Floaters and Flashes

The terms “Floaters and Flashes” have different meanings to different individuals. However, in ophthalmology they have very specific meanings. A floater is defined as an image seen by the human brain which is produced by a particle floating in the Vitreous Humour of the eye. It is not an image that is visible to other people. Usually patients have numerous particles floating about so the term used most often is floaters as opposed to floater.

Flashes are defined as flashes or streaks of light produced on the inside of the eye and visible only to the person(s) experiencing them. They are not real to the observer but are real to the patient. They are produced by trauma to the retina of the eye and sudden changes in the intra-ocular pressure. A classic example is the “seeing stars” phenomenon when one is punched in the eyeball.

As we get older most of will experience small, dark shapes that appear to float in our field of vision. These are called floaters as defined above. The shapes of these floaters may be round, ribbon shaped, oval or rectangular. These are floaters and they are particles in the vitreous humour of the eye. The vitreous humour is a jelly-like substance which fills the inside of the mammalian eye. The vitreous body is comes in contact to the retina of the eye. This is the light-sensitive tissue at the back of the eye which contains the rods and cones.

Floaters appear as if they are real images in the field of vision because they cast shadows on the retina which are transmitted to the brain. During an eye examination floaters become more obvious when the patient is asked to look at a clear back-ground. Examples of clear background include a bright blue sky, sheet of white or grey paper. Since floaters are “debri” floating in the eye, they move quickly when the eye is moved and they drift away when the eye stops moving. When a patient has many floaters it can interfere with vision. In extreme situations it can lead to blindness. Retinitis Pigmentosa is an extreme example. Some patients with floaters will barely experience any difficulty. Sometimes, floaters can come and go over many years.

In the image of the eye below floaters and flashes can be seen by the patient anywhere between the lens and the optic nerve.

Sometimes, small flashes of light may be seen by the patient with or without the appearance of floaters. Flashes are usually caused by the vitreous humour adjusting the pressure on the retina of the eye. The example given above (punch or blunt instrument trauma) characteristically brings about sudden changes which produce the flashes. This phenomenon (pressure changes) is also a normal part of the ageing process. In some patients flashes may last for a few seconds or several minutes. In other patients they may occur off and on for several weeks. For best visualization of flashes it is best to place the patient in a dark room. Some patients may say that they see flashes at night only on in poor lighting conditions.

Patients with Migraine headaches sometimes complain of flashes. These flashes often appear as jagged lines blocking an area of vision. These flashes are not related to the vitreous body but may be related to changes in intra-ocular pressure.

Normal and Abnormal: Floaters & Flashes.

Flashers and Floaters appear directly as a result of the normal aging process. As we age the intra ocular vitreous humour shrinks and is replaced with a more liquid fluid. The occurrence of this patho physiological process explains the formation, occurrence, distribution and symptoms associated with these changes. Hence, floaters appear in the watery vitreous humour. In some instances the shrinking vitreous separates from the retina, when this happens “posterior vitreous detachment” is said to have occurred.

This generally occurs in patients who are 55 years or older. These patients generally complain of one large floater and multiple flashes. Most of the time the floater disappears over some time and normal vision is restored. At other times, when the vitreous humour is more firmly attached to the retina, it may pull away the retina as it shrinks. This may cause bleeding and trigger a “shower” of floaters. This phenomenon is called a retinal tear. During retinal tear, fluid can cause the retina to be detached from the retina. Retinal Detachment is an ophthalmic emergency and the treating team must be notified immediately to prevent blindness. Immediate surgery is indicated.

As stated earlier floaters, flashes and posterior vitreous detachments may occur as normal aging or may be pathologically induced by trauma or other causes. The causes of floaters are discussed under the appropriate section.

Diagnosing Floaters and Flashes. Medically trained doctors and opthalmologists are trained to diagnose these disorders. Patients who complain of seeing flashers and or floaters should be referred to a doctor or an ophthalmologist. Changes in amount of floaters and flashers should also be referred to qualified practitioners.

