DIABETIC EYE : Complications and Care

DIABETIC EYE: Complications and Care
Sarael S. Brobo Jr., M.D

Out of the five senses, our vision seems to be of highest importance. Our eyes are the portals through which our brain sees the world, appreciates what is in it and makes wonderful memories. Loss of vision not only negatively impacts the person with diabetes but his family as well. It leads to reduced quality of life and poses a high financial burden.

Eye diseases that may affect a person with diabetes are as follows: diabetic retinopathy, glaucoma and cataracts.

Glaucoma
Glaucoma occurs when pressure builds up in the eye. The pressure causes drainage of the liquid inside the eyeball known as the aqueous humor to slow down so that it builds up in the anterior chamber of the eye increasing the pressure further. The increased pressure constricts the blood vessels supplying nutrients to the retina and optic nerve leading to gradual vision loss. There are drugs that can be used to reduce pressure in the eye, however, if pressure is not relieved, surgery may be required.

Cataract
People with diabetes more likely to develop this eye condition than those without. People with diabetes also tend to get cataracts at a younger age and have them progress faster. With cataracts, the eye’s clear lens clouds, blocking light.

For cataracts that interfere greatly with vision, doctors usually remove the lens of the eye. Sometimes the patient gets a new transplanted lens. In people with diabetes, retinopathy can get worse after removal of the lens, and glaucoma may start to develop.

Diabetic Retinopathy
One of the conditions that may affect the eyes of a person with diabetes is termed “diabetic retinopathy”. It is categorized into two stages, the non – proliferative and proliferative. Non – proliferative retinopathy is the early stage in which small blood vessels at the back of the eye balloon and form pouches and may lose their ability to control the passage of substances between the blood and the retina. Fluid then may leak into the macula, the part of the eye where focusing occurs. When the macula swells with fluid, vision blurs and can be lost entirely, this condition is called macular edema.

In some people, retinopathy progresses to a more serious form after several years, this is called the proliferative stage. The blood vessels become blocked because of further damage. Consequently, new blood vessels start to grow in the retina. These blood vessels are weak and can bleed. If bleeding occurs in the macula, vision is blocked leading to blindness. Eventually scar tissues form. The scarring can pull the retina out of position, a condition called retinal detachment.

Who are prone to develop these diabetic eye diseases?
Factors that can lead to development of these diabetic eye diseases include uncontrolled blood sugar, hypertension, and high cholesterol. The longer you’ve had uncontrolled diabetes, the more likely you are to have these conditions as well. Intensive diabetes management achieving near-normal sugar level will prevent or delay the onset and progression of diabetic retinopathy and potentially improve visual function.

How should I be screened if I have diabetes?
In its early stage, diabetic retinopathy may not have any symptoms, thus screening is advocated. An ophthalmologist who is knowledgeable and experienced in diagnosing diabetic retinopathy should perform the examinations. A person with diabetes should have an initial eye screening at the time of diagnosis and at least yearly thereafter. Since pregnancy is associated with a rapid progression of diabetic retinopathy, eye check – up should be done before conception, once in each trimester and one examination 2 months after delivery in pregnant diabetics.

How do I prevent diabetic eye disease?
It has been proven that optimum blood sugar, blood pressure and cholesterol control lowers the risk or slows the progression of diabetic retinopathy. Therefore, compliance to medications, regular check – up and a healthy lifestyle are of utmost importance.

Once diabetic retinopathy is confirmed, treatments such as laser photocoagulation, vitrectomy and anti-vascular endothelial growth factor (anti-VEGF) eye injection can be offered as it may prevent blindness in most patients. In photocoagulation, the ophthalmologist makes tiny burns on the retina with a special laser. These burns seal the blood vessels and stop them from growing and leaking. In cases where the retina has already detached or a lot of blood has leaked into the eye, surgical vitrectomy is needed. This procedure involves removal of scar tissue and cloudy fluid from inside the eye.

Vascular endothelial growth factor (VEGF) is a hormone that promotes the growth of weak, leaky blood vessels in the retina. A newer treatment which involves injection of an anti-VEGF drug directly into the eye can stop the growth of these weak blood vessels thereby improving vision.

In many cases, these treatments may need to be repeated every few months. The earlier retinopathy is detected, the more likely these treatments will be successful and the best results occur when sight is still normal.

Common misconceptions and facts

1. “I can still see clearly, I don’t need eye consult.”
Visual clarity does not necessarily mean that you do not have the disease. Retinopathy may have already set in before you notice any change in your vision. Most patients with non – proliferative retinopathy have no symptoms. Even with proliferative retinopathy, the more advanced form, patients sometimes have no symptoms until it is too late to treat them. Because of this, diabetic patients need regular eye check – up as recommended.

2. “Once treated, you are already healed.”
Once diabetic retinopathy sets in, it cannot be reversed to normal. However if proper treatment measures are taken, these may delay progression and prevent complications. Once complications are detected, these can be managed by photocoagulation, vitrectomy or anti-VGEF injection. It must be clear that the condition is lifelong thus repeated treatments should be expected.

3. “I cannot take aspirin anymore.”
Aspirin is an antiplatelet medicine which is commonly used for cardio protection. While one of its side effects is bleeding, current data showed no increase in the risk of retinal hemorrhage. Therefore, aspirin can be safely taken if prescribed by your physician.

4. “Cataract surgery will improve my vision if I have diabetic retinopathy.”
Cataract is a clouding of the lens in the eye leading to poor vision, while diabetic retinopathy involves the retina. Thus, implanting a lens inside the eye will not solve all problems but only the affected lens and not the diseased retina. In fact in some cases after cataract surgery, diabetic retinopathy worsened.

Blindness greatly affects a person’s quality of life together with his family. Diabetic eye disease is the most common cause of blindness and it can be prevented and treated. Persons with diabetes should comply with their medications and have regular check – ups in order to achieve optimum control of blood sugar, blood pressure and cholesterol. Regular screening should be done and if retinopathy is detected, different treatment modalities may be undertaken. Prevention is always the key, but if damage transpires, it can still be managed with proper consultation with an expert.
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References
Standards of Medical Care in Diabetes (2019, Jan). Diabetes Care. Volume 42, Supplement 1. Harshey, K (2019, Feb 1). Diabetic Retinopathy: Myths and Facts. Retrieved from https://www.practo.com Eye Complications (2018, Nov 19). Retrieved from http://www.diabetes.org. Lee, et al (2015). Epidemiology of diabetic retinopathy, diabetic macular edema and related vision loss. Eye and Vision. 2:17 Community Eye Health Online Course. Retrieved from http://www.uniteforsight.org

 

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