Abstract
Purpose :
We previously showed that vitreoretinal interface macrophage-like cells (MLCs) are increased in eyes with proliferative diabetic retinopathy (PDR). Here we tested the hypothesis that ischemia and MLCs are correlated. We measured MLC percent area and several metrics of ischemia using optical coherence tomography angiography (OCTA) and ultra-widefield (UWF) fluorescein angiography (FA) across a wide range of diabetic severity.
Methods :
Treatment naïve eyes were prospectively imaged with repeated OCTA (average 5.3 scans per eye) and UWF FA imaging. OCTA images were registered and averaged to generate a superficial vascular plexus (SCP), deep vascular plexus (DCP), and MLC slab (3 microns above the internal limiting membrane). We calculated geometric perfusion deficit (GPD) for the SCP and DCP. MLC percent area was quantified by two masked graders using our previously published semi-automated macro. MLC percent area from the 2 graders was averaged. Ischemia on UWF FA was measured to generate a non-perfusion index (NPI). MLC percent area was non-parametrically distributed using the Shapiro-Wilk test. Correlations between MLC percent area and ischemia metrics were evaluated with Spearman non-parametric test.
Results :
Forty-five treatment naïve eyes of 45 patients (59 ± 12 years of age; 56% female) were imaged. We included 10 eyes with no diabetic retinopathy (DR), 5 eyes with mild non-proliferative DR (NPDR), 20 moderate NPDR, 5 severe NPDR, and 5 PDR eyes. MLC percent area between graders was highly correlated (r=0.9592, p<0.0001). MLC percent area was correlated with DCP GPD (r=0.339, p<0.05), but not SCP GPD. MLC percent area was also positively associated with NPI on UWF FA (r=0.432, p<0.01).
Conclusions :
MLC percent area was correlated with global ischemia on UWF FA and DCP GPD, a parameter which our group previously showed to predict eyes with referable DR and DR eyes at risk for progression. These data suggest that MLCs may be a potential biomarker for ischemia.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.