Uveal Tract Diseases

Outline Uveal tract is inclined to be affected by autoimmunity、infection、metabolism、hematogenous factor、tumor, et al. melanin correlated Ag Choroidal blood flow is slow Ag of retina and lens cause uveitis Inflammation is the most common reason, tumor is the second.

Uveitis

Outline The term “uveitis” denotes inflammation of the uvea、retina、retinal vasculature and vitreous. Uveitis is a common cause of blindness, usually affects young people and associated with systemic autoimmune diseases.

Etiology and mechanism inflammation Autoimmune factor Oxidize damage The metabolites of arachidonic acid Immunogenetics

Classification According to causes：infective and non-infective uveitis According to clinical pathology：granulomatous and nongranulomatous uveitis According to anatomy：anterior、intermediate、posterior uveitis and panuveitis.

Anterior uveitis classify by process： Anterior uveitis consists of iritis、iridocyclitis、anterior cyclitis. classify by process： （1）acute anterior uveitis：HLA—B27 positive. （2）chronic anterior uveitis：such as Fuchs heterochromic uveitis、glaucomatocyclitic crisis, et al. （3）either acute or chronic: such as tuberculosis、syphilis、chronic arthritis.

Clinical findings Symptoms: Signs: pain、photophobia、tearing、blurred vision. Signs: （1）ciliary congestion or mixed congestion （2）KP: corneal endothelium injury inflammatory cells and pigments existence.

Classification of KP ： Stellate KP：neutrophil、lymphocyte and plasma cells, ——nongranulomatous uveitis. Medium sized KP：neutrophil、lymphocyte and plasma cells.——Fuchs heterochromic uveitis and uveitis secondary by herpes simplex virus keratitis. Mutton fat KP：macrophage and epithelioid.——granulomatous uveitis.

Location of KP Arlt’s triangle：the most common，seen in many types of anterior uveitis Pupillary cornea：seen in Fuchs heterochromic uveitis 、 uveitis due to herpes simplex virus and glaucomatocyclitic crisis. diffuse distribution：seen in Fuchs heterochromic uveitis 、 uveitis due to herpes simplex virus .

（3）Flare in the aqueous：It is because of the damage of blood-aqueous barrier and protein enter into aqueous, presents when anterior uveitis、ACG、blunt trauma. （4）Cell in the aqueous：inflammatory cells display uniform gray particles under slit lamp. Particularly severe anterior chamber inflammation may result in layering of inflammatory cells in the inferior angle（hypopyon）.

（5）Change in iris: may be edema、texture unclear, et al. the synechia between iris and the anterior surface of lens is called iris posterior synechiae. When posterior synechiae is exensive，aqueous cannot outflow，usually produce pupillary seclusion and forward bulging of the iris，is called iris bombe. Synechia between iris and the posterior surface of cornea is called iris anterior synechiae.

Iris nodules: ①Koeppe nodules: gray semitransparent nodules presenting at the iris margin——nongranulomatous uveitis ②Busacca nodules: white or gray semitransparent nodules presenting in the iris parenchyma——granulomatous uveitis ③Iris granuloma：single pink opaque nodules presenting in the iris parenchyma——sarcoidosis

（6）Change of pupil：miosis or irregular due to spasm of ciliary muscle and contraction of sphincter pupillae muscle. The pupil may be small or irregular due to the formation of the iris posterior synechiae. If iris synechiae reach 360 degree，is called Seclusio pupillae. If fibrous membrane cover the whole pupil，is called occlusion of pupil.

（7）Change of lens: some pigment may be deposit on the surface of lens in uveitis; circular shape pigment deposition often occur after release of iris posterior synechiea. （8）Change of posterior segment：Cells in the anterior vitreous ，cystoid macular edema、optic edema.

Complications Complicated cataract：due to the change of aqueous content or application of corticosteroid. Secondary glaucoma：inflammatory cells、fibrous exudation and tissue fragments block trabecular meshwork；the seclusion and occlusion of pupil impede aqueous outflow. Ocular hypotension and atrophy of eyeball：ciliary body atrophy——aqueous  ——IOP

Differential Diagnosis 1、Acute conjunctivitis 2、Acute angle closure glaucoma 3、intraocular tumor 4、diffuse uveitis

Treatment principle Mydri asis immediately : prevent iris posterior synechiae. Anti-inflammation in time: prevent tissue injury and complications.

1.Cycloplegics： 1%、2%、4% Atropine ①prevent and cure iris posterior synechiae，prevent complications； ②release the spasm of ciliary muscle and Sphincter pupillae muscle，then reduce congestion、edema、inflammation and pain. 2.Corticosteroids: local and systemic application 3.NSAID

4.Treat primary diseases： 5.Treatment of complications： Secondary glaucoma: take diamox orally and timolol eyedrop. If pupillary block exist, perform laser iridotomy or iridotomy in time. If Anterior chamber angle extensively adhere，perform trabeculectomy. Complicated cataract: when inflammation under good control，perform cataract extraction and IOL implantation.