You may sometimes see small little specks or clouds moving around in your field of vision. These are known as floaters. They are easier seen and more often when looking at a plain background, like at the sky or a wall. Floaters are defined as tiny clumps of gel or cells inside the vitreous in your eye. The vitreous is the clear gel-like fluid that fills the inside of your eye. Floaters are actually the “shadows” of these clumps of gel or cells that are falling on the retina.
Even if you have a history of floaters, you should schedule an appointment with an ophthalmologist if you suddenly notice new ones in your vision.
In some individuals floaters can be so dense and relatively fixed as to permanently and significantly impair vision and, hence, quality of life. One pervasive myth that continues to be circulated is that “nothing can be done for floaters.” This myth is incorrect and does a disservice to those patients who suffer from moderate to severe vision impairment due to advanced collection of floaters and/or significant clouding of the vitreous gel.
In select patients, the vitreous can be safely removed using standard sutureless outpatient vitrectomy. Due to advances in surgical technique, removal of severe persistent floaters has become an effective option for those who are suffering from loss of vision due to long-standing reduction in the clarity of the vitreous gel.
Macular Membrane/Pucker (EMM)
Macular membrane formation may occur in the wake of conditions such as retinal detachment or inflammation of the vitreous and/or retina. Most commonly, however, this condition arises simply as a response to the aging process. Unlike age-related macular degeneration, which involves the undersurface of the retina, macular membrane formation develops along the top surface of the macula. While the cause is not completely understood, it appears that cells which comprise the support layer of the retina manage to migrate to the surface where they give rise to projections that interlock and form a contracting translucent film. It is this contraction which causes varying degrees of distortion of the nerve elements of the retina. This condition often results in blurring and/or distortion of images in the affected eye.
Surgical removal of the tissue is advised when symptoms are bothersome. Because these membranes lie on the outer surface of the retina, they are readily approachable using modern surgical techniques. Surgery is performed on an outpatient basis under local anesthesia with sedation and is typically completed within 30-45 minutes. The majority of patients (95%) ultimately gain relief from most of the symptoms imparted by the membrane, though restoration of 20/20 vision occurs in no more than 15% of eyes.
Macular Degeneration (AMD)
Aging-related macular degeneration is the most common cause of visual impairment in seniors in the Western Hemisphere. While often regarded as a unified disease category, it is better described as a cluster of somewhat dissimilar disease states. While many genetic and environmental factors are connected with the development of AMD, the common thread that connects this group of vision-threatening conditions is age beyond 65 years. Caucasians are almost exclusively affected. General health conditions such as hypertension and obesity are recognized risk factors as is cigarette smoking.
It is easiest to divide AMD into two large categories:
Dry – Changes occur in the support lining of the retinal tissue along the undersurface, which lead to deposits of waste material (drusen), with or without areas of erosion or loss of the important support tissue at the center of the macula. Vision loss, if it occurs, tends to be gradual rather than sudden. There is currently no treatment to combat the effects or slow the progression of dry AMD, though in certain individuals at risk for developing progression to wet degeneration, daily supplementation with a vitamin/mineral complex has been shown to reduce the risk of this development by 25%.
Wet – A relatively small but significant percentage of patients who have evidence of dry macular degeneration will progress to the wet or leaking form. In this condition, blood vessels form at or near the defects in the lining of the macula and push through to the undersurface of the retina causing leakage of clear fluid (serum) and/or blood cells. These vessels break through into the undersurface of the retina much as weeds often appear along cracks in pavement. Symptoms associated with onset of wet AMD include distortion of images, loss of color perception, permanent dark spots in or near central vision, or just overall lack of ability to focus at near. At present, injection of a relatively new class of pharmaceutical agents into the vitreous of the eye is the treatment of choice. Vision is rarely restored to normal, though 80% to 90% of individuals treated by this method achieve stabilization of their vision with 30% to 40%, showing signs of improvement in vision.
Macular Hole (MH)
The vitreous is in contact with the retina throughout most of life. Starting around the sixth decade the vitreous material undergoes a slow process of softening and will eventually spontaneously separate from the retinal surface. A small percentage of individuals will have an undetectable adhesion between the vitreous and the macula in the center and this process can lead to a pulling response at the center of the macula. This can result in progressive thinning and even development of a small tear at the center of the macula resulting in formation of a hole.
Symptoms of macular hole include warped images and development of a blank spot in the central vision.
