Conjunctivitis

Conjunctivitis is one of the most common eye conditions in the world, affecting millions worldwide every year. Winter can be peak season for some types of conjunctivitis, as cold weather and indoor living create ideal conditions for viral and bacterial spread. Read on to learn all about conjunctivitis - from types and causes to symptoms and treatments.

What is Conjunctivitis?

Conjunctivitis, also known as pink eye, is an inflammation of the conjunctiva (the thin, transparent membrane that covers the white part of the eye and lines the inside of the eyelids). It can cause redness, irritation, watering and discharge in one or both eyes. The condition can affect people of all ages and may develop due to a viral or bacterial infection, an allergic reaction or exposure to irritants. While many cases are mild and can get better on their own, some require medical attention and appropriate management and treatment.

Types of conjunctivitis?

Understanding the different types of conjunctivitis, their symptoms and causes can help you manage the condition more efficiently and prevent it from spreading. Conjunctivitis is classified into different types depending on its underlying cause. The main types include:

1. Viral conjunctivitis

Viral conjunctivitis is highly contagious, commonly associated with adenoviruses and may occur alongside respiratory infections such as the common cold. It often begins in one eye and can spread to the other. The condition usually causes redness, watery discharge, irritation and a gritty sensation.

2. Bacterial conjunctivitis

Bacterial conjunctivitis develops when bacteria infect the conjunctiva. Common bacteria responsible include Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae. It commonly causes redness, eyelid swelling and thick discharge, which may appear yellow or green. The discharge can accumulate overnight, causing the eyelids to stick together upon waking. Many cases resolve without antibiotics, while others may require prescription antibiotic eye drops or ointment.

3. Allergic conjunctivitis

Allergic conjunctivitis occurs when the immune system reacts to allergens such as pollen, dust mites, pet dander or mould. It commonly affects both eyes and is characterised by intense itching, redness, excessive watering and swollen eyelids. People with other allergic conditions, such as hay fever or asthma, may be more susceptible. Unlike infectious conjunctivitis, allergic conjunctivitis cannot spread from one person to another.

4. Irritant or chemical conjunctivitis

Irritant conjunctivitis develops when the conjunctiva comes into contact with substances that cause irritation or inflammation. Common triggers include smoke, dust, air pollution, chlorine, perfumes, cleaning products and certain cosmetics. Symptoms may include redness, burning, watering and discomfort. The severity depends on the substance involved and the extent of exposure, with some chemicals potentially causing more serious eye injuries.

5. Neonatal conjunctivitis (ophthalmia neonatorum)

Neonatal conjunctivitis, also known as ophthalmia neonatorum, refers to inflammation of the conjunctiva in newborn babies, particularly during the first 28 days of life. It may develop from an infection acquired during childbirth or chemical irritation. Other conditions, such as a blocked tear duct, can also cause similar symptoms. Some infections are associated with sexually transmitted infections (STIs), particularly gonorrhoea and chlamydia, which can be transmitted from mother to baby during delivery.

Causes of conjunctivitis?

Several factors can contribute to the development of conjunctivitis depending on its type. Some of the most common causes and risk factors are:

• Exposure to infected individuals
• Contaminated cosmetics
• Poor contact lens hygiene
• Exposure to allergens
• Chemical exposure

Symptoms of conjunctivitis

The symptoms of conjunctivitis can vary depending on whether the condition is caused by an infection, an allergy or an irritant. The symptoms may develop in one or both eyes. The most common symptoms include:

• Redness
• Itching
• Excessive watering
• Eye discharge
• Burning or irritation
• Gritty sensation
• Swollen eyelids
• Sensitivity to light

Diagnosis of conjunctivitis

A healthcare professional can usually diagnose conjunctivitis by reviewing your symptoms, medical history and examining your eyes. During the examination, the doctor may assess:

• The degree of redness and inflammation.
• The presence and nature of eye discharge.
• Swelling of the eyelids and conjunctiva.
• Whether one or both eyes are affected.
• Any associated symptoms, such as pain, light sensitivity or changes in vision.

In most cases, additional testing is not necessary. However, an eye discharge sample may be collected for laboratory testing if the infection is severe, persistent, recurrent or suspected to be caused by an unusual microorganism. Testing may also be required in certain newborn infections. An eye examination is important because other conditions, including corneal infections and inflammation inside the eye, can cause similar symptoms.

Treatment for conjunctivitis

The treatment for conjunctivitis depends on its underlying cause. Some types resolve on their own, while others may require medication or measures to relieve symptoms.

Antibiotics are not effective against viral or allergic conjunctivitis. Always consult a healthcare professional before using prescription eye drops, particularly steroid-containing drops. It is important for contact lens wearers to stop wearing their lenses until symptoms have completely cleared or an eye care professional advises otherwise.

How to manage or reduce the spread of infectious conjunctivitis

Good eye hygiene and appropriate eye care can help reduce the risk of developing or spreading infectious conjunctivitis. Here are some precautions to follow:

• Wash your hands thoroughly and often, using soap and warm water
• Wash your pillows and face cloths using hot water and laundry detergent
• Do not touch/rub your eyes
• Do not share items like sunglasses, glasses and towels
• Avoid doing makeup around the eyes
• Maintain good eyelid hygiene
• Avoid wearing contact lenses until the infection has cleared and your symptoms have resolved.
• Do not go for a swim during an infection

In conclusion, conjunctivitis is generally manageable with the right care and understanding its causes and symptoms is essential for effective treatment and recovery. If your symptoms are severe, persistent or affect your vision, seek advice from an eye care professional to ensure appropriate care.

Frequently asked questions

Is conjunctivitis contagious?

Not all types of conjunctivitis are contagious. Viral and bacterial conjunctivitis can spread from one person to another through direct contact with infected eye discharge, contaminated hands, towels, pillowcases and other shared personal items. Allergic and irritant conjunctivitis are not contagious because they are not caused by infectious microorganisms.

Can water cause conjunctivitis?

Water itself does not necessarily cause conjunctivitis, but contaminated water and exposure to certain chemicals can irritate the eyes or increase the risk of infection. Swimming in poorly maintained pools, lakes or other contaminated water sources may expose your eyes to microorganisms that can cause infections. Chlorinated swimming pool water can also irritate the eyes. Pool chemicals may disrupt the tear film, the protective layer that keeps the surface of the eye lubricated.

Can you wear contact lenses if you have conjunctivitis?

No. You should stop wearing contact lenses while experiencing conjunctivitis symptoms. You can restart wearing them only after your symptoms have completely cleared and your eye care professional confirms that it is safe. Contact lens wearers experiencing a red eye should seek prompt professional assessment, as they may be at increased risk of corneal infections.

Can conjunctivitis cause permanent vision loss?

Most uncomplicated cases of conjunctivitis do not cause permanent vision problems. However, certain severe infections, particularly gonococcal conjunctivitis in newborns and infections involving the cornea, can cause serious complications if not treated promptly.

Can you go to work or school with conjunctivitis?

This depends on the cause and severity. Allergic and irritant conjunctivitis are not contagious. Viral and bacterial conjunctivitis can spread through close contact and contaminated surfaces, so maintaining good hygiene and following medical advice is important. You don’t normally need to stay home if you feel well enough, but if you feel unwell or cannot avoid close contact with others, then you should stay home.

How long does conjunctivitis take to clear?

Irritant conjunctivitis should clear up once the cause has been removed. Bacterial conjunctivitis usually improves after a few days, although it can take longer to clear completely. Conjunctivitis caused by sexually transmitted diseases will take longer to clear up and requires appropriate treatment. Viral conjunctivitis can take up to three weeks to go away.