Eye Infections

By Eyecare NG

Introduction   |  Signs   |   Types   |    Prevention   |   Treatment 

Introduction

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.  Almost all structures of the eye can get infected but the external structures such as the eyelids, conjunctiva and cornea are mostly affected.

Infections by different microorganisms may present the same way. For proper diagnosis and treatment, it may be necessary to carry out laboratory investigation to identify the particular organism causing the infection.

Signs and symptoms of eye infections

The following are common signs and symptoms of eye infections:

  • Redness
  • Pain
  • Blurry vision
  • Tearing and eye discharge
  • Burning sensation
  • Light sensitivity
  • Gritty sensation
  • Swollen eyes

Types of eye infections

There are many eye infections and they are usually classified according to the structures of the eye affected. These may be further broken down according to the microorganisms causing the infections. Some eye infections are listed below. Click on the plus (+) sign beside each infection to read more

Conjunctivitis
Infective conjunctivitis is the inflammation of the conjunctiva caused by bacteria, virus, or fungi. It is the commonest eye infection. In bacterial conjunctivitis, eye discharge is purulent, yellowish green in colour and contains pus.  In viral conjunctivitis, discharge is watery.

Infective conjunctivitis is very contagious. It spreads through various means such as through 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 conjunctivitis.

Blepharitis
Blepharitis is an inflammation of the eyelid margin. It occurs as a result of a bacterial infection, colonization of the eyelid margins by parasitic mites and/or due to a dysfunction of the meibomian (oily) glands in the eyelid. Symptoms include itching, burning, redness, swollen eyelid margins, crusty debris and sometimes loss of eyelash. Learn more about blepharitis.

Keratitis
Infectious keratitis is the inflammation of the cornea by bacteria, virus or fungi. Major causes include poorly managed corneal scratch or injury, contaminated contact lenses and viruses such as herpes simplex and herpes zoster viruses.

Corneal infections particularly those caused by bacteria are emergencies and should be treated immediately to prevent deep ulcers. This is because these ulcers leave white scars when they heal and this can cause blindness if it is the centre of the cornea that is affected.

Stye
This is a tender bump on the eyelid caused by a blocked meibomian gland duct. Bacteria can get into the blocked ducts and cause infection. An infected stye can be painful to touch. The eyelids may be sticky and the bump may discharge yellowish pus.

Uveitis
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.

The commonest infective causes are the Herpes Simplex and Herpes Zoster viruses. Other organisms that cause uveitis include cytomegalovirus and mycobacteria which are common in immunocompromised persons.

Infective uveitis requires prompt treatment to prevent the infection of the whole eye and permanent vision loss.

Orbital and Preseptal Cellulitis
Orbital cellulitis is the inflammation of the orbital structures around the eyeball such as fat and tissues while preseptal cellulitis is the inflammation of the anterior part of the eyelid. The two infections are often confused with each other because their signs and similar are almost the same.

Orbital cellulitis, however, is a serious infection that can spread to the brain and cause damage if not managed properly. Symptoms include pain, redness, swollen eye, bulging eyeball and restricted ocular movement. Preseptal cellulitis is milder. While its signs and symptoms are similar to that of orbital cellulitis, there is no bulging of the eye or restriction of ocular movement.

Dacryocystitis
Dacrocystitis is the inflammation of the tear sac and its drainage system. This inflammation is usually a result of an infection caused by the blockage of the tear duct. It may also be caused by an infection that spreads from surrounding structures to the tear sac (e.g. rhinitis).

Dacryocystitis is associated with pain, redness, swelling, watery eyes and yellowish-green discharge from the tear duct. This infection occurs mostly in children.

Endophthalmitis
This is a serious inflammation of the whole eye including the inner structures. It is normally caused by bacterial infections and can result in blindness if not managed promptly. It is normally seen in penetrating injuries and as a rare complication of some surgeries like cataract surgery. Endophthalmitis is characterized by a sudden decrease in vision, severe pain, lid swelling, redness, and light sensitivity. It is an emergency and requires prompt and aggressive treatment to prevent vision loss.

Trachoma
This is caused by a bacterium known as Chlamydia trachomatis. It mostly affects the inner surface of the eyelids, causing lid scarring and turning-in of eyelids (entropion) with the eyelashes rubbing on the cornea. The scratches on the cornea usually lead to corneal scars and blindness if the condition is not promptly taken care of.

House flies are responsible for the transmission of this infection. Hence, the infection is endemic in unhygienic environments. Good sanitation, antibiotics and regular washing of the face are recommended ways to prevent and treat trachoma.

Prevention of eye infection

Prevention of eye infections requires maintaining good hand and eye hygiene as well as getting the infection treated properly to avoid spread and reoccurrence.

  • Always wash your hands with soap and running water. Wash 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 and beddings.
  • Do not share eye makeup.
  • Do not use makeup products longer than recommended or past their expiry date (whichever comes first).
  • Don’t share eye drops or ointments
  • Clean eye discharges with disposable wipes and cotton wool and dispose 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.

Treatment of eye infections

Treatment of eye infections is targeted at the causative organism. Some may clear up on their own without treatment, while others require medications. Sometimes a laboratory test which involves culture and sensitivity test may be needed to identify the causative organism.

Generally, broad-spectrum antibiotic eye drops, ointments and tablets are used to treat common bacterial infections. Serious 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 its 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).

It is important to consult your 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, self-medicating or instilling substances such as breast milk, urine, herbs, sugar water or salt water into your eyes to treat eye infections. These practices increase your risk of developing severe sight-threatening infections.