by two retina specialists.

Results

Twenty eyes of 10 healthy subjects were included in the present study. Mean VPD values of P1, P2, P3 and P4 were 35.60, 31.67, 31.18 and 31.16 respectively. Mean VLD values of P1, P2, P3 and P4 were 7.54, 5.86, 6.74 and 4.40 respectively. A statistically significant difference was reported between P1 and P2, P3, P4 values both for VPD and VLD. No statistically significant differences were reported between P2, P3 and P4 values. In the qualitative assessment, P1 had the highest score and P4 had the lowest score from both graders in the foveal avascular zone and image quality assessment.

Conlusions

In the overall analysis of the qualitative assessment a statistically significant superiority was demonstrated for P1 compared to the other scanning patterns. In the quantitative assessment, P1 was shown an optimal scanning approach in detecting blood flow and seems less suffering from noise.