Retina is the light sensitive layer of cells at the back of the eye. It converts light into electrical signals which are sent to the brain through the optic nerve and the brain interprets them to produce the images that we see. A healthy retina is necessary for good vision.
To examine the retina, the ophthalmologist will dilate your eyes by using dilating drops. A retina specialist then uses a special magnifying lenses to examine your retina. The dilatation will reverse after 4-5 hours.
Diabetes can cause blood vessels to leak, causing fluid accumulation in the inner layers of the retina and thus affecting the vision. Abnormal blood vessels can also grow and possibly bleed. The damage and changes seen in the retina due to diabetes is called diabetic retinopathy.
A dilated retinal examination can reveal macular edema and proliferative diabetic retinopathy. Fluorescein angiogram and ocular coherence tomography (OCT) are useful in detecting subtle changes.
Most people with diabetic retinopathy do not have any symptoms or visual loss due to their retinopathy. Initial symptoms that may occur include blurred vision, seeing floaters and flashes, or even having a sudden loss of vision. Without treatment, diabetic retinopathy can gradually become worse and lead to visual loss or even blindness.
As many patients are not aware of the disease even when advanced damage is present, it is very important for diabetics to have a regular, complete eye and retinal examination with dilation of the pupil. Treatment for diabetic eye disease is better at preventing and controlling the diabetic retinopathy than at reversing it once it is well established.
Laser seals leaking blood vessels to reduce macular edema, helping to prevent further vision loss. It also slows or stops growth of abnormal blood vessels, decreasing the chance of bleeding in the eye.
Retinal vein occlusion is a common cause of vision loss. It is most common in people over the age of 60 and it seems to affect both sexes equally.