Visual Outcomes in Idiopathic Intracranial Hypertension

Laurie L. Barclay, MD


November 12, 2015

Risk Factors for Poor Visual Outcome in Patients With Idiopathic Intracranial Hypertension

Wall M, Falardeau J, Fletcher WA, et al; NORDIC Idiopathic Intracranial Hypertension Study Group
Neurology. 2015;85:799-805

Study Summary

The study goal was to identify risk factors for progressive visual field loss among participants with idiopathic intracranial hypertension and mild visual loss in the Idiopathic Intracranial Hypertension Treatment Trial. In this randomized controlled trial, participants received a low-sodium, weight-reduction diet and were also assigned to receive acetazolamide or placebo.

Protocol-defined treatment failure was designated as >2 dB perimetric mean deviation [PMD] change in patients with baseline PMD −2 to −3.5 dB or >3 dB PMD change with baseline PMD −3.5 to −7 dB. Use of logistic regression and classification tree analyses allowed identification of potential risk factors for treatment failure.

Of seven participants who met criteria for treatment failure, six had been assigned to diet plus placebo. Compared with patients who had grades I and II papilledema, those who had grades III to V papilledema had more than eightfold greater risk for treatment failure (odds ratio [OR], 8.66; P = .025).

For each one-unit decrease in the number of letters correct at baseline on the ETDRS (Early Treatment Diabetic Retinopathy Study) chart, there was a 16% increase in the odds of treatment failure (OR, 1.16; 95% confidence interval [CI], 1.04-1.30; P = .005). Males were 26 times more likely than females to have treatment failure (OR, 26.21; 95% CI, 1.61-433.00; P = .02).

Compared with patients who had 30 or fewer transient visual obscurations per month, those who had more than 30 had more than tenfold higher likelihood of treatment failure (OR, 10.59; 95% CI, 1.63-116.83; P = .010).


Limitations of this study include the small number of participants who experienced treatment failure. Nonetheless, the findings suggest that male patients, those with high-grade papilledema, and those with reduced baseline visual acuity are at greater risk for treatment failure, mandating vigilant monitoring for these patients. Because six of the seven patients with treatment failure were treated with diet alone and not with acetazolamide, aggressive treatment of their idiopathic intracranial hypertension should be considered in patients with these risk factors.