Patients with diabetes are more likely to develop eye problems such as cataracts and glaucoma, but the disease's effect on the retina is the main threat to vision. Over time, diabetes affects the circulatory system of the retina, and this effect is called diabetic retinopathy.
In its earliest phase, blood vessels in the retina become weakened and leak. These leaking vessels often lead to swelling (or edema) in the retina and cause decreased vision. As the condition worsens, circulation problems cause areas of the retina to become oxygen-deprived (or ischemic). New, fragile vessels (neovascularization) develop in an attempt to maintain adequate oxygen levels within the retina. These delicate vessels hemorrhage easily, causing blood to leak into the vitreous. The result causes symptoms of floaters or decreased vision. In the later phases of the disease, continued abnormal vessel growth and scar tissue may cause serious problems, such as retinal detachment.
Diabetic patients should have routine eye examinations so related eye problems can be detected and treated as early as possible. Retinal specialists rely on several tests to monitor the disease's progression and make treatment decisions. The most common cause of vision loss associated with diabetic retinopathy is diabetic macular edema. Laser treatment applied to the leaky blood vessels (focal photocoagulation) is helpful in preventing further vision loss. Two common procedures used in the treatment of proliferative diabetic retinopathy are pan retinal photocoagulation (PRP) and vitrectomy.
Pan retinal photocoagulation (PRP) is a type of laser surgery used to destroy oxygen-deprived retinal tissues outside of the patient's central vision. This treatment does create blind spots in the peripheral vision, but PRP prevents the continued growth of fragile vessels and seals the ones that leak.
Vitrectomy is used to remove the blood clots that occur in the gel-like substance that fills the center of the eye, called the vitreous. During a vitrectomy, the retina surgeon removes the blood and vitreous from the eye and replaces it with clear saline solution. The surgeon may also cut strands of vitreous attached to the retina that create traction, which may lead to retinal detachments if not removed.
Diabetic patients who are able to maintain appropriate blood sugar levels have fewer eye problems than those with poor control. Diabetic patients can also reduce the possibilities of eye complications by scheduling yearly dilated eye examinations with an eye doctor.