A new tool to assess retinal vessel caliber. Reliability and validity of measures and their relationship with cardiovascular risk.
OBJECTIVE
To analyze the reliability and validity of a semiautomated tool for assessing retinal vessel caliber and to describe the relationship of measures taken to cardiovascular risk and target organ damage.


METHODS
A total of 210 patients aged 34-75 years were selected with retinography. Retinal photographs were digitized, and superior and inferior temporal vessels were measured in an area 0.5-1 disk diameter from the optic disc with semiautomated software [arteriole/venule index (AVIx) calculator]. AVIx was also estimated. Vascular damage was assessed using carotid intima-media thickness and pulse wave velocity, cardiac damage using Cornell voltage-duration product, renal damage using the glomerular filtration rate and microalbuminuria, and cardiovascular risk with the Framingham score.


RESULTS
Interobserver intraclass correlation coefficient (ICC) ranged from 0.96 [95% confidence interval (CI) 0.94-0.97] to 0.99 (95% CI 0.98-0.99), and intraobserver ICC ranged from 0.97 (95% CI 0.94-0.98) to 0.99 (95% CI 0.99-0.99). In the Bland-Altman plot, the limit of interobserver agreement was -0.009 (0.066 to -0.086) in right AVIx and -0.001 (0.083 to -0.085) in left AVIx, whereas the limit of intraobserver agreement for overall AVIx was -0.005 (-0.057 to -0.047). Cardiovascular risk and albumin-creatinine ratio were higher in the first tertile of AVIx as compared with the other two (P < 0.05). In multiple regression, AVIx and venule caliber, but not artery caliber, behaved as predictors of cardiovascular risk and microalbuminuria.


CONCLUSIONS
This tool showed a high intraobserver and interobserver reliability, and results of the validity analysis agree with those from large studies in estimation of cardiovascular risk and evaluation of target organ damage.
Primary Care Research Unit La Alamedilla, SACYL, IBSAL, Salamanca, Spain. Lgarciao@usal.es
Luis
L
García-Ortiz
José I
JI
Recio-Rodríguez
Javier
J
Parra-Sanchez
Luis J
LJ
González Elena
María C
MC
Patino-Alonso
Cristina
C
Agudo-Conde
Emiliano
E
Rodríguez-Sánchez
Manuel A
MA
Gómez-Marcos
D000328:Adult; D000368:Aged; D000419:Albuminuria / Q000175:diagnosis; D001783:Blood Flow Velocity; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000503:physiopathology; D059168:Carotid Intima-Media Thickness; D004562:Electrocardiography; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000473:pathology / Q000503:physiopathology; D017379:Hypertrophy, Left Ventricular / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D007674:Kidney Diseases / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011673:Pulsatile Flow; D015203:Reproducibility of Results; D012161:Retinal Artery / Q000473:pathology* / Q000503:physiopathology; D012169:Retinal Vein / Q000473:pathology* / Q000503:physiopathology; D012307:Risk Factors; D059289:Vascular Stiffness / Q000502:physiology