Epilepsy and Cataracts: the Missing Link
A COLLABORATIVE RESEARCH effort from a team that included scientists from New Jersey Medical School, New Jersey Dental School and Columbia University discovered that the most common receptor for the major neurotransmitter in the brain is also present in the lens of the eye, a finding that may help explain the links between cataracts, epilepsy and use of a number of widely prescribed antiepileptic and antidepressant drugs.
"Recent studies identified associations between increased cataracts and epilepsy, and showed increased cataract prevalence with use of antiepileptic drugs as well as some common antidepressants," explains corresponding author Peter Frederikse, PhD, associate professor in the Department of Pharmacology & Physiology at New Jersey Medical School. "One common theme linking these observations is that our research showed the most prevalent receptor for the major neurotransmitter in the brain is also present in the lens."
|PETER FREDERIKSE, PHD|
The research team found glutamate receptor proteins, and specifically a pivotal GluA2 subunit, are expressed in the lens and are regulated in a remarkably similar manner to the way they are in the brain. In the nervous system, glutamate and GluA receptor proteins underlie memory formation and mood regulation along with being an important factor in epilepsy, which is considered the primary disorder of the brain. Consistent with this, these receptor proteins are also targets for a number of antiepileptic drugs and antidepressant medications.
"The presence of these glutamate receptors and neuron-like regulatory processes in the lens suggests they contribute to associations between brain disease and cataract, as well as providing secondary ‘targets' of current drugs," Frederikse notes. "Our goal now is to use this information to explore the potential effects of antiepileptics and antidepressants on these ‘off-target' sites in the lens, and to determine the role glutamate receptors have in lens biology and pathology."
Frederikse believes that these findings are not only useful in informing the medical community about the correlation between cataracts and epilepsy but in moving closer to his ultimate goal: determining if effective dosage of such drugs in current use can be found so that the lens may be protected in a related manner as the brain.
The research team included Rajesh Kaswala, DDS, and
Chinnaswamy Kasinathan, PhD, from New Jersey Dental School and
Norman Kleiman, PhD, from Columbia University's Mailman School
of Public Health. Their findings appear online in Biochemical and
Biophysical Research Communications. The research was supported by
a grant from the National Eye Institute of the National Institutes of
— Jerry Carey