The Uveal tract in the eye consists of Iris, cilliary body and choroid. It looks fluffy and reddish-brown in colour microscopically, and hence the name has been derived from Latin literature, meaning “a bunch of grapes”.




Uveitis is an endogenous or exogenous inflammation of the uveal tract. Since it is contiguous to Vitreous, Optic nerve, Cornea and Sclera, they can also be involved. The uveal tract is a highly vascular structure, and hence any pathologic occurrence can be worrisome in a long run.



CLASSIFICATION

Depending on the site of involvement, Uveitis is classified as:

Anterior uveitis (Iritis, Anterior cyclitis, Iridocyclitis)

Intermediate uveitis (pars planitis/ peripheral uveitis)

Posterior uveitis (vitritis, focal choroiditis, diffuse choroidits, chorioretinitis, retinochoroiditis, neuroretinitis)

Panuveitis(involvement of all structures)



ETIOLOGY

Uveitis according to its etiology:

Idiopathic uveitis: where its cause couldn’t be found, it is diagnosis of exclusion. It is 30 % among all cases

Secondary to Systemic diseases/Associated diseases with uveitis

   1.Seronegative arthritis

     1.Ankylosing spondylitis

     2.Reiter’s syndrome

*Psoriatic arthritis

1.Behcet’s disease

2.Juvenile rheumatoid arthritis (JRA)

1.Gastrointestinal

  1.Ulcerative colitis

  2.Crohn,s disease

*Whipple,s disease

1.Respiratory

   1.Sarcoidosis

  2.Pulmonary tuberculosis (TB)

2.Infectious causes (like Viral, fungal or parasitic infection of eye)

3.Lens induced

Phaco anaphylactic endophthalmitis or phacotoxic uveitis


5.Masquerade Syndrome

Retinoblastoma, intraocular foreign body, malignant melanoma, lymphoma, retinal detachment multiple sclerosis


6.Associated with septic conditions:

Meningitis, sinusitis, Otitis media, dental caries, tonsilitis, cholecystitis, pneumonia, Urinary tract infection (UTI) etc.



SYMPTOMS

Symptoms of patients with uveitis can range from pain, redness, photophobia, Dimness of vision, watering, Floaters, metamorphopsia.



SIGNS

Various tell tale signs anteriorly can be Circum ciliary congestion, aqueous flare, inflammatory cells in anterior chamber, hypopyon, keratic precipitates, posterior synechia, corneal edema, keratitis etc.






Fundus might show various signs like vitritis (vitreous haze, snow ball opacities in vitreous), retinitis, choroiditis, sheathing of vessels etc.









INVESTIGATIONS

History taking is an art and is the key in diagnosing uveitis. An approach to a patient with uveitis including careful clinical and general physical examination is extremely crucial. Based on review of systems and clinical examination, tailored laboratory test should be ordered.

Ideally speaking, there is no specific uveitic profile. It is never a platter; it has to be specific dish for specific person. Although, routinely ordered tests includes complete blood count, ESR/CRP, Chest X ray/ CT scan, Mantoux test, Serum ACE, VDRL/FTS-ABS, RA Factor, HLA B27, ANA, ANCA, Toxoplasma antibodies, HIV, Hepatitis antibodies etc. Ocular investigations might include OCT, Fluorescein angiography, Ultrasound and AC or Vitreous tap/tissue biopsy.



MANAGEMENT



MEDICAL TREATMENT

Aim of treatment is to prevent vision threatening complication, to relieve the patients’ discomfort, to prevent recurrence and to treat the underlying cause.

Corticosteroids are the cornerstone is managing uveitis. The dose is devised based on the severity of infection and these medications should not be stopped abruptly or it can cause rebound inflammation. Sometimes these medications need to be taken over long period of time to prevent recurrence of the disease. In severe cases, periocular or intravitreal steroids might also be used. Adverse effects of these medications could include ocular side effects like IOP rise, cataract formation etc. to systemic side effects like swelling of face, altered blood pressure etc., hence regular monitoring is extremely important.

Along with these medications, a mydriatic-cycloplegic drug is also very useful. The patient might feel photophobic while using these eye drops, but that effect is usually temporary.

