In the acute stage of the disease, a catarrhal conjunctivitis is present, with signs of ocular pain, usually blepharospasm, increased lacrimation, and photophobia. Miosis is also usually present. After a few days, this will progress to a keratitis and iridocyclitis. Other ocular problems may also occur, including conjunctival and corneal oedema, and aqueous flare.

After an acute flare-up, no clinical signs of disease may be seen for a prolonged period, which can vary from a few hours to a few years. With frequent acute incidents, though, additional clinical signs may be seen, including anterior and posterior synechiae, poor pupillary responses, cataracts, and a cloudy appearance to the vitreous humour.

Inflammation in the back of the eye is commonly characterized by:

- Floaters

- Blurred vision

- Photopsia or seeing flashing lights

Most common:

- Floaters

- Blurred vision

Intermediate uveitis normally only affects one eye. Less common is the presence of pain and photophobia.

Equine recurrent uveitis (ERU), also known as moon blindness, recurrent iridocyclitis or periodic ophthalmia, is an acute, nongranulomatous inflammation of the uveal tract of the eye, occurring commonly in horses of all breeds, worldwide. The causative factor is not known, but several pathogeneses have been suggested. It is the most common cause of blindness in horses. In some breeds, a genetic factor may be involved.

Symptoms of this disorder include floaters, blurred vision, photopsia (flashing lights in eyes), loss of color vision and nyctalopia. In an eye examination, light-colored spots on the retina are seen. Complete loss of visual acuity may happenThe name of the condition comes from the small light-colored fundus spots on the retina, scattered in a pattern like birdshot from a shotgun, but these spots might not be present in early stages.

Patients with ARN typically present

- floaters

- redness of the eye

- flashes

- decreased sharpness of vision

- photophobia.

Though uncommon, some patients may experience pain. Most patients will only experience this in one eye (unilateral), though possible for the condition to be seen in both (bilateral, BARN). If the first eye is left without treatment, some cases have shown the disease progressing to the other eye in a month's time. Further progressed stages of the disease can cause blindness in the eye experiencing ARN. Though the disease may be present itself, the inflammation of the retina may not been visualized for decades after the initial signs.

Symptoms of episcleritis include mild eye pain, redness, and watery eyes. The pain of episcleritis is typically mild, less severe than in scleritis, and may be tender to palpation.

There are two types of episcleritis: the diffuse type, where the redness involves the entire episclera, and the nodular type, where the redness appears more nodular, involving only a small, well-circumscribed area (sectoral). The diffuse type of episcleritis may be less painful than the nodular type. Sometimes, small nodules are present within the episclera, which move slightly over the sclera with gentle pressure.

Discharge is absent with episcleritis, and vision is unaffected. Patients with episcleritis experience far less photophobia than patients with uveitis. Episcleritis does not cause the presence of cells or flare in the anterior chamber of the eye.

Birdshot chorioretinopathy now commonly named "Birdshot Uveitis" or ""HLA-A29 Uveitis"" is a rare form of bilateral posterior uveitis affecting the eye. It causes severe, progressive inflammation of both the choroid and retina.

Affected individuals are almost exclusively caucasian and usually diagnosed in the fourth to sixth decade of their lives.

Episcleritis is a benign, self-limiting inflammatory disease affecting part of the eye called the episclera. The episclera is a thin layer of tissue that lies between the conjunctiva and the connective tissue layer that forms the white of the eye (sclera). Episcleritis is a common condition, and is characterized by the abrupt onset of mild eye pain and redness.

There are two types of episcleritis, nodular and simple. Nodular episcleritis lesions have raised surface. Simple episcleritis lesions are flat. There are two subtypes. In diffuse simple episcleritis, inflammation is generalized. In sectoral simple episcleritis, the inflammation is restricted to one region.

Most cases of episcleritis have no identifiable cause, although a small fraction of cases is associated with various systemic diseases. Often people with episcleritis experience it recurrently. Treatment focuses on decreasing discomfort, and includes lubricating eye drops. More severe cases may be treated with topical corticosteroids or oral anti-inflammatory medications (NSAIDs).

The sequence of clinical events in VKH is divided into four phases: prodromal, acute uveitic, convalescent, and chronic recurrent.

The prodromal phase may have no symptoms, or may mimic a non-specific viral infection, marked by flu-like symptoms that typically last for a few days. There may be fever, headache, nausea, meningismus, dysacusia (discomfort caused by loud noises or a distortion in the quality of the sounds being heard), tinnitus, and/or vertigo. Eye symptoms can include orbital pain, photophobia and tearing. The skin and hair may be sensitive to touch. Cranial nerve palsies and optic neuritis are uncommon.

