Diabetic Retinopathy: The Silent Eye Disease Stealing Sight from Kenyans with Diabetes

Diabetic retinopathy is one of the leading causes of preventable blindness among adults worldwide.[iStockphoto]

For many Kenyans living with diabetes, the greatest fear is often managing blood sugar levels, avoiding complications such as kidney disease, or preventing heart problems. Yet hidden among these well-known dangers is a sight-threatening condition that can silently damage the eyes long before symptoms appear.

Known as diabetic retinopathy, the condition is one of the leading causes of preventable blindness among adults worldwide and is increasingly becoming a public health concern as diabetes cases continue to rise in Kenya.

According to Dr Monika Bitok, Acting Head of the Eye Health Section at the Ministry of Health, diabetic retinopathy develops when persistently high blood sugar levels damage the tiny blood vessels that nourish the retina, the light-sensitive tissue located at the back of the eye.

“Diabetic retinopathy is a complication of diabetes. When someone has diabetes, the blood vessels can become damaged because of the high sugar levels in the blood. This damage can affect different organs in the body, including the kidneys, heart and eyes,” explains Dr Bitok.

“When the blood vessels in the eye become damaged, they can leak blood or fluid into the eye. If the condition is not detected and managed early, it can progress and eventually lead to vision loss or blindness.”

One of the biggest challenges with diabetic retinopathy is that many patients do not experience symptoms in the early stages.

Unlike other eye conditions that may cause pain or immediate visual changes, diabetic retinopathy often develops quietly.

“The early stages may have no symptoms at all,” says Dr Bitok. “A person can still see clearly and believe everything is fine, yet damage is already occurring inside the eye.”

This happens because the disease often begins in areas of the retina that do not immediately affect central vision. As a result, patients may only realise there is a problem when the disease has already advanced.

By the time symptoms such as blurred vision, difficulty reading, dark spots, floaters, or sudden vision loss appear, significant damage may already have occurred.

“In some cases, bleeding can occur inside the eye, and patients may even notice blood or dark shadows in their field of vision,” she says.

The silent nature of the disease is why health experts stress the importance of routine eye examinations for all people living with diabetes.

Anyone with diabetes can develop diabetic retinopathy, whether they have Type 1 or Type 2 diabetes.

However, several factors increase the risk. “The most important risk factor is the duration of diabetes. The longer a person has had diabetes, the greater their risk of developing diabetic retinopathy,” says Dr Bitok.

Poor blood sugar control is another major contributor. Patients whose glucose levels remain consistently high are more likely to develop eye complications than those who effectively manage their condition.

Other risk factors include: High blood pressure (hypertension), Cardiovascular disease, Obesity, Elevated cholesterol levels, Smoking and Poor adherence to diabetes medication

“These conditions worsen blood vessel damage and increase the likelihood of diabetic retinopathy progressing,” she explains.

Although comprehensive national data on diabetic retinopathy remains limited, available estimates indicate the condition affects a significant proportion of people living with diabetes.

The burden of diabetic retinopathy in Kenya is becoming increasingly evident as diabetes cases rise across the country. Worldwide, an estimated 537 million people are living with diabetes, according to the World Health Organisation (WHO), which attributes about 1.5 million deaths annually to the disease and its complications, including kidney failure, blindness and cardiovascular diseases.

In Kenya, diabetes affects approximately 4.5 per cent of the population, with prevalence increasing with age and occurring more frequently among men.

According to the Ministry of Health, about 30 per cent of people living with diabetes develop diabetic retinopathy, while approximately 10 per cent of those affected have vision-threatening disease that can lead to blindness if left untreated.

Research at Embu Provincial General Hospital found that 41 per cent of diabetic patients had diabetic retinopathy, yet only 29 per cent had ever undergone an eye examination, with lack of awareness cited as the biggest barrier to screening.

Another population-based study in Nakuru warned of a growing burden of diabetes-related blindness among older adults as non-communicable diseases continue to increase.

Health experts say these findings highlight the urgent need for routine eye screening, early diagnosis and better integration of eye care services into diabetes clinics to prevent avoidable vision loss.

