The Silent Threat Inside Diabetes
Millions of people manage their blood sugar every day without realizing that the damage is quietly happening somewhere else: in their eyes.
Diabetic retinopathy (DR) is eye damage caused by chronically high blood sugar levels harming the tiny blood vessels in the retina (the light-sensitive tissue at the back of the eye). It develops slowly, usually without symptoms in the early stages, and can lead to permanent vision loss or blindness if left untreated.
A Disease That Affects Working-Age Adults Most
Diabetic retinopathy is the leading cause of preventable blindness among working-age adults globally. In high-income countries, regular screening programs have helped catch it early. But in many low- and middle-income countries, those programs are limited or nonexistent.
A new cross-sectional study (a type of research that captures a snapshot of a population at one point in time) published on medRxiv examined diabetes patients attending a tertiary-care hospital (a specialized referral hospital) in Hargeisa, Somaliland. Researchers wanted to understand how common diabetic retinopathy was in this setting — and which patients faced the highest risk.
What Doctors Used to Think — and What This Changes
The standard expectation is that diabetic retinopathy rates are lower in settings where diabetes has been diagnosed and managed for shorter periods. Somalia and Somaliland have been seeing rising rates of type 2 diabetes as dietary and lifestyle patterns shift, but the assumption was that complications like DR would lag behind.
But here's the twist: the numbers were strikingly high. Over half of all patients screened already had some form of retinopathy — a rate comparable to, and in some comparisons exceeding, rates seen in populations that have had diabetes for longer periods.
How Diabetes Damages the Eye
Here's the biology, simplified. Blood sugar that stays too high for too long acts like a slow-acting acid on the microscopic blood vessels in your eye. Over time, those vessels weaken, leak, swell, or grow in abnormal ways.
Think of it like a garden hose left under too much pressure for too long — eventually the hose cracks, bulges, and leaks. In the eye, those leaks can blur vision, distort the center of your visual field (called macular edema, or swelling of the macula), or — in advanced stages — cause the retina to detach.
The particularly dangerous feature is that early stages often cause no pain and no obvious vision changes. By the time someone notices a problem, significant damage may already have occurred.
The researchers screened 384 adults with diabetes mellitus. Most (76%) had type 2 diabetes (the more common form, strongly linked to lifestyle factors). The average patient had lived with diabetes for about 9.7 years.
Of those 384 patients, 51% — more than half — had diabetic retinopathy. Within that group, 26% had macular edema (swelling in the central part of the retina, which is critical for sharp vision), and 17% had non-proliferative diabetic retinopathy (NPDR), an earlier stage of the disease.
This means that in a room of 100 diabetes patients at this hospital, more than 50 already had eye damage — most of it likely undiagnosed until this study.
The Risk Factors That Stood Out
The study identified several factors that significantly increased the odds of having diabetic retinopathy.
Patients over 40 years old were significantly more likely to have DR. Patients who had lived with diabetes for more than 10 years had approximately twice the risk of retinopathy compared to those diagnosed more recently. The presence of heart disease alongside diabetes also strongly predicted retinopathy — suggesting that when blood vessels suffer in one organ, they are likely suffering in others too.
Interestingly, literacy and employment status were also linked to retinopathy risk — likely because patients with less education and fewer economic resources had less access to diabetes management and eye care, allowing the condition to progress further before detection.
This Is Not Just a Problem for Somaliland
It would be easy to read these findings as a story about a distant health system with limited resources. But the underlying message applies globally: diabetes is widespread, diabetic retinopathy is common, and most cases go undetected until vision is already threatened.
In the United States, estimates suggest that about one-third of adults with diabetes have some degree of retinopathy. Globally, the numbers are similar or worse in many regions. Screening rates remain far below what is recommended everywhere.
If you have diabetes — type 1 or type 2 — the single most important thing you can do for your eye health is get a dilated eye exam every year. A dilated exam (where the pupil is temporarily widened with eye drops to allow a full view of the retina) can detect retinopathy long before you notice any vision changes.
Other steps that reduce your risk: keeping blood sugar as stable as possible, controlling blood pressure, and telling your doctor about any changes in vision immediately — blurring, floaters, dark patches, or distorted straight lines.
If you have had diabetes for more than 10 years, or if you also have heart disease or hypertension (high blood pressure), talk to your eye doctor about how frequently you should be screened.
The Limits of This Research
This study used a hospital-based sample, meaning patients who came to this specific hospital — not a random cross-section of all people with diabetes in Somaliland. Those who show up to a specialist hospital may already be sicker than average, which could inflate the retinopathy rates. Additionally, the study design (cross-sectional, or one-time snapshot) cannot prove that the risk factors identified actually caused the retinopathy — only that they were associated with it.
The researchers call for a formal health policy response in Somaliland: structured, regular eye screening programs for all diabetes patients, better integration of diabetes management and ophthalmology (eye care), and improved health education. The same call applies more broadly. Where screening programs exist and are funded, retinopathy-related blindness rates drop. Expanding access to annual eye exams for people with diabetes remains one of the highest-value interventions available in modern medicine.