Visual Field Mean Deviation at Diagnosis of Idiopathic Intracranial Hypertension Predicts Visual Outcome

A robust predictor of visual outcome in idiopathic intracranial hypertension (IIH) would be useful in management, but there is limited information on this point. The purpose of this study was to ascertain whether visual field mean deviation on standard static perimetry performed at diagnosis in a large patient cohort is a reliable predictor of visual outcome.

We retrospectively reviewed the automated visual field mean deviations at diagnosis and at final encounter in 79 patients with IIH examined in the neuro-ophthalmology clinics at a single academic medical center from 1999 to 2015.

Of the 79 study patients, 66 (84%) entered with visual field mean deviations of -7 dB or better. Of those 66 patients, 59 (89%) had final mean deviations of -4 dB or better and 33 (56%) had final mean deviations of -2 dB or better. The single patient who had an initial mean deviation of -7 dB or better and a poor final mean deviation (-32 dB) was nonadherent to prescribed medication. Of the 13 (21%) patients who entered with mean deviations worse than -7 dB, 11 (85%) ended up with poor visual outcomes, their final mean deviations ranging from -5 dB to -32 dB. Over half of those 13 patients had required surgery for IIH, often within 3 weeks of diagnosis, owing to severe papilledema and visual dysfunction at the time of diagnosis.

Based on this retrospective study, patients with IIH who have relatively mild visual dysfunction at diagnosis are likely to have a favorable visual outcome, provided they are adherent to recommended treatment. Many of those with poor visual function at diagnosis will have unfavorable visual outcomes despite aggressive treatment.