Damage to Hemifields
Scientists have determined that glaucoma patients who have damage to both hemifields (half of the visual field) of their eye will experience more rapid progression of the disease than patients who have damage to a single hemifield.
The study, published in the September 2009 journal Archives of Ophthalmology, reviews data from 205 patients. 79 were found with an initial superior defect, 61 with an initial inferior defect, and 65 with both hemifields affected.
Analysis showed significantly higher baseline intraocular pressure and thinner central corneal thickness in patients with initial damage to both hemifields.
The study authors concluded that initial damage to both hemifields increases the risk of glaucoma progression, and that doctors should consider more aggressive therapy for these patients.
Source: Glaucoma With Early Visual Field Loss Affecting Both Hemifields and the Risk of Disease Progression, De Moraes, et al, Arch Ophthalmol. 2009;127(9):1129-1134.
Race & Glaucoma Risk
Specific gene mutations can be the cause of glaucoma, according to Indian researchers. Almost 4% of glaucoma sufferers exhibit gene mutations. Scientists are identifying the specific mutations found in glaucoma patients in India and across the world; they have developed a database to make the statistical and clinical information and published it in the journal Bioinformatics. Since 20% of all glaucoma cases affect Indians and people of Indian decent, this research is of specific interest to this country’s researchers.
Source: The Times of India
Glaucoma tends to affect some racial groups more than others. In the US, African Americans are more than twice as likely to develop the disease than non-Hispanic whites. It has also been known for some time that Latinos have an elevated risk of glaucoma as well.
A 2011 study published in the journal Ophthalmology shows that Asian Americans also run a higher risk of developing glaucoma than their white American counterparts. Asian Americans have about a 6.5% chance of getting glaucoma.
The report also offered some specific details by ethnic group as well. People of Japanese decent are 10 times more likely to develop normal-tension glaucoma (when the intraocular pressure is not elevated; IOP has generally been considered the telltale sign of glaucoma, but you can have the disease without having elevated eye pressure.
Source: Medical News Today
Myopia & Glaucoma Risk
A Chinese study finds that there is a relationship between the biomechanical properties of the cornea and the degree to which an individual suffers from myopia. Amongst their findings, researchers describe how highly myopic subjects were more likely to have decreased corneal hysteresis (CH). CH is a measure of viscous damping in the corneal tissue. The figure indicates the “energy absorption capability” of the cornea – in other words, how it is able to scatter and diffuse light.
Scientists also notes that severe cases of myopia have been associated with an increased risk of glaucoma.
Source: Eye, (6 May 2011)
Learn more about myopia, also known as nearsightedness.
Glaucoma – Myopia Connection Studied
Researchers in Australia are working to unravel the genetic code of glaucoma and myopia.
Teams across the world have been building upon one another’s work to pinpoint the Caveolin that is thought to be responsible for glaucoma. These same researchers are also working with the results of studies in Europe that show the genes GJD2 and RASGRF1 to be related to the development of myopia.
Both of these discoveries rely on using Twins Eye Study to corroborate the researchers findings. Twins studies are essential to genetics twins share nearly 100% of their genetic polymorphisms and can help scientists determine whether conditions are causes by inherited or genetic factors.