Surgery for Crossed Eyes Not Just for Kids

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Posted on 2nd October 2012 by Pacific ClearVision Institute in Retina

Since she was a child, Katie Szymczak has had eyes that wandered. Her right eye, which was the worst, would look up and to the side, rather than straight ahead.

Her husband affectionately called them “googly eyes.” But other people could be mean. “They would say to me, ‘What’s wrong with your eyes, why aren’t you looking at me?’” Szymczak said. “It really hurt a lot.”

But since Dr. James McDonnell, an ophthalmologist at Loyola University Medical Center, performed surgery to repair the defect, Szymczak’s eyes have been in a normal position. “I don’t get comments anymore,” she said.

But many adults who have this defect, called strabismus, wrongly believe there’s no treatment. Many adult patients have had the condition all their lives. Others develop strabismus as a result of such conditions as stroke, tumor or brain injury. Studies show these patients think about their eyes almost every hour of every day.

But Szymczak said that since her surgery, she has been less self-conscious, and more confident doing presentations at work. And she has begun wearing make-up around her eyes. “I feel I can show them off now,” she said.

McDonnell has performed thousands of corrective surgeries in children and adults whose eyes are misaligned for various reasons. Patients are given many reasons why they shouldn’t get treatment: Nothing could be done after a certain age; they would outgrow the problem; they would need another surgery or if they had undergone a previous surgery nothing further could be done. Some patients are told that insurance won’t cover the procedure.

“None of these things are true,” McDonnell said. “This type of misinformation can come from friends, family doctors, and even ophthalmologists and optometrists.”

McDonnell has performed corrective surgeries on patients ranging in age from infancy to past 90, with excellent outcomes. In addition to restoring normal appearance, the surgery also can improve depth perception and eliminate double vision or eye strain.

About half of the strabismus surgeries McDonnell performs are on adults. To correct the misalignments, he operates on the muscles that control the movement of the eyes. He uses a different technique than those typically used on children. In some patients he uses an adjustable suture technique that allows him to fine-tune the eyes into the exact alignment.

“Our goal is to restore patients’ eyes to a normal functional alignment so they can use their eyes together to the best of their ability,” McDonnell said. “We want them to be able to look anyone directly in the eye and feel confident that their eyes appear normal. When you can’t look someone in the eye, it affects your fundamental ability to communicate. It can be very debilitating.”

Risks of the outpatient surgery, which are very rare, include infection and detached retina.

McDonnell said the surgery is very rewarding. “It’s wonderful and humbling to see each person after surgery,” McDonnell said. “It’s a shame when patients wait years to correct something we can address in about one hour.”

Some adult patients can be treated with Botox, which temporarily weakens muscles. The drug weakens the pull of a strong muscle, allowing the weaker muscle to gain strength. When the drug wears off in about two months, proper muscle balance and eye alignment often are restored, McDonnell said.

McDonnell is a professor in the Department of Ophthalmology at Loyola University Chicago Stritch School of Medicine. He was named to Chicago magazine’s 2012 list of Chicago’s Top Doctors.

Reduced Glaucoma Risk Found in Patients Who Take Statins

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Posted on 2nd October 2012 by Pacific ClearVision Institute in Retina

People who take statins to reduce their risk of cardiovascular disease are less likely to be diagnosed with the most common form of glaucoma, according to a nationwide study of more than 300,000 patients. A University of Michigan School of Medicine research team, directed by Joshua Stein, MD, MS, found that the risk for glaucoma was reduced by eight percent in patients who took statins continuously for two years, compared with patients who did not take statins.

The study, the largest to date on the topic, is published in the October issue of Ophthalmology, the journal of the American Academy of Ophthalmology.

Dr. Stein’s study was sparked by growing evidence that statin use may protect the optic nerve and retinal nerve fibers, structures that are essential to good vision and are damaged by glaucoma. His team used healthcare claims data for a diverse population of Americans aged 60 and older who took statins to control high blood levels of unhealthy fats, a condition known as hyperlipidemia, between 2001 and 2009, The researchers assessed patients’ risk for open-angle glaucoma (OAG). Unlike earlier studies, their analysis adjusted for patients who also had diabetes and/or hypertension to prevent distortion of the results.

