Macular blood flow measured by blue-field entoptoscopy and Heidelberg retinal flowmetry: comparison of two techniques in type 1 diabetes women during pregnancy.

PURPOSE: This study compared macular capillary leucocyte velocity values measured with a psychophysical blue-field entoptic simulation (BFS) technique and confocal scanning laser Doppler flowmetry. METHODS: A cross-sectional study was performed where macular capillary leucocyte velocity was measured by BFS using an Oculix BFS-2000 V2.1 psychophysical system and by confocal scanning laser Doppler flowmetry using Heidelberg retinal flowmetry (HRF) in 35 type 1 diabetes women during the second trimester. RESULTS: The macular leucocyte velocities measured with BFS correlated significantly with the 50th percentile (r = 0.345, p = 0.042, n = 35, Spearman's non-parametric correlation), the 75th percentile (r = 0.432, p = 0.009) and the 90th percentile (r = 0.373, p = 0.027) of HRF flow values during the second trimester. However, there was no correlation between BFS velocity and the 25th percentile of HRF measurements. CONCLUSIONS: Blue-field simulation is known to be an experimental technique that provides a quantitative measure of flow in the perifoveal capillary network. By contrast, HRF imaging reflects quantitative, multispectral, objective and non-invasive measurements in a two-dimensional projection of a three-dimensional retinal capillary bed. Our study showed that BFS velocity was correlated with HRF values in a group of women with diabetes during pregnancy. The positive correlation between BFS and HRF values suggests that the psychophysical BFS and scanning laser-based HRF measure similar functions in the retina.