From the abstract: A pilot cross sectional study was conducted to investigate the role of
red blood cells (RBC) deformability in type 2 diabetes mellitus (T2DM)
without and with diabetic retinopathy (DR) using a dual optical tweezers
stretching technique. A dual optical tweezers was made by splitting and
recombining a single Nd:YAG laser beam. RBCs were trapped directly
(i.e., without microbead handles) in the dual optical tweezers where
they were observed to adopt a “side-on” orientation. RBC initial and
final lengths after stretching were measured by digital video
microscopy, and a Deformability index (DI) calculated. Blood from 8
healthy controls, 5 T2DM and 7 DR patients with respective mean age of
52.4yrs, 51.6 yrs and 52 yrs was analysed. Initial average length of
RBCs for control group was 8.45 ± 0.25 μm, 8.68 ± 0.49 μm for DM RBCs
and 8.82 ± 0.32 μm for DR RBCs (p < 0.001). The DI for control group
was 0.0698 ± 0.0224, and that for DM RBCs was 0.0645 ± 0.03 and
0.0635 ± 0.028 (p < 0.001) for DR group. DI was inversely related to
basal length of RBCs (p = 0.02). DI of RBC from DM and DR patients was
significantly lower in comparison with normal healthy controls. A dual
optical tweezers method can hence be reliably used to assess RBC
deformability.
The movie below shows a red blood cell being stretched using our optical tweezers.
