Eye infections occur when harmful microorganisms (germs) such as bacteria, viruses, fungi and protozoa get into the structures of the eyes, multiply and cause damage.
The symptoms they often cause include:
- Blurry vision
- Eye discharge
- Burning sensation
- Light sensitivity
- Gritty sensation
- Swollen eyes
Almost all the parts of the eyes can get infected. But, the external structures like the eyelids, conjunctiva and cornea are most commonly affected. Then, sometimes infections by the different microorganisms present in the same way, making it difficult for a layman to differentiate one from the other.
For proper diagnosis and treatment, consult your eye doctor. S/he can identify the part of the eye that is infected, determine the type of microorganism causing it and recommend the best treatment for you.
Common Eye Infections
There are many eye infections. They are often named according to the structures of the eye infected and sometimes according to the microorganisms causing them.
Conjunctivitis is the inflammation of the conjunctiva. When this inflammation is due to microorganisms like bacteria, viruses, and fungi, it is known as bacterial conjunctivitis, viral conjunctivitis and fungal conjunctivitis respectively. Three of them together are known as infective conjunctivitis. In bacterial conjunctivitis, eye discharge is purulent, yellowish-green in colour and contains pus. In viral conjunctivitis, the discharge is watery.
Infective conjunctivitis is very contagious. It spreads through various means like contact with an infected person or contaminated surfaces and materials. Newborn babies can also contract conjunctivitis through the birth canal. For this reason, some antibiotic eye drops may be given to newborns immediately after birth to prevent infection.
Blepharitis is an inflammation of the eyelid margin. It is caused by either one or more of the following:
- A bacterial infection.
- Colonization of the eyelid margins by parasitic mites.
- Disorder of the meibomian (oily) glands in the eyelid.
The symptoms include itching, burning, redness, swollen eyelid margins, crusty debris and sometimes loss of eyelash. Learn more about blepharitis here.
Keratitis is the inflammation of the cornea, the transparent tissue in front of the coloured part of the eye. When the inflammation is due to microorganisms like bacteria, viruses and fungi, it is known as infectious keratitis.
Major causes include;
- Poorly managed corneal scratch or injury
- Contaminated contact lenses
- Herpes simplex and herpes zoster infections
Keratitis, particularly those caused by bacteria is an emergency and should be treated immediately to prevent deep ulcers. This is because these ulcers leave white scars when they heal and can cause blindness if it is the centre of the cornea that is affected.
Stye is an infection caused by the overgrowth of bacteria in a blocked meibomian gland (oily gland of the eyelid). It presents as a tender and painful bump on the eyelid. Learn more about stye here.
Uveitis is the inflammation of the middle layer of the eyeball known as the uvea. This includes the iris, ciliary body and choroid.
Infective uveitis is caused by bacteria, viruses, fungi and parasites. The infection can affect part or all of the uvea.
Infective uveitis requires prompt treatment to prevent the infection of the whole eye and permanent vision loss.
Prevention and Control of Eye Infections
This requires maintaining good hand and eye hygiene and also getting infections treated properly to avoid spread and reoccurrence.
- Avoid touching your eyes
- If you must touch your eyes, wash your hands before you do so. Always wash your hands with soap and running water before and after touching your face, before and after putting on contact lenses, as well as after contact with an infected person or contaminated materials.
- Don’t share towels, bedding and other personal items.
- Do not share eye makeup.
- Do not use makeup products longer than recommended or past their expiry date (whichever comes first). This is important, particularly for liquid eye makeup products like mascara and liquid eyeliner.
- Don’t share your eye drops or ointments
- Clean eye discharges with disposable wipes and cotton wool and discard them properly. Avoid using handkerchiefs, face towels or any other reusable materials to clean eye discharges.
- Use your contact lenses as recommended by your eye doctor. Ensure that you adhere to the usage, handling, storage and replacement guidelines and schedule. Handle them with clean hands and avoid sleeping or swimming with them.
Diagnosis and Treatment of eye infections
Consult the eye doctor whenever you have an eye infection to ensure that the infection is diagnosed accurately and that appropriate treatment is given. Avoid patronizing quacks or self-medicating. Doing these can worsen the condition and result in sight-threatening complications.
The eye doctor will perform an eye examination and also assess your symptoms to ascertain the type of organism causing the infection and the part of the eye affected. Sometimes a laboratory test may be needed to identify the specific organism causing it.
Generally, broad-spectrum antibiotic eye drops, ointments and tablets are used to treat common bacterial infections. Serious eye infections like orbital cellulitis and preseptal cellulitis may require intravenous antibiotics. However, bacterial infections like stye may respond to home remedies like warm compress and therefore resolve on their own without medications.
Most viral infections (except those caused by Herpes Simplex) are self-limiting and do not require medications. Common recommendations for treatment are cold compress for symptom relief and Vitamin C to boost the immune system. In serious cases, antibiotics may be prescribed to prevent or treat suspected secondary bacterial infections. If the cornea is affected, anti-inflammatory drops like steroids may be carefully introduced to treat the resulting inflammation (keratitis).