Located at the back of the eye, the retina is attached to the vitreous, the gel-like substance that makes up for most of the eye's volume. Although the vitreous begins as a thick substance with a firm shape, the consistency of the gel changes and becomes thinner and more watery as we age. A change in the shape of the vitreous can cause it to pull away from the retina and leave a tear. A retinal tear leaves the retina unprotected and can allow fluid to travel between the retina and the wall, which may lead to retinal detachment.
Retinal tears may occur in patients with myopia (nearsightedness), as the condition may cause the vitreous to pull away from the retina. Although a retinal tear does not cause pain, patients may experience flashes or floaters in their field of vision, a reduction of vision, a shadow or curtain forming in the peripheral vision, or other vision changes. It is important to see your doctor at the first symptom of a retinal tear.
Early detection and prompt treatment of a retinal tear can often prevent the retina from detaching through prompt treatment. A retinal tear is usually treated with a laser to burn the area around the tear, causing it to scar and seal the retina to the tissue underneath it. This prevents fluid from flowing through the tear and leading to retinal detachment. Treatment for a retinal tear is usually effective in relieving symptoms and preventing retinal detachment from occurring.
Blood and nutrient circulation to and from the surface of the retina is mostly done through one vein and one artery. If these passages or any of the smaller branches connected to them are blocked, blood flow to the retina can become seriously disrupted. Blockage of one of these passages is known as occlusion, and can result in sudden vision loss.
The retinal vein carries blood away from the body, and may cause blood to build up and hemorrhage if it is blocked. Retinal vein occlusion, also known as venous stasis retinopathy, can also cause swelling, bleeding and growth of abnormal blood vessels, which can in turn lead to other serious eye diseases.
This condition is most common in men and women over the age of 50, although the risk continues to increase with age. Other risk factors may include high blood pressure, high cholesterol, diabetes, smoking, glaucoma and, rarely, blood clotting and inflammatory conditions.
Although there is no cure for retinal vein occlusions, there are several treatment options available to help minimize risks, treat symptoms, and prevent further vision loss. The best treatment for each patient depends on the severity and location of the blocked vein, but may include laser photocoagulation or intraocular steroids.
The vitreous is the gel-like substance that makes up approximately two-thirds of the eye's volume and is located in between the lens in the front of the eye and the retina in the back of the eye. In normal, healthy vitreous gel, there are no blood vessels, but diseases such as diabetic retinopathy can lead to the development of new blood vessels which can grow into the vitreous gel. These blood vessels are often fragile and susceptible to leaking blood and fluids.
A vitreous hemorrhage occurs when one of these blood vessels ruptures and causes bleeding within the vitreous gel, causing visual symptoms. Normal blood vessels may also rupture, although less common, as a result of force from a retinal tear or detachment. Patients with vitreous hemorrhage usually notice a sudden, significant increase in the number and size of floaters blocking their vision. Severe bleeding can also cause vision to appear blurry, cloudy or hazy.
When symptoms occur, it is important for patients to seek prompt medical attention. Your doctor will examine your eye along with your medical history to determine the cause of the hemorrhage and then recommend an appropriate treatment. Treatment for a vitreous hemorrhage may include vitrectomy, cryotherapy, laser photocoagulation, or intravitreal injections.