Long-term visual outcome in idiopathic intracranial hypertension

To characterize the course, outcome, and risk of relapse or late worsening in a clearly defined cohort of idiopathic intracranial hypertension (IIH) over a long period of follow-up.

Retrospective chart review of patients with definite IIH was evaluated at the Sree Chitra Tirunal Institute for Medical Sciences and Technology between 1998 and 2006. Patients' demographic data, clinical, neuro-ophthalmic examinations, and treatment details were abstracted. Patients were further categorized into three groups based on whether they improved, worsened, or relapsed on follow-up. Final visual outcome of each patient was defined according to grading of the worse eye at the last visit. Statistical analysis included t test to compare group means and chi-square test to compare proportions.

Of the 43 women included, visual impairment was observed in 80 eyes (93%) at presentation and it was moderate to severe in 14%. The mean CSF opening pressure at presentation did not differ significantly in those with visual impairment compared to those with normal vision. Those having early severe visual impairment had significantly higher (P = 0.015) likelihood of severe visual impairment on last follow-up. Of the total, 34 patients (79%) improved, 4 (9.3%) relapsed on follow-up after period of stability, and 5 (11.6%) worsened over 56 months follow-up (range, 26-132 months). The groups were comparable, except those who improved were younger (P<0.05). At last examination, 9% had significant vision loss.

IIH patients can have delayed worsening or relapses and about tenth of patients can have permanent visual loss early or late in the course of the disease. All patients with IIH need to be kept under long-term follow-up, with regular monitoring of visual functions.