Several of the study’s findings suggest that statin use may be most important before glaucoma is diagnosed, or in the early stages of the disease. Dr. Stein’s research may lead to new preventive treatments that could especially benefit groups at increased risk, including African-Americans, Hispanics and those with a family history of glaucoma.

Glaucoma affects more than 2.7 million Americans age 40 and older . If untreated, glaucoma causes vision loss or blindness by damaging the eye’s optic nerve. The optic nerve sends signals from the retina — a layer of light-sensitive tissue at the back of the eye — to the brain, where these signals are interpreted as the images we see. Only about half of the people who have glaucoma know it, since symptoms are rarely noticed in the early stages and vision loss is very gradual in most cases.

“Statins’ apparent ability to reduce glaucoma risk may be due to several factors, including improved blood flow to the optic nerve and retinal nerve cells and enhanced outflow of the aqueous fluid, which may reduce intraocular pressure,” said Dr. Stein. “While more research is needed, we hope our results may contribute to saving the sight of thousands who are predisposed to glaucoma.”

Dr. Stein cautioned that the study results apply only to patients with hyperlipidemia, and that further study is needed to determine whether statins also protect patients who don’t have this diagnosis or have other characteristics that differ from the study population.

Monoclonal Antibody Fragment Treatments for ‘Wet’ Macular Degeneration Keep Elderly Drivers Behind the Wheel, Study Suggests

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Posted on 2nd October 2012 by Pacific ClearVision Institute in Retina

The advanced neovascular, or “wet,” form of age-related macular degeneration (AMD), left untreated, is the most common cause of vision loss among the elderly and a leading reason for their loss of driving privileges. But results of a new study, published in the online version of the journal Ophthalmology, suggest that monthly injections of ranibizumab improve eye chart test results required for a driver’s license, build driver confidence and keep those with AMD driving longer.

The wet form of AMD is marked by the abnormal scarring and leaking of new blood vessels in the macula, or center of the retina, the light-sensitive layer of the eye used for driving, reading or recognizing faces. Treatment with ranibizumab, a drug made partly from a human monoclonal antibody fragment, is done by injecting it monthly (or as needed with frequent evaluations) into the middle of the eye with a tiny needle about the diameter of a hair. The medicine eliminates or slows new scar and leaking blood vessel formation.

“Driving is an important measure of independence and quality of life for many people in the United States. Participants with wet AMD in our study perceived that they were not driving because of their diminished eyesight,” said senior author, Neil M. Bressler, M.D., the James P. Gills Professor of Ophthalmology and chief of the Retina Division at the Wilmer Eye Institute at Johns Hopkins Medicine. “Our study, believed to be the first of its kind to look at whether outcomes relevant to driving improve with treatment, suggests that monthly injections of ranibizumab may be an extremely helpful option in allowing the elderly to continue driving.”

During the phase III, multicentered, randomized two-year clinical trial, researchers used a 25-item National Eye Institute Visual Function Questionnaire to measure study participants’ driving ability, perception and self-reported driving status in two distinct studies. Investigators also conducted monthly assessments, over a two-year period, of the best corrected vision in each eye of 1,126 patients enrolled in these studies that evaluated treatments for AMD. One study compared results for those receiving ranibizumab versus sham (fake) injections; the second compared results of ranibizumab injections versus photodynamic (laser) therapy (PDT) that can seal abnormally leaking blood vessels.

Based on the results of two previous reports from these studies, ranibizumab was better than sham and PDT treatments with respect to avoiding loss of vision when treating patients with an eye affected by wet AMD. This new analysis of those trials by Bressler and colleagues looked beyond the results of these treatments on reading an eye chart to clinically relevant outcomes regarding the impact of this treatment on driving in three ways: treatment versus no treatment in those who said they were driving or not driving at the beginning and end of the study; treatment versus no treatment in participants who had vision at the beginning and end of the study that would qualify them for an unrestricted driver’s license in at least 45 of the U.S. states; and a standardized questionnaire assessing the patients’ own perception about the level of difficulty driving in difficult conditions such as rain or fog or at night. The 45 states all require correctable vision of at least 20/40 in one eye to qualify for an unrestricted driver’s license.

