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


METHODS
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).


CONCLUSIONS
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.
Berisha
Fatmire
F
Schepens Retina Associates Foundation, One Autumn Street, Boston, MA 02215, USA.
Feke
Gilbert T
GT
Hirose
Tatsuo
T
McMeel
J Wallace
JW
Pasquale
Louis R
LR
D001783:Blood Flow Velocity / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure; D017078:Laser-Doppler Flowmetry; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000473:pathology*; D009901:Optic Nerve Diseases / Q000175:diagnosis / Q000503:physiopathology*; D011446:Prospective Studies; D012039:Regional Blood Flow / Q000502:physiology; D012161:Retinal Artery / Q000503:physiopathology*; D012165:Retinal Ganglion Cells / Q000473:pathology*; D041623:Tomography, Optical Coherence