By Dr. Cheryl G. Murphy, OD
Catching things early and quitting smoking are two actions patients can take to minimize their risk of retinal damage (and vision loss) due to Type I Diabetes. Eye care professionals play an important role in not only checking for early warning signs of retinopathy by performing dilated eye exams on their diabetic patients at least once a year but also by counseling their patients to kick the habit if they smoke cigarettes, use smokeless tobacco, electronic cigarettes or smoking cessation products that contain nicotine.
Researchers have found that nicotine can increase the risk of diabetic damage inside the eyes particularly in those who have Type I Diabetes. “Nicotine alone has been shown to promote pathological effects on the retinal pigment epithelium, photoreceptors and cells in the outer nuclear layer in mice. Chronic nicotine toxicity has also been shown to increase the severity of induced choroidal neovascularization, diabetic nephropathy and cataract development in multiple experimental rodent models.”
According to the National Institute of Health (NIH), “diabetic retinopathy, the most common form of diabetic eye disease, is the leading cause of blindness in adults ages 20–74. It occurs when diabetes damages blood vessels in the retina [and] it affects 7.7 million Americans. That number is projected to increase to more than 14.6 million people by 2030. The longer a person has diabetes, the greater the risk for diabetic eye disease [and] once vision is lost, it often cannot be restored.”
The CDC says that one of the reasons why smokers can suffer from more diabetic complications than non-smokers is because “nicotine increases blood sugar levels and makes them harder to handle. People with diabetes who smoke often need larger doses of insulin to keep their blood sugar close to their target levels.”
Recent studies have shown that OCT (Optical Coherence Tomography) may be helpful in detecting neuronal loss in the retina due to diabetes even before signs of retinal blood vessel damage or oxygen deprivation appear. “Although vascular complications (changes to the blood vessels) are typically seen as a hallmark of the disease, the functional deficits often precede the breakdown of the blood-retina barrier, suggesting an early neurodegenerative component.”
Perhaps someday in addition to asking about a patient’s HbA1c number and performing a dilated eye exam, all eye care professionals will also perform OCT routinely on diabetic patients to check for GCL (ganglion cell layer) loss and for changes in TRT (total retinal thickness) which may be indicative of early diabetic changes in the retina.
Of course, smoking can negatively impact more than just eye health, it can harm many organs of the body. Smoking can damage the heart and other bigger blood vessels in the body. It damages the lungs and can cause respiratory illnesses and disease. It can cause damage to nerves and other organs.
photo credit: Michelle Ding- Unsplash