12-08-2016, 10:50 PM
Does Marijuana Use Affect a Person's Vision?
By Agata Blaszczak-Boxe, Contributing Writer | December 8, 2016
Regular <a data-ipb="nomediaparse" href="http://www.livescience.com/24558-marijuana-effects.html">marijuana use</a> may affect how well certain cells in the eye's retina function, a small new <span style="color:rgb(0,153,0);">study</span> finds.
But some experts say that the evidence presented in the study isn't <span style="color:rgb(0,153,0);">strong</span> enough to support the link between these two factors.
The cells that the researchers focused on in the study, called <span style="color:rgb(0,153,0);">retinal</span> ganglion cells, are located near the inner surface of <a data-ipb="nomediaparse" href="http://www.livescience.com/3919-human-eye-works.html">the eye's retina</a>. These cells collect visual information and transmit it to the <span style="color:rgb(0,153,0);">brain</span>.
The study included 52 <a data-ipb="nomediaparse" href="http://www.livescience.com/52543-marijuana-use-doubles-in-decade.html">people who had used marijuana</a> at least 7 times per week during the previous month and 24 people who had never used marijuana. The people in both groups were between 18 and 35 years old. The researchers verified the marijuana use by testing the people's urine for THC, marijuana's main psychoactive ingredient. [<a data-ipb="nomediaparse" href="http://www.livescience.com/55258-how-marijuana-affects-the-brain.html">7 Ways Marijuana May Affect the Brain</a>]
The researchers tested the participants' vision and found that their <a data-ipb="nomediaparse" href="http://www.livescience.com/18658-humans-eagle-vision.html">eyesight was relatively good</a>, and that no one in the study group reported having any visual problems from using marijuana such as <span style="color:rgb(0,153,0);">blurred</span> vision, according to the study, which was published today (Dec. 8) in the journal JAMA Ophthalmology.
To study how well the participants' <span style="color:rgb(0,153,0);">retinal</span> ganglion cells worked, the researchers used a method called pattern electroretinography, which provides information about how well those cells function, as well as how fast they <a data-ipb="nomediaparse" href="http://www.livescience.com/22465-does-sitting-too-close-to-the-tv-really-ruin-your-eyesight.html">transmit visual information</a> from the retina to the brain.
The test revealed that, compared to the people who didn't use marijuana, those who did use the drug had a slight delay in how long it took for information to be transmitted from the retina to the brain, according to the study.
It's not clear whether this potential <a data-ipb="nomediaparse" href="http://www.livescience.com/24554-medical-marijuana.html">effect of marijuana</a> is permanent, or would stop <a data-ipb="nomediaparse" href="http://www.livescience.com/23494-cannabis-withdrawal-symptoms.html">when a person stops using the drug</a>, said study co-author Dr. Vincent Laprvote, a <span style="color:rgb(0,153,0);">psychiatrist</span> at Ple Hospitalo-Universitaire de Psychiatrie du Grand Nancy in France.
But some experts argue that the <span style="color:rgb(0,153,0);">study</span> had significant limitations, and because of this, it's unclear whether or not there is an actual link between marijuana use and these effects.
More research is needed to determine whether marijuana use really is linked tochanges in the functioning of those cells, said Dr. Christopher J. Lyons, an ophthalmologist at the University of British Columbia, who was not involved in the study. [<a data-ipb="nomediaparse" href="http://www.livescience.com/55750-medical-marijuana-conditions-treat.html">Marijuana Could Treat These 5 Conditions</a>]
Lyons noted that although the electroretinography results suggested a <a data-ipb="nomediaparse" href="http://www.livescience.com/54513-does-marijuana-make-you-stupid.html">difference between marijuana users and nonusers</a>, the delay didn't seem to translate into actual,....
