The eye works like a camera. It has two parts, a lens and a film. The film layer lines the back wall of the eyes and is called the retina. There is an area of the retina responsible for the central vision called the macula.
Age-related macular degeneration (AMD) refers to specific age-related changes in patients 50 years and older. Wet age-related macular degeneration is characterized by the formation of undesirable abnormal new blood vessels. These blood vessels have a tendency to leak which decreases the quality of vision. Furthermore, if left untreated, these blood vessels may form scar tissue which leads to a permanent decrease in central vision.
In this case, there is scar tissue underneath the central vision which may limit the vision, even with treatment. Wet AMD comes in a spectrum from those who have driving level vision upon being diagnosed to others who are legally blind. The treatments that are available improve vision by about 1-2 lines during the first year of treatment and then maintain vision for many years. Treatment results vary for each eye.
It is important to mention that patients with this condition who have lost some of their central vision need not worry about their peripheral vision. AMD does not affect the peripheral vision. Therefore, even patients who do experience worsening of macular degeneration are able to see, just not clearly in the center of their vision.
The treatments available are treatments, not a cure. This means that patients will continue to need treatments for many years. Treatments are typically initiated every 4 weeks for 3 months. Afterwards, treatment is continued every 4 weeks until all blood and any fluid under the retina is resolved. Once they are resolved, the distance between injections is slowly increased by 1-2 weeks each visit. The maximum time between visits is typically 12 weeks.
The average patient requires approximately 10 treatments in the first year, 8 in the second year, 5 in the third year, 5 in the fourth year, and 4 in the fifth year. Your eye care specialist will customize the treatment regimen based on the way your eye responds to the medication.
Patients who miss appointments for treatment risk permanent visual loss. It is very important that the treatment regimen is followed to within a few days.
All treatments for wet macular degeneration are administered by an in office procedure called an intravitreal injection. This can be performed in a relatively painless manner.
Avastin is the most commonly used medication for the treatment of wet AMD worldwide. It is not FDA approved, but is considered to be safe and effective. The main risk inherent to this medication is the development of new floaters. This is uncommon but can occur due to silicone oil within the medication. If this occurs, it is typically temporary. It is very uncommon for patients to notice these floaters after the first few days.
The main risk of the procedure is the development of an infection called endophthalmitis. Fortunately, the risk of this infection is very low, occurring in approximately 1 in 3000 injections. The signs of infection are eye pain, sensitivity to light, and decreased vision. If it occurs, it typically occurs 3-5 days following the treatment, but may occur earlier or later. Patients with these symptoms need to contact their eye care specialist immediately. Patients can decrease their risk of developing an infection by avoiding rubbing, touching their eyes, or allowing water into their eyes for at least one week.
The goal of treatment in wet AMD is three fold: maximize vision in the affected eye, prevent the development of wet AMD in the other eye, and early detection of wet AMD in the other eye should it occur.
Patients who have both eyes affected by wet AMD do not need to take eye vitamins. Patients with only one eye affected by wet AMD will benefit from taking eye vitamins. The Age Related Eye Disease Study Number 2 (AREDS2) vitamin decreases the risk of losing vision from macular degeneration by 25%. This formulation is different from a multivitamin. Taking a multivitamin plus lutein/zeaxanthin does not contain the same contents as an AREDS2 vitamin. Patients who regularly take a multivitamin may take an AREDS2 in addition if recommended by their doctor.
Eating green leafy vegetables and fish on a regular basis decreases the risk of experiencing worsening macular degeneration. A diet rich in omega-3 vitamins may further decrease the risk of macular degeneration worsening. Using polarized sunglasses while outside for extensive amounts of time can decrease retinal damage from significant sun exposure. Maintaining a healthy weight can also decrease the risk of macular degeneration worsening.
Smoking increases the risk of macular degeneration worsening by 3 times compared to a non-smoker. Discontinuing smoking decreases this risk by 50%.
Monitoring vision is recommended for patients who have one eye with dry macular degeneration. Monitoring with an Amsler grid dramatically decreases the risk of vision loss from this condition. New distortion or blurriness discovered on an Amsler grid may be signs of wet macular degeneration. Early detection and treatment of wet AMD can result in a complete reversal of vision loss.
An Amsler grid should be used to check the eye with dry macular degeneration at a reading distance with the other eye closed. Patients are instructed to look at the black dot in the center of the grid paper. Patients who notice new distortion or missing lines should call their eye care specialist as this may be a sign of wet macular degeneration. They should ideally be seen within a day or two.
Many patients with wet AMD continue to see well during their lifetime and maintain their independence. Adhering to the treatment regimen and items we discussed will dramatically increase the risk of meeting this goal.
Patients should continue to follow up with their eye care specialist at their next scheduled appointment.