“What the study showed was that 85 percent of participants in the ranibizumab versus sham study and 88 percent in the ranibizumab versus PDT study read the eye chart better also achieved the level of vision required for an unrestricted license and in turn had greater confidence in driving,” noted Bressler. The researchers cautioned that more research is needed to determine whether driving skills or driving safety are actually maintained or improved, and whether they match up with patient perceptions of their abilities reported on the questionnaire.

“Our study has limitations because these two studies were not designed to directly assess the impact of ranibizumab on driving, and because there was just a small number of patients in the groups that were analyzed relative to the hundreds of thousands of patients affected by the wet form of AMD each year around the world,” Bressler stated. “One of our next steps is to look at these same outcomes when treatment is given for diabetic macular edema, swelling at the center of the retina as a result of diabetes, the most common cause of vision impairment in working-age adults in the U.S. and abroad.”

Specialty Contact Lenses May One Day Help Halt the Progression of Nearsightedness in Children

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Posted on 2nd October 2012 by Pacific ClearVision Institute in Retina

Nearsightedness, or myopia, affects more than 40 percent of people in the U.S. and up to 90 percent of children in some parts of Asia. The problem begins in childhood and often progresses with age. Standard prescription lenses can correct the defocus but do not cure nearsightedness, and do not slow progression rates as children grow. But recent experimental work by biomedical scientist David Troilo and colleagues at the State University of New York (SUNY) College of Optometry in New York City supports the development of a potential cure for myopia by using specialty contact lenses that coax the eye to grow in a way that can correct nearsighted vision while reducing myopia progression.

Troilo will describe his findings at the Optical Society’s (OSA) Annual Meeting, Frontiers in Optics (FiO) 2012, taking place Oct. 14 in Rochester, N.Y.

Myopia develops when the eye is too long, making it difficult to focus light from distant objects on the retina. Glasses or contact lenses that correct the defocus on the main visual axis can create a slight degree of farsightedness in the peripheral retina, Troilo says. The peripheral farsightedness may worsen myopia because as children grow, the eye grows to move the retina to where the light is focused, naturally lengthening the eye even further.

Troilo has shown that specially designed contact lenses that alter how light is focused in the peripheral retina can induce changes in growth that help reshape the eye in the desired way. The experimental lenses use different focal powers within a single lens: either alternating focal powers across the lens, or confined to the outer edge. Experiments with the new lenses found that they changed eye growth and refractive state, or focus, in a predictable way. The lenses successfully reduced the elongation of the eye that causes myopia progression.

Several contact lens designs may soon be available to help eye doctors manage the progression of myopia in children, Troilo says. Presentation FW1C.1 “Optical Approaches for Controlling Myopia Progression: Evidence from Experimental Models” takes place Wednesday, Oct. 17 at 8 a.m. EDT at the Rochester Riverside Convention Center.

Super Glue: Tests Show That Adhesive Could Improve Safety of LASIK Eye Surgery

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Posted on 2nd October 2012 by Pacific ClearVision Institute in LASIK

Kansas State University researchers have developed a glue mixture that may reduce risks after laser vision correction surgery.

Stacy Littlechild, a recent bachelor’s degree graduate in biology originally from Wakeeney, is the lead author of two studies that describe a new protocol involving fibrinogen, riboflavin and ultraviolet light that could improve the safety of the corrective surgery.

One study that demonstrates the ability of a glue to bind corneal surfaces has been published in the June edition of the journal Investigative Ophthalmology & Visual Science, or IOVS. Another study details the molecular mechanisms of how the glue creates adhesion and also will be published in IOVS.

