What is a Corneal Abrasion?
A corneal abrasion is a scratch or cut to the cornea, the clear, dome-shaped front surface of the eye. This injury often causes significant pain, a gritty or foreign body sensation, redness, tearing, and light sensitivity. While many minor abrasions heal quickly on their own, the risk of developing a bacterial infection is a primary concern, particularly with larger or deeper scratches. A bacterial infection, known as infectious keratitis, can lead to serious complications and even vision loss if not treated properly.
The Role of Antibiotic Eye Drops
To prevent a corneal abrasion from progressing into a dangerous infection, healthcare providers often prescribe prophylactic (preventive) antibiotic eye drops or ointments. These medications target potential bacteria that could enter the open wound on the eye's surface. The specific medication and dosage prescribed will depend on several factors, including the source of the injury, patient-specific risk factors, and whether contact lenses are worn.
Types of Antibiotic Eye Drops for Corneal Abrasion
Several classes of topical antibiotics are used, each with different properties. The choice often depends on the potential pathogens involved.
Fluoroquinolones
Fluoroquinolones are a common class of broad-spectrum antibiotics used for corneal abrasions, especially in patients at higher risk for infection, such as contact lens wearers. They are effective against a wide range of bacteria, including Pseudomonas aeruginosa. Examples include Moxifloxacin (Vigamox), Ciprofloxacin (Ciloxan), and Gatifloxacin (Zymaxid).
Aminoglycosides
Aminoglycosides are another option, particularly effective against gram-negative bacteria like Pseudomonas. Tobramycin (Tobrex) and Gentamicin (Garamycin) are examples available in drops and/or ointment forms.
Combination and Other Antibiotics
For less severe abrasions, older antibiotics may be used. Polymyxin B/Trimethoprim (Polytrim) is a combination drop effective against many bacteria. Erythromycin ointment is a cost-effective option, often used in children or at bedtime due to its lubricating properties and longer contact time.
Special Considerations for Contact Lens Wearers
Contact lens wearers face a higher risk of serious infection from Pseudomonas aeruginosa. Therefore, fluoroquinolones are the standard treatment for this group due to their strong anti-pseudomonal coverage. It is crucial to stop wearing contact lenses immediately until the abrasion is fully healed and the antibiotic course is finished.
Drops vs. Ointments: What's the difference?
| Feature | Eye Drops | Ointments |
|---|---|---|
| Comfort | More comfortable, less blurring of vision | Can cause temporary blurred vision |
| Frequency | Must be administered more frequently (e.g., every 2-4 hours) | Applied less often (e.g., 2-4 times daily) and useful overnight |
| Lubrication | Not primarily a lubricant, but can use lubricating drops | More lubricating, which can be comforting and aid healing |
| Patient Group | Generally preferred for most adults due to comfort | Often used in children whose tears wash out drops, or at bedtime |
| Administration | Requires careful handling to avoid contamination | May be easier for some patients to apply a ribbon |
How to Administer Eye Drops Properly
- Wash Your Hands: Always wash your hands thoroughly before touching your eyes or medication.
- Shake the Bottle: If using a suspension, shake the bottle well.
- Position Your Head: Tilt your head back or lie down. Look up at the ceiling.
- Create a Pouch: Gently pull down your lower eyelid with one finger to form a small pocket.
- Instill the Drop: Squeeze the prescribed number of drops into the pouch, being careful not to touch your eye with the dropper tip.
- Close the Eye: Gently close your eye and apply light pressure to the inner corner near the nose for a few moments to keep the medication in the eye.
- Do Not Rub: Avoid rubbing your eye, as this can worsen the abrasion and spread infection.
Healing and Recovery
Most simple corneal abrasions heal rapidly, often within 24 to 72 hours, with proper care. It is important to complete the entire course of antibiotics as prescribed, even if symptoms improve, to ensure the infection is fully prevented. Persistent or worsening symptoms, increased pain, reduced vision, or purulent discharge warrant an immediate follow-up with a healthcare provider.
Conclusion
For a corneal abrasion, preventing infection is the primary goal of antibiotic treatment. A healthcare provider will prescribe an appropriate antibiotic eye drop based on the severity of the abrasion, patient risk factors, and history of contact lens use. While options range from basic ointments like erythromycin to advanced fluoroquinolone drops like moxifloxacin, it is crucial to use the prescribed medication as directed and avoid any over-the-counter antibiotic products. By adhering to the treatment plan and following up as necessary, patients can minimize complications and ensure a smooth recovery. For further information and patient resources, see Corneal Abrasion: Symptoms, Treatment & Prevention (clevelandclinic.org).
