What is Diabetic Retinopathy?
Diabetic patients have abnormally high blood sugar levels, which causes the walls of tiny blood vessels throughout the body to deteriorate — including those in the retina. Blood and other substances leak from these damaged vessels, leading to a condition called diabetic retinopathy (DR). It is classified into two stages based on severity: the non-proliferative stage (no new blood vessel growth) and the proliferative stage (abnormal new blood vessel growth).
In the early stage, patients usually feel no symptoms at all. An eye exam may reveal small hemorrhages on the retina. If vessel leakage occurs, the retina swells and mild blurring of vision begins. As the disease progresses and blood vessels become blocked, the retina becomes deprived of blood supply, triggering the growth of new, fragile blood vessels (neovascularization). These vessels bleed easily and can cause scar tissue that pulls on the retina, leading to severe vision loss from both bleeding and retinal detachment.
Blurred vision can also result from swelling at the macula (macular edema), caused by fluid and fat leaking from blood vessels. Since the macula is the area responsible for sharp central vision, any damage there significantly affects sight. In severe cases, blood vessels at the macula can become blocked entirely, causing macular ischemia and permanent vision loss.
How Do You Know If You Have Diabetic Retinopathy?
Many patients with diabetic retinopathy experience no symptoms in the early stages — so by the time blurred vision appears, the disease has already progressed significantly. All diabetic patients should have their eyes examined by an ophthalmologist, who will dilate the pupils and perform a detailed retinal examination. If diabetic retinopathy is detected, the doctor will recommend appropriate advice and treatment.
How is Diabetic Retinopathy Treated?
Damage caused by diabetic retinopathy cannot be fully reversed. Current treatments aim to prevent the disease from progressing further. Keeping blood sugar and HbA1c within normal ranges, along with managing other conditions such as high blood pressure and kidney disease, can slow the progression. There are currently three treatment options:
- Laser treatment is the standard approach, used for patients in the proliferative stage or those with macular edema. The laser causes abnormal new blood vessels to shrink, reduces retinal swelling, and prevents further bleeding. Treatment may be divided into multiple sessions to avoid laser-induced swelling. Complications are very rare when patients cooperate and are treated by a specialist.
- Medication (intravitreal injection) is a newer approach where drugs are injected directly into the vitreous of the eye. These medications reduce vessel leakage and cause abnormal new blood vessels to shrink. While results are generally good, the effect does not last long, and there is a small risk of complications such as infection, vitreous hemorrhage, or retinal detachment.
- Surgery is considered when blood in the vitreous does not absorb on its own within 2–3 months, or when scar tissue causes retinal detachment. Vitrectomy surgery can prevent further progression and reattach the retina, though full restoration of vision depends on the severity of each individual case.
When Should Diabetic Patients Get an Eye Exam to Prevent Diabetic Retinopathy?
All diabetic patients should have an eye examination by an ophthalmologist at least once a year. With today’s diagnostic tools and treatments, diabetic retinopathy can be detected and managed more effectively when caught early. If abnormalities are found, the doctor will schedule follow-up appointments or begin appropriate treatment based on the stage of disease.
Maintaining blood sugar within normal levels is the most important step in slowing disease progression. Additionally, diabetic women who are pregnant should have an eye exam during the first trimester, as hormonal changes during pregnancy can accelerate the severity of diabetic retinopathy.
For questions or appointments, contact the Diabetes and Endocrine Center at Bangkok Hospital Pattaya through any available contact channel.
