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Flashes & Floaters

August 22, 2013
Know Your Diseases

What are Floaters?

Floaters are tiny dark shadows of different shapes like circle, cobweb, line ,dots which appears drifting aimlessly in visual field despite there is no such things in front of eyes.They are frequently visible when looking at a plain background such as a blank wall or blue sky with worsening in bright light.

What are Flashes(Photopsia)?

Flashes are the rays of light like lightening streakswhich appears to moving in visual field. These flashes are transient in nature and appear to originate from certain point of the visual field and traveling in different direction.

What causes floaters?

Most of the eye ball is filled with a jelly like structure called vitreous which is present in between lens and retina (a light sensitive layer of eye ball). Vitreous is mainly composed of water and proteinacous fibre like structures and is loosely attached to the retina except some points where it is firmly attached. In childhood, vitreous is well formed jelly (except certain diseased condtions), but with growing age the fibres startsto get clumped and because of aging, in old age most of the vitreous converted to liquid state and starts shrinking. The well form long proteinaceous fibrils of childhood become small fibre clumps suspending in liquid vitreous. This condition is known as vitreous syneresis. The suspending fibrous strands cast their shadows upon the retina and create an illusion of something moving in front of eye. These shadows are floaters.

What causes flashes?

Ordinarily, light entering your eye stimulates the retina. This produces an electrical impulse, which the optic nerve transmits to the brain. The brain then interprets this impulse as light or some type of image. If the retina is mechanically stimulated, a similar electrical impulse is sent to the brain. This impulse is then interpreted as a "flicker" of light. Since vitreous are shrinking in old age it starts to get detached from retina known as posterior vitreous detachment(PVD), but at places where it is firmly attached to retina it causes a tractional force upon the retina which stimulates the retina and resulting electrical impulse is interpreted by brain as light rays i.e. flashes.

Is there any disease condition causing floaters?

Certain conditions like high myopia, cataract surgery, YAG Laser surgery, diabetes, and other degenerative vitreoretinopathy tend to induce posterior vitreous detachment increase the development of floaters Vitreous traction over the retina may lead to tear in thin retina. This tear may lead to small amount of blood escape into vitreous cavity may lead to floaters. Other causes of blood in vitreous cavity may lead to floaters like proliferative diabetic retinopathy, trauma, venous occlusion, bleeding disorders. Inflammation inside the eyeball like intermediate uveitis, chorioretinitis, leading to outpouring of cells in the vitreous cavity also causes floaters.

What symptoms the patients will develop?

Patients may have variety of presentations. Patients may describe spider or insect darting across their vision, cobwebs, dirt on the windshield, spots, strands, black spots in their vision, squiggly lines. Floaters are generally more noticeable to patients in bright light conditions such as outdoor activity or brightly illuminated computer screens, binoculars, or microscopes. This is because the bright illumination increases the contrast between the darkness of the floater and the surrounding light, making the floaters more apparent. Floaters generally jiggle or move when the eye moves.Patients with conditions causing some loss of vision, such as cataract or macular degeneration, may not notice their floaters as much. Some patients with large or numerous floaters upon examination may have few complaints and minimize their symptoms. Other patients with demanding jobs or hobbies, such as professional truck drivers or outdoor athletes, may have more complaints and the presence of floaters may have a more profound impact upon their daily living.

When to search medical attention?

Usually floaters are harmless but it may be an indication of diseases which need immediate medical attention.Butit is quite impossible to determine whether or not a new onset floater is benign or pathologic based solely upon the symptoms. Thus patients with new onset floaters should consult their ophthalmologist. Patients with a longstanding history of floaters that are familiar in character to the patient need not suddenly panic and seek care unless there is an obvious change in the size, shape, intensity, or density of the floaters. Other alarming symptoms include blurred vision, a red eye, pain in the eye, tenderness, a severe discharge from the eye, photophobia or aversion to bright lights, new onset of flashes, and of course loss of vision. On the other hand some patients have a higher risk for pathologic causation of their floaters and should seek professional care immediately.These at risk patients include those with known retinal diseases, diabetes, previous eye surgery, previous eye trauma, recent eye trauma, previous eye inflammation or uveitis, bleeding disorders, chemotherapy, and anticoagulation therapy.