<a data-ipb="nomediaparse" href="http://www.livescience.com/57148-does-marijuana-use-affect-retinal-cells.html">http://www.livescience.com/57148-does-marijuana-use-affect-retinal-cells.html</a>
By Agata Blaszczak-Boxe, Contributing Writer | December 8, 2016
Regular <a data-ipb="nomediaparse" href="http://www.livescience.com/24558-marijuana-effects.html">marijuana use</a> may affect how well certain cells in the eye's retina function, a small new <span style="color:rgb(0,153,0);">study</span> finds.
But some experts say that the evidence presented in the study isn't <span style="color:rgb(0,153,0);">strong</span> enough to support the link between these two factors.
The cells that the researchers focused on in the study, called <span style="color:rgb(0,153,0);">retinal</span> ganglion cells, are located near the inner surface of <a data-ipb="nomediaparse" href="http://www.livescience.com/3919-human-eye-works.html">the eye's retina</a>. These cells collect visual information and transmit it to the <span style="color:rgb(0,153,0);">brain</span>.
The study included 52 <a data-ipb="nomediaparse" href="http://www.livescience.com/52543-marijuana-use-doubles-in-decade.html">people who had used marijuana</a> at least 7 times per week during the previous month and 24 people who had never used marijuana. The people in both groups were between 18 and 35 years old. The researchers verified the marijuana use by testing the people's urine for THC, marijuana's main psychoactive ingredient. [<a data-ipb="nomediaparse" href="http://www.livescience.com/55258-how-marijuana-affects-the-brain.html">7 Ways Marijuana May Affect the Brain</a>]
The researchers tested the participants' vision and found that their <a data-ipb="nomediaparse" href="http://www.livescience.com/18658-humans-eagle-vision.html">eyesight was relatively good</a>, and that no one in the study group reported having any visual problems from using marijuana such as <span style="color:rgb(0,153,0);">blurred</span> vision, according to the study, which was published today (Dec. 8) in the journal JAMA Ophthalmology.
To study how well the participants' <span style="color:rgb(0,153,0);">retinal</span> ganglion cells worked, the researchers used a method called pattern electroretinography, which provides information about how well those cells function, as well as how fast they <a data-ipb="nomediaparse" href="http://www.livescience.com/22465-does-sitting-too-close-to-the-tv-really-ruin-your-eyesight.html">transmit visual information</a> from the retina to the brain.
The test revealed that, compared to the people who didn't use marijuana, those who did use the drug had a slight delay in how long it took for information to be transmitted from the retina to the brain, according to the study.
It's not clear whether this potential <a data-ipb="nomediaparse" href="http://www.livescience.com/24554-medical-marijuana.html">effect of marijuana</a> is permanent, or would stop <a data-ipb="nomediaparse" href="http://www.livescience.com/23494-cannabis-withdrawal-symptoms.html">when a person stops using the drug</a>, said study co-author Dr. Vincent Laprvote, a <span style="color:rgb(0,153,0);">psychiatrist</span> at Ple Hospitalo-Universitaire de Psychiatrie du Grand Nancy in France.
But some experts argue that the <span style="color:rgb(0,153,0);">study</span> had significant limitations, and because of this, it's unclear whether or not there is an actual link between marijuana use and these effects.
More research is needed to determine whether marijuana use really is linked tochanges in the functioning of those cells, said Dr. Christopher J. Lyons, an ophthalmologist at the University of British Columbia, who was not involved in the study. [<a data-ipb="nomediaparse" href="http://www.livescience.com/55750-medical-marijuana-conditions-treat.html">Marijuana Could Treat These 5 Conditions</a>]
Lyons noted that although the electroretinography results suggested a <a data-ipb="nomediaparse" href="http://www.livescience.com/54513-does-marijuana-make-you-stupid.html">difference between marijuana users and nonusers</a>, the delay didn't seem to translate into actual,....
<a data-ipb="nomediaparse" href="http://www.livescience.com/57148-does-marijuana-use-affect-retinal-cells.html">http://www.livescience.com/57148-does-marijuana-use-affect-retinal-cells.html</a>