Retinopathy

• Retinopathy occurs when the small blood vessels (called capillaries) in the retina become damaged. The retina, located at the back of the eye, sends visual images to the brain where they are perceived. Because the capillaries nourish the retina, retinopathy may lead to partial or complete vision loss.
• There are many potential causes of retinopathy. The most common cause is high sugar levels in the blood caused by diabetes. Other causes include premature birth and high blood pressure. Some cases of retinopathy occur for unknown reasons.
• The severity of retinopathy varies depending on the underlying cause. Some cases, such as retinopathy of prematurity, may go away without treatments. Others, such as diabetic retinopathy, are more likely to cause permanent vision loss.
• Treatment for retinopathy depends on the underlying cause.

• Retinopathy of prematurity: There are no noticeable signs or symptoms of retinopathy of prematurity. Therefore, if an infant is born prematurely or has a low birth weight, an eye exam is performed to determine if he/she has the disease.
• Diabetic retinopathy: Symptoms of diabetic retinopathy may go unnoticed until the condition has progressed into the later stages of the disease. Common symptoms include blurred vision, sudden loss of vision in one or both eyes, difficulty reading or seeing detailed images, and seeing flashing lights or black spots.
• Hypertensive retinopathy: Patients with hypertensive (high blood pressure) retinopathy usually do not experience any signs or symptoms, which is why most cases are diagnosed after a routine eye exam. Some patients may experience blurred vision.
• If the patient develops papilledema, symptoms may include headache, nausea, vomiting, and hearing a machine-like sound.
• Central serous retinopathy: Symptoms of central serous retinopathy may include blurred or dim vision (which may or may not occur suddenly), blind sports, reduced visual sharpness, and seeing distorted shapes.

• Retinopathy of prematurity: Premature or low-birth-weight infants undergo an eye exam to determine if they have retinopathy of prematurity. An eye doctor (called an ophthalmologist) will look inside the eye to see if there are any abnormalities in the retina, macula, retinal blood vessels, and optic disc.
• Diabetic retinopathy: An ophthalmologist examines inside of the eye, including the retina, with an instrument called an ophthalmoscope. A colored dye may be injected into the patient's vein before the test. The dye travels through the blood vessels, including the retinal blood vessels, making it easier for the ophthalmologist to see leaky blood vessels caused by diabetic retinopathy.
• Hypertensive retinopathy: Hypertensive retinopathy is usually diagnosed during a routine eye exam because most patients do not experience any signs or symptoms of the disease. During an eye exam, an ophthalmologist uses an ophthalmoscope to look at the retina. If the patient has hypertensive retinopathy, tiny areas of the retina will appear pale or white because they are not receiving enough blood. Bleeding caused by broken blood vessels may also be visible. In some cases, the macula or optic nerve may also be swollen.
• Central serous retinopathy: During an eye exam, a doctor uses an ophthalmoscope to determine if clear fluid has leaked between the layers of the retina. The fluid looks like small bubbles on the retina. If fluid is present, a positive diagnosis is made.

