About macular diseases
Macular diseases are conditions that lead to the loss of central vision due to the damage of macula. The macula is an area of the retina at the back of your eye. Macula is located at the center of the retina. Macula disease is the most common cause of visual loss especially in the developed countries. Macular diseases are rare in young people but can occur as juvenile macular dystrophies. It is more common in old people from the age of 60 years and is known as age related mascular degeneration. People suffering from macular diseases have impaired vision in the central area of the visual field but their peripheral vision and side vision remain unaffected. Macular diseases advance slowly in some people and faster i others. Macular diseases occur in two forms the wet and dry macular diseases.
Types of macular diseases
There are two main types of macular diseases; the wet and dry macular diseases that occur mainly in old people.
Wet macular diseases
It occurs when the abnormal blood vessels behind the retina starts to grow under the macula. These new and abnormal blood vessels are fragile and tend to leak blood and fluids. These leaked blood and fluids raise the macula from its normal position at the back of the eye and hence, macula damage occurs rapidly. Wet macula diseases cause rapid loss of central vision. The early and best symptom of wet macular diseases is that straight lines appear wavy.
Dry macular diseases
Presents itself when the light sensitive cells in the macula break down slowly and gradually blur central vision in the affected eye. As dry macular disease upgrades, the affected person may see a blurred spot in the center of the vision and the central vision of the affected eye is lost with time. The common symptoms of dry macular diseases are blurred vision and drusen. Drusen are yellowish deposits that are found under the retina. Dry macular diseases has three stages.
- Early dry macular disease: characterized by small or medium sized drusen.
- Intermediate dry macular diseases: characterized by medium sized or large drusen and blurred spot at the center of the vision.
- Advanced dry macular diseases: characterized by large drusen, breakdown of light sensitive cells and supportive tissue at the central retinal area. The breakdown causes a blurred spot at the center which gets bigger and darker with time.
Causes and risk factors of macular diseases
The greatest macular diseases risk factor is age. Other risk factors include;
Race where white people are more likely to suffer from macular diseases than black people.
Family history where those with immediate family members who suffered from macular diseases are at risk of developing the disease.
Gender: women appear to at a greater risk of suffering form macular diseases than men.
Detection and treatment
Macular diseases are detected during eye test that include;
- Visual acuity test: the eye chart measures how well you see at various distances.
- Dilated eye exam: drops are placed on the eye to widen or dilate the pupils. The eye professional uses a special magnifying lens to examine the retina and optic sugns of macular diseases.
- Tonometry: an instrument is used to measure the pressure inside your eye. Numbing drops are applied to your eye during this test.
- Laser surgery: this is a procedure that use laser to destroy the fragile and leaky blood vessels. This surgery may sometimes destroy the surrounding healthy tissues and vision as well. Laser surgery is effective if the leaky blood vessels are away from the fovea. The risk of new blood vessels developing after a laser surgery is very high.
- Photodynamic therapy: a drug known as verteporfin is injected through your arm, travels in the body and sticks at the surface of new blood vessels. Alight is then shined in the affected eye for about 90 seconds, it activates the drug that in turn destroys the new blood vessels and causes a slow rate of vision decline. This therapy does not destroy surrounding tissue like laser surgery. Since the drug is activated by light, the patient should avoid direct sunlight for about five days after the treatment.
- Injections: wet macular diseases are treated with a new drug that is injected straight to the eye. This drug blocks the effect of abnormal growth in the eye. The injections should be administered monthly. After the injection the patient remains in the doctors room for monitoring. This treatment slows down vision loss and improves sight in some cases.