The clinical validity of the spontaneous retinal venous pulsation

The validity of the clinical dictum "the presence of spontaneous retinal venous pulsation (SVP) excludes raised intracranial pressure" has not been previously tested. We set out to determine the specificity and positive predictive value (PPV) of the presence of SVP to indicate normal intracranial pressure (ICP) in a routine clinical setting.

We prospectively recruited patients undergoing lumbar puncture (LP), and 2 clinicians were blinded to the indications for LP and cerebrospinal fluid opening pressure (OP). Interobserver reliability was assessed.

There were 106 patients in our cohort with a median age of 44 years (range, 18-79 years) and median body mass index of 27.5 kg/m (range, 18-48 kg/m). SVP was present in 94 of 106 patients (88.7%). Thirteen of 106 (12.3%) patients had high OP (≥30 cmH2O), and SVP was present in 11 of 13 patients (86%) with high OP. The sensitivity (95% confidence interval) of the presence of SVP to exclude raised ICP was 0.89 (0.88-0.92), specificity of 0.15 (0.05-0.37), PPV of 0.88 (0.87-0.9), and negative predictive value of 0.17 (0.05-0.4). Interobserver agreement was moderate for SVP (kappa = 0.42).

Although the sensitivity and PPV of the presence of SVP to exclude raised ICP is high, it is not absolute. SVP can be seen in some patients with high ICP. Relying on the presence of SVP to exclude raised ICP may give a false sense of reassurance.