title: Optical coherence tomography-based retinal vessel analysis for the evaluation of hypertensive vasculopathy.
abstract: OBJECTIVE
  Evaluation of retinal vessels in cardiovascular disease traditionally relies upon funduscopy, but more recently digital photo analysis has expanded the spectrum. As spectral domain optical coherence tomography (OCT) allows an in-vivo assessment of retinal tissue and its vessels on a histological scale, our study aimed at using this tool for the analysis of the retinal vasculature.
  
  
  METHODS
  Circumferential peripapillary OCT scans (3DOCT-2000; Topcon Inc., Tokyo, Japan), with centration on the optic nerve head, were taken from 20 eyes (20 participants) with normal blood pressure and 20 eyes (20 participants) with arterial hypertension above 120 mmHg (mean blood pressure). The diameter of all vessels intersecting the scan line was measured in the OCT and used to calculate central vessel equivalents, and the A/V ratios were calculated. Bland-Altman analysis was performed to evaluate reliability. Correlation coefficients were determined for reliability of the method as well as with the individual mean arterial blood pressures.
  
  
  RESULTS
  Forty eyes (40 participants) were included in the study. Mean arterial blood pressure was 96±4 mmHg in the control group and 132±7 mmHg in the hypertonic group. Mean A/V ratio as determined from OCT scans was 0.82±0.13 (normotonic) versus 0.62±0.11 (hypertonic). A Pearson's correlation coefficient of 0.67 (p<0.001) was determined between A/V ratio and blood pressure.
  
  
  CONCLUSIONS
  Our results highlight the feasibility of retinal vessel measurements in spectral domain OCT. A relation between mean arterial blood pressure and OCT-based A/V ratio was established. Further research will elucidate influencing factors and provide a broader basis for therapeutic approaches.
authors.affiliation: Medical Faculty Mannheim, Mannheim Institute of Public Health, Social and Preventive Medicine, Heidelberg University, Mannheim, Germany.
authors.forename: Alexander Karl-Georg
authors.initials: AK
authors.lastname: Schuster
authors.forename: Joachim Ernst
authors.initials: JE
authors.lastname: Fischer
authors.forename: Christine
authors.initials: C
authors.lastname: Vossmerbaeumer
authors.forename: Urs
authors.initials: U
authors.lastname: Vossmerbaeumer
mesh_terms: D000328:Adult; D062186:Arterial Pressure / Q000502:physiology; D001795:Blood Pressure Determination; D005260:Female; D006801:Humans; D058437:Hypertensive Retinopathy / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012161:Retinal Artery / Q000473:pathology*; D012169:Retinal Vein / Q000473:pathology*; D041623:Tomography, Optical Coherence; D014690:Venous Pressure / Q000502:physiology*
keywords: SD - OCT; arterial-venous ratio; central retinal vessel equivalent; hypertensive retinopathy; retinal vessel