Fundus imaging and perimetry in patients with idiopathic intracranial hypertension - an intermethod and interrater validity study.

BACKGROUND: There is a need to improve the diagnostic process of patients suspected of papilledema. In patients with known or suspected idiopathic intracranial hypertension we validated a fundus imaging and perimetric visual field assessment system (COMPASS) performed at a headache centre in comparison to an assessment (Topcon plus OCTOPUS) at a neuroophthalmological clinic.

METHODS: For intermethod assessment, blinded fundus images and perimetry from COMPASS versus Topcon plus OCTOPUS were assessed by a neuroophthalmologist. For interrater assessment, fundus images and perimetry obtained by the COMPASS system were assessed by an untrained medical doctor, a trained neurologist and a trained medical student and compared to the neuroophthalmologist's assessments.

RESULTS: For the intermethod variation of presence of papilledema on fundus images, a kappa value of 0.60, sensitivity of 87% and specificity of 73% were found. The interrater variation of presence of papilledema on fundus images showed kappa values ranging from 0.43 - 0.74, sensitivity values ranging from 69.8% - 96.2% and specificity values ranging from 45.6% - 93.4% when comparing the assessments made by the headache centre staff with neuroophthalmologist's assessments. The COMPASS showed a 59% sensitivity and moderate agreement in detecting visual field defects compared with OCTOPUS. The visual field assessment showed only slight to fair agreement from 0.19 - 0.31 between assessments made by the headache center staff and the neuroophthalmologist.

CONCLUSION: The COMPASS system can be used with reasonable sensitivity in the assessment of papilledema in patients suspected of IIH at a tertiary headache centre.