This is a series of videos explaining Diabetes and the Eye.

The first video describes how the body handles Glucose and how Insulin works.

Basics of Diabetes explains what Diabetes is and what effects it has on the body. Damage to small vessels affects the Retina, Kidneys and Peripheral nerves. Damage to large blood vessels causes stroke, heart attack and peripheral vascular disease.

Diabetes Control and Complications reviews the results for a landmark study (DCCT) which showed that small vessel complications were directly related to blood sugar levels, as measured by A1c levels.

The video on Diabetes and the Eye shows the ocular effects using photos and diagrams. There is discussion and photos of laser treatment.

Video 1: Glucose and Insulin

Video 2: Basics of Diabetes

Video 3: Diabetes Control and Complications

Video 4: Diabetes and the Eye

-CBlackwell Mar 2010

Even in covering the highlights of Macular Degeneration there is too much material for a ten minute video, so I have divided the subject into two parts, and it is still only highlights.

The first video describes the biology of the aging retina and how that evolves into Macular Degeneration.

The second discusses prevention and treatment. Prevention in terms of results from the Age Related Eye Disease Study, using antioxidant vitamins and zinc. Treatment was previously by laser, but now is mostly by the VEGF inhibitors Lucentis and Avastin.

Video 1: Macular Degeneration and the Aging Retina

Video 2: Macular Degeneration Prevention and Treatment

CB-2009

Click on the title below to access the Video.

Understanding Cataract

This Video describes:

• What a Cataract is
• How the surgery is done
• What is the laser surgery often done after cataract surgery

We all wonder what effect diet, exercise, sun exposure and other behaviors have on our general health and, since this is an eye site, our eyes. The proposition that we can take action to affect our health is an appealing idea to some and totally ignored by others. For those that are interested there are things you can do to affect your long term eye health.

One of the most significant articles to be published in 2007 was a review of literature regarding lifestyle exposures and eye disease, by Barbara and Ronald Klein. These authors, from the University of Wisconsin, have a decades long history as leading investigators in the epidemiology of eye disease making their comments particularly authoritative. (Amer J of Ophthalmol. 2007;144:961-969.)

Following are highlights from their review.

1. Cataract

Smoking. For every 10-pack-years of smoking the risk of cataract (nuclear type) increases 9%. (A pack-year amounts to smoking one pack per day for one year.) Smoking cessation reduces risk.

Diet and Supplements. Multiple large national studies have been done in the US, UK, Europe and Australia. Findings varied from study to study, and the recent AREDS group found no effect of their antioxidant formulation on cataract development. So if there is a protective effect it is mild. “Available data at this time are not sufficient to support a recommendation for taking high concentrations of vitamins, minerals, supplements, or a combination thereof to prevent cataract.” (p.963)

Light Exposure. It seems relatively clear that exposure to light, specifically Ultraviolet B, increases risk of cataract (cortical type). In the Beaver Dam, Wisconsin, group wearing glasses for refractive correction from an early age reduced nuclear cataract by 22% and cortical cataract by 33%. Wearing a hat and sunglasses reduced cataract slightly. Even so, a hat and UV protective lenses are recommended as prudent protective measures for people who spend a significant amount of time in the sun.

Note, UV protective coating is nearly clear. Dark glasses and polarization are helpful for comfort, but it is the UV coating that is protective.

2. Age-Related Macular Degeneration

Smoking. Increases risk of progression to late stage AMD; risk of 33% increase in atrophic form, and 25% increase in neovascular form. The risk is further increased in people with genes for Complement Factor H and LOC387715.

Diet and Supplements. AREDS is the one large randomized trial that found a positive effect of supplementing antioxidant vitamins and zinc. See Vitamins and Macular Degeneration for the details. Another 4 year, 1, 200 person study did not show any effect for Vitamin E alone.

The use of Lutein, Zeaxanthin and Omega-3 fatty acids have shown beneficial effects in epidemiologic studies. All three are being included in AREDS 2.

Light Exposure. Although there are theoretic reasons to expect macular damage from light, especially blue and UV, any effect on the retina must be small as it has not been detected in multiple large national studies.

