Abstract
Purpose :
Reductions in amplitude of spontaneous venous pulsation (SVP) may be associated with glaucoma severity and glaucomatous progression. We determined if reduced SVPs are associated with reduced visual field (VF) sensitivity in glaucoma and thus might be predictors of the development of VF loss and VF progression.
Methods :
38 randomly selected eyes of 38 glaucoma patients were included (67.3 ± 10.5 years, VF MD = -6.6 ± 5 dB at baseline). Of these 38, 20 were followed annually for three years. At each visit, patients had a dilated ocular examination followed by measurement of SVP using a dynamic vessel analyser (Imedos GmbH) and 24-2 Humphrey SITA (Carl Zeiss Meditec Inc.) testing. SVP amplitude (SVPA) was defined as the peak-to-trough change in vein diameter over ≥ 10 cardiac cycles controlled for individual IOP. Average SVPA in the superior and inferior hemi-retinae and average VF sensitivity (dB) in the corresponding inferior and superior hemi-fields were calculated. The association between SVPA in the hemi-retina with the lowest (i.e., “worse”) SVPA and VF sensitivity in the corresponding hemi-field was assessed using linear regression. Change over time (slope) of both parameters was assessed over 3 years in 20 eyes tested longitudinally.
Results :
Mean SVPA in the “worse” hemi-retina in years one, two and three was 3.5 ± 1.2 um, 3.1 ± 1 um and 2.8 ± 0.8 um, respectively. Mean sensitivities in corresponding hemi-fields in years one, two and three were 23.4 ± 5.7 dB , 22.9 ± 6.1 dB, and 21.8 ± 3.8 dB. A significant positive correlation between SVPA and threshold sensitivity was observed at year one (n = 38, r = 0.60, p <0.001, see Figure) and years two and three (n = 20, r = 0.70 and r = 0.66, p <0.001). No significant decrease in SVPA or VF sensitivity over three years was observed (one-way ANOVA, p >0.05). Slopes describing change over time of SVPA and VF sensitivities were not significantly different. The pooled slope was -0.39.
Conclusions :
This study confirms a positive association between SVP amplitude and glaucoma severity assessed by VF loss. While the overall VF loss was non-significant (likely due to study participant treatment), the rate of SVP amplitude drop was proportional to VF loss. Further longitudinal study is required to establish if SVP amplitude is predictive of repeatable visual field abnormality or glaucomatous progression.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.