The next time you look in the mirror, take a closer look at your eyes to see if you can spot any small black dots - "floaters". Dr. Ian Yeo, consultant ophthalmologist for Vitreo Retinal Service at the Singapore National Eye Center reports.
Floaters and retinal detachment
As we age, it is inevitable that we will start experiencing floaters because of the degeneration of the vitreous (or jelly) within the eye. Most patients start experiencing floaters in their 40s, but those who are myopic or have familial vitreoretinal weakness may notice them earlier. Floaters can come in various shapes and sizes and have been described in multiple colors. Most patients identify their floaters as small dots or as linear figures, often black or gray.
In most cases, floaters are caused by the vitreous breaking down and are generally harmless, but in some it may be more sinister. This is because sudden onset of floaters may coincide with the development of a retinal tear, which may result in a retinal detachment - a potentially blinding problem.
Who is at risk?
In retinal detachment, the retina separates from the outer layers of the eye, thus losing its function. Anyone can potentially develop a retinal tear and detachment as the vitreous degenerates. However, the risk increases in patients with high myopia, a family history of vitreoretinal weakness/retinal detachment, ocular trauma and previous ocular surgery, and if one has had a retinal detachment or laser treatment for retinal holes in the past.
What are the signs of a retinal detachment?
Sudden appearance of floaters may herald the onset of retinal detachment. In some eyes, sudden flashes of light (a sensation of flashing lights emitting from within the eye, like a camera flash) and progressive blurred vision might signal the start of retinal detachment. This blurred vision has been described as a "curtain effect" where the normally clear image progressively becomes distorted then "blackened" out - like a curtain being drawn across your visual area.
What should you do when you start to experience floaters?
There is no need to panic when you see floaters, especially if you have been seeing them for years. A thorough examination of the retina by an ophthalmologist after dilatation of the pupil is necessary to determine the cause of the symptoms.
However, if there is a sudden and very marked increase in floaters, especially associated with flashes and blurred vision, you should be examined immediately. Your eye doctor will have your eyes dilated to inspect the retina. This inspection is to detect any retinal holes and associated thin and weak areas of the retina.
What can be done if we find a retinal tear?
If the retina is torn but detachment has not yet occurred, prompt treatment may prevent the occurrence of a complete detachment. The retina can be repaired using a laser. The laser treatment is done as an outpatient procedure, sealing the tear and reducing the risk of progression into a retinal detachment. During the procedure, local anesthetic is applied onto the eye and a lens is place over the front of the eye to help direct laser into the eye. There is a slight pain as the laser is applied but the patient is well immediately after the procedure.
However, if the tear is large and has already progressed into a retinal detachment, the patient will need to undergo either a scleral buckling (external procedure) or a vitrectomy (internal procedure) operation or both. These are major forms of eye operation and the eye will take at up to three months to recover. There may be a need to fill the eye with gas or silicon oil to flatten the retina; as a result, the patient may need to adopt a facedown posture for a few weeks.
What is the success and prognosis after surgery?
The success of surgery depends on the complexity and duration of retinal detachment. In early and simple retinal detachments, the success rate in one operation is close to 90 percent. However, complex or late presenting retinal detachments may need multiple staged procedures and have lower success rates.
The final visual outcome will depend on whether the macula (center of the eye) is involved and on the complexity and duration of the retinal detachment. Once the macula is detached and if the retina has been off for a long time, the visual outcomes will be poor. One may only recover navigational vision and not restore the original vision.
Remember, if floaters develop suddenly, it could be serious - get your eyes checked immediately. Early detection allows retinal tears to be sealed with laser and prevents progression to a retinal detachment - which will mean major surgery with prolonged recovery.
Singapore National Eye Centre performs more than 1,200 vitreoretinal operations annually, and has state-of-the art digital imaging techniques and equipment facilitating rapidly evolving diagnostic and therapeutic modalities. For more information, see our website www.snec.com.sg or call 65-6100 9393. cFlyFreeForHealth2009
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