Repair of macular holes can be achieved through vitreous surgery. The procedure is performed under local anesthesia with IV sedation on an outpatient basis and is generally completed within 45 minutes. Surgical success rates are overall excellent with successful closure of the hole occurring in 95% to 98% of cases. Improvement in vision is seen in up to 75% to 80% of cases.
Diabetic Retinopathy (DME/PDR)
Retinal changes related to diabetes are the most common cause of vision impairment among working-age adults in the United States. There are two major subtypes that have the potential to cause vision impairment.
Diabetic Macular Edema (DME) – In this condition, the small capillaries that provide circulation and oxygen to the macula become abnormal and leak fluid and/or components of the blood stream into the macula. Over time, buildup of this material can interrupt the function of the sensitive nerve receptors in the central macula leading to loss of vision.
Proliferative Retinopathy (PDR) – In this more advanced site-threatening condition, abnormal blood vessels grow on the surface of the retina and attach themselves to the vitreous fluid. The vitreous responds by degenerating and contracting; thereby leading to the development of hemorrhage on the surface of the retina and often into the vitreous itself. More importantly, if left unchecked and untreated, these vessels develop a tough elastic scar tissue component that can lead to retinal detachment.
Even with excellent control of blood sugar levels, retinopathy can develop. The key to prevention of vision loss is early detection. There are multiple treatments available for all forms of diabetic retinopathy. The first line of defense is laser treatment, though advanced stages of retinopathy, including vitreous hemorrhage and retinal detachment must be treated by vitrectomy surgery. Frequent screening examinations of patients with elevated glucose levels is essential to allow for early detection. As in most disease states, early detection (and, hence, early treatment intervention) represent the best insurance against irreversible loss of vision
Retinal Vein Occlusion (BRVO, CRVO)
Interruption of blood flow within the complex system of blood vessels that supply the retina are the second most common cause of vision loss related to retinal vascular disease; second only to retinopathy related to diabetes. This condition is most commonly seen in individuals 65 and older. The most common associated medical condition is hypertension. Hardening and narrowing of blood vessels related to aging, hypertension, and genetic predisposition can lead to interruption of blood supply. The degree of associated vision loss can either be mild or severe, depending on the location and degree of the blockage. Laser treatment and injectable drug therapy are the most commonly employed treatment strategies resulting in varying degrees of success.
Retinal Tear / Detachment (RD)
The soft vitreous gel material is in contact with the retina throughout most of life. As the eye ages, there is a tendency for the gel to soften and eventually separate from the retinal surface. This is a normal and non threatening condition in the majority of people. In less than 1% of the population, there is a preexisting condition that leads to abnormal adherence between the vitreous and the retina in the outer edge of the retina itself. In these individuals spontaneous vitreous separation can lead to development of a snag in one or more areas, which can result in creation of an actual tear or gap in the peripheral retina. Fluid within the eye can gain access to the undersurface of the retina through this hole, much as rainwater will gain access to the inner structures of building if there is a breach in the roof. As fluid continues to work its way underneath the retina, the retina becomes separated from its support structures, thereby leading to eventual loss of vision.
Retinal tear formation is often accompanied by symptoms of sudden onset of dark spots in the vision (floaters) with or without development of light flashes in the peripheral vision. Retinal tears with little or no associated fluid under the retina can often be treated with laser or by means of a freezing pencil on the surface of the anesthetized eye (cryotherapy). Both procedures are performed in the physician’s office.
In the presence of significant fluid underneath the retina, neither of these methods will successfully reverse the process. Outpatient surgery is required to repair most retinal detachments with an overall success rate of 90% to 95% with one or more operations.
Inflammation (Retinitis, Vitritis)
Inflammation may develop in the deeper structures of the eye as a result of an actual infection. Most commonly, signs of inflammation occur because of some abnormality in the general immune system. Symptoms of ocular inflammation most frequently include sensitivity to light, sudden onset of floating spots within the central and peripheral vision, visible redness of the white portion of the external eye, and generalized blurring of vision. In some instances, appearance of the signs of inflammation are the first indication of a general health issue such as inflammatory arthritis and other related conditions affecting the immune system. The diagnosis of vitreous or retinal inflammation usually prompts an investigation coordinated with an internal medicine specialist or rheumatologist. Inflammatory conditions limited to the eye can often be successfully treated with medications designed to suppress the eyes’ response to the inflammatory stimulus.