Hemorheologic abnormalities associated with HIV infection: in vivo assessment of retinal microvascular blood flow.
OBJECTIVE
To evaluate retinal microvascular blood flow in human immunodeficiency virus (HIV)-infected individuals using scanning laser Doppler flowmetry (SLDF) and to seek correlations between flow and various laboratory measures that may predict alterations in flow.


METHODS
The Heidelberg Retina Flowmeter and SLDF software were used to acquire in vivo retinal blood flow data from 24 HIV-infected individuals and 16 HIV-negative control subjects. In each subject, separate scans were performed in each of six retinal regions: nasal parapapillary retina; macula; and the superior, nasal, inferior, and temporal periphery. Erythrocyte aggregation (assessed in vitro by a fully automatic erythrocyte aggregometer and by zeta sedimentation ratio [ZSR, a hematocrit-independent sedimentation rate]), serum fibrinogen level, plasma viscosity, and leukocyte rigidity (assessed in vitro with a cell transit analyzer) were compared with flow in selected regions.


RESULTS
Flow was significantly higher in the periphery (superior, nasal, inferior, temporal) than in the posterior retina (nasal parapapillary retina, macula). Flow was highest in the temporal periphery for both HIV-infected subjects and control subjects. Flow in the posterior retina was significantly lower in HIV-infected subjects than in control subjects (P < 0.0001). Among HIV-infected individuals, flow in the macula correlated negatively with ZSR (r = -0.397, P = 0.0547) and leukocyte rigidity (r = -0.505, P = 0.0119).


CONCLUSIONS
Microvascular blood flow in the posterior retina is reduced in HIV-infected individuals. Both increased erythrocyte aggregation and increased leukocyte rigidity contribute to this hemorheologic abnormality.
Dadgostar
Hajir
H
Ocular Inflammatory Disease Center, Jules Stein Eye Institute, UCLA, Los Angeles, CA 90095-7003, USA.
Holland
Gary N
GN
Huang
Xin
X
Tufail
Adnan
A
Kim
Alisa
A
Fisher
Timothy C
TC
Cumberland
William G
WG
Meiselman
Herbert J
HJ
Benjamin
Arthur
A
Bartsch
Dirk-Uwe
DU
D000328:Adult; D001783:Blood Flow Velocity; D001799:Blood Sedimentation; D001809:Blood Viscosity; D017726:Cytomegalovirus Retinitis / Q000097:blood / Q000209:etiology / Q000503:physiopathology; D004903:Erythrocyte Aggregation; D004907:Erythrocyte Deformability; D005340:Fibrinogen / Q000032:analysis; D015658:HIV Infections / Q000097:blood / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D017078:Laser-Doppler Flowmetry; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D012166:Retinal Hemorrhage / Q000097:blood / Q000209:etiology / Q000503:physiopathology*; D012171:Retinal Vessels / Q000502:physiology*
D005340:Fibrinogen