LASIK, or laser-assisted in-situ keratomileusis, surgery uses a laser to reshape the cornea, the eye’s outer layer that helps the eye focus. Many patients have the surgery so they do not have to depend on glasses or contact lenses.

During the procedure, a flap is cut in the cornea so that a laser can remove corneal tissue. The hinged flap is returned to its original position and is held on to the laser-modified cornea with nothing but surface tension.

The cornea has a limited ability to firmly re-adhere the LASIK flap and does not fully heal after the procedure, said Gary Conrad, university distinguished professor in the Division of Biology. Conrad, the principal investigator of the research, studies eye development and was Littlechild’s adviser.

“Although LASIK produces a flap that remains clear and normally lays smoothly on the modified corneal surface, if the eye is hit with blunt force trauma — from an auto airbag or a tennis ball, for example — the flap simply peels open again, resulting in contamination inside the cornea and requiring immediate medical attention, which can include corneal transplantation,” he said.

Cornea transplantation replaces part of the cornea with cornea tissue from a donor and is the most common type of organ transplantation in the U.S. Rejection occurs in about 20 percent of cornea transplants, according to the Mayo Clinic.

“Although a cornea transplant is a routine outpatient procedure, we need to do everything we can to avoid such a transplant,” Littlechild said. “These patients are in pain, out of work and can’t see for a few days afterward. If we can decrease the need for transplants by using a glue, then we won’t impede lives as much and protect patients from having future surgeries.”

In the first study, Littlechild tested the glue using corneas removed from dogfish sharks and rabbits to measure adhesive strength.

She discovered that using glue made from fibrinogen and riboflavin and then binding proteins and glue together using ultraviolet light — the type used in tanning salons — provided the best adhesion to keep the cornea’s flap in place. The substance is a nontoxic biodegradable glue that is used in cataract surgery and does not leave a cloudy scar.

“The idea is that if you use the glue, you’ll either reduce or alleviate the risk associated with LASIK surgery,” Littlechild said. “The hope is that you would never have to worry about needing a transplant later.”

In a second study, Littlechild analyzed specific molecular interactions that are responsible for the adhesion. She found that both covalent and zinc-mediated non-covalent mechanisms contributed to the adhesion.

The finding could prompt further development of the glue and could reveal alternative uses throughout the body, Littlechild said. The glue has the potential to bond other body tissues that are similar in chemical and molecular composition to the cornea.

For instance, tendon tissue that connects muscle to bone is similar to the cornea. Tendon tissue often heals slowly because it does not have many blood vessels; likewise, the cornea does not have any blood vessels.

Other collaborators in the research include Gage Brummer, a senior in biochemistry and premedicine, Prairie Village; John Tomich, professor of biochemistry; and Yuntao Zhang, research assistant professor of biology. Scott McCall, a May 2010 bachelor’s graduate in biochemistry, was the lead author on a related study detailing the effects of riboflavin and ultraviolet light used for strengthening the cornea connective tissue to treat keratoconus, the second-most frequent symptom requiring corneal transplantation.

Research funding came from the Maine IDeA Network for Biomedical Research Excellence in support of work at the Mount Desert Island Biological Laboratory in Salisbury Cove, Maine; the Kansas State University Johnson Cancer Research Center; Kansas IDeA Network for Biomedical Research Excellence; National Center for Research Resources; and the National Eye Institute of the National Institutes of Health.

Littlechild plans to attend Cardiff University in Wales, Great Britain, to earn a doctorate in biophysics. Littlechild presented posters at two annual ophthalmology meetings that led to the invitation to continue her research at Cardiff.

“I would not be where I am today without Kansas State University and Dr. Conrad’s continued support and patience,” said Littlechild, who originally applied for a student office job in the Division of Biology until she received a phone call from Conrad. “I owe my undergraduate success and everything that develops from it to Dr. Conrad’s unfailing efforts.”