• General: There are many treatments available for retinopathy, which include cryotherapy, photocoagulation, panretinal photocoagulation, sclera buckling, vitrectomy, and pneumatic retinopexy. Treatment depends on the underlying cause.
• Most cases of retinopathy of prematurity resolve without any treatment. However, because the condition may worsen in some cases, babies with retinopathy should undergo eye exams every one to two weeks until they are 14 weeks old to monitor their conditions.
• Controlling blood sugar levels in patients with diabetic retinopathy helps slow or stop the progression of the disease, but additional treatments are usually needed to prevent permanent vision loss.
• Controlling blood pressure in patients with hypertensive (high blood pressure) retinopathy successfully treats most cases. However, some retinal damage may persist once the condition has been treated.
• Most cases of central serous retinopathy go away without any treatment within three to four months. Full vision can return within six months. However, patients should visit their eye doctors regularly for three to six months to make sure the condition improves. If a medication is a suspected cause of the disorder, a different drug or dose may be recommended in order to prevent retinopathy from returning.
• Cryotherapy: If retinopathy of prematurity does not improve, patients may undergo a procedure called cryotherapy. This procedure helps stop the growth of abnormal blood vessels. During the procedure, an instrument, called a cryoprobe, is placed on the outside of the eye. This instrument freezes the abnormal blood vessels growing inside the eye. As a result, the blood vessels stop growing and shrink. The patient does not feel any pain because the eye is numbed.
• This treatment may also be used to prevent retinal detachment in patients who have retinal tears. Tears often develop before the retina starts to detach from the back of the eye. During the procedure, a cryoprobe is used to freeze the retina near the tear. This causes scar tissue to develop, which helps secure the retina to the eye wall. The patient's eye may be red and swollen for a few days after treatment.
• Photocoagulation: If retinopathy of prematurity does not improve, patients may undergo laser photocoagulation to remove abnormal retinal blood vessels. During the procedure, a laser is directed at the area of abnormal blood vessel growth. This destroys abnormal blood vessels.
• Laser photocoagulation has also been used to treat patients with diabetic retinopathy. The goal of this treatment is to stop blood and fluid from leaking into the retina. As a result, this helps slow the progression of diabetic retinopathy and vision loss. During treatment, a high-energy laser beam creates small burns in the abnormal blood vessels. This helps seal up any leaks.
• Patients who develop macular edema (swelling of the middle of the retina) may also undergo laser photocoagulation. During treatment, the laser is directed on leaking blood vessels near the macula. Patients who have blurred vision before surgery may not completely recover normal vision after treatment.
• Laser photocoagulation may also be used to treat retinal tears caused by retinopathy. The laser is directed near the retinal tear. This causes scars to form, which weld the retina to the underlying tissue. As a result, the retina becomes reattached to the inside surface of the eye.
• After laser treatment, vision is typically blurry for about one day. Patients who receive laser treatment for macular edema may see small spots for a few days. Patients should have follow-up visits after treatments to make sure the eyes are healing properly.
• Panretinal photocoagulation: Patients with proliferative diabetic retinopathy may undergo a laser surgery called panretinal photocoagulation. During this procedure, the entire retina, except for the macula (the middle section), is treated with scattered laser burns. As a result, abnormal blood vessels start to shrink and disappear. This reduces the risk of vitreous hemorrhage (bleeding) and retinal detachment. Panretinal photocoagulation is typically performed in two or more sessions.
• After treatment, patients may experience some loss of peripheral vision (also called side vision), which involves the edges of a person's visual field. Although some side vision is sacrificed, the procedure preserves as much central vision as possible. Some patients may also experience slightly impaired night vision after surgery. Patients should discuss the potential health risks and benefits before deciding on surgical treatments.
• Scleral buckling: A procedure called scleral buckling may be performed to treat retinal detachment in patients with retinopathy. During the procedure, a flexible band is placed around the back of the eye to buckle, or indent, the white part of the eye (called the sclera). This pushes the surface of the eye closer to the retina and helps reattach the retina. The band is then removed when the eye outgrows it or when the retina reattaches to the surface of the eye.
• Successfully reattaching of the retina does not guarantee normal vision. The patient's vision after surgery depends on whether or not the macula (middle of the retina) was affected by the detachment before the procedure. Vision is most likely to be impaired if the macula was detached.
• Although uncommon, complications of sclera buckling are possible. Complications may include loss of some or all vision in the involved eye, bleeding under the retina or into the vitreous cavity, and glaucoma. In rare cases, the surface of the eye may become scarred, making eye movement difficult and possibly causing double vision.
• Vitrectomy: In patients with diabetic retinopathy, abnormal blood vessels may leak blood into the vitreous. If this condition does not resolve on its own, it may be treated with a procedure called vitrectomy. The eye surgeon uses delicate instruments to remove the blood-filled vitreous. In addition to removing the vitreous fluid, scar tissue that is pulling on the retina is also removed. This helps reduce the risk of a retinal detachment and prevent the loss of vision. The removed tissue is then replaced with a salt solution (saline) in order to maintain the normal pressure and shape of the eye. Once the vitreous blood is removed, vision is restored.
• A vitrectomy may also be performed to remove scar tissue that starts to pull the retina away from the wall of the eye. Once the scar tissue is removed, the retina is able to settle back and reattach to the wall of the eye.
• After vitrectomy, the eye may be swollen, red, and sensitive to light for several days. After surgery, patients may wear eye patches and apply medicated eye drops to help healing and prevent infections. It may take several weeks for patients to fully recover.
• Complications of a vitrectomy may include recurring detachment of the retina, a cataract, infection, or a retinal tear. All of these complications may lead to partial or complete loss of vision in the affected eye.
• Pneumatic retinopexy: A pneumatic retinopexy may also be performed to treat a detached retina. This technique is usually performed when the tear is located in the upper part of the retina. First, the tear is treated with cryotherapy or laser therapy. Then, a bubble of expandable gas is injected into to the eye cavity. The gas bubble expands over the next few days, pushing the retina to help it reattach to the wall of the eye.
• After surgery, the patient might have to lie face down or hold the head in a cocked position for several days to ensure that the gas bubble seals the tear. It may take several weeks for the bubble to completely disappear. Patients should not lie on their backs until the bubble is gone. During recovery, patients should not travel by airplane or go to areas of high altitude because it may cause the gas bubble to expand rapidly, leading to dangerously high pressure inside the eye.
• Although this treatment is generally less effective than scleral buckling, it is less invasive. Complications are uncommon but may include infection, the development of scar tissue in the vitreous and retina, increased pressure inside the eye (called glaucoma), recurring retinal detachment, and gas under the retina. All of these complications may lead to partial or complete vision loss.
• Control blood sugar: Patients with diabetic retinopathy should closely monitor their blood sugar levels. Controlling blood sugar levels with medications and proper diet helps prevent the condition from developing or worsening.

