From the Guidelines
Corneal ulcers should be treated with topical antibiotic eye drops, such as fluoroquinolones, as the first line of treatment, with the specific choice and dosage guided by the severity and location of the ulcer, as well as the suspected or confirmed causative organism 1. The treatment of corneal ulcers depends on the cause, but generally, antibiotic eye drops are the preferred method of treatment in most cases of bacterial keratitis.
- Topical antibiotic eye drops, such as ciprofloxacin 0.3%, ofloxacin 0.3%, and levofloxacin 1.5%, have been shown to be effective in treating bacterial keratitis 1.
- For central or severe keratitis, a loading dose of antibiotic eye drops, such as every 5 to 15 minutes, followed by frequent applications, such as every hour, is recommended 1.
- Cycloplegic agents, such as cyclopentolate 1%, may be used to decrease synechiae formation and decrease pain from anterior segment inflammation associated with bacterial keratitis 1.
- Corticosteroids may be considered after 48 hours of antibiotic therapy when the causative organism is identified and/or the infection has responded to therapy, but should be avoided in cases of suspected Acanthamoeba, Nocardia, or fungus 1.
- Patients should avoid wearing contact lenses during treatment and should not touch or rub the affected eye, and severe cases may require hospitalization 1. The use of corticosteroids in the treatment of corneal ulcers is controversial, but may be beneficial in reducing morbidity in certain cases, such as when the corneal infiltrate compromises the central cornea, but should be used judiciously and with close follow-up 1. It is essential to monitor the patient's response to treatment and adjust the therapeutic regimen as needed, and to be aware of the potential risks of long-term topical corticosteroid therapy, including cataract and glaucoma 1.
From the FDA Drug Label
INDICATIONS AND USAGE: NATACYN ® (natamycin ophthalmic suspension) 5% is indicated for the treatment of fungal blepharitis, conjunctivitis, and keratitis caused by susceptible organisms including Fusarium solanikeratitis. PRECAUTIONS: General. FOR TOPICAL OPHTHALMIC USE ONLY — NOT FOR INJECTION. Failure of improvement of keratitis following 7-10 days of administration of the drug suggests that the infection may be caused by a microorganism not susceptible to natamycin.
The drug natamycin is used to treat fungal keratitis, which can be a cause of corneal ulcer. However, the term corneal ulcer is not explicitly mentioned in the context of the treatment of this condition with natamycin.
- The treatment of keratitis with natamycin is based on clinical diagnosis and laboratory diagnosis by smear and culture of corneal scrapings and drug response 2.
- The effectiveness of natamycin in treating corneal ulcer caused by fungal infections is implied through its use in treating fungal keratitis, but it is not directly stated 2.
From the Research
Definition and Causes of Corneal Ulcers
- Corneal ulcers are defined as a defect in the corneal epithelium and underlying stroma 3
- They can be caused by a variety of conditions, including bacterial, viral, and fungal infections, as well as trauma and contact lens use 3
Symptoms and Diagnosis
- Corneal ulcers are typically painful and can reduce vision 3
- A good understanding of the clinical presentation of corneal ulcers can aid in diagnosis and guide treatment 3
- Diagnosis is often made through a combination of clinical examination and laboratory tests, such as corneal cultures 4, 5, 6
Treatment Options
- Topical application with a broad-spectrum antimicrobial is the preferred method for the pharmacological management of infectious corneal ulcers 4
- Antibiotic-only treatment and antibiotic-steroid combination treatment have been compared in clinical trials, with no significant difference in outcomes found in one study 7
- Moxifloxacin has been shown to be effective in the treatment of bacterial keratitis, with equivalent healing rates to combination therapy with fortified cefazolin and tobramycin 5, 6
Management and Referral
- Prompt diagnosis and adequate management are needed to prevent visual morbidity 3
- Urgent referral to an ophthalmologist is recommended for cases of trauma and infectious keratitis to prevent endophthalmitis and loss of vision and/or the eye 3
- General practitioners can play an important role in timely referral and initiating oral antiviral treatment, as well as educating patients on preventive measures such as contact lens hygiene 3