What evaluation will be done by an ophthalmologist?

A chief complaint of eye floater, particularly of recent onset, requires a full eye evaluation and examination, including dilation of the pupils in one or both eyes. The evaluation includes a vision check (visual acuity), an eye pressure measurement (tonometry), examination under the slit lamp or biomicroscope, and examination of the vitreous and retina after dilation. Additional tests may include photography of the posterior segment, visual field testing to asses loss of central or peripheral vision, retinal tomography imaging to determine the thickness of the retina or optic nerve, or fluorescein angiography to assess blood vessel leakage. Complete evaluation and treatment of pathologic causes of eye floaters may require several visits to your eye doctor.

Is any treatment is needed for floaters or flashes?

Benign eye floaters caused by vitreous syneresis and posterior vitreous detachment (PVD) do not require specific treatment. Only close observation will be sufficient. Patients are advised to remain vigilant for more serious symptoms suggestive of retinal disease, including

  1. onset of new or more dense floaters,
  2. onset or worsening of flashes or photopsias,
  3. worsening of visual acuity,
  4. Appearance of a curtain of lost vision emanating from any direction.

These changes are the signs of retinal hole, retinal detachment, vitreous haemorrhage, or other vitreo-retinopathy. These conditions are mostly acute emergency and need immediate medical or surgical interventions. The treatment of a retinal hole is accomplished most readily by a laser surrounding the hole and thus sealing the retina from ingress of fluid that could cause a detachment. The repair of a retinal hole will not in itself decrease the symptom of floaters. Sometimes a retinal hole may require more aggressive intervention, including the injection of gas into the vitreous cavity (pneumatic retinopexy), freezing therapy (cryotherapy), or even a vitrectomy.

Is there any medicine for floaters?

Although medicine has no role in management of benign floaters, medications recommended by ophthalmologists may be necessary to control underlying conditions leading to vitreous haemorrhage or retinal disease in case of pathologic floaters.These medications may be taken in conjunction with laser, cryotherapy, pneumatic retinopexy, vitrectomy, or retinal detachment surgery.

Is there any surgical treatment needed?

Usually benign floaters do not need any treatment but if a person annoyed by the floaters they are best advised to avoid those circumstances in which the floaters are most bothersome. Some professionals by nature of their job like pilots, drivers, athletes and outdoor workers working in bright sunshine feel difficulty by large and central floaters warrants surgical removal of floaters.Pars plana vitrectomy (PPV) is a remarkable modern technique that can remove most of the vitreous contents, including virtually all the noticeable central floaters. Due to the significant effort and cost entailed by PPV and side effects associated with surgery, its use for minor conditions is not recommended. Development ofany serious symptom indicates towards the retinal detachment or vitreous haemorrhage immediate surgical intervention needed. If retinal detachment has developed with macular involvement, the earlier the intervention is better.

Can it be prevented?

Benign eye floaters occur due to aging process so it can occur at any age without any apparent reason. But pathologic floaters can be prevented by taking appropriate precautionary measures like frequent check up with ophthalmologists, proper controls of blood pressure, blood sugar level, prevention of eyes from trauma, like appropriate protection during games & other activities in which there is possibilities of injury to eyes.

What is the prognosis of floaters?

The outlook for benign floaters is highly positive but in case of pathologic floaters, early detection and appropriate treatment with the highly sophisticated tools available to modern medicine also portend a generally favourable prognosis in uncomplicated cases.Benign eye floaters generally do not disappear completely. The vitreous gel and its protein remain within the eye for life. However, the density of floaters often decreases with time and decreases more rapidly with the separation or if PVD is complete and the posterior vitreous face has been completely removed from the optic nerve. In addition, some patients only notice their floaters in bright lighting conditions or in situations where there is a bright homogenous white background, such as looking out an airplane window or into a microscope. Furthermore, the brain becomes accommodated to the presence of floaters and learns to ignore them in everyday life. This adaptation to the presence of the floaters renders the condition less bothersome or annoying.