Physical Activity. In one large study in Beaver Dam, Wisconsin, people who were significantly active at least 3 times a week were 70% less likely to develop neovascular complications. The authors point out this population had the same incidence of AMD and the same rate of geographic atrophy whether they exercised or not.

3. Diabetic Retinopathy

Smoking. Though multiple studies did not confirm the expected worsening of retinopathy with smoking, the authors recommend cessation of smoking because overall mortality is 1.5 times greater in diabetics who smoke.

Diet and Supplements. After controlling for blood sugar and blood pressure there are several studies showing that dietary supplements do not affect the course of diabetic retinopathy.

Physical Activity. Because exercise has such a good effect on diabetes in general it is unexpected that there is little epidemiologic data studying exercise and retinopathy.

4. Glaucoma.

There is no data suggesting smoking or dietary factors affect open angle glaucoma.

Small studies suggest exercise might help reduce pressure.

If you want to read the article in full it is in the American Journal of Ophthalmology, December 2007, pages 961 to 969. In the article each category has a discussion of the pertinent study or studies with a full set of references.

So, exercise is good for many things. Smoking is bad. UV protection is recommended. Dietary supplement with antioxidants probably helps slow macular degeneration.

Macular Degeneration (AMD) is one of the biggest unsolved problems in ophthalmology. In the later decades in life there is gradual deterioration of the central part of the retina resulting in reduced central vision for reading and seeing details.

Retinal Photo of moderate Macular Degeneration (AMD).

The yellow spots, called “drusen,” are the accumulation of waste products in the pigmented layer under the retina. There is no leakage, so this is the “dry” type.

There are two general categories of AMD:

• The “Dry” type: There are drusen and or atrophy, but there is no leakage of serum or blood. Vision worsens progressively, but slowly.
• The “Wet” type. Starts as dry, but at some point new blood vessels invade the space under the retina. The new vessels leak serum or blood which causes a relatively rapid and severe loss of central vision.

Historically, there was nothing we could do about dry type, except maintain a vigil for development of leakage. If leakage developed, and was caught early, a laser could be used to cauterize the leaking vessels. More recently this is being treated with an injected medication.

In 1988 a small study was published (Newsome, Arch Ophthal 1988; 106: 192-198) suggesting dietary supplement with the mineral zinc could slow progress of macular degeneration. That led to a much larger nationwide study looking at age-related eye diseases, particularly cataract and macular degeneration, to see if supplementation with antioxidant vitamins and or zinc would be of help.

AREDS

AREDS, the Age Related Eye Disease Study, followed almost 5,000 people for ten years. They were divided into the following treatment groups:

• Antioxidant Vitamins (daily dose):

Beta Carotene 15 mg; Vitamin C 500 mg; Vitamin E 400 IU

• Minerals: Zinc 80 mg; Copper 2 mg
• Antioxidant Vitamins and Zinc
• Placebo

After AREDS started two contemporary studies looking at vitamins and lung cancer found that smokers who took Beta-Carotene had increased risk of lung tumors and mortality. Smokers in the study were allowed to drop out or change to a supplement without Beta-Carotene.

Copper was included because Zinc and Copper compete for absorption so if you supplement one you must balance with the other.

The above vitamin dosages are available by taking 2 tablets of Preservision (Bausch & Lomb) or 4 tablets of ICaps (Alcon).

The Study

There are several things you need to know to understand the study result.

At the outset each participant’s retina was graded according to the severity of the AMD. The grading was on a scale of 1 to 4, from mild to advanced, represented on the chart below by the different colors.

The Dry Type, given enough time, can progress to wasting or “atrophy” of the central retina with severe vision loss.

The Results

Arch Ophthal 2005;123:1570-1574.

The above graph summarizes the study results over 10 years of followup.

The X-axis is years. The Y-axis is the percentage of people that developed advanced vision loss, either from the dry type advanced to atrophy or from the wet type.

Within each group half received placebo, and half the supplement. The dashed line represents those receiving a placebo. The solid line represents those receiving both antioxidant vitamins plus zinc.

It is fairly clear that within each group taking the vitamins lessened the chance of developing severe vision loss. It did not reverse degeneration or eliminate vision loss, but it did provide a measurable benefit.