Keratic precipitate (KP) is an inflammatory cellular deposit seen on corneal endothelium. Acute KPs are white and round in shape whereas old KPs are faded and irregular in shape. Mutton-fat KPs are large in shape and are greasy-white in color and are formed from macrophages and epithelioid cell. They are indicative of inflammatory disease. Mutton fat Kps are due to granulomatous iridocyclitis. Another variant called red KPs may be seen in hemorrhagic uveitis.

While the vast majority of hyphemas resolve on their own without issue, sometimes complications occur. Traumatic hyphema may lead to increased intraocular pressure, peripheral anterior synechiae, atrophy of the optic nerve, staining of the cornea with blood, re-bleeding, and impaired accommodation.

Secondary hemorrhage, or rebleeding of the hyphema, is thought to worsen outcomes in terms of visual function. Rebleeding occurs in 4-35% of hyphema cases and is a risk factor for glaucoma.

According to recent research not a single theory is able to explain the cause fully. However current plausible theories include infection with "Toxoplasma gondii", Herpes simplex virus, Rubella, neurogenic causes, and autoimmune pathology.

Hyphemas require urgent assessment by an optometrist or ophthalmologist as they may result in permanent visual impairment.

A long-standing hyphema may result in hemosiderosis and heterochromia. Blood accumulation may also cause an elevation of the intraocular pressure. On average, the increased pressure in the eye remains for six days before dropping. Most uncomplicated hyphemas resolve within 5–6 days.

Fuchs heterochromic iridocyclitis (FHI) is a chronic unilateral uveitis appearing with the triad of heterochromia, predisposition to cataract and glaucoma, and keratitic precipitates on the posterior corneal surface. Patients are often asymptomatic and the disease is often discovered through investigation of the cause of the heterochromia or cataract. Neovascularisation (growth of new abnormal vessels) is possible and any eye surgery, such as cataract surgery, can cause bleeding from the fragile vessels in the atrophic iris causing accumulation of blood in anterior chamber of the eye, also known as hyphema.

Those with conjunctivitis may report mild irritation or scratchiness, but never extreme pain, which is an indicator of more serious disease such as keratitis, corneal ulceration, iridocyclitis, or acute glaucoma.

Of the many causes, conjunctivitis is the most common. Others include:

"Usually nonurgent"

- blepharitis - a usually chronic inflammation of the eyelids with scaling, sometimes resolving spontaneously

- subconjunctival hemorrhage - a sometimes dramatic, but usually harmless, bleeding underneath the conjunctiva most often from spontaneous rupture of the small, fragile blood vessels, commonly from a cough or sneeze

- inflamed pterygium - a benign, triangular, horizontal growth of the conjunctiva, arising from the inner side, at the level of contact of the upper and lower eyelids, associated with exposure to sunlight, low humidity and dust. It may be more common in occupations such as farming and welding.

- inflamed pinguecula - a yellow-white deposit close to the junction between the cornea and sclera, on the conjunctiva. It is most prevalent in tropical climates with much UV exposure. Although harmless, it can occasionally become inflamed.

- dry eye syndrome - caused by either decreased tear production or increased tear film evaporation which may lead to irritation and redness

- airborne contaminants or irritants

- tiredness

- drug use including cannabis

"Usually urgent"

- acute angle closure glaucoma - implies injury to the optic nerve with the potential for irreversible vision loss which may be permanent unless treated quickly, as a result of increased pressure within the eyeball. Not all forms of glaucoma are acute, and not all are associated with increased 'intra-ocular' pressure.

- injury

- keratitis - a potentially serious inflammation or injury to the cornea (window), often associated with significant pain, light intolerance, and deterioration in vision. Numerous causes include virus infection. Injury from contact lenses can lead to keratitis.

- iritis - together with the ciliary body and choroid, the iris makes up the uvea, part of the middle, pigmented, structures of the eye. Inflammation of this layer (uveitis) requires urgent control and is estimated to be responsible for 10% of blindness in the United States.

- scleritis - a serious inflammatory condition, often painful, that can result in permanent vision loss, and without an identifiable cause in half of those presenting with it. About 30-40% have an underlying systemic autoimmune condition.

- episcleritis - most often a mild, inflammatory disorder of the 'white' of the eye unassociated with eye complications in contrast to scleritis, and responding to topical medications such as anti-inflammatory drops.

