World Diabetes Day 2023: How might diabetes cause problems with the eyes?

Dr Ajay Sharma

Diabetes, a widespread chronic ailment affecting millions globally, is renowned for its influence on blood sugar regulation. However, it is crucial to acknowledge that diabetes can also give rise to various complications, notably eye-related diseases. According to a comprehensive all-India study published in The Lancet, nearly three million people aged 40 and above in the country are at the risk of blindness due to diabetes.

Most worrisome
This is one of the most worrisome eye conditions associated with diabetes. It accounts for a substantial portion of blindness cases in working-age adults. This condition is instigated by heightened levels of blood sugar, which inflict damage on the fragile blood vessels situated in the retina, positioned at the rear of the eye. As these blood vessels sustain damage, they may swell and leak, leading to symptoms like blurry vision or disrupted blood flow. In some cases, abnormal blood vessels may start to grow, exacerbating vision problems. It is worth noting that diabetic retinopathy typically affects both eyes, compounding the potential for vision loss.

Risk Factors 
Individuals who have been diagnosed with type 1 diabetes, type 2 diabetes, or experience gestational diabetes during pregnancy are vulnerable to developing diabetic retinopathy. It’s important to note that the duration of the diabetes diagnosis significantly impacts the likelihood of this eye condition manifesting. The longer a person has been living with diabetes, the higher their risk of experiencing diabetic retinopathy. Uncontrolled high blood sugar, elevated blood pressure, and abnormal cholesterol levels also heighten the risk of diabetic retinopathy. Smoking, a known contributor to vascular damage, even exacerbates this risk.

Different stages
Diabetic retinopathy can be categorised into two primary stages, each with its own set of symptoms and implications:
Early Stage (Nonproliferative): In this stage, the blood vessel walls in the retina weaken and form tiny, imperceptible pouches. These pouches can leak blood and fluid, leading to macular edema, which causes the macula to swell and distort vision. Macular edema is a common cause of blindness in people with diabetic retinopathy, with approximately half of those affected experiencing it.
Advanced Stage (Proliferative): In the advanced stage, the retina initiates the growth of fragile new blood vessels that often bleed into the vitreous, the clear gel between the lens and retina. Minor bleeding results in the appearance of dark spots in the field of vision, while significant bleeding can lead to complete vision obstruction. These new vessels contract and pull retina in later stages leading to detachment of retina and total blindness.

 Treatment
The good news is that diabetic retinopathy is treatable, and prompt intervention can repair damage to the eye and prevent blindness in the majority of cases. Treatment may commence before visual impairment becomes evident, enhancing the chances of preserving sight. Treatment modalities include laser therapy (laser photocoagulation), which creates a scar tissue barrier to impede the leakage or retard the growth of new blood vessels, and injection of VEGF inhibitors, a category of medications capable of slowing down or reversing the progression of diabetic retinopathy. In certain cases, vitreous removal surgery (vitrectomy) may be required to address issues within the gel-like substance of the eye, where the surgical reattachment of the retina becomes necessary when retinal detachment, a complication of diabetic retinopathy, occurs. Additionally, corticosteroid injections and implants are also available as a management option for this condition, collectively providing effective tools for preventing blindness and preserving vision in those affected by diabetic retinopathy.

Raising awareness
On World Diabetes Day, it is crucial to raise awareness about the close relationship between diabetes and eye diseases. This year’s theme is “Know your risk” and “know your response”. Early detection, management, and treatment of diabetic retinopathy and other diabetes-related eye problems can go a long way in preserving vision. We need to realise that almost every diabetic is at risk of developing diabetic retinopathy but those having duration more than 20 years and those with family history of vision loss are at much higher risk. By understanding the risk factors and the importance of regular eye exams, we can work towards preventing unnecessary blindness in individuals living with diabetes.

Dr Ajay Sharma is Chief Medical Director, Eye Q