Hypopyon

Hypopyon
Classification and external resources
File:Hypopyon.jpg Hypopyon seen as yellowish exudate in lower part of anterior chamber of eye
ICD-9	364.05
DiseasesDB	7150

Hypopyon is pus in the eye.

It is a leukocytic exudate, seen in the anterior chamber, usually accompanied by redness of the conjunctiva and the underlying episclera. It is a sign of inflammation of the anterior uvea and iris, i.e. iritis, which is a form of anterior uveitis. The exudate settles at the bottom due to gravity.

Differential diagnosis

Hypopyon can also be present in a corneal ulcer, particularly of fungal etiology like Aspergillus and Fusarium sp., Behcet's disease, endophthalmitis, and panuveitis/panophthalmitis. Hypopyon is also known as sterile pus, as it occurs due to the release of toxins and not by the actual invasion of pathogens. The toxins secreted by the pathogens mediate the outpouring of leukocytes that settle down in the anterior chamber of the eye. Hypopyon is the only pus in the body that does not require any specific treatment as treatment of the underlying cause results in its resolution. An inverse hypopyon needs to be differentiated from a standard hypopyon. Inverse hypopyon is seen sometimes after a pars plana vitrectomy with insertion of silicon oil (as a replacement of the vitreous humour that has been removed in the operation; the silicon oil maintains internal tamponade). When the silicon oil emulsifies, it seeps into the anterior chamber and settles at the top of the anterior chamber. Compare from the hypopyon resulting due to the toxins where the leukocytes settle at the bottom of the anterior chamber. This is due to the effect of gravity, hence the name inverse hypopyon.

References

Gonzalez-Granado LI. Aspergillus endophthalmitis: Pars plana vitrectomy is an alternative Indian J Med Sci 2009;63(8):366-367. DOI: 10.4103/0019-5359.55892

See also

• Hyphema
• Uveitis

External links

• http://www.stlukeseye.com/Conditions/Hypopyon.asp