One fish could hold the key to helping millions of patients with potentially blinding eye conditions around the world. The fish in question is called a zebrafish, and it's thanks to the researchers at Nashville's Vanderbilt University that eye doctors are hopeful they can soon find a cure for both age-related macular degeneration (AMD) and retinitis pigmentosa.
Professors took the zebrafish involved in this study and blocked one inhibitory receptor, known as GABA, in some of their eyes. Researchers found that the zebrafish with blocked GABA receptors significantly increased their retinal cell regeneration rate. They also found that the retinae in these fish healed quite rapidly.
Amazingly, many of the zebrafish involved in this study were blinded before the test. Blocking GABA literally restored sight to numerous zebrafish involved in this amazing study.
Thomas Greenwell, who works for the National Eye Institute, told reporters that this study proves the retina has the ability to repair itself with the right manipulation. He believes that if this regeneration is possible in a fish, it could theoretically be possible in humans. Of course, more tests need to be done, but Dr. Greenwell is hopeful for future mice and human trials.
Professors also increased the GABA in certain zebrafish to see what effect it would have on their retinal cell production. As they expected, increased GABA dampened the production of retinal cells.
Greenwell says he hopes people in the medical community will learn more about GABA's function from this study. He also hopes more research is done on how horizontal cells, Muller glia, and GABA function in mammals as opposed to fish.
AMD generally starts to affect people around the ages of 40 to 60. A few symptoms include blurred vision, the inability to see in dim areas, spotty vision, and partial vision loss. If not caught in time, AMD could lead to blindness. A few treatments for AMD currently used include blood vessel growth inhibitors, laser surgery, and corrective lenses. AMD is suspected to affect about 50% of the 370,000 people registered as partially sighted or blind in the UK.
Just like AMD, retinitis pigmentosa affects a person's retina, could lead to blindness, and usually appears later in life. A few symptoms of this disease include tunnel vision, blurred vision, and general vision loss. Doctors recommend people with this disease wear a good pair of sunglasses whenever going outside for extended periods of time to protect their eyes.
The full Vanderbilt study was published in the magazine Stem Cell Reports with the title "Neurotransmitter-Regulated Regeneration in the Zebrafish Retina."