A Cochrane Review sought to evaluate the effects of perioperative antibiotic prophylaxis for endophthalmitis following cataract surgery. The review showed high-certainty evidence that antibiotic injections in the eye with cefuroxime at the end of surgery lowers the chance of endophthalmitis. Also, the review showed moderate evidence that antibiotic eye drops (levofloxacin or chloramphenicol) with antibiotic injections (cefuroxime or penicillin) probably lowers the chance of endophthalmitis compared with injections or eye drops alone. Separate studies from the research showed that a periocular injection of penicillin with chloramphenicol-suphadimidine eye drops, and an intracameral cefuroxime injection with topical levofloxacin resulted in a risk reduction of developing endophthalmitis following cataract surgery for subjects.

In the case of intravitreal injections, however, antibiotics are not effective. Studies have demonstrated no difference between rates of infection with and without antibiotics when intravitreal injections are performed. The only consistent method of antibioprophylaxis in this instance is a solution of povidone-iodine applied pre-injection.

A hypopyon should not be drained, because it offers protection against the invading pathogen due to the presence of white blood cells, although long-standing hypopyon can cause close-angle glaucoma and anterior synechiae.

The patient needs urgent examination by an ophthalmologist, preferably a vitreoretinal specialist who will usually decide for urgent intervention to provide intravitreal injection of potent antibiotics. Injections of vancomycin (to kill Gram-positive bacteria) and ceftazidime (to kill Gram-negative bacteria) are routine. Even though antibiotics can have negative impacts on the retina in high concentrations, the facts that visual acuity worsens in 65% of endophthalmitis patients and prognosis gets poorer the longer an infection goes untreated make immediate intervention necessary. Endophthalmitis patients may also require an urgent surgery (pars plana vitrectomy), and evisceration may be necessary to remove a severe and intractable infection which could result in a blind and painful eye.

Steroids may be injected intravitreally if the cause is allergic.

In patients with acute endophthalmitis, combined steroid treatment with antibiotics have been found to improve visual outcomes, versus patients only treated with antibiotics, but any improvements on the resolution acute endophthalmitis is unknown.

Diagnosis is done by direct observation under magnified view of slit lamp revealing the ulcer on the cornea. The use of fluorescein stain, which is taken up by exposed corneal stroma and appears green, helps in defining the margins of the corneal ulcer, and can reveal additional details of the surrounding epithelium. Herpes simplex ulcers show a typical dendritic pattern of staining. Rose-Bengal dye is also used for supra-vital staining purposes, but it may be very irritating to the eyes. In descemetoceles, the Descemet's membrane will bulge forward and after staining will appear as a dark circle with a green boundary, because it does not absorb the stain. Doing a corneal scraping and examining under the microscope with stains like Gram's and KOH preparation may reveal the bacteria and fungi respectively. Microbiological culture tests may be necessary to isolate the causative organisms for some cases. Other tests that may be necessary include a Schirmer's test for keratoconjunctivitis sicca and an analysis of facial nerve function for facial nerve paralysis.

Hypopyon can be present in a corneal ulcer. Behcet's disease, endophthalmitis, panuveitis/panophthalmitis and adverse reactions to some drugs (such as rifabutin).

Hypopyon is also known as "sterile pus", as it occurs due to the release of toxins and not by the actual invasion of pathogens. The toxins secreted by the pathogens mediate the outpouring of leukocytes that settle in the anterior chamber of the eye. .

An inverse hypopyon is different from a standard hypopyon. Inverse hypopyon is seen after a pars plana vitrectomy with an insertion of silicone oil (as a replacement of the vitreous humour that has been removed in the operation; the silicone oil maintains internal tamponade). When the silicone oil emulsifies, it seeps into the anterior chamber and settles at the top of the anterior chamber. This is in contrast to hypopyon resulting from toxins where the leukocytes settle at the bottom of the anterior chamber. This is due to the effect of gravity, hence the name inverse hypopyon.

The diagnosis is made by an ophthalmologist/optometrist correlating typical history, symptoms and signs. Many times it may be missed and misdiagnosed as bacterial ulcer. A definitive diagnosis is established only after a positive culture report (lactophenol cotton blue, calcoflour medium), typically taking a week, from the corneal scraping. Recent advances have been made in PCR ref 3./immunologic tests which can give a much quicker result.

