Conjunctivitis is commonly an infection of the conjunctiva (the thin transparent tissue covering the outer part of the eye). One type of this infection, that occurs commonly, is also known as “ Madras Eye”.
Cause and Routes of Spread
Conjunctivitis is caused by a group of viruses called Adenovirus. This virus group also causes common cold. So this disease resembles common cold in many ways.
This infection will occur in epidemics. The virus will be present in tear secretion. The patient’s hand will be contaminated while wiping the watering eye. From the unwashed hand of the patient, the virus can spread on to others’ hands, other common surfaces like furniture, bed sheets, towels etc. These viruses can be alive in these places even up to a few weeks. Anybody who is in contact with these items will get infected.
However, this infection cannot spread by air. That is, you cannot get conjunctivitis just by looking into the infected person’s eyes from a distance
Signs and symptoms
This disease has three stages.
The acute symptoms may last for upto three weeks. In the first week, the virus multiplies in the conjunctival cells. At this stage, the eye will become reddish and lids swell. There will be continuous watering, sensation of some foreign material within the eye and sticky discharge on the lids while waking up. Sometimes the lid swelling will be so severe that one cannot open the lids at all.
This will gradually reduce by the second week. In the second week, Cornea, which is seen as the black part of the eye, will be affected. The virus affects the outer corneal cells. So, minute grayish spots will appear in this layer. The irritation may increase and the patient will find it difficult to see in bright light. By the third week, the virus replication will come down spontaneously, so the actual infective phase will be over. But the remaining dead virus particles deposited in the corneal tissue will incite an immune reaction resulting in coin like lesions on the cornea in some cases.
This is the most problematic stage. Though it is good that our body is fighting against the virus, the resulting lesions will cause disturbing symptoms. If the opacities are in the center of the cornea and many in number, they will cause glare, which is severe while looking at lights in the night. One cannot see the headlights of the oncoming vehicles, making night driving difficult. Visual acuity itself will go down in some cases. Some people will feel recurrent irritation. Fortunately this stage is a self-limited one. That is, whether you treat it or not, it will clear completely after some time. But the time it will take may vary from person to person.
Since it is a viral infection, common antibiotics will not be effective in either preventing or curing this infection. But to prevent secondary bacterial infection, usually a mild anti-biotic drop will be prescribed. It is enough to use this drop 4 – 6 times a day. In the initial stage, inflammation of the conjunctiva is the main problem. To reduce this, your ophthalmologist may give some anti-inflammatory drugs in the form of drops or tablets. It is preferable to restrict the topical drops, as much as possible. The inflamed eye cannot tolerate the preservatives in the eye drops. Also, this inflammation will cause a dry feeling in the eye. To reduce discomfort, one can use preservative-free artificial teardrops frequently. You can also gently mop the closed lids with a clean wet cloth. Hot water should not be used. The presently available anti-viral drugs are not very effective against this virus. Steroid medication also should be avoided as far as possible. This is because, steroids can reduce our body’s immune reactions and can actually increase the viral multiplication. In the later stages of immune reaction, steroids may suppress this reaction and improve symptoms like glare. But again, this suppression is only temporary and once the drug is stopped, the symptoms will recur. So this treatment will actually prolong the course of the disease. Therefore, it is better to avoid steroids. Your ophthalmologist may prescribe steroids, if the inflammation is found to be very severe, to prevent scarring. Discuss with your ophthalmologist as to when you should use these drugs.
Preventing Spread of Infection
Isolation of the patient is an effective preventive step. The patient should restrict his activities especially in the common areas used by others. Personal items used by him, even eye drops, should not be shared with others. A tissue or clean handkerchief should be used for wiping the watery secretion from the eye. Hands should be washed frequently.
In some viral infections like small pox, our body will develop lifelong immunity once affected. That means, the same disease will not affect the same person again throughout his life. But viral conjunctivitis is not like that. Like common cold virus, this group of Adeno-virus has many sub-groups. A different sub-group causes each epidemic.
Source: Aravind Eye Hospital, Madurai, India