B

Good scientific evidence

• Grapeseed, OPCs
  : The leaves, sap, and fruit of grape (Vitis cognetiae, Vitis vinifera L.) have been used medicinally since the time of the Greek empire. Preparations from different parts of the plant have been used historically to treat a variety of conditions, including skin and eye irritation, bleeding, varicose veins, diarrhea, cancer, and smallpox. Active components of grapeseed extract (GSE) include oligomeric proanthocyanidins (OPCs). The antioxidant properties of OPCs have made products containing these extracts candidate therapies for a wide range of human disease. Early study using OPCs, and the brand name product Endotelon®, have shown beneficial effects in stopping the disease progression of diabetic retinopathy. Additional high quality clinical study is needed in this area.
• OPCs appear to be well tolerated with few side effects noted in the available literature. However, long-term studies assessing safety are lacking. Use cautiously in patients taking anticoagulants such as warfarin, aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or anti-platelet agents, as OPCs may alter platelet function and the ability to form clots. Based on animal studies, grape seed may increase the risk of bleeding. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. It has been advised to stop all use of grape seed extract at least two weeks prior to surgery or dental procedures. Caution is also advised in patients with blood pressure disorders or those taking ACE inhibitors. The use of grape seed during pregnancy or breastfeeding is not recommended due to a lack of safety information.