Gene Linking Cataracts and Alzheimer’s Disease Identified

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Posted on 2nd October 2012 by Pacific ClearVision Institute in Cataracts

In a recent study, investigators at Boston University Schools of Medicine (BUSM) and Public Health (BUSPH) identified a gene linking age-related cataracts and Alzheimer’s disease. The findings, published online in PLoS ONE, contribute to the growing body of evidence showing that these two diseases, both associated with increasing age, may share common etiologic factors.

Gyungah Jun, PhD, from the departments of medicine, ophthalmology and biostatistics at BUSM and BUSPH, served as the study’s lead author. Lindsay A. Farrer, PhD, professor of medicine, neurology, ophthalmology, genetics & genomics, epidemiology and biostatistics and chief of the Biomedical Genetics Section at BUSM, was the study’s senior author.

Using the Framingham Offspring Eye Study cohort, investigators looked at brain MRI findings on or after 10 years from the original eye exam and concluded that there was a significant correlation between a quantitative measure of cortical cataract and several Alzheimer’s disease-related measures of brain degeneration, in particular volume of the temporal horn which is a brain structure that is progressively enlarged in patients with Alzheimer’s disease. Another strong correlation in these same individuals, between cortical cataract formation and poorer performance on several cognitive tests administered at the time of the MRI scan, further supports this link.

With such a link not confounded by age or sex, the investigators then performed a genome-wide association study looking at nearly 190,000 single-nucleotide polymorphisms (SNPs), or DNA sequence variations. Three intronic (non-coding) SNPs in the gene encoding ?-catenin came to the fore. This protein is a key component in cell adherence and formation of cell junctional structures. Previously, ?-catenin was also implicated in brain and eye development, but not directly in either cataracts or Alzheimer’s disease. To establish a more direct link of ?-catenin to Alzheimer’s disease, the researchers transfected into neuronal cells ?-catenin bearing a mutation near the location of the top-associated SNPs and observed a significant and specific increase in the toxic form of amyloid ?, the protein that aggregates in Alzheimer brains and thought to be central to development of the disorder. In addition, the researchers found increased deposits of ?-catenin in lens tissue obtained from autopsy-confirmed Alzheimer’s cases but not from subjects lacking Alzheimer’s-associated neuropathology.

“Though much work remains to be done, a link between cataracts and Alzheimer’s disease supports the idea of a systemic rather than brain-limited focus for processes leading to Alzheimer’s disease,” said Farrer. “This study gives hope that we are moving toward earlier diagnosis and new treatment targets for this debilitating disease.”

Cholesterol-Lowering Drugs May Be Linked to Increased Cataract Risk

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Posted on 2nd October 2012 by Pacific ClearVision Institute in Cataracts

Patients using cholesterol-lowering statin drugs may be at increased risk of developing age-related cataracts, according to a study — “Age-related Cataract Is Associated with Type 2 Diabetes and Statin Use,” in the August issue of Optometry and Vision Science, official journal of the American Academy of Optometry.

While further research is needed to understand the true nature of the association, the additional risk of cataracts in statin users appears similar to that associated with type 2 diabetes, according to the study by Carolyn M. Machan, OD, and colleagues of University of Waterloo, Ont., Canada.

Statins and Diabetes Both Increase Cataract Risk The study included nearly 6,400 patients seen at the optometry clinic at the University of Waterloo in 2007-08. Of these, 452 patients had type 2 diabetes. Statin treatment and diabetes were evaluated as possible risk factors for age-related cataracts, controlling for other factors including sex, smoking, and high blood pressure.

Fifty-six percent of patients with type 2 diabetes were taking statins, compared to 16 percent of those without diabetes. Both diabetes and statin use were significantly associated with an increased rate of age-related cataracts.

With adjustment for other factors, diabetes was associated with an 82 percent increase in cataract risk and statin use with a 57 percent increase. Statistically, the increase in cataract risk associated with statins was similar to that associated with diabetes.

The associations differed for different types of cataracts. For one specific type long linked to diabetes (posterior subcapsular cataract), the association with diabetes was no longer significant after adjustment for statin treatment.

