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An Ottawa company is developing computerized glasses to help those with severe visual impairments maximize the vision they have left.
The glasses, which look like an oversize pair of sunglasses, have a high-resolution camera on the outside and tiny LCD screens on the inside that project images to the wearer’s eyes. The glasses will also zoom in on and replay what has been seen with the press of a button.
The company, eSight Corp., received a $500,000 grant from the Ontario government to develop its evSpex product, and hopes to start commercial production next year.
Before the image is projected, it’s custom-processed by a tiny computer. “So that when it’s presented to a person who has diseased eyes … it’s presented to the pieces of their vision that are most functional,” said eSight Corp. company president Rob Hilkes.
Because the device continually records a loop of video, the user can save the last 10 seconds of what they saw at the press of a button so they can look again at something that went by too quickly. The video can be viewed later on a DVD player or computer. Users can also zoom in on certain things in their field of view
The product is expected to be able to help people with age-related macular degeneration, diabetic retinopathy, glaucoma and retinitis pigmentosa. In the future, the company hopes to market the technology to people with normal vision as wearable binoculars, night vision goggles or video gaming devices.
SOURCE: High-tech glasses help the nearly blind see, CBC News, Sept. 11, 2009, http://www.cbc.ca/technology/story/2009/09/11/ottawa-esight-glasses-technology-company-blind.html
Glaucoma may continue to progress after the reduction of IOP to targeted levels. Research is providing increasing support for the idea that vascular risk factors may be the cause.
Several population-based studies have suggested that low diastolic perfusion pressure is associated with an increased
incidence of open-angle glaucoma (OAG). Perfusion pressure is defined as the difference between arterial and venous pressure, which, in the eye, by convention equals IOP. Blood pressure and IOP are therefore the principal components of ocular perfusion pressure (perfusion pressure = blood pressure – IOP).
• Choi J, Kim KH, Jeong J, et al. Circadian fluctuation of mean ocular perfusion pressure is a consistent risk factor
for normal-tension glaucoma. Invest Ophthalmol Vis Sci. 2007;48:104-111.
• Tielsch JM, Katz J, Sommer A, et al. Hypertension, perfusion pressure, and primary open-angle glaucoma. A population-based
assessment. Arch Ophthalmol. 1995;113:216-221.
• Leske MC, Connell AM, Wu SY, et al. Risk factors for open-angle glaucoma. The Barbados Eye Study. Arch Ophthalmol.
1995;113:918-924.
• Hulsman CA, Vingerling JR, Hofman A, et al. Blood pressure, arterial stiffness, and open-angle glaucoma: the Rotterdam study.
Arch Ophthalmol. 2007;125:805-812.
Perfusion pressure can be affected by IOP and blood pressure, but which is really the most important? In a given patient, it
could be IOP alone, blood pressure alone, or a combination of the two.
For more information on ways to help preserve optic nerve health, go to www.naturaleyecare.com
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Scientists in Greece have released results of a study in which they questioned whether there should be limits on exercise with regard to effects on inter-ocular pressure (IOP) of the eyes. This study, published in the August issue of BMC Ophthalmology, found that people with glaucoma do not need to limit exercise, as IOP decreased during aerobic activity.
145 participants were given a preliminary ophthalmologic exam. 45 participants had primary (open-angle) glaucoma; 100 did not have glaucoma. The IOP of both eyes was measured before and after exercise (biking or jogging).
A significant decrease in IOP was found during exercise. Researchers found that the aerobic exercise reduced IOP in those eyes in which a b-blocker, a prostaglandin analogue or an alpha-agonist were previously instilled. The IOP was also decreased in glaucoma patients who were already under antiglaucoma treatment.
Study authors determined that glaucoma patients benefited from aerobic exercise regardless of the antiglaucoma medication instilled, as all participants had a post-exercise reduction of IOP.
Learn more about glaucoma, including natural treatment options
SOURCE: Aerobic exercise and intraocular pressure in normotensive and glaucoma patients, Natsis, et al, BMC Ophthalmology 2009, 9:6doi:10.1186/1471-2415-9-6.
A team of Italian researchers may have developed a new type of eye drop for glaucoma, according to an article published in the Proceedings of the National Academy of Science.
Researchers noted that elevated intraocular pressure (IOP) in glaucoma leads to loss of retinal ganglion cells (RGCs) as well as damage to the optic nerve. Although IOP is controlled with medication, no treatment is currently available to restore retinal and optic nerve function.
In this new study, rats with glaucoma were treated with the eye drops containing a protein known as nerve growth factor. When researchers determined that these drops prevented nerve degeneration in these rats, human tests were initiated on three patients with advanced glaucoma.
After three months of treatment all three participants showed improvements in visual sharpness and ability to detect contrast. Two of the three participants showed improved visual fields, while the visual field stabilized for the third.
The team, led by Alessandro Lambiase of the University of Rome, reported that improvements were still evident three months after the treatments were finished.
SOURCE: Experimental and clinical evidence of neuroprotection by nerve growth factor eye drops: Implications for glaucoma, Lambiase, et al, Proceedings of the National Academy of Science, Aug. 3, 2009.
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New technology may replace eye drops currently used by people suffering from glaucoma and dry-eye.
Studies have found that a majority of glaucoma patients regularly skip their eye drops, putting themselves at risk for blindness, and that even when drops are used regularly, only a small percentage of the medication tends to be absorbed into the eye.
In an article published in the July issue of Investigative Ophthalmology and Visual Science, scientists announced that they have developed a contact lens that delivers medication to the eye at a constant rate for over 4 weeks. The lenses should not affect the wearer’s vision.
The special lenses were created by dissolving a biodegradable polymer called PLGA in an organic solvent, to which medication was added. After the solvent evaporated, researchers coated the polymer film/medication mix with a hydrogel called pHEMA — the same material used to make regular contact lenses. Researchers believe they can vary the molecular weight of the polymer to change the rate of drug release as needed.
To date the researchers have only tested the diffusion properties of the lens in a lab dish, but expect to be able to test the lenses in humans within a year.
SOURCE: A Drug-Eluting Contact Lens, Ciolino, et al, Investigative Ophthalmology and Visual Science. 2009;50:3346-3352.)
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