Eye Health Risk Connected to Weight-Loss Medications
There's an ongoing conversation about certain weight-loss drugs that are also used to manage diabetes and obesity. These medicines work by mimicking a hormone that controls hunger and blood sugar levels, hence helping people drop excess pounds and manage their blood sugar.
However, recent findings indicate that these drugs may slightly increase the likelihood of serious eye problems and vision loss.
What's the Concern?
The primary concern is a rare yet severe eye condition known as Non-arteritic anterior ischaemic optic neuropathy (NAION). This condition, also referred to as an "eye stroke," occurs when the blood flow to the optic nerve is suddenly reduced or blocked. The exact cause of NAION remains a mystery, and there are currently no available treatments. People with diabetes are particularly vulnerable to this condition.
Unlike other eye conditions that develop gradually, NAION causes a sudden, painless loss of vision. Patients typically become aware of the condition when they wake up and discover vision loss in one eye.
Approximately 70% of people suffering from NAION do not experience any improvement in their vision. In addition to NAION, there's evidence that these drugs can exacerbate diabetic eye disease, or diabetic retinopathy, a condition caused by high blood sugar levels damaging the small blood vessels in the retina, leading to vision loss.
What Does the Research Say?
Earlier studies showed that people prescribed these drugs for diabetes were four times more likely to develop NAION. For those taking it for weight loss, the risk was almost eight times higher. However, recent studies suggest the risks may be lower than initially thought.
Two newly released studies examined people with type 2 diabetes living in the United States over two years. The studies analyzed the medical records of 159,000 to 185,000 people.
One study found that of 159,000 people with type 2 diabetes taking these drugs, 35 people (0.04%) developed NAION, compared with 19 patients (0.02%) in the comparison group.
The researchers also found an increased risk of developing "other optic nerve disorders". However, the exact nature of these disorders remains unknown due to unspecified medical record codes.
The second study did not find an increased risk of NAION among those taking these drugs. However, they did find a small increase in the number of people developing diabetic retinopathy in those prescribed these drugs.
Interestingly, participants on these drugs experienced fewer sight-threatening complications related to their diabetic retinopathy and required less invasive eye treatments compared to the group taking other diabetes medications.
What Does This Mean for Patients?
While NAION is a serious condition, it's essential to balance these risks with the benefits of these medications in managing diabetes, treating obesity, reducing heart attack risks, and extending lives.
The key is informed decision-making and identifying varying levels of risk. People with multiple NAION risk factors, such as sleep apnea, high blood pressure, and diabetes, should discuss these risks with their doctor before starting these medications.
Regular comprehensive eye examinations with your optometrist or ophthalmologist are also crucial. They can detect other drug-related eye problems, including worsening diabetic retinopathy, and can identify patients with crowded optic nerve heads, a risk factor for NAION. Patients should also inform their doctors if they are taking these medications so they can closely monitor their eye health.
Improving heart health, managing high blood pressure, diabetes, and cholesterol can also help reduce risks of developing NAION. Patients with heart conditions who better adhere to their medication prescriptions have lower risks of NAION than those who don't.
Doctors should discuss NAION risks during prescribing decisions and work with eye care providers to monitor regularly for diabetic eye disease. Patients need clear instructions to seek immediate medical attention for sudden vision loss and the need for regular eye examinations.
Aggressive treatment of sleep apnea and other heart conditions may also help reduce NAION risks. However, more research is needed to understand how these medications can affect the eye.