Immunomodulators mean any drug or substance that suppresses the immune response. It is a chemical agent that modifies the immune response or the functioning of the immune system (as by the stimulation of antibody formation or the inhibition of white blood cell activity). These agents are thought to re-educate the immune system to a level that the recurrent autoimmune inflammation of ocular tissues are prevented. There are multiple such drugs in the market, namely Azathioprine, Methotrexate, Mycophenolate Mofetil, Tacrolimus, Ciclosporin, Dapsone, Cyclophosphamide, Infliximab Etc.

Immunomodulator therapy (IMT) should be considered in:
  *sight-threatening ocular inflammation
  *unacceptable/intolerable side effects due to steroids
  *inadequate response to corticosteroids
  *long-term dependence on steroid therapy
  *contraindications of steroid therapy
  *steroid-sparing agents or in severe cases to control the inflammation with a target for durable remission

For some specific diseases during the acute episode, though steroids are crucial for immediate control, early initiation of IMT is vital. IMT once initiated usually take a few weeks to start its effect. When the ocular inflammation becomes stable and IMT begins to take effect, the steroid can be tapered off early and IMT is continued long-term in these diseases. These diseases include Vogt-Koyanagi-Harada syndrome (VKH), Sympathetic Ophthalmia (SO), Amantiades-Behcet disease (ABD), Ocular cicatricial pemphigoid (OCP), Necrotizing scleritis (NS) associated with systemic vasculitis, Serpiginous choroiditis (SC). Although these entities may respond to steroids alone during acute episode, initial treatment with IMT has been noted to improve long-term prognosis and maintain visual acuity.

Before starting IMT certain conditions must be fulfilled:
  *Active infection including tuberculosis/fungal infection must be ruled out
  *There should be no hematological/renal/hepatic contraindication
  *The patient must understand the nature of therapy and must be able to come in a regular follow-up every 4-8 weekly depending on the medication used.
  *Informed consent of the patient with an explanation of the side effects of the drug including allergy, increased risk of infection and rarely malignancy; though most of the patients tolerate these drugs well. Compliance with follow-up is important. If they do not tolerate the medication, there is a plenty of options of other IMT drugs.
  *The patient should not plan pregnancy/conception during the IMT.
  *The patient should not receive any live vaccines.
  *Meticulous follow-up and regular blood labs to monitor any early side effects. The patient should preferably be co-managed with a physician/managed by ocular immunologist who by the virtue of experience and training is qualified to prescribe and monitor such medications and can manage the toxicities personally.
  *Good hydration, exercise and smoking cessation are good practices during this therapy.
Most of the uveitic diseases have a systemic correlation. Systemic disease associated with uveitis should get treated simultaneously by their specialist. A team approach is something that works in the best in uveitis.




SURGICAL TREATMENT

Surgery is not indicated in all cases of uveitis. It is required in severe cases only in case of complications like cataract, glaucoma, severe vitritis (severe opacified vitreous), retinal detachment etc. Major surgeries like phacoemulsification, vitrectomy or buckling that are required in such cases are usually done under steroid or IMT cover.




PROGNOSIS

Patients with uveitis may follow a course of recurrent bouts of acute inflammation. The disease free interval may range from weeks to years, but it’s very important to keep monitoring in this period. If the episodes are treated early, the prognosis is usually good. Uveitis associated with systemic disease has higher recurrence rate and higher incidence of complication. If not treated on time, it can result into permanent loss of vision and decrease in size of eyeball (phthisis). Hence, timely and appropriate management with a specialist is of utmost importance.






PATIENTS PERSPECTIVE

“A stitch in time saves nine!” is quite a relevant quote for uveitis. Uveitis is not just disease of the eye; in most of the times, it is the disease of body where eye involvement is one of the features. So the treatment of the disease should be accordingly and timely. As the mainstay of treatment is steroids, abrupt discontinuation of the treatment should not be done. A good compliance and a team approach is the solution to managing uveitis.




AUTHORS:

Dr Dhaivat Shah (MS DNB FMRF) (Vitreoretinal Surgeon)

Dr Manan Solanki (DOMS) (DNB Asp)

For any queries related to this topic, kindly mail on: dhaivatkshah@gmail.com