Quantitative analysis of microvasular densities in retina and choroid using wide field swept source optical tomography angiography

Abstract

Purpose : Optical tomography angiography (OCTA) has been used to quantify changes in microvasculature in diabetic retinopathy, however mostly focused on the macula. The present study investigated the possible changes of both retina and choroid in a wide field by swept source OCTA (SS-OCTA).

Methods : We conducted a prospective, observational study in Mass Eye and Ear from December 2018 to February 2019. Treatment naïve non-proliferative diabetic retinopathy (NPDR), diabetic patients with no diabetic retinopathy (DR) and healthy control eyes with no ocular diseases were included. All patients were imaged with a SS-OCTA (PLEX® Elite 9000; Carl Zeiss Meditec, Inc, Dublin, CA) and the montage image composed of two 15mm by 9mm angio image (superior and inferior) was used for analysis. Vessel density (VD) and skeleton density (SD) of superficial retina, deep retina and choriocapillaris were calculated using Image J (NIH). All statistic analyses were performed using SPSS software 22.0 (SPSS Inc, Chicago, IL) and one-way ANOVA was used for multiple comparisons between groups.

Results : Twenty-two eyes (13 eyes with NPDR, 4 eyes of diabetic patients without DR and 5 healthy control eyes) were included in the study. Severe NPDR had significant lower VD and SD in both superficial and deep retina compared to other groups (P<0.001). Compared to mild NPDR (VD 0.496±0.015, SD 0.207±0.004), VD (0.524±0.028) and SD (0.220±0.009) of superficial retina in healthy control were significantly higher (P<0.05). VD in both superficial (0.527±0.018) and deep layer (0.614±0.017) of retina in eyes of diabetic patients without diabetic retinopathy were significant higher than those in mild NPDR (superficial VD 0.496±0.015, deep VD 0.571±0.015, P<0.05). However no statistically significant changes were detected between healthy controls and diabetic patients without diabetic retinopathy. The average choriocapillaris VD (0.527±0.027) and SD (0.266±0.012) in eyes with diabetic retinopathy was lower than those in control (VD 0.549±0.043, SD0.272±0.014), but this did not reach statistical significance (P>0.05).

Conclusions : Quantitative analysis of wide filed OCTA images could indicate the severity of diabetic retinopathy.

This abstract was presented at the 2019 ARVO Imaging in the Eye Conference, held in Vancouver, Canada, April 26-27, 2019.