Diabetes can cause blood vessels to leak causing macular edema and abnormal blood vessel to grow and possibly bleed causing proliferative diabetic retinopathy (PDR)
The eye is like a tiny camera, and the retina is the “film” in the back of this camera. The centre of the retina is a tiny spot called the “macula”, which supplies all of our sharp, central vision. The earliest form of diabetic retinal damage is called “background diabetic retinopathy”. About 50% of patients with diabetes for 10-15 years have some signs of this such as bleeding, or swollen pockets within the retina. If these swollen areas affect the macula, dim or blurry vision may result.
If the eye disease worsens, areas of the retina may not get enough blood. The eye responds by growing thin new vessels. This is called “proliferative diabetic retinopathy”. Unfortunately, these new vessels frequently break open and bleed, filling the eye with blood and stimulating scar tissue to grow, sometimes leading to retinal detachment.
Most people with diabetic retinopathy do not have any symptoms or visual loss due to their retinopathy. However, without treatment, diabetic retinopathy can gradually become worse and lead to visual loss or even blindness. Initial symptoms that may occur include blurred vision, seeing floaters and flashes, or even having a sudden loss of vision.
In some cases, advanced damage may be present without the patient even being aware. Also, most treatments for diabetic eye disease work better at preventing and controlling the diabetic retinopathy than at reversing it once it is well established. Because of this, it is very important for diabetics to have a regular, complete eye and retinal examination that should include drops to dilate the pupil.
Macular edema and proliferative diabetic retinopathy can be accessed through a dilated eye exam. In addition, tests such as a fluorescein angiogram and ocular coherence tomography (OCT) can be conducted. Macular edema also can be assessed by using an OCT.
Treatment and Drugs
In mild cases, treatment for diabetic retinopathy is not necessary. Regular eye exams are critical for monitoring progression of the disease. Strict control of blood sugar and blood pressure levels can greatly reduce or prevent diabetic retinopathy. In more advanced cases, treatment is recommended to stop the damage of diabetic retinopathy, prevent vision loss, and potentially restore vision.
Treatment options include:
Treatment is an outpatient procedure; admission to hospital is not required. The patient sits at a slit lamp similar to that used in routine ophthalmic examination but modified to accept a laser fibreoptic cable. Drops are used to anaesthetize the cornea and a therapeutic contact lens is applied. As treatment is started, the patient experiences bright flashes of light but no pain. The eye must be kept as still as possible during treatment to ensure accurate application of the laser and to avoid damage to the fovea; a typical treatment takes about ten minutes
Patient can communicate with the ophthalmologist in case of any discomfort; so that the treatment can be safely interrupted. Commonly the patient is very dazzled after the treatment, and sometimes the laser spots are visible to the patient. Typically though not invariably, this effect fades over the next few days. No special precautions need to be taken after the laser. Additional eye drops or oral therapy may be required in certain co are needed.
Dr. Shrutika Kankariya
Retina & Diabetes Eye Specialist MBBS (KEM,Mumbai), DNB (Sankara Nethralaya, Chennai),FRCS(Glasgow), FICO(UK), Fellow Retina (Sankara Nethralaya & USA),