Ranibizumab Therapy Improves Driving Ability in Macular Degeneration Patients

Chicago, IL – A study presented at the American Academy of Ophthalmology and Middle East Africa Council of Ophthalmology 2010 Meeting shows that patients suffering from neovascular age-related macular degeneration (AMD) are more likely to continue driving with less difficulty if they are given a monthly intravitreal injection of ranibizumab.

According to the study’s lead author, patients who are treated with 0.5 mg of intravitreal ranibizumab believe they drive better at night than patients who are not given this treatment.

Past studies have shown that patients who are treated monthly with ranibizumab have better visual acuity on average. This study was designed to show whether the findings of improvement can be translated into reduced difficulty driving.

The analysis was performed by researchers as part of the Minimally Classic/Occult Trial of the Anti-VEGF Antibody Ranibizumab in the Treatment of Neovascular AMD (MARINA). This was a double-masked phase 3 trial done to evaluate the safety and efficacy of ranibizumab on patients with choroidal neovascularization. Patients were put into three random groups and received injections every month for two years.

There were 712 patients in the trial. Of these, 237 received placebos, 236 received 0.3 mg of ranibizumab, and 239 received 0.5 mg of the medication. The patients completed the National Eye Institute’s (NEI) 25-item Visual Function Questionnaire (VFQ-25) at baseline and another eight times during the trial. The questionnaire included a subscale, which asked the patients to rate levels of driving in different conditions.

These included driving in the daytime in familiar places, driving in the evening, and driving in bad weather, rush hour, city traffic, and the freeway. Each subject was to respond on a scale ranging from no difficulty to extreme difficulty to “stopped doing this because of eyesight. There were 627 out of 712 responses to the questionnaire, and 488, nearly 69% of them, responded they were still driving.

Eating Fatty Fish May Reduce Risk of AMD

A study published in Ophthalmology suggests that older adults who consume fatty fish at least once weekly may have a reduced risk of age-related macular degeneration (AMD). The study does not actually prove that fish consumption directly reduces the risk of advanced AMD, but contributes to a growing body of evidence that people who eat fish regularly tend to have lower rates of AMD. Overall, the study found that the older adults who ate at least one serving of fish containing Omega-3 fatty acids weekly were sixty percent less likely to have advanced AMD.

These results also lend credibility to other studies touting the benefits of Omega-3 fatty acids, present in fatty fish, for preventing and slowing development of AMD. While there is no cure available for AMD, doctors have some weapons, such as high doses of antioxidant vitamins, to slow the progression of intermediate AMD. This study definitely suggests that eating Omega-3-rich fish is good for your eyes, but more research is needed to prove a definite link.

Other factors also influence the risk of age-related macular degeneration. Women, white people, and cigarette smokers appear to be groups with an increased risk of AMD. AMD is the leading cause of blindness among Americans 65 and older.

To learn more about age-related macular degeneration or other eye diseases and conditions, please visit our directory to find an ophthalmologist in your area.

Eye Lessons from Evolution

Many people know that your retina contains two types of photoreceptors, rods and cones, dedicated respectively to low-light vision and color of light discrimination. Many do not know that bird eyes have not two types of photoreceptors, but six: rod cells, four different types of cones, and a special double-cone. The different types of cone cells are dedicated to sensing different colors, giving birds incredible sensitivity to color. The double-cone photoreceptor is thought to be dedicated to enhanced motion sensing.

Why are bird’s eyes so well-developed in terms of color and motion sensitivity? Partly, it is due to the intense selection pressure on birds to adapt to specific ecological niches. The “visual ecology” of birds has been intensely studied and has shown that not only the types of cells, but their distribution is different among the different species of birds, reflecting the specific visual needs of birds in different “visual ecologies.” For example, land birds have a distribution of photoreceptors that is designed to even out the different type of light radiated from the ground as opposed to received by the sky, whereas sea birds have an opposite gradient to counter the intensity of light reflected from the water.

However, the evolution of bird’s eyes is not the only factor, because many of the features of bird’s eyes are thought to be closer to primitive vertebrate eyes than those of human eyes. Instead, we must look at humans’ evolutionary history to get the other part of the answer. The lack of double-cones is common to all placental (that is, non-marsupial) mammals. Another aspect of avian photoreceptors that is lacking in humans and other placental mammals is an oil droplet that helps to filter and reduce light incoming to the receptor. As a result of these two missing adaptations, scientists speculate that all placental mammals developed from a single ancestor or small group of ancestors that lived a nocturnal lifestyle for an extended period of time, losing the double-cone and oil-drop features that give birds such strongly-adapted diurnal vision. This hypothesis is supported by the presence of oil-drops and rudimentary double-cones in marsupials.

From our early nocturnal origins, mammals have adapted to many diurnal niches, but our lack of fully daylight-adapted eyes drives home the importance of several aspects of eye health. Continual exposure to bright daylight and other sources of ultraviolet radiation has been implicated in the incidence of cataracts, and the retinal condition age-related macular degeneration. Therefore, it is crucial that you attempt to protect your eyes from sun during extended or repeated exposure. It is also important to ensure that you are getting the proper nutrition for your eyes.

To learn more about eye safety and vision for life, please contact a local ophthalmologist today.

