Diabetic Eye Care

How does diabetes affect the eye?

Diabetes can impact the eye in many ways. Fluctuations in blood sugar can blur vision by making a patient’s nearsightedness or farsightedness change. Diabetes can also cause cataracts and can lead to glaucoma. Perhaps the most serious consequence of diabetes is its effect on the retina, which is called diabetic retinopathy.

One of the most concerning aspects of diabetic retinopathy is that is can pass unnoticed by the patient until it reaches an advanced stage. This is why regular annual dilated exams are so important.

Over time, diabetes affects the circulatory system of the retina. The earliest phase of the disease is known as background diabetic retinopathy. In this phase, the small arteries in the retina become weakened and start to leak, forming small, dot-like hemorrhages. When sufficiently numerous, these leaking vessels can lead to swelling or edema in the retina and decreased vision.

The next stage is known as proliferative diabetic retinopathy. In this stage, damage to the small arteries becomes so great that areas of the retina become oxygen-deprived and ischemic. New, fragile, vessels develop as the circulatory system attempts to maintain adequate oxygen levels within the retina. This complication is called neovascularization. Unfortunately, these delicate vessels break and hemorrhage easily. Blood may leak into the retina and vitreous, causing spots or floaters, along with decreased vision.

Photo of background diabetic retinopathy, showing yellow proteinaceous deposits and scattered dot-like hemorrhages. Photo of neovascularization over optic nerve in center of photo, and scattered blood in vitreous above retina.


In the later phases of the disease, continued abnormal vessel growth and scar tissue may cause serious problems such as retinal detachment and glaucoma.

Signs and Symptoms

The affect of diabetic retinopathy on vision varies widely, depending on the stage of the disease. Some common symptoms of diabetic retinopathy are listed below.

  • Blurred vision (this is often linked to blood sugar levels
  • Floaters and flashes
  • Sudden loss of vision

Detection and Diagnosis

Diabetic patients require routine eye examinations so related eye problems can be detected and treated as early as possible. Over the past two decades significant advances have been made in controlling vision loss from the complications of diabetes mentioned above. By monitoring patients, generally once a year with a dilated exam, patients can be followed for the more serious signs of proliferative diabetic retinopathy discussed previously. Large clinical trials such as the Diabetic Retinopathy Study (DRS) and the Early Treatment Diabetic Retinopathy Study (ETDRS) have shown the effectiveness of laser treatment in reducing the chance of significant vision loss due to diabetic retinopathy. For this reason it is important that diabetic patients have regular dilated exams with an eye M.D. to determine if laser is needed.

Perhaps the most important aspect of preventing progression toward severe diabetic retinopathy is good control of blood sugar. This has been demonstrated by another large clinical trial called the Diabetes Control and Complications Trial (DCCT) which demonstrated that intensive control of blood sugar reduced the risk of developing diabetic retinopathy by 76%.

Dr Phillips has been evaluating and treating diabetic retinopathy for over ten years. Exams are conducted at our office and laser treatments, if indicated, are performed at the Foothill Surgery Center on a new Zeiss Visulas 532 NM laser.