Hypopyon is the collection of pus in the bottom of the anterior chamber of the eye. It can be clearly visualized as a fluid level and the sedimentation is governed by the gravity. The composition of the pus would be only white cells or leucocytes without any pathogens of bacterial, fungal or even viral origin.
1. Pathophysilogy of hypopyon
The basis on its appearance is not due to the infectious organism per se, but it is due to the toxins that are released in certain instances. These toxins will make more and more white blood cells which are the defense against any pathogen or chemical harm to the body, to pour out from the blood vessels in the region. The hypopyon being pus collection in the anterior chamber indicates inflammatory process in that region, mainly the iris and the uvea.
2. Related structures
The iris is the area which gives color to the eye. The uvea on the other hand is divided into several sections as it extends around the eye globe towards the retina.
The front of the eye is covered by a thin mucous membrane called the conjunctiva. It also lines the inside of the eye lids and overlies the white of the eye, known as the sclera. The function of the conjunctive is to prevent any microbes from entering into the eye chambers and causing any infections. In some instances the conjunctive can be breeched prior to hypopyon.
3. Causes
Infections of the iris and the uvea can be caused by both systemic as well as local conditions. Some of them are,
a) Corneal ulcers
Corneal ulcers are damages in the cornea due to foreign bodies or chemicals. It can also be caused by trauma to the eye. In any instance the danger will be the possibility of harmful pathogens entering into the eye through the breech. Sometimes the foreign bodies can be lodged inside. The resultant infection and inflammation will give rise to a hypopyon.
b) Tuberculosis
The mycobacterium tuberculosis is the pathogen responsible for causing tuberculosis or TB in the lungs and other sites of the body. The same bacteria can cause a uveitis kind of eye disease that can lead to a hypopyon.
c) Herpes Simplex and Herpes Zoster
These viruses that are causative organisms for the herpes infection and chicken pox are culprits in creating a form of hypopyon.
d) Lyme disease and toxocariasis
Both of these infections are systemic infections that can manifest as a hypopyon.
e) Multiple sclerosis and Psoriatic arthritis
The conditions are being driven by an autoimmune process and it has been found to cause pus formation in the eye without a underlying infection.
4. Treatment
The treatment of hypopyon is dependent on its cause, if it’s caused by tuberculosis, to treat the pathogen due to the TB should be an idea option.
On the other hand, the hypopyon will go away on its own without any treatment, however, if the underlying condition is not treated, it can result in glaucoma, visual impairment, cataract formation, and even retinal detachment.
