Macular degeneration is a chronic eye condition that involves the loss of central vision. Also known as Age Related Macular Degeneration (AMD or ARMD), the condition typically affects individuals over the age of 50 and is the leading cause of vision in people aged 55 years and older in the United States. In macular degeneration, the central part of the retina, also known as the macula, deteriorates, causing loss of central vision. The macula is the part of the retina that allows us to see color and detail. The loss of central vision affects many daily activities including reading, driving and watching TV.
The experienced specialists at OMNI are specially trained in detecting changes in your eyesight even before you may notice a problem with your vision. Through advanced diagnostic techniques, our team of physicians has your best eye health in mind and will work closely with you in diagnosing and treating your macular degeneration.
Types of Age Related Macular Degeneration
Dry Macular Degeneration
Ninety percent of patients have the “dry” form of macular degeneration. This form is slowly progressive and patients rarely suffer from severe vision loss. In dry macular degeneration, the thinning or deterioration of the tissues of the macula and/or the appearance of abnormal yellow deposits or spots in the macula is thought to be the cause of this condition.
There is often little that needs, or can be, done to prevent this condition, although preventative measure earlier in life such as a healthy diet, exercise and wearing protective sunglasses may help.
Wet Macular Degeneration
Only about 10 percent of patients suffer from the “wet” form of the disease, an advanced and damaging form of ARMD. In this form of macular degeneration, abnormal “leaky” vessels grow between the layers of the retina. This leakage of fluid severely damages the light-sensitive retinal cells, causing the development of blind spots in a person’s central vision. Substantial loss of central (e.g. reading) vision may be lost in a few weeks to months.
How is ARMD Treated?
The physicians at OMNI Eye Specialists are committed to stay abreast of the latest in new, advanced therapies for treating macular degeneration, particularly for the “wet” form of the disease including:
- Ocular Photodynamic Therapy (OPDT)
This treatment for wet AMD was approved several years ago and is the mainstay to treating patients with subfoveal choroidal neovascularization. It selectively inhibits growth of the abnormal blood vessels, thus usually preserving, and sometimes improving, central vision. Other treatments will be emerging in the next few years.
- Photodynamic Therapy (PDT) for the Treatment of Exudative ARMD
Since the FDA approval of Visudyne (Verteporfin for injection, Novartis), Photodynamic Therapy (PDT) has become the mainstay of treatment for patients with the wet form of the disease that develop abnormal blood vessels underneath the macula. These patients usually respond well to this treatment. PDT involves injection of a medicine (Verteporphin) which accumulates in the abnormal vascular complex. This infusion occurs over a 10 minute period and affects only the abnormal tissue. This is beneficial as the therapy does not affect normal surrounding tissue, unlike treatments utilizing thermal lasers.
PDT usually needs to be repeated with most patients requiring three to four treatments over the first year and about two treatments over the second year. Significant preservation of vision can be achieved when adhering to this protocol. Many patients may also experience improved vision after the initial treatment, with subsequent treatments of PDT continuing to maintain improvement in vision.
- Vitamins and ARMD
Vitamin supplementation has been proven helpful to only a small subset of patients with ARMD as described by the Age-Related Eye Disease Study (AREDS). Vitamins can reduce the chance of severe vision loss from choroidal neovascularization by 25%, but these effects are found only in the highest risk group. Advertisements for these nutritional supplements seem to indicate that vitamin supplementation is beneficial for all patients with macular degeneration. Bausch and Lomb originally formulated the vitamins used in the AREDS study. This formulation is sold over the counter as Ocuvite® PreserVision®. Other companies now market similar compounds.
Ask your OMNI Eye professional if this treatment option is right for you.
Other Treatments and Investigational Therapies for ARMD
- Classic photocoagulation using a thermal laser was the first line of treatment and was described in the Macular Photocoagulation Study Group in the early 1990s. Its main drawback is the formation of permanent black spots or “scotomas” in the patient’s vision. This is one reason why PDT has become so popular. Still, there are cases where this treatment may be preferred, for example, in cases where the neovascularization is not directly underneath the macula.
- Transpupillary Thermotherapy Technique (TTT) utilizes a lower energy diode laser to treat the neovascular complex. The adjacent cells may be left intact and undamaged. The exact mechanism of action is not known. It may be an attractive alternative to PDT as expensive injections are not needed. Similar techniques have been employed to treat ocular tumors such as retinoblastoma and choroidal melanoma.
- Feeder Vessel Treatment with High Speed ICG Angiography is currently under investigation. The dye, similar to fluorescein, is infused to identify a single feeder vessel. If a vessel can be identified and is treatable, the size or total area of treatment is smaller than compared to conventional methods. Treating only this area limits the amount of laser applied to the retina and thus minimizes scotoma formation.
- Rheopheresis is a method by which certain toxic substances are filtered from the bloodstream. Certain “vascular risk factors” are removed from the blood during treatment. There is evidence that suggests progression of the ARMD may be reduced if these factors, such as LDL cholesterol, fibrinogen and lipoprotein A are reduced. Rheopheresis is under investigation.
Promising alternative treatments will involve intravitreal drug injection and delayed intraocular delivery of key medicines that can further inhibit or destroy these “leaky” blood vessels. Present treatments are limited to those patients with the wet form of the disease. Several drugs are under investigation and may be approved for patient use in the next one to two years.