Dr Bitok notes that diabetes prevalence in Kenya is estimated at approximately two per cent of the population.

Among people diagnosed with diabetes, about 30 per cent develop diabetic retinopathy.

Of those with diabetic retinopathy, roughly 10 per cent have what specialists refer to as vision-threatening diabetic retinopathy, a severe form of the disease that significantly increases the risk of blindness.

“In simple terms, about three out of every ten people with diabetes will develop diabetic retinopathy, and one in ten of those cases will be severe enough to threaten their sight,” she says.

The burden is expected to rise as Kenya experiences increasing rates of non-communicable diseases (NCDs), driven by urbanisation, sedentary lifestyles, unhealthy diets and obesity.

Because symptoms may be absent for years, eye specialists recommend regular screening even when vision appears normal.

“Waiting until symptoms develop means we miss many patients who could have been treated much earlier,” says Dr Bitok.

Current Ministry of Health recommendations advise that all individuals with diabetes should undergo comprehensive eye examinations at least once every year.

Screening becomes particularly important from the age of 15 years onwards, especially for individuals who have lived with diabetes for several years.

“The absence of symptoms does not mean the eyes are healthy,” she warns. “Regular screening allows us to detect damage early and begin treatment before vision is affected.”

Patients found to have mild disease may only require annual reviews, while those with more advanced changes may need more frequent monitoring every six months or even sooner.

The good news is that diabetic retinopathy can be treated, especially when detected early.

However, successful treatment starts with controlling the underlying diabetes.

“You cannot effectively manage diabetic retinopathy if blood sugar levels remain uncontrolled,” says Dr Bitok.

She emphasises that eye specialists and diabetes care teams must work together to ensure patients achieve optimal glucose control.

Similarly, managing hypertension and other cardiovascular risk factors plays a critical role in preventing disease progression.

Depending on the severity of the condition, treatment options may include:

Laser therapy helps seal leaking blood vessels and reduce abnormal vessel growth within the retina.

“It is one of the most effective treatments for preventing further damage and reducing the risk of severe vision loss,” she explains.

Patients with swelling of the retina or abnormal blood vessel growth may receive anti-VEGF injections directly into the eye.

Anti-VEGF stands for anti-vascular endothelial growth factor, a treatment that blocks proteins responsible for abnormal blood vessel formation.

Some patients benefit from steroid medications injected into the eye to reduce inflammation and retinal swelling.

In advanced cases involving severe bleeding or retinal detachment, surgery may be required.

Procedures such as vitrectomy surgery remove blood and scar tissue from the eye, helping preserve remaining vision.

Retinal detachment surgery may also be necessary if the retina becomes separated from the back of the eye.

Despite available treatments, many patients continue to present late, when irreversible damage has already occurred.

According to Dr Bitok, lack of awareness remains one of the biggest barriers.

“Convincing someone who can still see clearly to come for screening is extremely difficult,” she says.

Many patients only seek care after experiencing vision problems.

Health workers themselves may also miss opportunities to refer patients for routine screening because of limited awareness about the asymptomatic nature of the disease.

To address this challenge, the Ministry of Health is integrating diabetic retinopathy screening into diabetes clinics across the country.

Rather than referring patients separately to eye clinics, healthcare workers are increasingly conducting eye screening within diabetes clinics.

“When patients have already spent hours at the diabetic clinic, many do not want to queue again at the eye clinic,” Dr Bitok explains.

“By providing services under one roof, we have significantly increased the number of people being screened.”

The ministry is also working to expand specialist eye care services beyond Nairobi, where most retinal specialists are currently concentrated.

Recent efforts have seen specialist services extended into western Kenya, with plans to further increase access in underserved regions.

As Kenya grapples with rising rates of diabetes and other NCDs, experts say prevention remains the most effective strategy.

Maintaining a healthy body weight, engaging in regular physical activity, following prescribed treatment, controlling blood pressure and attending annual eye examinations can significantly reduce the risk of blindness.

“Diabetic retinopathy is largely preventable when detected early,” says Dr Bitok.

“Our message to Kenyans is simple: if you have diabetes, do not wait until your vision changes. Have your eyes checked every year. Early detection can save your sight.”