Variations on Macular Degeneration
There are two distinct forms of macular degeneration.
Wet age-related macular degeneration
Dry age-related macular degeneration
Approximately 85 to 90 percent of cases of macular degeneration are dry, while 10 to 15 percent of the population appears to have the moist form.
Wet Macular Dystrophy
The onset of wet macular degeneration can be sudden and painless. The individual may experience vision problems. Initial symptoms of macular degeneration include blurred and distorted vision. Vision impairment may include a blind area in the centre of the visual field. This blind spot may be black, grey, or even scarlet in colour. For instance, a person with macular degeneration will be able to see the sides of a clock, including the numbers, but may not be able to see the middle portion of the needles.
In wet age-related macular degeneration (AMD), abnormal blood vessels, also known as choroidal neovascularization (CNV), begin to develop in the macula, a small portion of the central retina. Macula allows for the perception of fine details and is responsible for central vision. The blood vessels that form beneath and within the macula of the retina are extremely fragile and frequently discharge blood and fluid. The blood and fluid leak alters the macula’s normal position and raises it slightly at the rear of the eye.
It disrupts the function of the retina and causes scarring of the macula, leading to a rapid loss of central vision. Under such circumstances, vision impairment can be severe. Nevertheless, choroidal neovascularization (CNV) may be the only visual change some patients observe. Patients who are at risk for CNV should undergo periodic eye examinations.
If CNV has developed in one eye, there is a high likelihood that it will also develop in the other eye, regardless of whether visual impairment has occurred.
In all cases of moist macular degeneration, the CNV causes vision loss. Wet macular degeneration lacks stages, as opposed to dry macular degeneration. Wet macular degeneration causes greater vision loss than dry macular degeneration, and individuals with dry macular degeneration have a high risk of also developing wet macular degeneration.
Vision is impaired by dark patches in the eye’s middle. The objects appear to change shape and size, and their colours may appear to disappear or diminish.
The individual with moist macular degeneration is bothered by glaringly bright colours and has difficulty transitioning from a darker to a lighter environment. Eye irritation can also be observed when attempting to move from a dark to a light environment.
Reading and writing will be difficult for the individual, and straight lines may appear curved, like the door frame, and streetlights may appear distorted. This is a common symptom of watery macular degeneration.
Dry Age-Related Macular Degeneration
In dry macular degeneration, the macula’s light-sensitive cells degenerate. When the macula is less functional, central vision begins to deteriorate. Dry AMD typically affects only one eye, but it can eventually spread to the other. It is still unknown what causes dry macular degeneration, but it has been linked to retinal drusen.
Retinal Drusen are yellow deposits located beneath the retina. They manifest in the later phases of life, around age 60. Drusen of the retina can be observed during a dilated eye exam. Drusen are not solely liable for vision impairment. Scientists are uncertain regarding the relationship between drusen and AMD. However, the number of retinal drusen is associated with the dry form of macular degeneration. During an eye exam, a high number of drusen has been observed in individuals with dry macular degeneration.
