Research Updates

According to a recent University of Iowa Health Care study, beta-blocker eyedrops, commonly used to treat glaucoma, may put some people with the condition at increased risk for further visual loss by aggravating the fall of blood pressure during sleep. This is the first study that monitored blood pressure for a 24-hour period. The UI studies seem to suggest that beta-blockers— taken in pill form for high blood pressure or in eyedrop form for glaucoma— can cause excessive blood pressure fall during sleep, particularly when the medication is taken in the evening or at bedtime.

Sohan Singh Hayreh, M.D., Ph.D., lead author of the study, cautions people not to stop taking their medication on their own because it can be extremely dangerous. Instead, consult with your ophthalmologist or other physician about whether they are at increased risk for problems and should adjust their treatment (Sources: SVN News Service—Sterling (Ill.) Daily Gazette, Jan. 25, 2000 and American Journal of Ophthalmology, September 1999).

Raman spectroscopy, a new diagnostic test is being used to measure the levels of the macular carotenoid pigments in the human retina. This noninvasive test takes less than one second to perform and has many advantages over currently used techniques. This instrument may prove useful in early detection of individuals at risk for blindness from ARMD and in monitoring nutritional intervention to prevent visual loss (Source: Science Writers Seminar in Ophthalmology, Research to Prevent Blindness, Sept. 27, 1999).

[top]

Genetics (Rapid Movement of the Eye)….

The function of the gene RGS9-1, first discovered in 1998 by Dr. Theodore Wensel at Baylor College of Medicine, has now been proven by scientists at Baylor, Stanford University, California Institute of Technology in Pasadena. The gene makes the eye see rapidly moving objects. Researchers now have a new tool for studying vision defects in humans (Sources: Nature, Feb. 3, 2000 and Texas Medical Center NEWS, Feb. 15, 2000).

Scientists at Johns Hopkins University have identified drugs that block the faulty growth of blood vessels in the eyes of mice with retinopathy. Drugs that block the action of a protein, vascular endothelial cell growth factor (VEGF) may prevent diabetic retinopathy. Clinical studies on humans are scheduled for April/May, 2000 (Sources: Reuters Health, Feb. 11, 2000 and American Journal of Pathology, February 2000).

Retinitis Pigmentosa (RP)

An effective gene therapy approach for dominant forms of retinitis pigmentosa, which are inherited, has shown dramatic preservation of retinal structure and function over the lifetime of the animals tested. The RNA, ribozyme-based therapy has been tried on people to combat HIV infection and the spread of cancer cells, but this is the first attempt to use this technique to combat inherited disease. It would be worthwhile for patients with RP to learn the genetic basis of their condition to determine whether they may be candidates for this type of future treatment (Source: Science Writers Seminar in Ophthalmology, Research to Prevent Blindness, Sept. 27, 1999). 

The Visionary, published as a service of the Illinois Society for the Prevention of Blindness,
is available upon request. The information contained in this issue,
taken from sources considered to be accurate,
does not replace the need for professional eye care consultations and treatments.

[top]