What is the Retina?
The retina is a thin sheet of nerve tissue in the back of the eye where light rays are focused and transmitted to the brain via the optic nerve. Tiny blood vessels supply the retina with oxygen and other nutrients. Arteries deliver the blood, and veins carry it out.
Common Retina Issues:
- Retinal Vein Occlusion
- Diabetic Retinopathy
- Macular Hole
- Retinal Detachments
- Macular Degeneration
- Macular Edema
Retinal Vein Occlusion
Sometimes one of these arteries hardens or swells and presses on a nearby vein. The vein can then become blocked, or occluded, making it difficult for blood to leave the eye. This is called a retinal vein occlusion. The restricted circulation leads to high pressure in the eye, which can in turn cause swelling, bleeding, growth of abnormal blood vessels, and partial or total vision loss.
Retinal vein occlusions are the second most common cause of blood vessel-related vision loss (the first is diabetic retinopathy). The condition occurs most often in men and women over the age of 50, particularly those in their 60s and 70s. Risk factors include atherosclerosis (hardening of the arteries), high blood pressure, high cholesterol, diabetes, smoking, glaucoma, and, in rare cases, blood clotting and inflammatory conditions.
Treatment and prognosis depend on the severity of the blockage and the location of the occluded vein. If the largest vein leaving the eye is affected, the condition is known as a central retinal vein occlusion, or CRVO; otherwise, it is called a branch retinal vein occlusion, or BRVO. Retinal vein occlusions do not cause a change in physical appearance, and BRVOs often occur with no pain or noticeable loss of vision. For these reasons, it is important to have routine eye exams and also to check one’s own vision by closing one eye at a time.
There is no cure for retinal vein occlusions, so emphasis is placed on risk management, treatment of symptoms and prevention of further vision loss. It is critical to control high blood pressure, high cholesterol, diabetes and other health conditions that increase the risk of vascular hardening, narrowing and blood clotting.
The macula is at the back of the eye, situated in the middle of the retina. It is a light-sensitive layer, which converts light into signals that tell the brain what we are looking at. The macula enables us to see sharp, clear images. A hole is caused when the vitreous, the gel-like substance in the eye, shrinks and starts to come away from the retina.
In severe cases, a hole in the macula can cause loss of central vision and the ability to see finely detailed images. A macular hole can also be called a retinal hole, a macular cyst, or retinal perforation. Macular holes are more prevalent in women than men.
It is important to point out that a macular hole is not the same as macular degeneration. Macular degeneration is a different eye-related condition that also affects elderly people.
Retinal detachments are a very serious problem that almost always causes blindness unless it is treated. As a person’s normal eye ages, the vitreous gel contracts and becomes more liquid. As the vitreous gel becomes more liquid, it may pull on the retina and create a retinal tear (and then tear.) When fluid passes through a tear, it will lift the retina from the back of the eye, creating a retinal detachment.
Retinal Detachment Risk Factors
- Extreme Nearsightedness (myopia)
- Family history of retinal detachments
- Previous injury to the eye
Macular Edema is also called Cystoid Macular Edema or (CME). Macular Edema sets in when blood vessels leak into the eye and form cysts and swelling that obstruct central vision. CME can best be seen from a diagnostic vision test called fluorecein angiography.
Causes of Macular Edema
- Cataract surgery or repair of retina detachment
- Macular degeneration
- Medication side effects
- Blocked or clogged veins of the retina
- Eye injuries
Diagnosing Macular Edema
During routine dilated eye exams, our eye doctors may detect central yellow spots. Depending on the amount of fluid that has leaked, these spots may be easy or hard to detect. A fluorescein angiography procedure is conducted where sodium fluorescein dye is injected into an arm or hand and then retina photographs are taken. If there are any abnormalities on the retina, the dye will usually reveal them by leaking, staining or by its inability to get through blocked blood vessels.
Macular Edema Treatments
Your ophthalmologist will provide expert treatment options to deal with macular edema. The treatment type will depend on the severity and progression of the macular edema. Some of the treatment options include:
- Avastin Injections make blood vessels less leaky and decreases macular edema.
- Ocular steroid injections are used to stabilize the retinal barrier and decrease vascular growth within the eye.
- Anti-inflammatory eye drops (steroid based) are used to reduce the inflammation of the retina.
- Vitrectomy Surgery removes vitreous gel and membranes to allow the retinal to flatten again.
Vitrectomy Surgery removes vitreous gel and membranes to allow the retina to flatten again. It is a microsurgical procedure in which specialized instruments and techniques are used to repair retinal disorders. These types of retinal disorders were previously not operable.
The first step in this procedure is usually the removal of the vitreous gel through very small (˜1.4mm) incisions in the eye wall, hence the name “vitrectomy.” The vitreous is removed with a miniature handheld cutting device and replaced with a special saline solution similar to the liquid being removed from the eye. A high level intensity fiberoptic light source is used to illuminate the inside of the eye while the surgeon works. The ophthalmic retinal surgeon uses a specialized operating microscope and contact lenses, which allow a clear view of the vitreous cavity and retina at various magnifications. A vitrectomy is performed in an operating room under local or general anesthesia.
Page Topics Include: Content Updated October 2015 – Retina Surgery Erie, PA. About the Retina, Retinal vein occlusion, Diabetic Retinopathy, Macular Hole, Retinal Detachments, Macular Degeneration, Macular Edema