- tick borne illnesses like Rocky Mountain spotted fever - the eye is not primarily involved, but the presence of conjunctivitis, along with fever and rash, may help with the diagnosis in appropriate circumstances.

A corneal dystrophy can be caused by an accumulation of extraneous material in the cornea, including lipids and cholesterol crystals.

Corneal dystrophy is a group of rare hereditary disorders characterised by bilateral abnormal deposition of substances in the transparent front part of the eye called the cornea.

Treatment should be sought immediately in order to avoid hospitalization. If not treated, hospitalization for an extended period of time (usually two weeks) is likely. During hospitalization, the patient is tested for signs of system degradation, especially of the skeletal structure and the digestive tract. By this time open sores will develop on the upper torso. Some will be the size of dimes, others will be large enough to stick a couple fingers into. They will crust up, causing cohesion to any fabric the sores touch, which is extremely painful to remove. It is recommended to sleep on one's sides until the cystic condition subsides, in order to avoid any uncomfortable situations. Debridement and steroid therapy is preferred over antibiotics. Recurrent AF is extremely rare. Bone lesions typically resolve with treatment, but residual radiographic changes, such as sclerosis and hyperostosis, may remain. Scarring and fibrosis may result from this acute inflammatory process.

The disease activates at the height of puberty, usually at around 13 years of age. Acne fulminans predominantly affects young males aged 13 to 22 years with a history of acne.

Herpes zoster ophthalmicus (HZO) and also known as ophthalmic zoster is a disease characterised by reactivation of dormant varicella zoster virus residing within the ophthalmic nerve (the first division of the trigeminal nerve). This condition is an important subtype of shingles, representing 15% of all cases.

Herpes zoster ophthalmicus is transmitted via direct contact or droplets. Varicella zoster virus is a DNA virus which produces acidophilic intranuclear inclusion bodies. The virus is neurotrophic in nature.

The frontal nerve is more commonly affected than the nasociliary nerve or lacrimal nerve.

Acne fulminans (also known as "acute febrile ulcerative acne") is a severe form of the skin disease, acne, which can occur after unsuccessful treatment for another form of acne, acne conglobata. The condition is thought to be an immunologically induced disease in which elevated level of testosterone causes a rise in sebum and population of "Propionibacterium acnes" bacteria. The increase in the amount of "P acnes" or related antigens may trigger the immunologic reaction in some individuals and lead to an occurrence of acne fulminans. In addition to testosterone, isotretinoin may also precipitate acne fulminans, possibly related to highly increased levels of "P acnes antigens" in the patient's immune system. Acne fulminans is a rare disease. Over the past several years, fewer cases of this disease have occurred, possibly because of earlier and better treatment of acne. Approximately 100 patients with acne fulminans have been described.

Any potential ocular involvement should be assessed by an ophthalmologist as complications such as episcleritis and uveitis may occur.

Incomitant esotropias are conditions in which the esotropia varies in size with direction of gaze. They can occur in both childhood and adulthood, and arise as a result of neurological, mechanical or myogenic problems. These problems may directly affect the extra-ocular muscles themselves, and may also result from conditions affecting the nerve or blood supply to these muscles or the bony orbital structures surrounding them. Examples of conditions giving rise to an esotropia might include a VIth cranial nerve (or Abducens) palsy, Duane's syndrome or orbital injury.

The prognosis for each patient with esotropia will depend upon the origin and classification of their condition. However, in general, management will take the following course:

1. Identify and treat any underlying systemic condition.

2. Prescribe any glasses required and allow the patient time to 'settle into' them.

3. Use occlusion to treat any amblyopia present and encourage alternation.

4. Where appropriate, orthoptic exercises can be used to attempt to restore binocularity.

5. Where appropriate, prismatic correction can be used, either temporarily or permanently, to relieve symptoms of double vision.

6. In specific cases, and primarily in adult patients, botulinum toxin can be used either as a permanent therapeutic approach, or as a temporary measure to prevent contracture of muscles prior to surgery

7. Where necessary, extra-ocular muscle surgery can be undertaken to improve cosmesis and, on occasion, restore binocularity.

Vasculitis secondary to connective tissue disorders. Usually secondary to systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), relapsing polychondritis, Behçet's disease, and other connective tissue disorders.

Vasculitis secondary to viral infection. Usually due to hepatitis B and C, HIV, cytomegalovirus, Epstein-Barr virus, and Parvo B19 virus.

