Subject: Re: floater
Forum: The Eye Care Forum
Topic Area: Misc (Eye Problems)
Posted by HFHS M.D. -PE on February 09, 1999 at 14:13:27:
In Reply to: floater posted by Babette Dorn on February 09, 1999 at 07:14:40:

I am myopic (OS -10,0 cyl. -1,75; OD -5,75, cyl. -2,50) and both eyes have been argon-lasered in September because of a risk of RD.

My right eye also has a small central anterior cataract I have since my birth (not changing).

What I am wondering about is this:

Whenever floaters are discussed they are described as best seen on white background (I have those small dots or "hairs", too).

This new spot is quite different:

I can only see it when there is a lamp in front of me, slightly on the right, but then it is a completely black area. It is annoying when I drive a car at night (the lights in the mirrors somehow lighten it).

Should I return to have it controlled or is there a simple explanation? What causes it? Can floaters be so different?

Thank you very much! Babette Dorn

Vitreous floaters are caused when there is a shadow caused by denser particles which float in the liquid virteous in the back of the eye. The vitreous cavity is a large chamber in the back of the eye in
which a jelly- like material - the vitreous humor resides. The vitreous is usually in contact with the retina (the light sensitive film like structure in the back of the eye) and in some palce is actually
attached to it. As you get older especially in individuals like yourself who are very myopic, the vitreous begins to liquefy. Eventually the more solid parts which remain collapse towards the front of
of the eye, while the more liquid portion pools in the back of the eye (nearer to the retina). The floaters are actually particles of more solid vitreous debris which are floating in the liquid portion.
As the jelly collapses forwards, it pulls on the retina, this can cuase the retina to be stimulated resulting in flashes of light, usually better seen in a dim-lit room. The retina can also tear when it
is pulled, this results in bleeding and often patients will note "cobweb" like strands in their visual field. Breaks in the retina can cause a detachment of the retina from the wall of the eye as fluid
gets behind the break in the retina and "peel" the retina off of the eye wall and its blood supply. This caused loss of vision if it is not treated. Breaks and weak areas in the retina can be treated
with a laser beam or with a freezing probe to make the retina stick to the wall of the eye by forming a scar. This prevents a detachment.

Vitreous floaters are better seen against a light colored background or in bright lights because the particles are creat a shadow on the retina which are seen, and these shadows are more pronounced when the
light is brighter. This is similar to the effect of looking at the shadow cast by a building in bright sunlight vs overcast illumination. The shadow will be more pronounced in bright sunlight.

Any new floater which appear in the field of vision could represent a new break in the retina and should be evaluated by a dilated examination performed by an Ophthalmologist. You should have your eyes
examined to make sure there are no breaks in the retina. Floaters will change shape and size depending on their orientation as they float in the liquid vitreous.

This information is intended for medical education purposes and not to diagnose and treat any specific condition. Please consult your Ophthalmologist for examination.

I hope this helped.

*Keyword: floaters, vitreous separation, vitreous detachment, retinal detachment, retinal tears, retinal breaks

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