From eu.usatoday.com
The five human senses include sight, hearing, smell, taste, and touch. While each of these matter for different reasons, they aren't perceived as being equal. For instance, according to a YouGov public survey, only 2% of Americans say that, of the five senses, they would miss their ability to smell the most; 3% of respondents said their sense of touch matters most; and 5% said taste is most important. 7% said their ability to hear was the sense they appreciated more than any other. But by far the sense people cared most about was their ability to see. A whopping 70% of Americans say they would miss their sense of sight more than losing any of the other five senses.
While many eye conditions can affect or diminish vision, myopia is the most prevalent one with about 30% of the global population having it. Other degenerative eye conditions or diseases go beyond diminished vision, however, and can completely rob you of your ability to see. For example, age-related macular degeneration, retinitis pigmentosa and glaucoma can all lead to blindness.
Diabetic retinopathy is another condition that can cause complete loss of vision - and it's also one of the most frequently occurring. "Diabetic retinopathy is the most common cause of irreversible vision loss and blindness among people in the working age range in the USA and in many other countries," says Dr. Charles Wykoff, a medical and surgical retina specialist and an ophthalmologist practicing in Texas.
What is diabetic retinopathy?
Diabetic retinopathy (DR) is an eye-related complication that can occur in people who have diabetes. It affects blood vessels in the retina - the "light-sensitive layer of tissue in the back of the eye," explains Wykoff. DR can lead to peripheral or night-time vision loss, visual disturbances such as oversensitivity to light and floaters, and, if left untreated, blindness.
DR has two stages, explains Dr. Sun Kim, an endocrinologist at Stanford University, who specializes in treating diabetes. The first and earlier stage is called nonproliferative retinopathy and occurs when the retina begins to swell, leading to mild vision loss. "Proliferative retinopathy is the advanced stage of DR that can cause severe and sometimes even complete loss of vision," Kim says.
The National Eye Institute estimates that nearly half of the 800 million people with diabetes worldwide will develop some degree of diabetic retinopathy. "The biggest risk factor for the development of DR in type 2 diabetes is duration of the disease - how long a person has had it," says Dr. Sara Weidmayer, a practicing physician at the LTC Charles S. Kettles VA Medical Centre in Michigan.
What causes diabetic retinopathy?
DR is caused by high blood sugar levels that, over time, "affect the integrity of blood vessels, especially very small micro-vessels called capillaries," says Weidmayer. She explains that sustained glucose levels can cause the inside lining of these capillaries to become damaged, which then causes leakage that harms the retina. "The capillaries can also become plugged, leading to inadequate blood flow to many areas of the retina," she adds, which can further deteriorate vision.
While such leakage and plugged capillaries can persist for extended periods of time without causing noticeable vision loss, "if left untreated, it can eventually progress to permanent and irreversible vision loss," says Dr. Lloyd Paul Aiello, a professor of ophthalmology at Harvard Medical School.
In fact, the longer someone has diabetes and the less controlled their blood sugar is during that time, the more likely they are to develop more advanced degrees of DR. This is especially worrisome because "many patients don’t know they have prediabetes or diabetes for years before an official diagnosis due to lack of screening," cautions Weidmayer.
Indeed, about one in three American adults have prediabetes and more than eight in ten don't know they have it, notes the U.S. Centers for Disease Control and Prevention.
How is diabetic retinopathy treated?
Because of this, treating DR starts with monitoring your blood sugar levels and getting checked for prediabetes or type 2 diabetes. This is essential when it comes to preventing the worst outcomes of vision loss associated with DR, because, unlike type 1 diabetes where it is very rare to have severe diabetic retinopathy within the first 5 years after diagnosis, "in type 2 diabetes, retinopathy can exist at the time of diagnosis," Aiello explains. "For this reason, an initial retinal eye exam is recommended at the time of diagnosis for those with type 2 diabetes - and even if there is no retinopathy initially discovered, a patient will generally need to have their eyes examined at least annually."
Once the condition has been diagnosed, treatments are usually first focused on preventing further damage. "In early stages of DR, optimizing...risk factors such as elevated blood sugar levels, high blood pressure, and cholesterol levels is ultimately the best thing to do to prevent the development and/or worsening of diabetic retinopathy," says Weidmayer.
She says such measures include things like improving your diet, getting regular cardiovascular exercise, and quitting smoking. If needed, losing weight can be especially beneficial in improving blood sugar levels, Kim says - especially if your body mass index (BMI) is high.
If damage persists despite dietary and exercise improvements and you're found to have advanced DR, other interventions are recommended. "Medications may be injected into the eyes, laser procedures may be used, and often surgeries are needed to manage complications of DR," Weidmayer says.
"Most people with diabetic retinopathy do not go blind if they are screened for diabetic retinopathy as needed and receive appropriate treatment by a retina specialist," offers Wykoff. "This is why you shouldn't wait until you have blurry vision to see an eye doctor."