C

Unclear or conflicting scientific evidence

• Arnica
  : Arnica is native to the meadows and mountainous regions of Europe and North America. The flowers of the plant are most often used for their medicinal benefit. Homeopathic arnica has been used to improve retinal microcirculation, thereby slowing the progression of damage to the retina of the eye in diabetics. The form of arnica used was not specified in the studies. Although early study is promising, additional study is needed to better understand the effects of arnica on diabetic retinopathy.
• Arnica should only be used if it is very diluted. Use cautiously if allergic to arnica, sunflowers, marigolds, or any related plants (such as daisies, ragweed, or asters). Avoid contact with open wounds or near the eyes and mouth. Use cautiously with a history of stroke. Use cautiously with diabetes drugs or if taking blood-thinners. Stop two weeks before and immediately after surgery or dental or diagnostic procedures with bleeding risks. Avoid if pregnant or breastfeeding.
• Ayurveda
  : Ayurveda is a form of natural medicine that originated in ancient India more than 5,000 years ago. Ayurveda is an integrated system of techniques that uses diet, herbs, exercise, meditation, yoga, and massage or bodywork to achieve optimal health on all levels. Evidence from well-designed study suggests that the Ayurvedic herb Saptamrita Lauha may aid in the rapid absorption of hemorrhages (bleeds) and help prevent future bleeding in patients with diabetic and hypertensive retinopathy. Further research is needed to confirm these results.
• Ayurvedic herbs should be used cautiously because they are potent and some constituents can be potentially toxic if taken in large amounts or for a long time. Some herbs imported from India have been reported to contain high levels of toxic metals. Ayurvedic herbs can potentially interact with many other herbs, foods, or drugs. A qualified healthcare professional should be consulted before taking.
• Bilberry
  : Bilberry is an herb made from the wrinkled, black berries of a small deciduous shrub. The use of bilberry fruit in traditional European medicine dates back to the 12th Century to treat diarrhea, mucus membrane inflammation, and a variety of eye disorders. Based on animal research and several small human studies, bilberry may help treat patients with diabetic retinopathy or vascular retinopathy. However, this research is early, and it is still unclear if bilberry is beneficial for these indications.
• Long-term side effects and safety of bilberry remain unknown. Avoid if allergic to bilberry, anthocyanosides (a component of bilberry), or other plants in the Ericaceae family. Do not consume bilberry leaves. Use cautiously in patients with bleeding disorders or diabetes. Use cautiously if taking anticoagulant/anti-platelet medications or drugs that alter blood sugar levels. Stop use before surgeries or dental or diagnostic procedures that have bleeding risks. Use cautiously in doses higher than recommended. Avoid if pregnant or breastfeeding, due to a lack of safety evidence.
• Ginkgo biloba
  :
  Ginkgo biloba has been used medicinally for thousands of years. Early research suggests that Ginkgo biloba extract may offer benefit to individuals with diabetic retinopathy. Further clinical trials are required to better determine its effectiveness.
• Avoid if allergic or hypersensitive to members of the Ginkgoaceae
  family.
  If allergic to mango rind, sumac, poison ivy or oak, or cashews, then allergy to ginkgo is possible. Avoid if taking anticoagulants due to an increased risk of bleeding. Ginkgo should be stopped two to three weeks before surgical procedures. Use cautiously in patients with seizures. Use cautiously in children. Ginkgo seeds are dangerous and should be avoided. Skin irritation and itching may also occur due to ginkgo allergies. Do not use ginkgo in supplemental doses if pregnant or breastfeeding.
• Kudzu
  : An herb called kudzu has been traditionally used in China to treat alcoholism, diabetes, gastroenteritis, and deafness. Preliminary evidence suggests that injections with puerarin, a constituent of kudzu, may reduce the thickness of blood, improve microcirculation, and help treat diabetic retinopathy. Well-designed clinical trials are needed to confirm these results before a recommendation can be made.
• Avoid if allergic to kudzu, its constituents, or members of the Fabaceae/Leguminosae family. Avoid if taking methotrexate. Use cautiously if taking anticoagulants, drugs used to treat diabetes, benzodiazepines, bisphosphonates, mecamylamine, neurologic agents, drugs that have estrogenic activity, drugs that lower blood pressure, or drugs that are broken down by the liver. Avoid if pregnant or breastfeeding, due to a lack of safety evidence.
• Pycnogenol
  : Pycnogenol® is the patented trade name for a water extract of the bark from the French maritime pine, which is grown in coastal southwestern France. Several studies report benefits of Pycnogenol® in the treatment and prevention of retinopathy, including slowing the progression of retinopathy in diabetics. Better-quality research is needed before a firm conclusion can be reached regarding the safety and effectiveness of Pycnogenol®).
• Avoid if allergic/hypersensitive to pycnogenol, its components, or members of the Pinaceae family. Use cautiously with diabetes, hypoglycemia (low blood sugar), or bleeding disorders. Use cautiously if taking lipid-lowering agents, medications that may increase the risk of bleeding, drugs that increase blood pressure, immunostimulants, or immunosuppressants. Avoid if pregnant or breastfeeding, due to a lack of safety evidence.
• Rutin
  : Rutin is a yellow crystalline flavonol glycoside (chemical structure: C27H30O16) that is found in various plants, especially the buckwheat plant, black tea, apple peels, onions, and citrus. Preliminary evidence does not suggest that tri-(hydroxyethyl)-rutin offers benefits to retinopathy patients. Well-designed studies in this field are required before a firm recommendation can be made.
• Avoid if allergic/hypersensitive to O-(beta-hydroxyethyl)-rutosides or plants that rutin is commonly found in, such as rue, tobacco, or buckwheat. Use cautiously in elderly patients. Use cautiously with skin conditions. Use cautiously if taking diuretics, anti-coagulants, or medications used to treat edema. Use cautiously if pregnant or breastfeeding.

• Retinopathy of prematurity: Pregnant mothers should visit their obstetricians regularly to ensure that they and their fetuses are in good health. Obstetricians can also make recommendations for good prenatal care.
• Infants who are born at less than 36 weeks of gestation or weigh less than four pounds, six ounces at birth should be screened for retinopathy.
• Diabetic retinopathy: Controlling blood sugar with medications and a proper diet may help prevent diabetic retinopathy. Yearly eye exams are recommended for diabetics. This can allow treatment to begin before symptoms are evident. Prompt treatment helps reduce the risk of permanent vision loss.
• Hypertensive retinopathy: Individuals with histories of high blood pressure should regularly visit their healthcare providers and eye doctors. Patients who have high blood pressure should regularly take their blood pressure-lowering medications. Lifestyle changes, including regular exercise and a healthy, well-balanced diet may also help lower blood pressure.
• Central serous retinopathy: Central serous retinopathy cannot be prevented because the cause remains unknown. In general, individuals should regularly visit their eye doctors to ensure that their eyes are in good health.