Age-related Macular Degeneration

This disease occurs in the macula (yellow spot) - the central viewing point of the eye.

Figure 1. Demonstration of dry and wet types of senile macular degeneration.

It is known as yellow spot disease colloquially. It has two types: wet and dry. The dry type is more common. This disease is characterized by the emergence of yellow-colored accumulations called drusen. It is slow in progress. Vision is slowly disrupted over the years. The wet type constitutes 10-15% of the patients and it may cause sudden and serious loss of vision. This disease is characterized by the formation of new vessels underneath the retina. If these vessels are not treated, they destroy the visual cells in the retina, thus causing an irreversible loss of vision.

Figure 2. Preoperative (upper) and postoperative (lower) optical coherence tomogaphy images of a patient who received anti-VEGF injection for wet age-related macular degeneration.

The basic risk factor is advanced age. It is more common in people over 60 years of age. Genetic predisposition, smoking, light-colored hair and eyes, unhealthy nutrition are among other known risk factors. Women are more at risk than men.

First findings are blurred vision, seeing straight lines as curved, seeing objects smaller or bigger. AfterwardS the patient describes a blurriness or dark spot in the middle of the viewed point.

Since the dry type is slow in progress, it is in general diagnosed incidentally during visual examination.The wet type, however, is diagnosed after the patient seeks medical advice since it causes a sudden loss of vision. 

On the other hand, patients whose other eye has a good vision sometimes do not realize the loss of vision in the other eye. When they do however, it is too late for treatment. Drusen, bleeding in or under the retina if any, or accumulations called exudates can be detected in the retinal examination carried out after the pupil is enlarged with the help of drops. The most important diagnostic method is Fundus Fluorescein Angiography. Following the injection of a colorant called fluorescein through the vessels of the arm, the base of the eye is serially photographed, allowing the display of abnormal vessel structures underneath the retina. In order to see the vessels in the choroidal area, a similar angiographic procedure can be applied with the injection of an indocyanine green colorant. The tomographic image of the macula can be viewed with the optical coherence tomography device. In the plotting paper test called Amsler Grid, the persons are asked to look at the paper from a 30-cm distance in an illuminated environment with their reading glasses if any. The test is applied by closing the other eye. When the patient looks at the middle of the paper, s/he pays attention whether all the lines are straight and whether there is any deletion. The patient is asked whether there is any fraction or deletion in the lines in any area. Positive test result indicates the existence of the wet type of the disease.

Figure 3. Optical coherence tomography angiography image of a patient diagnosed with choroidal neovascular membrane secondary to wet age-related macular degeneration.

In general it is an irreversible disease, but its progress can be decelerated or, in some cases, can be stopped.

There is no certain treatment method for the dry type; however, it is noted that some vitamin and mineral supplements and some medications antioxidant in nature (multivitamin preparation) slow the progress of the disease.

In wet type, quite different treatment methods have been applied over the years. Widely-accepted methods are argon laser, photodynamic treatment, and anti-VEGF medication injections administered intraocularly. Argon laser treatment is applied onto the leaking vessels and destroys all the tissues in the application area. Therefore, it is not used in cases in the center of the macula; it is used in cases where there are abnormal vessels located far from the center of the macula constituting only a few (5-7%) of the cases requiring treatment. In Photodynamic treatment, after a light-sensitive colorant administered through the vessels of the arm reach the abnormal vessels in the eye, a laser beam specific to this colorant is sent onto the abnormal vessel, thus closing the vessel. Anti-VEGF medication treatment administered through intraocular injection is the most valuable treatment method today. It is the only treatment method increasing the current visual ability of the patients. In this treatment method, the medication is injected into the eye, thus preventing abnormal vessel development and blocking the developed vessels. In order to suppress the factors triggering the development of new vessels, more than one injection can be required at the beginning of the treatment. The disease may recur during follow-up. In this case, re-injection into the eye is required.