Conjunctivitis is inflammation of the conjunctiva, or the white part of the eyes, said Dr Lee Sao Bing, medical director of Shinagawa Lasik & Eye Centre at Wheelock Place.
Different types of conjunctivitis have slightly different symptoms. In general, the conjunctiva changes colour - ranging from pink to very red - and the person starts tearing, which may also cause him to have an increased sensitivity to light.
When the condition is severe, the person also has blurred vision. Inflammation of the conjunctiva can be due to infection from viruses or bacteria, allergies, such as dust or haze, or chemical injury, Dr Lee said.
Allergic and viral conjunctivitis are commonly associated with other symptoms, such as white discharge from the eyes and itchiness. In bacterial or severe viral conjunctivitis, there is thick yellow or green discharge that crusts over the eyelashes, especially after one wakes up.
Identifying the cause correctly is crucial to guiding treatment. Those whose conjunctivitis is caused by a chemical irritant, such as paint, should wash their eyes copiously with saline. The doctor may prescribe steroids to ease the inflammation, antibiotics to prevent infection and lubricants to keep the eyes moist, said Dr Lee.
Allergic conjunctivitis is treated with anti-allergic medication and lubricants, while bacterial conjunctivitis is treated with antibiotics and lubricants, he added.
Viral conjunctivitis is treated with lubricants and, if severe, with steroid eye drops. This is the most common kind of conjunctivitis that can be prevented, he said.
First, the infected person must be aware that the virus can be transmitted through tears. If he rubs his eyes and then shakes another person's hands, this individual's hands will be contaminated. This person will also get conjunctivitis if he rubs his eyes.
Dr Lee said: "It is important to think of all points of contact, such as utensils and towels. I always tell my patients with sore eyes to wash their hands after touching their eyes and be aware of what they touch."
Bacterial conjunctivitis is quite rare, occurring in babies who have been exposed to bacteria in the birth canal during delivery and adults who have sexually transmitted diseases.
Allergic conjunctivitis can be prevented if sufferers can avoid the allergens that they are sensitive to, but most patients are hard-pressed to identify these, Dr Lee said.
People should wear protective eyewear, such as goggles, in an environment that raises the risk of chemical irritants entering their eyes, for instance, when working in a chemical laboratory or while swimming.
No food, herb or supplement, including mulberry leaves, are used by doctors for the treatment of conjunctivitis, Dr Lee said.
In general, he said that if the eyes are itchy and red, the most common cause is dry eyes. But if these symptoms are accompanied by tearing and the presence of discharge, then the sufferer should consult an eye doctor.
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