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单词 retinal hemorrhage
释义

retinal hemorrhage


retinal hemorrhage

Bleeding into the retina caused by diabetes mellitus, hypertension, or by blockage of the vein that drains blood from the retina.

Retinal Hemorrhage


Retinal Hemorrhage

 

Definition

Retinal hemorrhage is the abnormal bleeding of the blood vessels in the retina, the membrane in the back of the eye.

Description

The retina is the part of the eye that converts light into nerve signals that are processed by the brain into visual images. The retina is the inside surface of the back of the eye, consisting of millions of densely arranged, light-sensitive cells called rods and cones. Blood flow to the retina is maintained by the retinal vein and artery, and a dense network of small blood vessels (capillaries) supplies the area with circulation. These blood vessels can become damaged by injury and disease and may bleed (hemorrhage) and cause temporary or permanent loss of visual accuracy. Because the cells of the retina are so dense and sensitive, even small injuries to the blood vessels can translate into vision problems. Diseases that affect the health of the circulatory system, such as diabetes and high blood pressure, also affect the blood vessels of the eye. Damage to the blood vessels in the retina, including hemorrhage, is termed retinopathy.

Causes and symptoms

Retinal hemorrhages can be caused by injuries, usually forceful blows to the head during accidents and falls, as well as by adverse health conditions. In infants, retinal hemorrhage is frequently associated with child abuse and has been termed shaken baby syndrome. A condition called retinopathy of prematurity occurs in prematurely born infants or infants with low birth weights. When children are born prematurely, the blood vessels in the eye may not have had time to fully develop and may become damaged easily, leaking or hemorrhaging. The condition must be determined by an opthalmologist, as the symptoms are not readily observable.Diabetic retinopathy is a common eye problem associated with diabetes. Diabetes, by stressing the circulatory system, can cause damage, including hemorrhaging, to the small blood vessels of the retina. Non-proliferative retinopathy occurs when the damaged or leaking blood vessels do not spread. Symptoms of this disorder include vision spots, floaters (floating areas of blurred vision), decreased or loss of vision, or loss of fine vision for detailed activities such as reading. Proliferative retinopathy occurs when new blood vessels begin to form in damaged areas of the retina, and may lead to spots, floaters, decreased vision, or sudden loss of vision. Sudden vision loss may occur if one of the newly formed blood vessels ruptures. Due to increased pressure in the area, the retina may detach from the back of the eye, a serious condition and a cause of blindness.People with high blood pressure (hypertension) may develop hypertensive retinopathy, in which blood vessels in the retina become damaged from increased blood pressure. Symptoms are typically not pronounced, but blurred or decreased vision may be caused by the disorder.Central serous retinopathy is a condition in which the vessels behind the retina leak and cause fluid to collect in small blisters behind the retina. Symptoms include sudden blurry areas in the vision, blind spots, distorted vision areas, and loss of vision. This condition is most common in males between 20 and 50 years of age.

Diagnosis

Diagnosis of retinopathy is performed by an opthalmologist, particularly one who specializes in disorders of the retina (retinal specialist). The opthalmologist may perform an opthalmoscopy, using an instrument called an opthalmoscope to examine the inside of the eye. For a detailed view of the blood vessels of the retina, a fluorescein angiography test might be performed, in which a florescent dye is injected into the patient's bloodstream and photographs record the status of the blood vessels in the retina. Vision tests, patient history, and blood tests might also be ordered by the diagnosing physician.

Treatment

Laser surgery by an opthalmologist is a common treatment for retinal hemorrhages, in which a laser beam is used to remove or seal off damaged or bleeding blood vessels in the retina. Some vision loss occurs with this technique. For retinal hemorrhages associated with diabetes and high blood pressure, treating the overall condition is required.

Alternative treatment

Alternative treatment of retinal hemorrhages focuses on providing nutrients to strengthen and heal the injured blood vessels. Nutritional supplements include antioxidant vitamins A, C, and E; vitamin B-complex including B6 and B12; the mineral zinc; and essential fatty acids including omega-3 from fish oil and flaxseed oil. Herbal supplements include bilberry, grape seed extract, pine bark extract (pycnogenol), and lutein.

Key terms

Diabetes — Disease in which the body does not properly produce or use insulin, resulting in fluctuating blood sugar levels.Hypertension — Condition caused by high blood pressure.Opthalmologist — Physician specializing in the diagnosis and treatment of disorders of the eye.

Prognosis

For retinal hemorrhages associated with retinopathy of prematurity, nearly 85 percent of cases heal without treatment. Diabetic retinopathy is the leading cause of blindness for those between 20 and 65 years old in the U.S. Diabetic retinopathy typically takes years to develop in people with diabetes, but occurs in nearly 80 percent of those with diabetes for over 20 years and who are treated with insulin. Regular monitoring and treatments can slow the degeneration of the eye, while advanced cases of the disorder lead to blindness. Retinopathies requiring laser treatment have a partial loss of vision due to the surgery. For hypertensive retinopathy, most vision problems go away when high blood pressure is treated and lowered. The majority of cases of central sirous retinopathy disappear after three to four months, and full vision generally returns within six months, although recurrence of the disorder is common.

Prevention

The first step in sound prevention is for people with vision problems, including visual spots, flashes or floaters in the vision, and loss or distortion of visual accuracy, to see an opthalmologist as soon as possible. To prevent complications of retinal hemorrhages in infants, the prevention includes regular prenatal care and monitoring of infants with high risks of the disorder (born prematurely or with weight less than four pounds and six ounces). For diabetic retinopathy, control of blood sugar and blood pressure fluctuations is necessary, as well as frequently scheduled eye exams by an opthalmologist. For retinal hemorrhages associated with hypertension, controlling high blood pressure through diet, exercise, and stress reduction is recommended. Central sirous retinopathy has been associated with high stress levels, so preventative care for this disorder includes stress management practices.

Resources

Books

Abel, Robert. The Eye Care Revolution: Prevent and Reverse Common Vision Problems. Kensington, 1999.Anshel, Jeffrey. Smart Medicine for Your Eyes. Avery Publishing, 1999.Cassel, Gary H. The Eye Book: A Compete Guide to Eye Disorders and Health. Johns Hopkins University Press, 1998.Grossman, Marc. Natural Eye Care: An Encyclopedia. McGraw Hill, 1999.

Organizations

American Academy of Ophthalmology. P.O. Box 7424, San Francisco, CA 94120. (415) 561-8500. http://www.aao.org.National Eye Institute. 2020 Vision Place, Bethesda, MD 20892-3655. (301) 496-5248. http://www.nei.nih.gov.
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更新时间:2024/12/23 21:58:46