CORNEAL INFECTIONS

Exposure to viruses, bacteria, fungi or parasites – particularly in contact lens users – can cause the
eyes to become infected.

What is a Corneal Infection?

A corneal infection is an infection of the cornea, the clear section in front of the eyeball that allows light into the eye (find out more about how the eye works). Infections can be due to micro-
organisms such as bacteria, fungus, parasites – acanthamoeba & microsporidia, and viruses such
as herpes simplex.

Pseudomonas	Acanthamoeba	Microsporidia

What causes Corneal Infections?

Poor contact lens hygiene is the most common cause of corneal infections in Singapore. The yearly incidence of infections related to contact lens wear varies between 1 in 10,000 hard contact lens users, 4 in 10,000 soft contact lens users to 22 in 10,000 extended wear contact lens wearers. The yearly incidence of vision loss from contact lens related infections has been estimated to be approximately 0.6 in 10,000 users in studies carried out in Australia and India.

Corneal infections usually occur because of exposure to bacterial, viral or microbiological agents that cause the eyes to become red and swollen. In severe cases, it can cause changes to the corneal shape leading to astigmatism, opacification of the cornea from scarring or a combination of both.

Apart from contact lens related infections, infections can also occur due to existing abnormalities or disturbances of the eye surface or cornea or in cases of eye injury.

Can Corneal Infections be prevented?

As contact lens related infections are the most common, simple measures when wearing contact lenses can help reduce the risk of infections.  These include:

• Improving contact lens hygiene
• Reducing contact lens wear time
• Avoiding high risk activities
• Changing the type of contact lens used

However, any form of contact lens wear still carries the risk of corneal infection. Avoiding contact lens wear completely in patients who have predisposing diseases of the cornea or surface of the eye may be necessary.

Corneal infections after eye trauma can also be prevented in work site-related injuries with the appropriate use of safety googles.

How are Corneal Infections treated?

Corneal infections are usually treated with anti-infective eyedrops and eye ointment. In the case of bacterial infections, antibiotic eyedrops are usually prescribed. In most cases, patients with severe corneal infections are admitted into hospital and samples from the infection are taken to identify the likely organism before the start of the treatment. Treatment with intensive eye drops is administered and adjusted until the infection improves.

Is surgery necessary?

Surgery for corneal infections may be indicated in very severe infections or when the infection is not responding to medical treatment i.e. eyedrops. Surgery may also be indicated later on if vision is reduced due to corneal scarring from the infection. Surgery carried out in these situations aims to remove the diseased cornea (where scarring or severe infections is present) and replace the removed cornea with a corneal graft or transplant.

What does cornea graft surgery involve?

Corneal graft surgery may involve:

1. removing all the affected cornea and replacing it with a full thickness corneal graft (Penetrating 
    Keratoplasty)

2. removing only the layers affected and replacing with a partial thickness corneal graft (Lamellar
    Keratoplasty)

Please visit the following relevant links :-

Corneal & External Eye Disease Service
Outcome Results on Corneal & External Eye Disease Procedures
Corneal & External Eye Disease Service Clinical Staff
I Want an Eye Examination / an Appointment
How the Eye Works
Feedback