Topical antibiotics are used at hourly intervals to treat infectious corneal ulcers. Cycloplegic eye drops are applied to give rest to the eye. Pain medications are given as needed. Loose epithelium and ulcer base can be scraped off and sent for culture sensitivity studies to find out the pathogenic organism. This helps in choosing appropriate antibiotics. Complete healing takes anywhere from about a few weeks to several months.

Refractory corneal ulcers can take a long time to heal, sometimes months. In case of progressive or non-healing ulcers, surgical intervention by an ophthalmologist with corneal transplantation may be required to save the eye. In all corneal ulcers it is important to rule out predisposing factors like diabetes mellitus and immunodeficiency.

Prevention of trauma with vegetable / organic matter, particularly in agricultural workers while harvesting can reduce the incidence of fungal keratitis. Wearing of broad protective glasses with side shields is recommended for people at risk for such injuries.

There is no specific pathological testing or technique available for the diagnosis of the disease, although the International Study Group criteria for the disease are highly sensitive and specific, involving clinical criteria and a pathergy test. Behçet's disease has a high degree of resemblance to diseases that cause mucocutaneous lesions such as "Herpes simplex" labialis, and therefore clinical suspicion should be maintained until all the common causes of oral lesions are ruled out from the differential diagnosis.

Visual acuity, or color vision loss with concurrent mucocutaneous lesions or systemic Behçet's disease symptoms should raise suspicion of optic nerve involvement in Behçet's disease and prompt a work-up for Behçet's disease if not previously diagnosed in addition to an ocular work-up. Diagnosis of Behçet's disease is based on clinical findings including oral and genital ulcers, skin lesions such as erythema nodosum, acne, or folliculitis, ocular inflammatory findings and a pathergy reaction. Inflammatory markers such ESR, and CRP may be elevated. A complete ophthalmic examination may include a slit lamp examination, optical coherence tomography to detect nerve loss, visual field examinations, fundoscopic examination to assess optic disc atrophy and retinal disease, fundoscopic angiography, and visual evoked potentials, which may demonstrate increased latency. Optic nerve enhancement may be identified on Magnetic Resonance Imaging (MRI) in some patients with acute optic neuropathy. However, a normal study does not rule out optic neuropathy. Cerebrospinal fluid (CSF) analysis may demonstrate elevated protein level with or without pleocytosis. Imaging including angiography may be indicated to identify dural venous sinus thrombosis as a cause of intracranial hypertension and optic atrophy.

According to the International Study Group guidelines, for a patient to be diagnosed with Behçet's disease, the patient must have oral (aphthous) ulcers (any shape, size, or number at least 3 times in any 12 months period) along with 2 out of the following 4 "hallmark" symptoms:

- eye inflammation (iritis, uveitis, retinal vasculitis, cells in the vitreous)

- genital ulcers (including anal ulcers and spots in the genital region and swollen testicles or epididymitis in men)

- pathergy reaction (papule >2 mm dia. 24–48 hrs or more after needle-prick). The pathergy test has a specificity of 95 percent to 100 percent, but the results are often negative in American and European patients

- skin lesions (papulo-pustules, folliculitis, erythema nodosum, acne in post-adolescents not on corticosteroids)

Despite the inclusive criteria set forth by the International Study Group, there are cases where not all the criteria can be met and therefore a diagnosis cannot readily be made. There is however a set of clinical findings that a physician can rely upon in making a tentative diagnosis of the disease; essentially Behçet's disease does not always follow the International Study Group guidelines and so a high degree of suspicion for a patient who presents having any number of the following findings is necessary:

- arthritis/arthralgia

- cardio-vascular problems of an inflammatory origin

- changes of , psychoses

- deep vein thrombosis

- epididymitis

- extreme exhaustion

- inflammatory problems in chest and lungs

- mouth ulcers

- nervous system symptoms

- problems with hearing or balance

- stomach or bowel inflammation

- superficial thrombophlebitis

- any other members of the family with a diagnosis of Behçet's disease.