Pass the Prozac for the Eye Floaters? Posterior Vitreous Detachment is a common condition, which occurs in about 75 per cent of people over the age of 65. As people get older the vitreous, a jelly-like substance inside the eye changes. This can cause posterior vitreous detachment. The vitreous is a clear jelly-like substance within the eye, which takes up the space behind the lens and in front of the retina, the light sensitive layer at the back of the eye. It is 99 percent water. The other 1 percent consists of substances, which are important in maintaining the shape and structure of the vitreous. The outer part of the vitreous (the cortex) has the highest concentration of collagen. The vitreous is attached to the retina, more strongly in some places than others.
When a Posterior Vitreous Detachment starts the outer layer of the vitreous starts exerting traction at the points where it is adhered to the retina. The firm jelly-like substance of the vitreous changes with age. The central part of the vitreous becomes more liquid and the outer part (cortex) peels away from the retina. As it comes away from the retina it can cause the symptoms of posterior vitreous detachment. Many people are never aware that they have developed a posterior vitreous detachment but some patients notice symptoms such as floaters or flashing lights. Floaters can present with many different forms varying from little dots, circles, lines, to clouds or cobwebs. Sometimes people experience one large floater, which can be extremely distracting and make reading a difficult task. The flashing lights that occur are also caused by the posterior vitreous detachment. As the outer part of the vitreous detaches from the retina it can pull on this light sensitive membrane, especially where there are strong anchor attachment points. The pull of the vitreous in these areas stimulates the retina. This stimulation causes the sensation of flashing lights since the brain interprets all stimulation of the retina as signals for light. Sudden head movements often precipitate flashes as they cause the vitreous to move inside the eye.
Can anything be done to help with the posterior vitreous detachment? Yes but not what you would probably expect. Central floaters can be extremely distracting and interfere with daily functioning when they first occur. Unfortunately at this juncture there are no good medical procedures to remove eye floaters. Fortunately most people find that the symptoms calm down after about six months and eventually they largely dissipate from awareness. While there are no good studies to substantiate the perceptual adjustment the brain makes, Optometrists have observed the brain eventually learns to ignore floaters given adequate time, except in certain lighting environments and with eye movements. Logically this makes sense because the retina extinguishes any images that remain fixed and don’t move across the eye. Normal micro-eye movements that are always present assure that the world we live in is always visible. The blood vessels inside the eye do block the retina receptor cells but move in sync with the eye since they are attached to the top of the retina. That is why during an eye examination with an eye microscope you may notice a tree branch like pattern; the light is casting shadows from the blood vessels in areas that do not occur during normal illumination. The intensity and movement of the microscope light beam creates an unnatural pattern the brain has not adapted for. Several Eye Doctors have used laser therapy to disrupt floaters but this is not currently accepted standard of care due to the associated risks of damaging the retina. Also, on rare occasions special surgery may be done to replace the fluid inside the eye. The risk is generally not acceptable for the benefit.
What you can do once the diagnosis is certain is request treatment for the psychological disruption caused by central floaters. You will have to pursue this as your own advocate as Eye Doctors generally do not recognize how disabling central floaters can be initially. They proceed on the knowledge that it will improve on it’s own over time and no treatment is usually needed. In the interim, patients are left with a perceptual deficient and anxiety. Treatment can include stress management techniques by a Psychologist or Therapist, (Eye Movement Desensitization and Reprocessing Therapy), hypnosis, anti-anxiety medications, Selective serotonin inhibitors medications like Prozac, or other alternative treatments to reduce anxiety and cause perceptual shifts away from the eye floater. Another possibility is fitting a tinted contact lens on the affected eye to degrade the overall image and lessen the focal awareness of a central deficit. Artificial tears transitionally used for the treatment of dry eyes can be used on a regular basis as distraction therapy.
Having something directly in your line of sight can be extremely disruptive and other than monitoring for any long-term retinal problems the primary therapy should be focused on reducing the effects of this disruption until the brain adapts. Posterior vitreous detachment does not in itself cause any permanent loss of vision. Your visual acuity should remain the same and you will be able to see just as you could before the posterior vitreous detachment started. You may have some difficulties to begin with because of the floaters and flashing lights though these do not cause permanent sight loss. The only threats to vision are the small chance of a retinal tear leading to a retinal detachment or a retinal membrane formation causing distortions in your vision. It is important to stress that retinal tears and detachments are much rarer conditions and that very few people with posterior vitreous detachments go on to develop either of these problems. Sometimes the vitreous is so firmly attached to the surface of the retina that as the jelly collapses it pulls quite strongly on the retina. In a few people this may lead to the retina tearing which in turn could lead to a loss of vision because of a retinal detachment.
Warning signs of a retinal tear or detachment could be an increase in size and number of your floaters, a change or increase in the flashing lights you experience, or a blurring of vision. If you experience any of these symptoms you should seek medical advice within 24 hours. This is particularly important if you notice a dark “curtain” falling across your vision, as this may mean that the retina has already partially detached. Early intervention may allow treatment of a tear before it becomes a detachment and increase the chances of a good recovery from a retinal detachment. It is important to remember that posterior vitreous detachment has been estimated to have occurred in over 75 per cent of the population over 65 and that while a posterior vitreous detachment does cause some disturbing symptoms it normally does not threaten sight. Your Optometrist will give you a thorough examination and dilate your eyes during your first visit. You can expect some light pressure on your eye as the sclera is depressed to see out to the edges of the retinal eye tissue. They will pay special attention to whether or not the retina is in any danger. If it isn’t then they should see you for regular eye examinations until the vitreous detaches and the period of risk is over. If you begin to experience the symptoms warning of a possible retinal detachment, such as increased or definite change in floaters, more severe flashing lights or a curtain falling over your vision don’t delay until the weekend is over, call to be seen the same day. The retina is extremely dependent on oxygen to live and postponing care 48 hours could result in blindness. Floaters can be particularly annoying. They get in the way of seeing things and can make some things difficult, for example reading a book. There is another way of trying to cope with this that some people find useful. If you move your eyes around you can create currents in the fluid within your eyes that can move the floater out of your direct field of vision. This is a strategy to use after a complete posterior vitreous detachment has occurred and the risk of retinal detachment has become minimal. Most people find that with time the floaters become less and less of a problem. In the interim, seek the type of treatment you need to deal with the perceptual and psychological sequel of the eye floaters.