Long-term visual outcome in a Danish population of patients with idiopathic intracranial hypertension

Idiopathic intracranial hypertension (IIH) is characterized by raised intracranial pressure (ICP), normal cerebrospinal composition and exclusion of alternative causes to increased ICP. The aim of this study was to evaluate long-term visual outcome in a Danish population of IIH patients.

Retrospective chart review of 41 women diagnosed with IIH between June 2007 and March 2013. Best-corrected visual acuity (BCVA), colour vision, grade and type of visual field (VF) defects and grade of papilloedema according to the Modified Frisén Score were recorded at baseline visit (V0), 2-6 months (V1) and 13 months follow-up visit (V2) from time of diagnosis.

Best-corrected visual acuity (BCVA) was reduced in 25% of eyes at V0, in 10% at V1 and in 15% at V2. Colour vision was barely affected. Visual field (VF) was affected (>grade 0) in 87% of eyes at V0 and VF defect grade significantly improved by 0.58 at V1 (p-value <0.0001) and by 0.55 at V2 (p-value <0.001). The most common type of VF defect at V0 was a nerve fibre layer defect (56.4%), and the second most common type was an enlarged blind spot (20.5%). There was no correlation between BCVA and VF defect type. Mean grade of papilloedema decreased from 2.2 at V0 to 0.5 at V2. The grade of papilloedema at V2 was not significantly related to the severity of papilloedema at V0 (p-values 0.65 and 0.48).

Idiopathic intracranial hypertension (IIH) is associated with long-term loss of visual function, and relevant treatment strategies need to be improved.