Diabetes damages retinal capillaries before clinical changes appear. Optical
coherence tomography can quantify changes in vessel length density and vessel area
density in diabetics without retinopathy and can lead to a reduction of these metrics in
different capillary plexuses. The mean values of vessel densities vary according to the
device used. Here, we review the values of vessel length density, vessel area density,
and foveal avascular zone metrics in diabetics without retinopathy in a 3 x 3 mm map
of the most used commercially available devices. We included measurements for the
superficial, intermediate, and deep capillary plexuses in the parafoveal region. The
information refers to adult type 2 diabetic people according to densities in the foveal,
parafoveal, and whole map measurements. We also included parafoveal distribution by
field as well. There are references to the foveal avascular zone—a common variable
measured to detect ischemia in patients with diabetic retinopathy—and we report them
for both superficial and deep capillary plexuses. We also include the proposed cut-off
values for normality for metrics of the superficial capillary plexus and propose an
explanation for the differences that exist between measurements with the same device
as related to diabetes duration.
Keywords: Area, Deep capillary plexus, Diabetes, Foveal avascular zone, Middle capillary plexus, Perimeter, Superficial capillary plexus, Vessel area density, Vessel length density.