The acute uveitic phase occurs a few days later and typically lasts for several weeks. This phase is heralded by bilateral panuveitis causing blurring of vision. In 70% of VKH, the onset of visual blurring is bilaterally contemporaneous; if initially unilateral, the other eye is involved within several days. The process can include bilateral granulomatous anterior uveitis, variable degree of vitritis, thickening of the posterior choroid with elevation of the peripapillary retinal choroidal layer, optic nerve hyperemia and papillitis, and multiple exudative bullous serous retinal detachments.

The convalescent phase is characterized by gradual tissue depigmentation of skin with vitiligo and poliosis, sometimes with nummular depigmented scars, as well as alopecia and diffuse fundus depigmentation resulting in a classic orange-red discoloration ("sunset glow fundus") and retinal pigment epithelium clumping and/or migration.

The chronic recurrent phase may be marked by repeated bouts of uveitis, but is more commonly a chronic, low-grade, often subclinical, uveitis that may lead to granulomatous anterior inflammation, cataracts, glaucoma and ocular hypertension. Full-blown recurrences are, however, rare after the acute stage is over. Dysacusia may occur in this phase.

Clinical signs include redness of the eye, pain, blurring of vision, photophobia and floaters.

Symptoms may include the presence of floating black spots, blurred vision, pain or redness in the eye, sensitivity to light, or excessive tearing.

Acute Retinal Necrosis (ARN), is a medical inflammatory condition of the eye. The condition presents itself as a necrotizing retinitis. The inflammation onset is due to certain herpes viruses, Varicella Zoster Virus (VZV), Herpes Simplex Virus (HSV-1 and HSV-2) and Epstein-Barr Virus (EBV).

People with the condition usually display redness of the eye, white or off-white colored patches that are patches of retinal necrosis. ARN can progress into other conditions such as uveitis, detachment of the retina, and ultimately can lead to blindness.

The disease was first characterized in 1971, in Japan. Akira Urayama and his colleagues had six patients whose cases showed signs of acute necrotizing retinitis, retinal arertitis, choroiditis, and late-onset retinal detachment. The combination of the conditions was given the name acute retinal necrosis. The first reports of ARN came about in 1971. It is unclear whether it was previously just reported as something else. Urayama and his colleagues reported the disease that they saw in six Japanese patients. Since then the disease has been seen in patient's with AIDS, children, and people who are immunocompromised. In 1978, Young and Bird named the disease when presented in both eyes, Bilateral Acute Retinal Necrosis, otherwise known as BARN.

The disease is characterised by bilateral diffuse uveitis, with pain, redness and blurring of vision. The eye symptoms may be accompanied by a varying constellation of systemic symptoms, such as auditory (tinnitus, vertigo, and hypoacusis), neurological (meningismus, with malaise, fever, headache, nausea, abdominal pain, stiffness of the neck and back, or a combination of these factors; meningitis, CSF pleocytosis, cranial nerve palsies, hemiparesis, transverse myelitis and ciliary ganglionitis), and cutaneous manifestations, including poliosis, vitiligo, and alopecia. The vitiligo often is found at the sacral region.

Intermediate uveitis is a form of uveitis localized to the vitreous and peripheral retina. Primary sites of inflammation include the vitreous of which other such entities as pars planitis, posterior cyclitis, and hyalitis are encompassed. Intermediate uveitis may either be an isolated eye disease or associated with the development of a systemic disease such as multiple sclerosis or sarcoidosis. As such, intermediate uveitis may be the first expression of a systemic condition. Infectious causes of intermediate uveitis include Epstein-Barr virus infection, Lyme disease, HTLV-1 virus infection, cat scratch disease, and hepatitis C.

Permanent loss of vision is most commonly seen in patients with chronic cystoid macular edema (CME). Every effort must be made to eradicate CME when present. Other less common causes of visual loss include retinal detachment, glaucoma, band keratopathy, cataract, vitreous hemorrhage, epiretinal membrane and choroidal neovascularization.

• Typically affects short sighted (myopic) women. (90% of cases are female).

• The average age of patients with PIC is 27 years with a range of 16–40 years.

• Patients are otherwise healthy and there is usually no illness, which triggers the condition or precedes it.

• The inflammation is confined to the back of the eye (posterior). There is no inflammation in the front of the eye (anterior chamber) or vitreous (the clear jelly inside the eye). This is an important distinguishing feature of PIC.

• It usually affects both eyes.

• The appearance of gray-white or yellow punctate (punched out) areas (lesions) at the level of the inner choroid. These lesions are typically located centrally at the back of the eye (posterior pole).

