Several factors are associated with glaucoma progression, most notably elevated intraocular pressure (IOP), age, stage of the disease and presence of optic disc haemorrhages.^1–4 In this issue of the British Journal of Ophthalmology, Balaratnasingam et al⁵(see page 441) describe a new factor associated with glaucoma progression—that is, the ophthalmodynamometric force (ODF) necessary to induce central or hemiretinal vein pulsation. In their study, baseline ODF, measured in subjects with glaucoma or suspects of having glaucoma, predicted increased optic disc excavation determined by masked assessment of optic disc stereophotography (average of 82 months of follow-up). The same group of investigators have previously shown that approximately 50% of patients with glaucoma have spontaneous venous pulsation (SVP), compared to 98% of age-matched normal controls,⁶ which was confirmed in other cohorts.^7,8 Moreover, a strong inverse correlation was observed between the ODF and the mean deviation of the visual field. In cases where different ODF was required to induce pulsation of the two hemi-veins, there was a strong association between differences in the ODF measured in the two veins and differences in the corresponding hemifield mean sensitivities.^6,7 These findings suggest that determining the presence of SVP and …