Age Related Eye Disease Therapies Do Not Increase Heart Risks

Durham, NC – According to a report in this month’s issue of Archives of Ophthalmology, new treatments for age-related macular degeneration (AMD), including an injection into the eye of a chemotherapy drug, are not associated with an increased risk of  heart problems or death when compared to other existing therapies.

The authors, doctors at Duke University, state that 12 percent of the over 1.5 million Americans with age-related macular degeneration have neovascular disease. This occurs when blood vessels form in the eye and accounts for 80 percent of cases of severe vision loss. There used to be only two approved therapies for this condition, which slowed vision loss, but did not improve visual acuity. These were:

  • Photodynamic, or laser,  therapy in combination with the photosensitizing medication verteporfin
  • eye injections with pegaptanib octasodium, a nucleic blocking abnormal blood vessel growth

Another treatment included using the cancer drug bevacizumab, an antibody that blocks the growth of blood vessels. This treatment is associated with an increased risk of heart problems in chemotherapy patients, but it is administered 150 times less in the AMD treatment than in the systemic treatment, and has been deemed much safer.  Another cancer drug called ranibizumab was approved by the FDA in 2006, but the off-label eye treatment use of bevacizumab has continued – probably because it’s cheaper per dose.

The study’s authors analyzed records from over 146,000 Medicare beneficiaries who received AMD treatment in 2005 and 2006. They tracked reports of heart attacks, strokes, bleeding and death through 2007. There were no differences in the therapy risk groups. Patients who received ranibizumab were actually less likely to suffer heart attacks or die than those who received photodynamic therapy, and less likely to have a heart attack than those given pegaptanib.

The authors conclude that there is no evidence of increased risk of death or other serious heart problems among Medicare patients who received the cancer drug treatments for AMD.

If you would like to speak to one of our experienced eye doctors about AMD, please visit us at www.eyes.com today.

Smoking and Your Eyes

Around 4,000 chemicals are present in cigarette smoke. By inhaling cigarettes, you are introducing these harmful chemicals into your bloodstream and increasing your risk of eye damage. Smoking can damage the membrane covering your eye (called your conjunctiva), resulting in bloodspots and eye irritation. Age-related macular degeneration and cataract development is also linked to smoking.

At Eyes.com, we strive to provide you with comprehensive and accurate information so you can make the best decisions about your eye health.

Macular Degeneration

The risk of developing age-related macular degeneration (AMD) increases with cigarette use. A British study found that cigarette smoking was associated with roughly 25 percent of AMD cases that ultimately resulted in vision loss. The study also revealed that people who live with a smoker have twice the chance of developing AMD that those who do not live in a smoking household.

Cataracts

Studies also reveal that smoking increases your chance of developing a cataract, or clouding of your eye’s natural lens. Heavy smokers (who smoke 15 cigarettes or more each day) are up to three times more likely to develop a cataract, compared to nonsmokers. It is not yet clear whether quitting smoking will reduce your risk of developing cataracts.

If you are looking for an experienced eye surgeon near you, please contact our office today.

Nanotechnology Gene Therapy Shown to Prevent Retinal Degeneration

In a revolutionary study, researchers at Tufts University this week published study results showing that nanotechnology can be used to deliver vision-saving gene therapy to the eyes. The goal was to show that a nanoparticle could be used to deliver a protein (Glial Cell Line-Derived Neurotrophic Factor (GDNF)) that protects eyes from diseases of the retina, such as age-related macular degeneration and retinitis pigmentosa. Gene therapy is a favored potential treatment for retinal degeneration, but the previous delivery method, using a virus to deliver genetic material, had several drawbacks. According to the senior author in this study, Rajendra Kumar-Singh, PhD, “While viruses are very efficient carriers, they can prompt immune responses that may lead to inflammation, cancer, or even death. Non-viral methods offer a safer alternative, but until now, efficiency has been a significant barrier.”

In the study, some mice eyes were injected with the GDNF-carrying nanoparticle, while others were injected with just the nanoparticle, and still others with just a buffer solution. Then all mice were subjected to blue light that stimulates retinal degeneration. Overall, the mice injected with the GDNF-carrying nanoparticle saw a 3.9-7.7-fold reduction in retinal damage. When the eyesight of the mice was measured, it was shown that 7 days after treatment the GDNF-nanoparticle-injected mice had 27-39% better eyesight than mice in the control group. Even at 14 days after treatment, the GDNF-nanoparticle-injected mice had outer nuclear layers of the retina that were 23.6-39.3% thicker than controls. However, by 14 days the functional improvement in vision had disappeared.

Although the results were very temporary, this research shows that there is significant potential for nanotechnology to develop an effective carrier to deliver gene therapy, and that this therapy can lead to new treatments for retinal diseases. According to Dr. Kumar-Singh, “The next step in this research is to prolong this protection by adding elements to the DNA that permit its retention in the cell.”

Age-related macular degeneration is the leading cause of blindness among Americans over age 65, but there is currently no treatment capable of reversing this disease. Even a short-term rescue of vision is a positive step in protecting or restoring the vision of older Americans.

You can learn how to recognize the early signs of macular degeneration, but the most important thing you can do to protect your vision is to get regular eye exams that will help you detect this disease in its early stages. Click here to find an eye doctor near you and schedule an appointment.