Seeing spots
Retinal detachment is the separation of the retina from the back of the eye. Without urgent surgery, sight will be lost permanently.
ONE of the most common problems we will face in our life is seeing “spots or lines” in our vision. This is commonly referred to as “floaters”. These floaters are usually due to a natural process of ageing in our eye called posterior vitreous detachment (PVD).
The vitreous is the clear gel that fills the central cavity of the eye. It occupies 80% of the volume of the eyeball and is formed by a network of collagen fibrils, hyaluronate and water. This vitreous gel liquefies with age, and eventually falls away or separates from the retina, which is the delicate nerve tissue that lines the back wall of the eye.
This event is called a PVD, and it is a normal event occurring in most people, usually those above the age of 50 years. Rarer causes of floaters include calcium crystals, infection, and inflammation in the eye.
As this gel separates from the retina, we will see a variety of shapes like dots, tadpoles, or lines that appear in our vision, and these may move with our eyes. It can be very frightening when this happens and many people are very affected by these floaters. It can appear like insects flying around in your eye!
Sometimes, the vitreous gel can pull on a blood vessel on the retina and cause bleeding in your eye. Then, you may see a shower of many small black spots that can completely block your vision.
Other symptoms of PVD that you may notice are flashing lights in the corner of your eye.
PVD on its own is harmless. With time, these annoying floaters will eventually go away. This is because the vitreous gel is gradually broken down in the eye and the floaters will go out of focus.
Some people may be very affected by the floaters, especially if they block the centre of their vision and affect their work.
For most people, the floaters will eventually resolve, but this can take months. Very rarely, surgery or laser treatment can be carried out to remove floaters if they are causing significant loss of quality of life to the person.
The separating vitreous can also cause a tear in the retina layer. Once a retinal tear has occurred, the fluid in the eyeball can enter this hole and detach the retina from the eye.
About 10% of PVD cases will have a retinal tear present and that is why it is important to have your eyes examined if you experience a sudden onset of floaters or flashing lights in your eyes.
Finding a retinal break can be difficult and requires a very complete examination of the far edges of the retina. The pupil must be dilated for a complete examination.
Sometimes, indirect ophthalmoscopy with scleral depression is done. This is the procedure where the eye doctor wears a light source on his head and examines the retina with a hand–held lens while pushing in on the edge of the eyeball with a stick–like instrument through the lids to bring the periphery of the retina, where most breaks are, into view.
If there is a retinal tear, this can be treated with laser or cryotherapy to prevent retinal detachment.
Retinal detachment is the separation of the retina from the back of the eye. Without urgent surgery, sight will be lost permanently. It is probably the most important structure in your eye because it converts what you see into electrical impulses to your brain.
You can imagine a retinal detachment to be like wallpaper coming off the wall when it is loose. Since most tears occur in the peripheral retina, the detachment will first cause loss of your peripheral vision. This can be seen as a curtain or shadow in the corner of your eye that does not go away.
As the detachment extends towards the macula (the centre of your retina), the shadow will also enlarge. Central vision will be lost if the macula is affected.
Most retinal detachments will eventually involve the entire retina, and when this happens, all vision will be lost.
Retinal detachment occurs in less than one in 10,000 people, and it is more common in people with myopia, those who have had previous eye trauma, or complicated eye surgery. It is also more common in the older age group compared to children.
Retinal detachment is a medical emergency and needs to be treated by a trained retinal surgeon. Surgery is normally done by vitrectomy surgery to remove the vitreous gel, laser to seal the retinal holes, followed by insertion of special gas or silicone oil into the eye to prevent the retina from redetaching.
Modern vitrectomy surgery can now be done without sutures. Sutureless surgery allows faster recovery after surgery, with less pain.
Another way to treat retinal detachment is by suturing a piece of silicone called a scleral buckle to the outside of the eye and treating the retinal hole with freezing treatment called cryotherapy. This procedure is known as “cyro-buckle”. The scleral buckle can also be combined with vitrectomy in more complicated retinal detachments. This buckle presses the eyeball inwards to help close the retinal hole.
Surgery for retinal detachment is quite successful and we can reattach the retina 90% of the time with one operation. How well you can see after surgery depends on how bad the retinal detachment is at the time of surgery.
If the macula has not yet detached, you will usually get back most of your vision. But, if the macula is already detached, there may be permanent loss of central vision even if surgery is successful.
Basicly, the sooner the surgery is done, the better the outcome.
In summary, if you have any symptoms of retinal detachment, like floaters, flashing lights, or loss of vision, you should seek expert advice. There is no pain when retinal detachment occurs. Do not delay treatment as it may result in permanent loss of vision.
If retinal detachment surgery is done before the detachment involves the macula, you can normally retain your vision as before. Unfortunately, PVD or retinal detachment cannot be prevented by diet or supplements. (For further information, please refer to www. eyeretina.my.)
Dr Fong Choong Sian is a consultant ophthalmologist while Goo Chui Hoong is a consultant dietitian. They are publishing a book on eye health and diet next year. For further information, e-mail starhealth@thestar. com.my. The information provided is for educational and communication purposes only and it should not be construed as personal medical advice. Information published in this article is not intended to replace, supplant or augment a consultation with a health professional regarding the reader’s own medical care. The Star does not give any warranty on accuracy, completeness, functionality, usefulness or other assurances as to the content appearing in this column. The Star disclaims all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.