The ophthalmologist or doctor may use mydriatrics (medications which dilate the pupils of the eye) to examine the interior of the patients eyes. An instrument known as an opthalmoscope will be used to view the interior or the eye. The qualified trained practitioner will be able to diagnose any and all of the following:

1. posterior vitreous detachment,
2. retinal tear,
3. retinal detachment and
4. intraocular bleeding

Individuals who report occasional floaters and flashes should have an annual eye examination. This will facilitate early detection and treatment of any abnormality which may arise.

IMPORTANT ROLE OF YOUR OPHTHALMOLOGIST

I have written this article with the sole intention of providing information to the general public and nursing students. Please do not consider this article as expert advice. It cannot replace the role of a qualified ophthalmologist or a medical practitioner. This article does not contain all information about floaters, flashes, retinal detachment etc.

After you have read this article you may have questions which are unanswered. Write them down carefully and your doctor and ophthalmologist will be pleased to answer them for you. If you are still not convinced of the risk to benefit ratio then you should seek a second or third opinion.

CONSENT FOR PROCEDURE FORM: In most institutions you will need to sign a document agreeing to the surgical treatment or procedure. Your ophthalmologist will explain the risks associated with the procedure. Please read the consent carefully.

There is usually a clause which states that the surgeon may perform any other procedure which may become necessary when doing the agreed procedure.

COMMON TREATMENTS: FLOATERS AND FLASHES

Generally, floaters and flashes are an annoying phenomenon with no long term consequences. However, in some instances they can indicate underlying problems. If these are not treated or managed properly the consequences can be a significant, deterioration of quality of life for the patient.

For many people treatment of floaters and flashes is not necessary and should not be considered because the side effects and complications of treatment could have disastrous consequences. Floaters and flashes usually subside over time, causing no permanent deterioration to vision. Wearing sunglasses during driving or reading may be helpful in controlling the “symptoms” associated with floaters and flashers. However, if there is a sudden onset of new floaters and/or flashes then the condition must be taken seriously. These indicate serious potential problems including potential tears and retinal detachment.

Treatment of Floaters: Large and persistent floaters that obstruct vision can be surgically removed during a procedure known as a vitrectomy. This involves using special instruments to remove the floaters, among with some or all of the vitreous body. The vitreous is usually replaced with a clear salt solution; rarely, a synthetic gas or silicon oil may be used. Vitrectomy surgery is usually performed under local anesthesia or, occasionally, general anesthesia.

As possible complications can be serious and may not be worth the risk, vitrectomy surgery is recommended only in unusual cases. Complications can include retinal detachment, cataract information, glaucoma and ultimate loss of vision in the operated eye, among other possible acceptable option if floaters drastically affect driving, reading or the ability to work.

Management of Flashes:

Flashes which are due to posterior vitreous detachment, as a rule, do not need treatment. This rule holds true as long as the retina is not torn at any point. However, if retinal tear is present then quick and early treatment must be initiated. The goal of such treatment is to seal the tear and arrest further retinal detachment.

Retinal tears are best managed by both or either of these methods:

1. Laser treatment which brings about photocoagulation and fibrosis of the affected area. The beam is focused on the area to be treated through the pupil. The tiny resultant burns heal and scar tissue holds the tear in one place.
2. Freezing or cryotherapy is another frequently used and recognised intervention. Cryotherapy is sometimes called freezing treatment. During this treatment a probe is applied to the exterior of the eye. The cold freezes through to the retinal tear and holds the two ends together as a consequence of the newly formed fibrous tissue.

Cryotherapy and photocoagulation are usually performed under local anesthesia in the operating theatre under aseptic conditions. Slight discomfort is often experienced and this is usually explained to the patient. There is always the possibility of reduced vision and a need for further treatment. Sometimes retinal detachment occurs and surgery becomes necessary. Statistical studies show that the risk associated with surgery is lower than the risk of vision loss due to leaving the retinal tear untreated.

If you require surgery for a detached retina, your ophthalmologist will have more information about the benefits, risk and limitations of treatment

Management & treatment costs.

In Australia costs may be covered by your private insurance plan. Alternatively, you can seek help from state hospitals. Your ophthalmologist and doctor can help you reduce out-of-pocket expenses. If you are paying out of your pocket you may want to ask for a written estimate before you agree to the procedure and treatment.

It is generally considered better to get an accurate estimate of costs before treatment rather than seeking remedies afterwards.