Uveitis

What is uveitis?

Uveitis is an inflammatory process affecting the uvea, the thin vascular layer of the eye which is interposed between the external ocular membrane (sclera and cornea) and the retina.

Although the term "uveitis" expresses only inflammation of the uvea, very often this word is improperly used to indicate inflammatory processes affecting other ocular structures, such as the retina, sclera and cornea. The popular imprecise use of the term uveitis is soon explained by the fact that so-called "pure" inflammations (which exclusively affect the "uvea) are quite rare: more often, in fact, uveal infections tend to expand to involve adjacent structures, such as the sclera, retina and" endothelium eye.
Uveitis - like most eye inflammations - requires immediate medical attention: this is because a disease of this type can lead to extremely serious complications. Just think, for example, that 10 -15% of patients with uveitis go blind.

Let's be clear

Each infection involving a single ocular structure is qualified with a precise term:

Scleritis: inflammation of the sclera
Keratitis: inflammation of the cornea
Keratoconjunctivitis: inflammation of the cornea and conjunctiva
Retinitis: inflammation of the retina
Iritis: inflammation of the iris
Iridocyclitis: inflammation of the iris and ciliary bodies

Types of uveitis

We have seen that the uvea is the ocular membrane placed between the outer layer of the eye (sclera and cornea) and the nervous layer (retina). More precisely, the uvea is an ocular structure consisting of three very important sections: choroid, ciliary and crystalline body. Precisely on the basis of the ocular element involved in the inflammation, several types of uveitis can be distinguished:

Anterior uveitis: inflammatory process affecting the iris and ciliary body or only the iris
Intermediate uveitis: inflammation limited to the ciliary body
Posterior uveitis: inflammation (inflammation) of the choroid
Panuveitis (or more simply uveitis): inflammation involving all three structures of the uveal tract

Although this classification is extremely precise and limited to a particular sheet of the uveal tract, let us remember once again that in most cases the uveitis tends to expand, involving more ocular anatomical structures (sclera, cornea, retina, etc.).

Causes

A second classification of uveitis can be performed according to the triggering causes. For this purpose, the endogenous variant of uveitis is distinguished from the exogenous one.
The table shows the most common causes of uveitis:

Causes of exogenous uveitis

Brucellosis
Piercing wounds
Dental granulomas
Herpetic infections
Toxoplasma infections
Leptospirosis
Lyme disease
Sarcoidosis
Syphilis
Surgical interventions
Tuberculosis
Corneal ulcers

Causes of endogenous uveitis

Systemic lupus erythematosus
Behçet's disease
Kawasaki disease
Rheumatic diseases
Local immunological reactions
Multiple sclerosis
Fuchs syndrome (rare inherited disease manifesting as corneal edema)
Ankylosing spondylitis
Eye cancer

In recent years it has been discovered that even cigarette smoking could increase the risk of uveitis: this is because smoking alters (and weakens) the efficiency of the immune system.
Although numerous potential causes of uveitis have been identified, it is often not possible to understand the precise origin.

Symptoms

Very often, patients with uveitis become suspicious of the disease from the very first symptoms: the eye becomes very sensitive and intolerant to light, it is evidently red (ocular hyperemia), and the vision is blurred.
The perception of spots in front of the eyes is also a rather frequent symptom accused by affected patients. In the "uveitis intermedia, for example, the appearance of vitreous floaters (which in technical terms is called floaters) is an obvious warning sign.
More often than not, intermediate and posterior uveitis do not cause unsustainable ocular pain. In chronic anterior uveitis, the disease may even go unnoticed because the symptoms are not so ferocious, and the eye - at least apparently - is also in good health. in the presence of severe inflammation of the uveal tract.
Depending on the causative agent, the symptoms with which uveitis begins may involve only one eye or both.

The typical symptoms of uveitis do not always appear in a sudden and evident way: sometimes, in fact, the onset of the disease is subtle and ambiguous precisely because it does not develop any characteristic symptom that suggests a first diagnostic hypothesis.

Complications

In many patients, uveitis is particularly difficult to eradicate; tant "is that very often the inflammations of the uvea tend to become chronic.
The chronic course of uveitis is the main cause of complications, such as in particular:

Increased intraocular pressure (glaucoma)
Blindness
Damage to the optic nerve
Swelling / detachment of the retina
Inflammation of the cornea
Lens opacity (cataract)

Given the complications and danger of the disease, it is therefore necessary to undergo an ocular examination as soon as possible: in this way, it will be possible to ascertain the uveitis unequivocally in order to undertake a specific therapy as soon as possible.