Headache and amaurosis fugax in an obese woman
BMJ 2015; 351 doi: https://doi.org/10.1136/bmj.h6365 (Published 01 December 2015) Cite this as: BMJ 2015;351:h6365
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I read the spot diagnosis piece by Tripathy and Ramesh with interest. Although Tripathy and Ramesh mention some features that help differentiate true papilloedema from pseudopapilloedema, there is no mention of spontaneous venous pulsations (SVPs). These are cyclical variations of the calibre of retinal veins, which are best seen near the optic disc. They are present in 90% of individuals without raised intracranial pressure (ICP), but disappear when intracranial pressure is raised. Levin showed that SVPs disappear when ICP rises above 18-19 cmH20 (1). They can, however, be absent in 10% of normal individuals without raised ICP (1). This means that in the assessment of discs with possible papilloedema, the identification of SVPs is a re-assuring sign that raised ICP is not present. However, the reverse does not hold true - the absence of SVPs does not necessarily mean the individual has raised ICP.
More detailed optic disc analysis is possible with spectral domain optical coherence tomography imaging (SD-OCT), which has also been shown to be helpful in differentiating true papilloedema from psudeopapilloedema (2,3). In addition, through its high resolution images, subtle changes in disc swelling can be measured. This makes SD-OCT a useful tool in the monitoring of patients with papilloedema.
Furthermore, in addition to visual fields, colour vision testing should also form part of the assessment of patients with papilloedema. It is a sensitive marker for optic nerve dysfunction and can be performed quickly and easily without the requirement of specialist ophthalmic equipment (4).
1) Levin E, Barry E. The Clinical Significance of Spontaneous Pulsations of the Retinal Vein. Arch Neurol. 1978;35(1): 37-40. doi:10.1001/archneur.1978.00500250041009
2) Sarac O, Tasci Y, Gurdal C et al. Differentiation of Optic Disc Edema From Optic Nerve Head Drusen With Spectral-Domain Optical Coherence Tomography.doi: Journal of Neuro-Ophthalmology. 2012;32(3): 207-211. doi: 10.1097/WNO.0b013e318252561b
3) Bassi S and Mohana K. Optical coherence tomography in papilledema and pseudopapilledema with and without optic nerve head drusen. Indian J Ophthalmol. 2014;62(12): 1146–1151. doi: 10.4103/0301-4738.149136
4) Obi E, Lakhani B, Burns J et al. Optic nerve sheath fenestration for idiopathic intracranial hypertension: A seven year review of visual outcomes in a tertiary centre. Clinical Neurology and Neurosurgery. 2015;137: 94-101. doi:10.1016/j.clineuro.2015.05.020
Competing interests: No competing interests
Difference between papilloedema and pseudopapilloedema
The authors thank Dr. Malem for his interest in this article. We congratulate him for his comments on differences between papilloedema and pseudopapilloedema which are very relevant and clinically important. The word-limits of the specific type of articles may prevent detailing all important clinical features of patients. Our patient did not have spontaneous retinal venous pulsations bilaterally. Interested readers may please be referred to authoritative text elsewhere [Michael C. Brodsky. Congenital Anomalies of the Optic Disc. In: Miller NR, Newman NJ. Walsh and Hoyt’s Clinical Neuro-Ophthalmolgy, 6th Ed. Baltimore: Lippincott Williams and Wilkins, 2005].
We are adding a representative table comparing papilloedema versus pseudopapilloedema.
Competing interests: No competing interests