Diabetic Retinopathy
Introduction
Anatomy
The anterior chamber is located behind the cornea and in front of the iris. The anterior chamber is filled with a fluid that maintains eye pressure, nourishes the eye, and keeps it healthy.
The iris is the colored part of your eye. The iris contains two sets of muscles. The muscles work to make the pupil of your eye larger or smaller. The pupil is the black circle in the center of your iris. It changes size to allow more or less light to enter your eye.
After light comes through the pupil, it enters the lens. The lens is a clear curved disc. Muscles adjust the curve in the lens to focus clear images on the retina. The retina is located at the back of your eye.
Your inner eye, or the space between the posterior chamber behind the lens and the retina, is the vitreous body. It is filled with a clear gel substance that gives the eye its shape. Light rays pass through the gel on their way from the lens to the retina.
The receptor cells in the retina send nerve messages about what you see to the optic nerve. The optic nerves extend from the back of each eye and join together in the brain at the optic chiasm. The optic chiasm is the place where the optic nerves from the right and left eye meet and cross one another. From the optic chiasm, the nerve signals travel along two optic tracts in the brain and eventually to the occipital cortex.
Causes
There are two types of diabetic retinopathy, nonproliferative and proliferative. Nonproliferative retinopathy, also called background retinopathy, develops first. In this stage, high blood sugar levels damage the walls of the small blood vessels in the retina. The blood vessels become weak and leak. The leaking fluid may lead to retina swelling or deposit formation. Nonproliferative retinopathy can cause macula edema and macula ischemia. Macula edema is swelling of the macula that can result in central vision loss. Macula ischemia results when the blood vessels close and cannot supply blood to the macula. This may cause blurred vision because the macula does not receive enough blood.
Proliferative retinopathy is a more advanced stage of diabetic retinopathy. This results when there is a widespread closure of retinal blood vessels. The growth of new abnormal blood vessels is then triggered. The new blood vessels attempt, but are unable to resupply the retina with blood. Proliferative retinopathy can cause both central and peripheral vision loss. Bleeding, retinal detachment, or glaucoma may cause vision loss. Bleeding results when the new blood vessels bleed into the eye. Retinal detachment may develop from shrinking scar tissue that pulls the retina from its normal position. These scars form in the eye from recurrent bleeds. This can cause severe vision loss if the macula or large portions of the retina are affected. Glaucoma results from increased eye pressure that can occur if abnormal blood vessels grow and block fluid drainage. The increase in inner eye pressure can cause damage to the optic nerve and blindness.
Symptoms
Diagnosis
Your doctor will review your medical history and perform a thorough eye examination. He or she will look for blood vessel leakage or damage, macular edema (retina swelling), and damaged nerve tissue. The pressure inside of your eye will be measured. A vision test will be used to determine how well you see at different distances.
In some cases, a fluorescein angiogram is used to detect blood circulation problems in the retina and choroid. The test uses an injected dye and a special camera to take photos of the blood vessels in the eye vascular structures. Fluorescein angiography is a simple and short test that is performed in your doctor’s office.
Treatment
Prevention
Complications
Advancements

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This information is intended for educational and informational purposes only. It should not be used in place of an individual consultation or examination or replace the advice of your health care professional and should not be relied upon to determine diagnosis or course of treatment.
The iHealthSpot patient education library was written collaboratively by the iHealthSpot editorial team which includes Senior Medical Authors Dr. Mary Car-Blanchard, OTD/OTR/L and Valerie K. Clark, and the following editorial advisors: Steve Meadows, MD, Ernie F. Soto, DDS, Ronald J. Glatzer, MD, Jonathan Rosenberg, MD, Christopher M. Nolte, MD, David Applebaum, MD, Jonathan M. Tarrash, MD, and Paula Soto, RN/BSN. This content complies with the HONcode standard for trustworthy health information. The library commenced development on September 1, 2005 with the latest update/addition on April 13th, 2016. For information on iHealthSpot’s other services including medical website design, visit www.iHealthSpot.com.