Abstract
Purpose: :
Swollen discs may be a sign of a life-threatening condition due to increased intracranial hypertension (papilledema), or a sign of benign conditions (pseudopapilledema) like optic nerve head drusen It is not uncommon to have difficulty in differentiating between those conditions. The goal of this study was to show that optic nerve ultrasonography is a reliable, accurate, readily available and low-cost tool to differentiate papilledema from pseudopapilledema.
Methods: :
Forty-four patients with bilateral swollen discs were prospectively evaluated. They all underwent comprehensive medical and ophthalmological examinations, imaging (brain and orbit CT/MRI) and a lumbar puncture, as well as optic nerve ultrasonography for detecting pathological widening of the nerve. We compared the optic nerve ultrasonographic findings to the final diagnosis that had been reached after the workup and follow-up, and calculated the sensitivity and specificity of optic nerve ultrasonography for differentiating papilledema from pseudopapilledema.
Results: :
Twenty-three males and 21 females aged 12±6.5 y (2.5-30.5) participated. The average follow up was 1.5 y. The calculated sensitivity of the examination was 95%, with a specificity of 58%, a positive predictive value of 66%, a negative predictive value of 93% and a correlation coefficient of +0.56 (p<0.001).
Conclusions: :
According to our results evaluation of optic nerve head by ultrasonography had high sensitivity and specificity. Since this was a historic prospective study and not a case-control study, it was possible to calculate the positive and negative predictive values of the procedure for detecting papilledema. This information gives a statistical basis for decision-making when determining the etiology of bilateral swollen discs. According to our findings , optic nerve ultrasonography has significantly higher sensitivity than funduscopy. As such, a combination of a thorough clinical examination and optic nerve ultrasonography may be definitive and render further workup unnecessary in some cases.
Keywords: optic disc • neuro-ophthalmology: diagnosis • imaging/image analysis: clinical