Retinal blood flow and nerve fiber layer measurements in early-stage open-angle glaucoma

Am J Ophthalmol. 2008 Sep;146(3):466-472. doi: 10.1016/j.ajo.2008.04.034. Epub 2008 Jun 24.


Purpose: To evaluate the relationship between retinal circulatory abnormalities and retinal nerve fiber layer (RNFL) thinning in early-stage open-angle glaucoma (OAG) to help elucidate the mechanisms underlying the development of glaucomatous optic neuropathy.

Design: Prospective cross-sectional.

Methods: Twelve patients with early OAG and a known maximum untreated intraocular pressure less than 22 mm Hg (age, 61.4 +/- 9.7 years; Humphrey visual field mean deviation -2.7 +/- 2.1) and eight age-matched healthy control subjects (age, 58.5 +/- 8.3 years) were included in the study. Blood column diameter, centerline blood speed, and retinal blood flow were measured in the major inferior temporal retinal artery using a Canon laser Doppler blood flow instrument (CLBF 100; Canon, Tokyo, Japan). Peripapillary RNFL thickness was measured using a Stratus optical coherence tomography instrument.

Results: On average, there were significant reductions in retinal blood speed (P = .009) and flow (P = .010) in OAG patients compared to controls. The RNFL was significantly thinner in the OAG patients compared to controls (P = .002). There were significant inverse correlations between retinal blood flow and average RNFL thickness and RNFL thickness in the inferior quadrant within the glaucoma group (Rsq = 0.50, P = .01; Rsq = 0.62, P = .003).

Conclusion: The results showed that a thinner RNFL was associated with a higher retinal blood flow in patients with early-stage OAG. The mechanisms underlying this phenomenon remain to be elucidated.

MeSH terms

  • Blood Flow Velocity / physiology
  • Cross-Sectional Studies
  • Female
  • Glaucoma, Open-Angle / diagnosis
  • Glaucoma, Open-Angle / physiopathology*
  • Humans
  • Intraocular Pressure
  • Laser-Doppler Flowmetry
  • Male
  • Middle Aged
  • Nerve Fibers / pathology*
  • Optic Nerve Diseases / diagnosis
  • Optic Nerve Diseases / physiopathology*
  • Prospective Studies
  • Regional Blood Flow / physiology
  • Retinal Artery / physiopathology*
  • Retinal Ganglion Cells / pathology*
  • Tomography, Optical Coherence