Rating papilloedema: an evaluation of the Frisén classification in idiopathic intracranial hypertension
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The appearance of the optic disc is a key measure of disease status in idiopathic intracranial hypertension (IIH). The Frisén classification describes stages of optic disc swelling (grades 0–5). It is the only classification of papilloedema, and is used internationally in clinical and research practice. Despite this, there has been very limited evaluation of the scale. We assessed the inter-rater reproducibility and ability to discriminate optic disc changes over time using the Frisén classification compared with a system of ranking papilloedema severity in patients with IIH. Paired disc photographs (before and after treatment) were obtained from 47 patients with IIH (25 acute and 22 chronic). Six neuro-ophthalmologists blinded to patient identity, clinical information and chronology of the photographs reviewed the discs and allocated a Frisén grade and ranked the paired discs in order of papilloedema severity (disc ranking). A total of 188 optic disc photographs were reviewed. All six reviewers agreed in only three comparisons (1.6%) when using the Frisén classification, compared with 42 comparisons (45.2%) when using disc ranking. The probability of agreement between any two reviewers was 36.1% for Frisén grade and 70.0% for disc ranking. Disc ranking had significantly greater sensitivity for finding differences in degree of disc oedema, identifying a difference in 75.3% of paired photographs compared to 53.2% detected using the Frisén classification (p < 0.001). This study demonstrated the limited reproducibility and discriminative ability of the Frisén classification in identifying changes in serial optic disc photographs in IIH. Simple optic disc ranking appears to be a more sensitive and reliable tool to monitor changes in optic disc appearance. The use of disc ranking in clinical practice and research studies is recommended to monitor alterations in optic disc appearance until alternative schemes, specific to IIH, have been developed.
KeywordsFrisén classification Papilloedema Idiopathic intracranial hypertension Grading
We would like to thank Jonas Brane, Medical illustrations Technician, Sandwell and West Birmingham Hospitals NHS Trust, for his help with the fundus photography. This study was funded by the Vera Down (Neurological Diseases) 2005, and Clark & McMaster (Blinding Diseases) 2005 Awards, British Medical Association, UK, a Research and Development award 2005 from Sandwell and West Birmingham Hospitals NHS Trust, and by The West Midlands Neuroscience Teaching and Research Fund, UK. Alexandra Sinclair is a MRC Clinical Training Fellow (London, UK). The Academic Unit of Ophthalmology is supported by the Birmingham Eye Foundation (Registered (UK) Charity 257549.
Conflicts of interest
- 8.Sinclair A, Burdon M, Ball A, Nightingale N, Good P, Matthews T, Jacks A, Lawden M, Clarke C, Walker E, Tomlinson J, Stewart P, Rauz S (2010) Low energy diet and intracranial pressure in women with idiopathic intracranial hypertension: prospective cohort study. BMJ 7:341Google Scholar