The history should include questions about risk factors for corneal ulcers such as contact lens use (the type of lens, storage habits, hygiene, history of prolonged use, swimming or showering in lenses), prior ocular surgery, recent ocular trauma, personal history or exposure to herpes, work exposures, and use of immunosuppressant medications. Other important points in the history include the quality and severity of pain, the rapidity of onset, and the presence or absence of any photophobia or blurry vision. Patient’s past medical history should be explored as diseases such as diabetes and rheumatoid arthritis, and other collagen vascular diseases can predispose patients to develop corneal ulcers.

The physical exam should include testing of visual acuity, intraocular pressures (if no concern for globe rupture or perforated ulcer), and pupillary response. The eyelids and conjunctiva should be examined for any injection, swelling, or discharge as well as for the presence of ciliary flush. A thorough slit lamp examination should be performed to determine the size, location, and shape of the lesion or lesions. Seidel's test can is useful if there is any concern for rupture.

The patient with a bacterial corneal ulcer will often present with rapid onset of pain, photophobia, and conjunctival injection, and a variable degree of vision loss. On slit lamp exam these ulcers appear as clearly defined infiltrates with stromal inflammation and edema.[5] Culture by an Ophthalmologist is often necessary to guide treatment.

The patient with HSV keratitis or corneal ulcer will usually present similarly to the patient with bacterial keratitis. They will often have foreign body sensation, photophobia, conjunctival injection, and blurred vision. Slit lamp exam will classically reveal dendritic lesions with fluorescein uptake.[5]

Fungal infections tend to have a more indolent course and often do not have the impressive conjunctival injection seen with bacterial infections. On slit lamp exam fungal lesions appear as gray-white feathery dry appearing lesions with irregular margins. Ulcers due to yeast appear as superficial, white, raised colonies with clearly defined borders.[5]

The patient presenting with Acanthamoeba keratitis will classically present with pain out of proportion to physical exam findings. Severe photophobia is also common. The exam may reveal diffuse punctate epithelial lesions, dendritic-like lesions, or ring-shaped infiltrates.[5] Definitive diagnosis is made with direct scraping, histology, or PCR identification of Acanthamoeba DNA.[15] 

Patients presenting with peripheral ulcerative keratitis (PUK) due to an underlying autoimmune disease may already carry a diagnosis or the corneal ulcer may be the first manifestation of the disease.[10]The damage seen in PUK is usually crescent-shaped and located in the limbal region of the corneal.[9] The patient may have stigmata of their underlying disease, such as swollen and tender joints or rashes. Evaluation in these patients would include a full ophthalmologic examination as well as lab work and imaging to help diagnose or monitor the underlying autoimmune condition. 

Treatment of bacterial keratitis and corneal ulcers consists first of topical antibiotics, most commonly with fluoroquinolones such as ciprofloxacin or ofloxacin.[7] Due to growing antibiotic resistance of common ocular pathogens corneal culture and sensitivity testing is recommended for all corneal ulcers, especially those that are large, central, and correlate with significant stromal involvement.  An ophthalmologist should perform a culture of the corneal ulcer. Hospitalization with systemic therapy with ceftriaxone as well as topical therapy is necessary for ulcers caused by gonococcus. Systemic antibiotics may also be necessary for severe infections caused by the more common bacterial pathogens. Hospital admission should also be a consideration for those unable or unwilling to comply with treatment. Adjuvant corticosteroids are controversial but may be beneficial in specific subgroups of patients with culture-positive non-Nocardia bacterial keratitis and low vision or central ulcers covering the central 4mm of the pupil.[16] (Level V) The treating ophthalmologist should decide whether to use adjuvant corticosteroids. 

Treatment for HSV includes topical antivirals and adjuvant topical steroids. In the US the most common topical antiviral is trifluridine while in Europe topical acyclovir is the first line. (Level II) Other options include ganciclovir which also treats VZV and CMV keratitis. Oral acyclovir or valacyclovir are additional options. Oral valganciclovir is the treatment of choice for CMV stromal keratitis, but the patient requires close monitoring while on this medication due to significant side effects such as aplastic anemia.[7]

Fungal ulcers tend to have worse outcomes than bacterial as there are far fewer treatment options. Currently, the primary treatment is natamycin, a topical polyene, first introduced in the 1960s. (Level II) Amphotericin B 0.3% to 0.5% is an alternative, but toxicity limits use. A newer generation triazole called voriconazole recently was found to be inferior to natamycin in the Mycotic Ulcer Treatment Trail (MUTT I).[17] (Level I)

Treatment of Acanthamoeba keratitis and corneal ulcers generally involves epithelial debridement and 3 to 4 months of antiamoebic therapy.[5] Antiamoebic therapy starts with chlorhexidine and poligexametilen biguanide which, when combined, are effective against trophozoites and cysts.[18] In severe cases, additional agents such as diamidines, fluconazole, itraconazole, neomycin, and iodine-containing medications may be added.[18]  

Treatment of peripheral ulcerative keratitis associated with autoimmune and collagen vascular diseases should be treated with systemic immunosuppressants and cytotoxic agents and requires co-management by both a rheumatologist and ophthalmologist.[10] (Level III). These patients need careful monitoring and frequent bloodwork while on these immunosuppressant medications. 

 An ophthalmologist should see all patients presenting with corneal ulcers within 12 to 24 hours. Emergent ophthalmologic consultation should be considered for a culture of the ulcer to guide antibiotic selection for suspected bacterial ulcers.

The differential diagnosis for the patient presenting with red, painful eye includes corneal abrasions, nonulcerative keratitis, foreign body, iritis, acute angle-closure glaucoma, chemical burns, episcleritis, scleritis, and anterior uveitis.[6]

Prognosis depends on the etiology, size, and location of the ulcer as well as the response to treatment. 

Complications of untreated or inadequately treated corneal ulcers include corneal scarring, vascularization, or perforation, glaucoma, irregular astigmatism, cataracts, endophthalmitis, and vision loss.

The most significant risk factor for corneal ulcers is contact lens use. Therefore, patient education about proper use is one of the most important aspects of prevention of these ulcers.[19] Patient education should include instruction on how to properly insert, clean, and store contact lenses as well as the importance of avoiding overnight or prolonged use. Patients should receive education about the dangers of swimming/showering in contacts and of purchasing contacts from nonmedical sources as well as the increased risk of infection with extended wear lenses. 

Corneal ulcers are a vision-threatening ocular emergency. It is imperative that health care providers across specialties work together so that these patients may have the best possible outcome and avoid the many potential complications. The patient will often first present in a clinic or emergency department setting and so primary care, and emergency health care professionals must be able to rapidly identify this disease and communicate effectively with their ophthalmology colleagues. Pharmacists should be consulted to help with antimicrobial selection or, in the case of peripheral ulcerative keratitis, immunosuppressants. Nurses are essential for successful treatment plans and patient education.