Symptoms typically include:

1. Blurring of vision

2. Partial ‘blind spots’ or scotoma. These areas of diminished or lost areas of the visual field are typically near the centre of vision but occasionally can be peripheral. These may be temporary or permanent.

3. Seeing flashing lights. This is known as photopsia.

The PIC lesions, which form scars deep in the choroid layer of the eye, may result in new blood vessels forming. These can be seen as the body’s attempts at repair, but these new blood vessels (neovascularisation) are weak, can spread to form a membrane and can threaten the vision. It is

suspected that at least 40% of patients with PIC develop CNV (choroidal neovascularization). This is a complication, which can occur in other white dot syndromes and other eye conditions such as macular degeneration but occurs rarely in other forms of uveitis.

CNV is a sight threatening complication and so must be picked up early and always treated. It may occur whether the uveitis is active or not. CNV, if not treated, may lead to subretinal fibrosis (scarring), a further complication, which is more difficult to treat, and which leads to poor vision.

Good monitoring for patients with PIC is therefore very important.

The onset of ocular symptoms are usually preceded by episode of viral or flu-like symptoms such as fever, cough or sore throat (however this is not always the case). Patients can typically present erythema nodosum, livido reticularus, bilateral uveitis, and sudden onset of marked visual loss associated with the appearance of multiple lesions in the retina. These lesions may be colored from grey-white to cream-shaded yellow.

Other symptoms include scotomata and photopsia. In weeks to a month times the lesions begin to clear and disappear (with prednisone) leaving behind areas of retinal pigment epithelial atrophy and diffuse fine pigmentation (scarring). Rarely choroidal neovascularization occur as a late onset complication.

Eye floaters and loss of accommodation are among the earliest symptoms. The disease may progress to severe uveitis with pain and photophobia. Commonly the eye remains relatively painless while the inflammatory disease spreads through the uvea, where characteristic focal infiltrates in the choroid named Dalén-Fuchs nodules can be seen. The retina, however, usually remains uninvolved, although perivascular cuffing of the retinal vessels with inflammatory cells may occur. Papilledema, secondary glaucoma, vitiligo, and poliosis of the eyelashes may accompany SO.

Chorioretinitis is an inflammation of the choroid (thin pigmented vascular coat of the eye) and retina of the eye. It is a form of posterior uveitis. If only the choroid is inflamed, not the retina, the condition is termed choroiditis. The ophthalmologist's goal in treating these potentially blinding conditions is to eliminate the inflammation and minimize the potential risk of therapy to the patient.

Uveitis may cause pain of the affected eye together with changes in vision. It may be accompanied by nonspecific systemic symptoms such as fever, involuntary weight loss, fatigue, loss of appetite, abdominal pain, and joint pains.

Punctate inner choroiditis (PIC) is an inflammatory choroiditis which occurs mainly in young women. Symptoms include blurred vision and scotomata. Yellow lesions are mainly present in the posterior pole and are between 100 to 300 micrometres in size. PIC is one of the so called White Dot Syndromes. PIC has only been recognised as a distinct condition as recently as 1984 when Watzke identified 10 patients who appeared to make up a distinct group within the White Dot Syndromes.

Acute posterior multifocal placoid pigment epitheliopathy (APMPPE) is an acquired inflammatory uveitis that belongs to the heterogenous group of white dot syndromes in which light-coloured (yellowish-white) lesions begin to form in the macular area of the retina. Early in the course of the disease, the lesions cause acute and marked vision loss (if it interferes with the optic nerve) that ranges from mild to severe but is usually transient in nature. APMPPE is classified as an inflammatory disorder that is usually bilateral and acute in onset but self-limiting. The lesions leave behind some pigmentation, but visual acuity eventually improves even without any treatment (providing scarring doesn't interfere with the optic nerve).

It occurs more commonly in females and is more likely to affect persons between 20 and 30 years of age, but has been seen in people aged 16 to 40. It is known to occur after or concurrently with a systemic infection (but not always), showing that it is related generally to an altered immune system. Recurrent episodes can happen, but are extremely rare.

Sympathetic ophthalmia (SO) or Sympathetic uveitis is a bilateral diffuse granulomatous uveitis (a kind of inflammation) of both eyes following trauma to one eye. It can leave the patient completely blind. Symptoms may develop from days to several years after a penetrating eye injury.

The eye involvement can cause the following inflammatory disorders:

- endophthalmitis

- uveitis

- chorioretinitis

In contrast to visceral larva migrans, ocular toxocariasis usually develops in older children or young adults with no history of pica. These patients seldom have eosinophilia or visceral manifestations.