Uveitis

Uveitis is generally a range of conditions that cause inflammation inside the eye. However, in most cases, uveitis affects the middle layer tissue of the eyewall known as the uvea. The major function of the uvea is the absorption of light and focusing. The layer consists of several parts, such as: 

1. Iris- The coloured part of the eye surrounding the pupil 
2. Choroid- It is a group of blood vessels underneath the retina and helps the lens in focusing 
3. Ciliary body- It is a muscle ring present behind the iris and connects the retina to the sclera. 

Besides, uvea uveitis can also affect the retina and sclera. The development of uveitis could either be gradual or sudden

The cause of uveitis in most cases is unknown and might be considered an autoimmune disorder. However, probable causes could be: 

1. Any side-effect of a particular medicine 
2. Injury in the eye or eye surgery 
3. Lymphoma- an eye cancer 
4. Infections such as AIDS, herpes, tuberculosis, syphilis, histoplasmosis etc. 
5. Autoimmune conditions like rheumatoid arthritis, ulcerative colitis, Crohn's disease, sarcoidosis etc. 

Individuals more prone to develop uveitis are: 

1. Regular smokers 
2. Women  
3. Middle age people i.e., 20-60 years 
4. Pregnancy 
5. Vitamin D concentration

Uveitis signs might be present in either single or both eyes. Few signs and indications that are observed in uveitis are:  

1. Pain 
2. Red eyes 
3. Pressure on eyes 
4. Dark, floating shapes in view of your vision 
5. Reduced vision 
6. Sensitivity to light 
7. Headache  

For diagnosis of uveitis, the doctor will conduct a proper eye examination and will study your medical records. The various techniques of eye examinations are: 

1. Vision assessment and your response to light: The doctor might also ask you to read the eye chart. 
2. Tonometry: It is employed to measure the intraocular pressure, i.e., pressure in the eyes. 
3. Slit-lamp examination: A slit lamp is a microscope that uses an intense line of light to magnify and enlighten the frontal region of the eye. This examination is required to detect tiny inflammatory cells in the anterior chamber of the eye. 
4. Ophthalmoscopy/fundoscopy- In this, the pupils are dilated, and with the help of bright light, the doctor examines the posterior region of the eyes.  
5. Other diagnostic tests include: 
   1. Colour photography of the retina 
   2. Optical coherence tomography (OCT) imaging: It is performed to measure the thickness of the choroid/retina to examine the inflammation. 
   3. Fluorescein angiography or indocyanine green angiography: is performed to examine the blood vessels present in the posterior region of the eye. 
   4. Gonioscopy: it is performed to examine the exterior region of the eye. 
   5. Blood tests
   6. Analysis of aqueous and vitreous fluids 
   7. Imaging tests such as MRI, CT scan and radiography

Treating the uveitis accurately and timely is essential as the severity of the disease might lead to various other temporary as well as permanent eye conditions like blindness. 

If the cause of uveitis is an underlying condition, then the therapy might focus on the specific condition. 

There are several treatment options, among which the most common is eye drops or ointments. However, the therapy the doctor suggests can also depend upon the kind of uveitis developed. 

1. Drugs aimed to reduce inflammation: Anti-inflammatory eye drops help to reduce the inflammation in anterior uveitis. However, for intermediate and posterior uveitis, doctors suggest corticosteroid injection or tablet as eye drops cannot reach the further regions. 
2. Drugs regulating spasms: To reduce pain, the doctor suggests eye drops that dilate the pupil. Pupil dilation controls the spasms of the iris and ciliary body.  
3. Antibiotics/antivirals: The doctor might prescribe an antibiotic/antiviral or even other medications if the uveitis is caused by an infection. The medication can either be with or without a corticosteroid. 
4. Immunosuppressants: It is prescribed if the severity of the case increases or the body shows no response to other therapy. 

Treating uveitis is very important as untreated uveitis can cause severe eye issues and even blindness. Uveitis is known as the most common reason for blindness among individuals in the middle age group. Other possible conditions could be cataracts, glaucoma, optic nerve damage, retinal swelling, and retinal detachment. 

Disease Progression

The severity of uveitis can be predicted by the area in which it may have occurred. There are four types of uveitis based on their area of occurrence- 

1. Anterior uveitis: It is also known as iritis and is the most common form, affecting the front region of your eye, i.e., amid cornea and iris. It is the least severe uveitis and can be treated easily. 
2. Intermediate uveitis: It is also known as iridocyclitis, and affects the middle region of the eye that includes pars plana- a region amid the choroid and iris. 
3. Posterior uveitis: It is also known as choroiditis as it affects the choroid and retina. These can develop in individuals with autoimmune diseases or an infection. However, the rarest form is comparatively more serious than anterior uveitis. 
4. Panuveitis: In panuveitis, the disease affects every region of the eye. It comprises a combination of features and symptoms of other kinds of uveitis.