Glaucoma News Archive (2013)
Contacts That Deliver Glaucoma Medication May Soon Be a Reality
December 2013 Contact lenses that deliver glaucoma medication over long periods are getting closer to reality, say researchers at the Massachusetts Eye and Ear Infirmary.
In their study, the lenses delivered the glaucoma drug latanoprost (brand name Xalatan) continuously to laboratory animals for a month. The goal, researchers said, is to someday have these lenses replace eye drops now used to treat the eye disease. Glaucoma is the leading cause of irreversible blindness worldwide.
The lenses, which appeared safe in cell culture and animal studies, are the first to be shown to release drugs for this long in animals, according to the researchers. The study will appear online and in the January print issue of the journal Biomaterials.
The lens the research team developed is capable of delivering large amounts of drug at substantially constant rates over weeks to months, according to researchers at the Laboratory for Biomaterials and Drug Delivery at Boston Children's Hospital. They believe a non-invasive method of sustained eye drug delivery could save millions of people from blindness if it helps them comply with their medication regimen.
Connection Found Between Glaucoma and Sleep Apnea
November 2013 Sleep apnea is an independent risk factor for open-angle glaucoma, says new research from Taipei Medical University.
This obstructive sleep apnea sufferer is using a CPAP (continuous positive airway pressure) machine to keep his airway open during sleep.
The retrospective study took information from data collected across the population and found that those who had been diagnosed with sleep apnea were 1.67 times more likely to have open-angle glaucoma in the five years after diagnosis than those without the sleep condition.
Glaucoma affects nearly 60 million people worldwide and is the second-leading cause of blindness. If left untreated, glaucoma reduces peripheral vision and eventually may cause blindness by damaging the optic nerve.
According to the World Health Organization, sleep apnea is a chronic condition that blocks breathing during sleep for more than 100 million people worldwide.
In obstructive sleep apnea, the airway becomes blocked, causing breathing to stop for up to two minutes. Symptoms include loud snoring, gasping or choking while asleep, morning headaches and persistent daytime sleepiness.
Higher Glaucoma Risk for Oral Contraceptive Users
November 2013 Women who have taken oral contraceptives for three or more years are twice as likely to suffer from glaucoma, says a newly reported study. Glaucoma is one of the leading causes of blindness and affects nearly 60 million people worldwide.
The study is the first to establish an increased risk of glaucoma in women who have used oral contraceptives for three or more years. The researchers used 2005-2008 data from the National Health and Nutrition Examination Survey, which included 3,406 female participants aged 40 years or older from across the United States who completed the survey's vision and reproductive health questionnaire and underwent eye exams.
It found that females who had used oral contraceptives, no matter which kind, for longer than three years are 2.05 times more likely to also report that they have the diagnosis of glaucoma. Previous studies in the field have shown that estrogen may play a significant role in the pathogenesis of glaucoma.
According to the researchers, though this finding does not prove using birth control pills causes glaucoma, it indicates that long-term use of oral contraceptives might be a potential risk factor for glaucoma, especially when combined with other known glaucoma risk factors, such as a history of high eye pressure, a family history of glaucoma, and African-American ethnicity.
The study authors also advised gynecologists and eye doctors to be aware that oral contraceptives might play a role in the development of glaucoma, and to recommend that women who are taking birth control pills routinely have their eyes screened for the disease.
The study was conducted by researchers at University of California, San Francisco, Duke University School of Medicine and Third Affiliated Hospital of Nanchang University, Nanchang, China.
Widespread Brain Changes Found in Glaucoma Patients
July 2013 Glaucoma traditionally has been defined as damage to the optic nerve (usually caused by high eye pressure) that results in visual field loss. A new study offers evidence that glaucoma may instead be a neurological disorder with wider implications.
MRIs revealed differences in brain structures of people with glaucoma vs. people without the disease.
Researchers at Wills Eye Institute in Philadelphia have discovered widespread structural changes in the brains of glaucoma patients. They looked at MRIs of brain structures of 15 people with glaucoma of varying severity and 15 without glaucoma, matched for age, race and sex. None of the participants had any known neurological or other disorders that could affect the visual field, and all passed a mental health screening.
The MRI scans were analyzed to measure the volumes of 93 brain structures and to identify structures that differed significantly between the glaucoma group and the control group. Also, the volumes of all brain structures in the glaucoma group were correlated with the severity of the patients' glaucoma.
Five brain structures differed significantly between the two groups, all of which are involved in visual processing: the right and left inferior occipital gyri, the right middle occipital gyrus, the right inferior temporal gyrus, and the right occipital lobe white matter. Surprisingly, all of these structures were larger in the glaucoma group than in the control group.
Within the glaucoma group, 38 percent of all brain structures showed a link between decreased volume and glaucoma severity.
These results suggest patients with glaucoma "undergo widespread and complex changes in cortical brain structure and that the extent of these changes correlates with disease severity," according to the study authors.
The study report appeared online this month in the journal Investigative Ophthalmology & Visual Science.
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