MACULAR DEGENERATION

What is Macular degeneration?

Macular is a sensitive area in the centre of the retina which provides us with sight in the centre of our field of vision. It allows us to see the fine details when we look directly at something.

In macular degeneration, a layer beneath the retina, called the retinal pigment epithelium (RPE), gradually wears out from its lifelong duties of disposing of retinal waste products. Eventually, the capacity of the RPE layer to handle these metabolic products is overwhelmed and the RPE begins to degenerate. Moreover, hereditary factors, ultraviolet rays, blue or low pigment density iris colour may also hasten loss of the RPE layer and thus result in macular degeneration. A large proportion of macular degeneration cases are age- related. It is a common problem among older adults and it increases in frequency with increasing age. It is the leading cause of significant vision loss among patients over the age of 50.

Two different forms of macular degeneration

There are basically two forms of macular degeneration: dry and wet type.

Dry macular degeneration is characterized by tiny yellowish deposits under the macular part of the retina. These deposits may increase in number and size over time. Then areas of loss of retinal and RPE layers in the macular may gradually appear. Small clumps of brown pigment from the degenerating RPE layer can also be seen.

Wet macular degeneration can be associated with more sudden loss of vision due to leakage or bleeding under the macular from abnormal vessels arising from one of the deepest layers, called the choriocapillaris. Lastly, these areas of bleeding or fluid accumulation can develop into a dense mass of scar tissue beneath the retina, resulting in permanent loss of central vision.

Causes

Actually, the cause of macular degeneration is still unknown today. But it has been known for nearly 100 years that there are some form of macular degeneration that are inherited, for example the Best's disease, which can affect children as young as one year of age.

Symptoms

1. Blurry vision

2. Straight lines appear wavy or curved

3. A dark or empty area appears in the centre of vision

Treatments

Similar to retinal detachment, macular degeneration is also a disease that cannot be cured completely. The goal of all macular degeneration treatments are to help the patient see better and stabilize the condition.

Between the two types of macular degeneration, one who suffers from dry type is much more unlucky than the other type for there is no proven treatment for dry macular degeneration. However, some people believe that antioxidants or zinc supplements may help.

And for wet macular degeneration, out-patient laser surgery may be an option for people with severe condition. The laser beam is used to destroy the abnormal blood vessels and works best when these vessels have not grown under the macular. Nevertheless, when the abnormal blood vessels have already grown under the macula, the laser might cause as much damage as the presence of abnormal blood vessels. This explains again why early diagnosis is so important!

Unlike retinal detachment, the people who have severe macular degeneration would never go blind even nothing is done with the disease. With the help of low vision aids, people can continue to enjoy many of their favourite activities and lead normal lives.

A PATIENT'S EXPERIENCE

------- Mr. Alexandria Leung (My Uncle Seven)

Just I year before I was diagnosed to have retinal detachment, my Uncle Seven had already been diagnosed to have a serious kind of macular degeneration. He told me that he always find the vision of his right eye blurry and becoming worse. What more he detected include frequent flashes and large floaters. Although he was diagnosed to have eye disease earlier than I was, he undergone the operation at my heels because of certain reasons. I remember my Uncle was so nervous the few days before the operation and I helped him to calm down by sharing my experience with him.

Eventually, his operation was also finished successfully and now it seems that he recovers even better than me.