Functional slit lamp biomicroscopy metrics correlate with cardiovascular risk

Ocul Surf. 2019 Jan;17(1):64-69. doi: 10.1016/j.jtos.2018.09.002. Epub 2018 Sep 22.


Purpose: Our aim was to correlate cardiovascular risk factor estimation with bulbar conjunctival blood flow metrics as measured through Functional Slit Lamp Biomicroscopy (FSLB).

Methods: Cross-sectional study of individuals with otherwise healthy eyelid and corneal anatomy recruited from the Miami Veterans Affairs (VA) Healthcare System eye clinic. We measured conjunctival microvascular hemodynamics by mounting a camera on a slit lamp and cardiovascular risk using the Framingham risk score. Our main outcome measures were correlations between conjunctival vessel parameters (axial and cross-sectional blood flow velocity, blood flow rate) and Framingham score.

Results: We included 84 patients who underwent FSLB. The mean age was 60 years, the majority were male (88%) and approximately half the patients were black (54%). Mean vessel diameter was similar between all Framingham score categories. Axial and cross-sectional blood flow velocities and blood flow rate were lower in individuals with higher Framingham risk score. Specifically, mean cross-sectional blood flow velocity in individuals with a low Framingham risk score was 0.37 ± 0.0.9 mm/s, with an intermediate score was 0.30 ± 0.09 mm/s, and with a high score was 0.29 ± 0.10 mm/s, p = 0.04. Mean blood flow rate in individuals with a low Framingham risk score was 133.4 ± 59.6 pl/s, with an intermediate score was 123.6 ± 39.3 pl/s, and with a high score was 121.9 ± 52.6 pl/s, p = 0.04. The beta coefficient of the blood flow rate for change in Framingham score was -0.73; 95% CI-1.34-0.13, p = 0.02, adjusted for race.

Conclusion: FSLB correlates with cardiovascular risk estimation. Future studies should evaluate if FSLB can predict cardiovascular outcomes.

Keywords: Cardiovascular risk estimation; Conjunctival blood vessels; Functional slit lamp imaging.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aged
  • Blood Flow Velocity / physiology*
  • Cardiovascular Diseases / diagnosis*
  • Cardiovascular Diseases / epidemiology
  • Cardiovascular Diseases / physiopathology
  • Conjunctiva / blood supply*
  • Conjunctiva / diagnostic imaging
  • Cross-Sectional Studies
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Incidence
  • Male
  • Microcirculation / physiology*
  • Microvessels / diagnostic imaging*
  • Microvessels / physiology
  • Middle Aged
  • Predictive Value of Tests
  • Prevalence
  • Prospective Studies
  • Risk Assessment / methods*
  • Risk Factors
  • Slit Lamp Microscopy / methods*
  • United States / epidemiology