Women who are using or who had used Hormone Replacement Therapy (HRT) have higher rates of cataract removal than women who have never used HRT. This was the finding of an eight-year study of more than 30,000 postmenopausal Swedish women.

Results of the study showed that the risk for cataract removal was increased by 14 percent in women who had previously used HRT and an 18 percent increase was noted in current HRT users as compared to women who did not use HRT. The longer HRT was used resulted in an increased risk. In addition, women using HRT who consumed more than one alcoholic drink a day had a 42 percent increased risk compared to women who did not use HRT or drank alcohol.

Cataracts are more common in postmenopausal women than in men which indicates that hormonal differences play a role in their development. Estrogen receptors have been found in the eye’s lens. The lens is the area that becomes cloudy and inflexible upon formation of a cataract. The exogenous estrogens which are used in HRT increase C-reactive protein levels which have been linked with cataract development.*

Andrea Schumann
Staff Writer

Predominantly considered a disease of the eye, scientists have discovered that the first signs of injury in glaucoma actually take place in the brain.

The details of the discovery are in this week’s Proceedings of the National Academy of Science. The revelation will prompt researchers to look at glaucoma in a new light.

Typically, glaucoma therapies have revolved around lowering ocular pressure within the eye. The increased ocular pressure causes damage to the retina and optic nerve (both parts of the central nervous system). Blindness is the end result if glaucoma is not detected early.

The results of this new study, however, directs the focus to studying neuronal activity in the middle of the brain where the optic nerve forms its first connections. This new approach to addressing glaucoma will lead to new targets for potential treatment of the debilitating disease.*

Andrea Schumann
Staff Writer

A researcher has discovered the process which causes retinal cells to die causing blindness in diabetic patients. It has long been known that high blood sugar levels from diabetes damage blood vessels in the eye. The new discovery isolates the siah-1 protein as being a key component in the vascular damage in the eyes which leads to diabetic retinopathy.

The January 29th issue of the Journal of Biological Chemistry has the details of the research.

Previous studies showed that high sugar levels cause GAPDH, another protein, to build up in the nuclei of Muller cells which are located in the retina. What scientists didn’t know was how the GAPDH was getting in the nuclei.

The siah-1 protein delivers GAPDH into the nucleus of Muller cells. When GAPDH accumulates in the nuclei, the Muller cells die which leads to the vascular damage. While production of GAPDH cannot be regulated, it is hoped that scientists will be able to stop the production of siah-1. If there is no siah-1 to transport the GAPDH to the nuclei, then diabetic retinopathy would no longer occur.

Andrea Schumann
Staff Writer

Advanced Cell Technology, Inc. has filed a request with the FDA to test a treatment for macular degeneration. Advanced Cell would be conducting the clinical trial with the Foundation Fighting Blindness which is bound by National Institute of Health (N.I.H.) regulations.

A proposal by the N.I.H. would expand it’s current definition of human embryonic stem cells which would enable researchers that it finances to work with cells derived from blastomeres.

Advanced Cell pioneered the development of embryonic stem cells from blastomeres and has since learned how to convert these cells into the specific cells that form the basement membrane of the retina. Animal testing of these blastomere-derived cells has resulted in the retinal cells growing well and reproducing light-detecting rod and cone cells which resulted in the improved vision of the lab animals.

Andrea Schumann
Staff Writer

Researchers have mapped five types of light receptors in a chicken’s eye. What researchers at Washington University School of Medicine in St. Louis discovered is that the receptors were laid out in interwoven mosaics which afforded the chicken the ability to see several colors in any given part of the retina.

Details of the study are in the February 1, 2010 journal of PLoS ONE. Scientists are hoping that this knowledge will allow them to use stem cells and other new therapies to treat the various genetic disorders that can cause various forms of blindness.

The difference between the avian and human retina is that humans have cones which are sensitive to red, blue and green wavelengths while birds have cones sensitive to red, blue, green and violet wavelengths. They can even detect some ultraviolet wavelengths. In addition, our avian friends have a double cone which is believed to help them detect motion.

Since many of the conditions that cause blindness in humans involve cones and rods, it is hoped that studying the organization of the chicken’s retina will help scientists understand and fix related problems in the human eye.

Andrea Schumann
Staff Writer