What are uveitis?

The uveal tract of the eye consists of the iris, ciliary body and choroid.

The color of the iris depends on the amount and arrangement of the pigment. The opening on the iris – the pupil/pupil has the function of an aperture, it determines the amount of light that will reach the deeper layers of the eye and the macula. It contracts in stronger light, and slightly expands in the dark.

The ciliary body produces aqueous humor and thus regulates the tone of the eyeball, and also participates in the process of accommodation.

The choroid contains a rich network of blood vessels and participates in the nutrition of the retina.

Uveitis is inflammation of the uveal tract of the eye!

Division of uveitis according to the localization of the inflammatory process:

• anterior uveitis – iritis/iridocyclitis are inflammations of the iris and ciliary body
• intermediate uveitis – pars planitis
• back/posterior – affected vitreous body, choroid and retina
• panuveitis – the entire ear is affected

Division of uveitis according to cause:

• infectious (spells are viruses, bacteria, fungi, parasites)
• non-infectious (associated with autoimmune diseases)

Non-infectious uveitis is more common. They are associated with autoimmune diseases, such as: arthritis, inflammatory bowel diseases – ulcerative colitis and Crohn’s disease, psoriasis, nephritis, sarcoidosis…). The first symptoms of a systemic disease can appear right in the eye. Often, inflammatory conditions in the eye arise as a result of the presence of some process, i.e. foci in the body, around the roots of the teeth, tonsils, paranasal cavities, ovaries.

Infectious uveitis is most often caused by herpes viruses, then CMV, HIV, rubella virus, but also parasites such as toxoplasma, toxocariasis, fungi and bacteria (tuberculosis bacillus, treponema, borrelia, etc.).

The most common are anterior uveitis!

The main symptoms of anterior uveitis are:

• sensitivity to light / photophobia
• pain in the eye
• vision loss
• increased lacrimation / epiphora

Signs of anterior uveitis are:

• Redness, i.e. hyperemia of the eye of the ciliary type-perilimbal
• Changes on the cornea and in the anterior chamber of the eye (appearance of precipitate on the corneal endothelium as well as inflammatory cells and proteins floating inside the anterior chamber of the eye – exudation, appearance of nodules on the iris…)
• Pupil constriction/ miosis
• A drop in eye pressure and sometimes a jump in eye pressure
• The appearance of synechiae-adhesions between the cornea and the lens, as well as between the lens and the lens, in which the pupil becomes irregularly shaped, in a chronic course due to fibrinous escultation

The pupil is irregularly shaped, due to the presence of adhesions, there are also changes in the cornea – precipitates – accumulations of inflammatory elements

Ciliary hyperemia – redness of the eye is most pronounced around the cornea like a ring

In the anterior chamber of the eye as well as on the front surface of the lens, fibrin deposits can appear – fibrin exudation.

The exudation can be purulent – the appearance of a whitish level at the bottom of the anterior chamber – hypopyon, as well as hemorrhagic in the most severe cases.

Fibrin cake

Hypopion

In the case of intermediate uveitis, in addition to the above – mentioned symptoms, there is also the appearance of floating opacities due to the spread of the process into the vitreous body. Very often there is swelling in the yellow spot and appearance of distortion of the image – metamorphopsia.

Vitreous opacities – look like snowballs

Posterior uveitis is characterized by changes in the vessels and retina, changes are also present in blood vessels (vasculitis). Swelling of the head of the optic nerve is often present as well as macula-points of clear vision due to leakage of blood vessels.

Color fundus photo

Fluorescence angiography – FA

Posterior uveitis – you can see scattered infiltrates, foci – chorioretinitis in the form of cottony whitish zones of accumulation of inflammatory cells, inflammation can also be primarily of blood vessel origin – vasculitis, then you can see infiltrates around blood vessels, “muffling” and gradually develop occlusion, clogging of blood vessels, all that in the fresh phase, it results in swelling of the retina, bleeding and then occlusion/clogging of blood vessels with consequent ischemia and the development of neovascularization.

Fresh focus – chorioretinitis

Uveitic old focus in toxoplasmosis of central localization

The diagnosis of uveitis is made based on the present signs and symptoms, by examining the patient under a biomicroscope. It is also important to mention additional diagnostic procedures (OCT of the macula/ optic nerve papillae/ layer of nerve fibers, US examination in severe vitreous opacities such as I FA – fluorescein angiography to assess the condition of the external and internal hematoretinal barrier). In addition to the examination, laboratory analyzes and additional examinations (eg X-ray of the joints, lungs, endoscopic examinations…) are also important in order to establish a precise diagnosis, i.e. to determine the cause.

Treatment of uveitis is a long and often complicated process. Anterior uveitis usually resolves after application of local therapy in the form of drops – corticosteroids, mydriatics (drops that dilate the pupil), anti-inflammatory drugs are used. Application of subconjunctival therapy (application of corticosteroid drugs and mydriatics in the form of injections under the conjunctiva) is necessary in the presence of adhesions. Intermediate and posterior uveitis require the use of parabulbar therapy, intravitreal and sometimes systemic therapy (specific therapy, corticosteroids, immunosuppressants). The appearance of uveitis in both eyes certainly requires systemic therapy.

It is important to contact the ophthalmologist on time so that a diagnosis can be made as soon as possible and treatment can begin! Uveitis often recurs! The chronic course, frequent relapses, inadequate treatment, as well as treatment not undertaken on time, lead to numerous complications:

• secondary glaucoma due to adhesions
• cataract of inflammatory etiology (difficult for surgery due to the presence of adhesions)
• permanent vision loss due to changes in blood vessels-occlusions
• chronic cystoid edema in the macula
• exudative and traction retinal ablation
• due to deep ischemia and neovascular glaucoma