Necrotizing vasculitis also called Systemic necrotizing vasculitus (SNV) is a category of vasculitis, comprising vasculitides that present with necrosis.

Examples include giant cell arteritis, microscopic polyangiitis, and granulomatosis with polyangiitis.

ICD-10 uses the variant "necrotizing vasculopathy". ICD-9, while classifying these conditions together, doesn't use a dedicated phrase, instead calling them "polyarteritis nodosa and allied conditions".

When using the influential classification known as the "Chapel Hill Consensus Conference", the terms "systemic vasculitis" or "primary systemic vasculitides" are commonly used. Although the word "necrotizing" is omitted, the conditions described are largely the same.

The average age at onset is 3–7 years, but CVS has been seen in infants who are as young as 6 days and in adults who are as old as 73 years. Typical delay in diagnosis from onset of symptoms is 2.7 – 3 years. Females show a slight predominance over males; the female-to-male ratio is 57:43.

How common the condition is, is not clear. A prospective study found that 3 in 100,000 five-year-olds are diagnosed with the condition. Two published studies on childhood CVS suggest nearly 2% of school-age children may have CVS. However, diagnosis is problematic and, as knowledge of CVS has increased in recent years, more and more cases are emerging.

Type III hypersensitivity occurs when there is accumulation of immune complexes (antigen-antibody complexes) that have not been adequately cleared by innate immune cells, giving rise to an inflammatory response and attraction of leukocytes. Such reactions progressing to the point of disease produce immune complex diseases.

While the prognosis of cryofibrinoginemic disease varies greatly depending on its severity as well as the severity of its associated disorders, satisfactory clinical outcomes are reported in 50-80% of patients with primary or secondary disease treated with corticosteroid and/or immunosuppressive regimens. However, relapses occur within the first 6 months after stopping or decreasing therapy in 40-76% of cases. Sepsis resulting from infection of necrotic tissue is the most common threat to life in primary disease whereas the associated disorder is a critical determinant of prognosis in secondary disease.

Allergenic extracts, hormones and vaccines can also cause serum sickness.

Some clinical examples:

Other examples are:

- Subacute bacterial endocarditis

- Symptoms of malaria

Fitzpatrick et al. (2007) identified 41 children with CVS. The mean age of the sample was 6 years at the onset of the syndrome, 8 years at first diagnosis, and 13 years at follow-up. As many as 39% of the children had resolution of symptoms immediately or within weeks of the diagnosis. Vomiting had resolved at the time of follow-up in 61% of the sample. Many children, including those in the remitted group, continued to have somatic symptoms such as headaches (in 42%) and abdominal pain (in 37%).

Most children who have this disorder miss on average 24 school days a year. The frequency of episodes is higher for some people during times of excitement. Charitable organizations to support sufferers and their families and to promote knowledge of CVS exist in several countries.

Kawasaki disease affects boys more than girls, with people of Asian ethnicity, particularly Japanese and Korean people, most susceptible, as well as people of Afro-Caribbean ethnicity. The disease was rare in Caucasians until the last few decades, and incidence rates fluctuate from country to country.

Currently, Kawasaki disease is the most commonly diagnosed pediatric vasculitis in the world. By far, the highest incidence of Kawasaki disease occurs in Japan, with the most recent study placing the attack rate at 218.6 per 100,000 children <5 years of age (about one in 450 children). At this present attack rate, more than one in 150 children in Japan will develop Kawasaki disease during their lifetimes.

However, its incidence in the United States is increasing. Kawasaki disease is predominantly a disease of young children, with 80% of patients younger than five years of age. About 2,000-4,000 cases are identified in the U.S. each year (9 to 19 per 100,000 children younger than 5 years of age).

In the United Kingdom, estimates of incidence rate vary because of the rarity of Kawasaki disease. However, it is believed to affect fewer than one in every 25,000 people. Incidence of the disease doubled from 1991 to 2000, however, with four cases per 100,000 children in 1991 compared with a rise of eight cases per 100,000 in 2000.

In the continental United States, Kawasaki Disease is more common during the winter and early spring, boys with the disease outnumber girls by ≈1.5–1.7:1, and 76% of affected children are <5 years of age.

Some of the drugs associated with serum sickness are:

- allopurinol

- barbiturates

- captopril

- cephalosporins

- griseofulvin

- penicillins

- phenytoin

- procainamide

- quinidine

- streptokinase

- sulfonamides

- rituximab

- ibuprofen

- infliximab