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CONJUNCTIVITIS

What is Conjunctivitis ?

Conjunctivitis means an inflammation of the conjunctival layer. This layer covers the white of the eye and the inside surface of the eyelids. Conjunctivitis caused by a bacterial infection results in reddening and stickiness of the eye. It feels sore and vision is slightly blurred. On waking, the eyelids may be stuck together. In conjunctivitis which is due to a virus infection, the eye is pink and watery rather than sticky. Conjunctivitis also occurs due to allergy. This typically occurs during the hay fever season. However people with asthma may suffer with significant allergic conjunctivitis for many months of the year. The surface of the clear cornea at the front of the eye can also be affected by inflammation or infection. This is called keratitis. Severe viral conjunctivitis may result in an associated keratitis. Bacterial or allergic conjunctivitis is rarely complicated by keratitis. There is usually significant pain or discomfort and blurred vision with keratitis.

How does Conjunctivitis occur ?

In bacterial or viral conjunctivitis, an infectious organism affects the conjunctival layer. In allergic conjunctivitis the reaction is typically due to pollens however pet animal hair typically cats or guinea pigs /hamsters may be responsible in children. Allergy can occur due to long term use of eye drops or contact lens solutions. Viral conjunctivitis is commonly associated with a sore throat which precedes the eye inflammation by a couple of days. A specific type of viral conjunctivitis/keratitis is due infection with Herpes simplex virus (cold sore virus). This can result in recurrent inflammation resulting in scarring of the cornea with consequent loss of visual acuity. Contact lenses can become contaminated with bacteria and in rare instances with amoeba (acanthamoeba). Strict hygiene is important when storing and handling contact lenses especially soft lenses. Use of extended wear contact lenses is associated with a greater risk of corneal infection that can be serious resulting in loss of vision. For this reason many practitioners discourage the use of these type of lenses. The Chlamydial organism is an important cause of chronic conjunctivitis. In certain developing countries it is a common cause of blindness due to the condition of Trachoma. Chlamydia however also causes chronic conjunctivitis often affecting only one eye. It is associated with chlamydial genital infection. New-born infants can acquire the infection during birth which also may result in a chest infection.

Why does Conjunctivitis occur ?

Viral conjunctivitis is often associated with a sore throat or flu. The infection is therefore caught from others by droplet spread or by direct contact with tears. Some forms are highly contagious. Chronic eyelid inflammation (Blepharitis) is a common cause of recurrent bacterial conjunctivitis. A deficient tear film (dry eye), a blocked tear duct, or a turned out lower lid makes means the eye is more vulnerable to bacterial infection. Wearing soft contact lenses is an important cause of bacterial infection occurring when cleaning regime is not adhered to. However serious corneal infection can occur spontaneously with extended wear lenses. Herpes simplex virus corneal infection affects patients who have had exposure to the virus in the past. The infection is likely to have been acquired in childhood by contact with someone with a cold sore on the mouth for example. Most people develop strong immunity or resistance to the virus and so it does not cause any problem. Those who are affected tend to get attacks of Herpes Keratitis when they are ill or stressed. Recurrences are also common after exposure to ultraviolet light.

Treatment Involved for Conjunctivitis

A swab may be taken to confirm whether conjunctivitis is due to a virus or bacteria, especially in babies. Treatment for bacterial conjunctivitis is by regular application of antibiotic eye drops. The infection should improve within a few days. Treatment for common viral infection is less satisfactory. The bodies own immune system will eventually clear the infection however in more severe infections the symptoms may persist for more than a week. Antibiotic eye drops are often prescribed to prevent a bacterial infection occurring, however this is unlikely. Simple lubricant eye drops often give some symptomatic relief. Severe viral conjunctivitis which results in corneal infection (Keratitis) causing reduced vision needs treatment by an eye specialist. Weak steroid drops are usually necessary. Herpes simplex keratitis is treated with a specific antiviral ointment (Acyclovir) applied to the eye. The treatment will need to be monitored by an eye specialist. It is wise for individuals who suffer with recurrent herpes to take Acyclovir ointment with them when travelling. Chlamydial infections generally require treatment with an antibiotic course taken by mouth usually a tetracycline. Any sexual partners will also require treatment. Bacterial corneal ulceration is serious and requires intensive antibiotic treatment. Hosspital admission may be advised. Allergic conjunctivitis is treated with anti inflammatory eye dops and or anti histamines. Opticrom eye drops are often effective in preventing or reducing episodes. Severe allergic conjunctivitis with keratitis needs treatment by a specialist. Steroid eye drops are usually required. These should never be used randomly for red eye or eye infections. Herpes infections in particular can be made very much worse leading to corneal scarring with loss of vision.

During Treatment for Conjunctivitis

Improvement occurs within days for a bacterial and often after some weeks for a viral conjunctivitis. Occasionally particularly after prolonged treatment the eye drops can cause an inflammatory conjunctivitis. This can be due to an allergic or toxic reaction to the antibiotic or the preservative in the eye drop preparation. Contact lenses must not be worn during treatment and it may be necessary to leave them out even for a number of weeks after the infection has resolved. It is important to check with the optometrist or eye specialist.

If Conjunctivitis is Left Untreated

Even without treatment, bacterial and viral conjunctivitis normally get better within 2 or 3 weeks. An untreated corneal ulcer can worsen quickly. If the infection goes deeply enough to enter the eye, vision can be permanently damaged. For herpes simplex, withholding treatment would cause the scarring and inflammation to be more severe, and vision would become much worse.