Antibiotics for Eye Infections

Every year, Americans make nearly a million visits to doctors’ offices and emergency rooms for eye infections. Antibiotics can help to treat some but not all eye infections. The proper treatment depends on the cause of the eye infection.

Please keep reading to find out more about some common eye infections and whether antibiotic use is indicated for their treatment.

What are the most common eye infections?

Allergic Conjunctivitis

Contrary to popular belief, this condition is not an infection. This inflammatory response to an allergen is part of a larger reaction in people with seasonal allergies. People with allergic conjunctivitis can experience eye redness, swelling, itching, and increased tearing. Prescribing antibiotics does not help conjunctivitis caused by allergies. This condition is best treated with a cold compress, anti-allergy eye drops, and/or oral antihistamines.

Viral Conjunctivitis

Conjunctivitis or “pink eye” is a common condition. It is an infection and inflammation of the conjunctiva, the transparent membrane that covers the white part of the eye. The most common cause of infectious conjunctivitis is viruses, with up to 90% of cases caused by adenovirus. Less commonly, the cause is herpes simplex virus or zoster virus. Viral conjunctivitis is more common in adult patients than in children. It is a self-limiting condition and there is no specific treatment for it. Cold compress, topical antihistamines, and artificial tears can be used to reduce discomfort.

Bacterial Conjunctivitis

This condition is caused by bacteria, as the name suggests. It is less common than viral conjunctivitis. Bacterial conjunctivitis occurs more often in children than adults. Antibiotic eye drops can help treat this condition.

Infectious keratitis

Infectious keratitis is an emergency that requires medical attention as it can progress quickly. This condition is an infection of the cornea, the transparent covering of the ocular surface (of the iris and the pupil). Keratitis can be bacterial or vial with bacteria being the most common culprits. Severe cases of keratitis can result in vision loss if left untreated. Treatment for this type of infection will depend on what causes it. Inappropriate use of contact lenses is one of the leading causes of bacterial keratitis.

How do you know if an eye infection is viral or bacterial?

Both viral and bacterial eye infections can cause the following symptoms: Eye pain, redness, swelling, and light sensitivity.

However, green-yellow pus or watery discharge are common symptoms of acute bacterial conjunctivitis (bacterial eye infection).

On the other hand, a history of cold sores or shingles or the presence of a herpes rash is a strong clue that an eye infection may be due to herpes simplex or zoster virus. Your doctor will examine the affected eye(s) and decide on the appropriate treatment.

How do I get rid of a bacterial infection in my eye?

Studies comparing antibiotics versus placebo have shown that the use of antibiotic eye drops can improve symptoms and effectively treat bacterial eye infections. Your doctor may prescribe a broad-spectrum topical antibiotic (antibiotic eye drops). There is no strong clinical evidence that any particular antibiotic eye drop is better than others.

What medication is prescribed for eye infections?

Treatment of Bacterial Eye Infections

Antibiotic eye drops or ointments are the mainstay of treatment for bacterial keratitis and bacterial conjunctivitis. You should notice an improvement in your symptoms within a few days. Call your doctor if your symptoms don't improve after a few days of using antibiotic eye drops.

Some of the antibiotic drops that are used to treat bacterial eye infections include gentamicin (Garamycin), ciprofloxacin (Ciloxan), tobramycin (Tobrex), bacitracin (Ocu-Tracin), moxifloxacin (Vigamox), gatifloxacin (Zymar), azithromycin (Azasite), ofloxacin ophthalmic (Ocuflox), and polymyxin B/trimethoprim (Polytrim).

If you have a bacterial eye infection, your doctor may ask you to apply 1-2 drops of antibiotic eye drops every 2 to 4 hours for the first 2 days and then every 6-8 hours for up to 7 days. Follow the exact instructions by your doctor or ophthalmologist, and do not stop using the eye drops sooner than the prescribed length of therapy.

Treatment of Viral Eye Infections

There is no specific treatment for viral eye infections except cold compresses, over-the-counter artificial tears, and topical antihistamines for symptom relief.

For viral conjunctivitis caused by herpes simplex or zoster virus, your doctor may prescribe an antiviral medication such as ganciclovir gel or acyclovir ointment. In severe cases, your primary care doctor may refer you to an ophthalmologist (eye doctor). They may prescribe oral antivirals or topical steroids to suppress the immune system and prevent post-viral keratitis.

According to the American Academy of Ophthalmology, topical antibiotics (eye drops or ointments) are not effective against viral or fungal keratitis or conjunctivitis.

Inappropriate use of antibiotics can lead to antibiotic resistance and make it harder to treat bacterial infections in the future.

Can oral antibiotics treat eye infections?

Oral antibiotics such as azithromycin or doxycycline are effective in treating chlamydial conjunctivitis.

In some cases, oral ciprofloxacin, in combination with other antibiotics, can be used to treat endophthalmitis, a severe eye infection that is commonly caused by kataract surgery.

What are the side effects of antibiotic drops?

Antibiotic eye drops can cause temporary blurred vision and other vision changes. More serious side effects of antibiotic eye drops may include an allergic reaction. You should seek immediate medical attention if you have signs and symptoms of an allergic reaction, such as difficulty breathing, skin rash, hives, or itching.

Can you wear contact lenses while using antibiotic eye drops?

In general, medicated eye drops, including antibiotic drops, should not be used with contact lenses as they can cause eye redness and irritation. Ask your doctor for specific instructions.