Bacterial and fungal infection occurs readily after the initial ulceration, as disruption of the corneal epithelium allows attachment and colonisation of the underlying tissues by normal corneal commensals. Commonly isolated bacteria include Staphylococcus, Streptococcus and Pseudomonas, and empirical anti-microbial therapy should be effective against these bacteria. Symptoms
Ocular Pain
Blepharospasm
Increased lacrimation
Photophobia
Corneal Oedema (1⁰/2⁰)
Scleral injection
Conjunctivitis

Diagnosis
Differential diagnoses for the painful equine eye:

Ulceration
Uveitis
Blepharitis
Conjunctivitis
Glaucoma
DachrocystitisA full ocular exam should be performed for every case of eye pain. Fluoroscein staining is usually diagnostic for corneal ulcers, although staining with Rose Bengal is also recommended as it can pick up early viral/fungal lesions, which will appear as multifocal disturbances to the tear film. Culture and sensitivity is recommended for rapidly progressive or deep corneal ulcers. Cotton swabbing is often inadequate, and corneal scraping, for example, with the blunt side of a scalpel blade is usually required. This can be greatly facilitated by the use of local nerve blocks and topical anaesthesia. There is almost invariably a secondary uveitis present with corneal ulceration, and signs of this may also be seen: miosis, corneal oedema, aqueous flare, hypopyon, IOP changes. Treatment
Medical therapy should be based upon the severity of disease initially, and then by the response to therapy. The aims of the initial therapy are:

Antibiosis
Analgesia
Anti-inflammatory
MydriaticThe initial choice of antibiotic depends upon personal choice, experience and availability, but could include chloramphenicol, chlortetracycline, bacitracin-neomycin-polymyxin (BNP), ciprofloxacin, ofloxacin and tobramycin. Topical gentamicin formulations are also available, but in the opinion of some, should be reserved for cases with stromal melting.
The anti-CD20 monoclonal antibody rituximab has been found to be effective in treating some otherwise refractory cases of pemphigoid. A 2010 meta-analysis of 10 randomized controlled trials showed that oral steroids and potent topical steroids are effective treatments, although their use may be limited by side-effects, while lower doses of topical steroids are safe and effective for treatment of moderate bullous pemphigoid.IgA-mediated pemphigoid can often be difficult to treat even with usually effective medications such as rituximab. Prognosis
Bullous pemphigoid may be self-resolving in a period ranging from several months to many years even without treatment. Poor general health related to old age is associated with a poorer prognosis. Epidemiology
Very rarely seen in children, bullous and non-bullous pemphigoid most commonly occurs in people 70 years of age and older. Its estimated frequency is seven to 14 cases per million per year, but has been reported to be as high as 472 cases per million per year in Scottish men older than 85. At least one study indicates the incidence might be increasing in the United Kingdom. Some sources report it affects men twice as frequently as women, while others report no difference between the sexes.Many mammals can be affected, including dogs, cats, pigs, and horses, as well as humans. It is very rare in dogs; on average, three cases are diagnosed around the world each year. Research
Animal models of bullous pemphigoid have been developed using transgenic techniques to produce mice lacking the genes for the two known autoantigens, dystonin and collagen XVII.