Despite the high rate of statin use among patients with diabetes, the two risk factors appeared independent of each other. At older ages, the risk of cataracts increased fastest in diabetic patients who took statins and slowest in nondiabetic patients who did not take statins. On average, cataracts developed 5.6 years earlier in diabetic patients who took statins, compared to nondiabetic patients who did not take statins.

Type 2 diabetes is a known risk factor for the development of age-related cataracts — a common vision problem caused by clouding of the crystalline lens of the eye. Studies in animals have shown a clear link between long-term treatment with statins (at high doses) and cataracts.

The new study suggests that statins may also be linked to cataracts in humans. The authors emphasize that the study can’t prove that statins play any role in causing cataracts, but suggest that such a link is biologically plausible.

While further studies are needed, Dr Machan and colleagues emphasize that the known benefits of statin treatment for patients with type 2 diabetes probably outweigh any increased risk of cataracts. They believe their results will help to increase awareness of the risks of treatments for type 2 diabetes, and may encourage the development of alternative cholesterol-lowering drugs that are not associated with an increased risk of cataracts.

Anthony Adams, OD, PhD, Editor-in-Chief of Optometry and Vision Science, comments, “Considering the increase in the prevalence of diabetes and the corresponding increase in the use of statins, the authors feel these findings serve to encourage further research on the long-term effect of statins on the human crystalline lens.”

Cataract Surgery may Lower Risk of Hip Fractures

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Posted on 2nd October 2012 by Pacific ClearVision Institute in Cataracts

Older patients who underwent cataract surgery have a lower risk of hip fractures, finds study published in JAMA.

Visual impairment has been found to be strongly associated with an increased risk of fractures, a significant cause of illness and death in the elderly population. “Specifically, vision plays an important role in providing a reference frame for postural balance and stability, and cataract-induced changes in vision have been found to be associated with postural instability,” according to background information in the article. “Furthermore, cataracts have been found to be the most common cause of fracture-related visual impairment, with untreated cataract causing up to 49 percent of visual impairment in patients with femoral neck fractures related to decreased vision.” Despite the association of poor vision and cataracts with increased fall and fracture risk, only a limited number of studies have examined the influence of cataract surgery on fall incidence in visually impaired adults.

Victoria L. Tseng, M.D., of the Warren Alpert Medical School of Brown University, Providence, R.I., and colleagues examined the association between cataract surgery and fracture incidence at 1-year. The study included a 5 percent random sample of Medicare Part B beneficiaries with cataract who received and did not receive cataract surgery from 2002 through 2009. Analyses were adjusted for various factors.

There were 1,113,640 Medicare beneficiaries 65 years and older with a diagnosis of cataract between 2002 and 2009 in the 5 percent random sample. Of these patients, the majority were female (60 percent) and white (88 percent). Of patients with cataract, 410,809 (36.9 percent) underwent cataract surgery during the study period. During this period, the overall 1-year fracture incidence was 1.3 percent (n = 13,976) for hip fractures. Analysis of the data indicated that cataract surgery was associated with a 16 percent decrease in the adjusted odds of hip fracture 1 year after the procedure. “In patients with severe cataract, the association between cataract surgery and lower odds of hip fracture was even stronger, with a 23 percent reduction in the adjusted odds of hip fracture in the cataract surgery group compared with the cataract diagnosis group,” the authors write.

Osteoporosis was the most common fracture-related comorbidity (co-existing illness) (12.1 percent). The most common ocular comorbidity was glaucoma (19.1 percent).

“Cataract surgery may be associated with lower odds of subsequent fracture in patients aged 65 years and older in the U.S. Medicare population. Future prospective studies using standardized registries of patients with cataracts will help further elucidate the association between cataract surgery and fracture risk. Cataract surgery has already been demonstrated to be a cost-effective intervention for visual improvement, with an estimated cost per quality-adjusted life-year gained for cataract surgery in the first eye of $2,023 in the United States and $2,727 in the second eye. The results in this study suggest the need for further investigation of the additional potential benefit of cataract surgery as a cost-effective intervention to decrease the incidence of fractures in the elderly,” the researchers conclude.