Saturday, 23 July 2011

Preventing Retinal Detachment

Published in "Panorama"

Preventing Retinal Detachment

Retinal detachment is one of the most encountered eye emergencies, next to central retinal artery occlusion and chemical burns. What is Retinal detachment and how does it happen? The retina is essentially like a photographic film, the light-sensitive layer at the back of the eye, responsible for clarity of vision. A retinal detachment is a separation of the retina from the back wall of the eye. When the retina has a tear, liquid from the vitreous may pass through the tear, and detach the retina. Greater the fluid accumulation, larger the detachment and when this is left untreated, vision loss and blindness may result.

Are there certain categories of people who are at greater risk of suffering retinal detachment? Dr.Azim Siraj, Specialist Eye Surgeon, Prime Medical Centre, Dubai explains, “There are three types of retinal detachments. The most common type occurs when there is a break in the sensory layer of the retina, and fluid seeps underneath, causing the layers of the retina to separate. Those who are very nearsighted, having an eye power greater than minus 3, individuals who have undergone eye surgery, especially cataract surgery, or have experienced a serious eye injury, a blunt one as from boxing bouts, being hit with a golf or cricket ball, or a penetrative one as from sharp objects like darts hitting the eye, are at greater risk for this type of detachment.”

The second most common type, the tractional type of retinal detachment, explains Dr.Azim, “occurs with a pulling mechanism whereby there is neither a tear nor a hole in the retina. This pulling mechanism is usually due to fibrous bands in the eye cavity. This occurs in severe diabetics when strands of vitreous or scar tissue create traction on the retina, pulling it loose.”

The third type of retinal detachment happens when fluid collects underneath the layers of the retina, causing it to separate from the back wall of the eye, explains Dr.Azim. The retina is consequently elevated due to eye inflammations. Or it can happen because of a mass, or tumour which grows and pushes the retina away. This type usually occurs in conjunction with another disease affecting the eye that causes swelling or bleeding.”

Another category of people prone to retinal detachment are hypertensives. Says Dr.Azim, “Hypertension itself does not lead to retinal detachment; but when the blood pressure rises, it causes pressure effect on the vein, leading to vein block in the eye. When the veins which are responsible for the drainage of fluid get blocked, it leads to fluid accumulation. So it affects the retina with abnormal blood vessels developing and consequent retinal detachment. More importantly, retinal detachment runs in families since the causes which cause retinal detachment are hereditary.

It is possible that retinal detachment occurs in some people due to a combination of the above three types.

What are the symptoms of retinal detachment? “The most important and significant symptoms are flashes, which occur when the retina, enriched with blood vessels and nerves, is being torn away. It is a cry of the pulled nerves which results in flahes, which are electric spark-like light. Flashes which normally occur when the retina is not torn as yet but is just beginning to tear, if ignored could result in a hole formation & retina being stretched.”

The second most important symptom is the appearance of, and increasing numbers of floaters, which are fly or bug-like objects seen before the eyes, more than the normal of 3-4.

A third symptom could be the appearance of a screen-like object in front of the eye, causing misty vision; alternatively, there could be a sudden drop in vision or even absence of vision.
If any part of the vision is missing, like you see a person and his face, but you’re unable to see his hand, or you see his hands but the face is not very clear. This is an equally significant symptom of retinal detachment, says Dr.Azim.

While these are the commonest symptoms of retinal detachment, “it should be emphasized that retinal detachment can still occur without any symptoms and there are people who get picked up for the condition on routine eye examination,” cautions Dr.Azim. “This is so because if it is the extreme periphery of the retina which is getting detached, and not the central retina, the patient will not realize it as it may be symptomless.”

The less common symptoms of retinal detachment could include alteration in type of vision, says Dr.Azim. For instance, the person may see a certain object he’s been used to seeing regularly, appearing different - having a different colour! This is an indication that he needs to seek medical help. However, this may not be retinal detachment; it could be something else!”
Are there other eye conditions, the symptoms of which mimic that of retinal detachment? Most certainly, yes, says Dr.Azim. Even migraine sufferers could see flashes, but the differentiating feature is that people with retinal detachment, do not have headache.

Similarly, floaters could also happen in other conditions causing bleeding into the eye due to diabetes without retinal detachment. It can occur as part of the ageing process, after cataract surgery or even if there is some inflammation. Screen-like objects can also happen in other inflammations without retinal detachment. Sudden drop in vision can happen due to artery blocks, optic nerve problems and in severe glaucoma. But again, all these conditions will have other associated symptoms to differentiate it from retinal detachment. Hence, it is very important for individuals to seek medical help should they see any of these symptoms to reach correct diagnosis.”

Certain factors can speed up the process of retinal detachment or worsen the condition. These include lifting weights, constipation, violent bouts of coughing and vomiting bouts. People with retinal detachment or those belonging to the high risk category, especially with myopia of minus 10 and those who have retinal holes or weak spots, should avoid frequent gymnasium, pushups and weight-lifting.

How is retinal detachment diagnosed? Dr.Azim emphasizes, “It should be done only by an ophthalmologist and not by an optometrist! You cannot confirm diagnosis of retinal detachment without dilating the eye. Only by doing so can you find out an impending or happening retinal detachment. Diagnosis is done by using specialized lenses and a detailed examination of the retina is undertaken, especially of the peripheral attachments where degenerations, holes and detachments usually start. In cases where other eye problems are co-existing, Ultra sound is used to study the back of the eye to find out if there is any retinal detachment in the presence of a media opacity as in cataract.

Once diagnosis is confirmed, what is the treatment modality? There is no medical cure for retinal detachment, emphasizes Dr.Azim. “Medicines have no role in correcting this problem. Treatment of retinal detachment is viewed in terms of Preventive and Curative Treatment. Prevention is better than cure: hence individuals in the high risk categories should have periodic eye checkups. Diabetics should keep their sugar levels and blood pressure in control and avoid smoking to save the eye. In individuals in whom we spot a hole without detachment during a routine check up, we must treat him immediately since, over a period of time he is going to get retinal detachment – this can happen over hours, days or weeks. In such a case, the appropriate thing would be to prevent retinal detachment by sealing the hole, either by using laser or by going in for cryoprobe (ice therapy).

However, if retinal detachment has occurred, which is what happens in a vast majority of cases, you need to do surgical procedures, says Dr.Azim. “The appropriate surgery depends on the type, severity and location of the detachment.”

How successful are these surgeries and what is the risk involved in them? Early detection is key for surgery to be successful, emphasizes Dr.Azim. “Success of surgery will depend upon the location and size of the hole, the number of holes, the time and type of surgery done and whether there are other associated eye problems co-existing to complicate the issue. In simple cases, success is very good, when you diagnose the problem early.”

As for the risk of surgery, there is nil risk for life, apart from anesthesia, assures Dr.Azim. However, the eye may or may not become okay; it may become partially successful in the sense that if the detachment had been huge, it could become okay and then happen again. Even if a person has undergone treatment and surgery and the hole has been sealed, it does not mean the individual is free from the disease. In fact, the treated individuals could be the ones who should still look out carefully for the symptoms because this is a disease which can happen again, and happen in the other eye. Ideally, a patient should get a periodic checkup every six months from the same surgeon who treated the condition.”


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