Page 24 - The Indian Digital Edition September-October 2020

CKD ANTIDEPRESSANT DRUG TO TREAT

ASSOCIATED ADULT AMBLYOPIA
WITH VISION treat depression and pain, evokes
Adult amblyopia, a brain
IMPAIRMENT disorder also known as “lazy eye,” rapid and long-lasting antidepressant
can now be effectively treated with effects in human patients. Although
subanesthetic ketamine, which is ketamine has the ability to control
Patients with chronic used for pain management and as an how the nervous system makes
kidney disease (CKD) are more antidepressant in humans. structural changes in response to
likely to have ocular issues, as per internal and external demands, a
a new study. This was the finding of a new process called neural plasticity, it
study undertaken by researchers
According to a report from the University of California, was not known exactly how the drug
in Review of Optometry, Irvine School of Medicine. The worked, until now.
researchers have found a strong study has been published in Current “Our research team showed
association between CKD Biology. that ketamine down-regulates
patients and visual impairment. NRG1 expression in PV inhibitory
“Our study, demonstrates how
In a cross-sectional study, the a single-dose of subanesthetic cells, resulting in sustained cortical
researchers evaluated more than ketamine reactivates adult visual disinhibition to enhance cortical
5,500 survey participants aged 40 cortical plasticity and promotes plasticity in adult visual cortex,” said
years or older. The team defined functional recovery of visual acuity Steven F. Grieco, PhD, a postdoctoral
corrected visual acuity of worse defects resulting from amblyopia,” scholar in the Xu lab and lead author.
than 20/40 in the better-seeing explained Xiangmin Xu, PhD,
“Through this neural plasticity-
eye as visual impairment. a professor of anatomy and based mechanism, ketamine
The research findings showed neurobiology and director of the mediated functional recovery from
that the prevalence of visual Center for Neural Circuit Mapping at adult amblyopia,” revealed Xin Qiao,
impairment and major eye the UCI School of Medicine. PhD, a postdoctoral staff in the Xu
diseases was approximately According to the researchers, lab who is a co-first author for the
two- to seven-fold higher subanesthetic ketamine, used to published paper.
in participants with CKD.
They further found that CKD
was associated with visual STUDY ON IMPACT OF SQUINTING
impairment, ocular disease and ON ASTIGMATISM
retinopathy, including diabetic
retinopathy; but, no association
was noted between CKD and Researchers in Korea undertook The researchers noticed that
cataract surgery, AMD or a study to determine a tried-and- squinting decreased astigmatism
glaucoma. However, they did true visual aid almost everyone uses and increased aberrations in the
find a noteworthy association at some point – squinting – with ATR astigmatism groups but had
between CKD and ocular disease the help of a model eye linked to a the opposite effect for emmetropia
among non-diabetic participants, wavefront analyzer. They then tested and WTR astigmatism: it increased
adding that the presence of four different refractive statuses: astigmatism and decreased
CKD was closely related to visual -1.50D and -3.00D of both with-the- aberrations.
impairment and retinopathy rule (WTR) and against-the-rule They study team concluded
among diabetic participants. (ATR) simple myopic astigmatism. with, “It’s hardly surprising given

These findings highlight The study results showed the horizontal nature of squinting
“the importance of ocular that a squint created with a 2mm that distance vision is improved in
screening among CKD patients horizontal slit placed in front of WTR astigmatism and near vision
and potential common the model eye caused a hyperopic in ATR astigmatism. This pseudo-
pathogenesis underlying these shift of approximately +6.69µm accommodation effect can cause an
conditions,” the study authors with -1.50D WTR, but -2.01µm for overestimation of near visual acuity
wrote in their paper. -1.50 ATR. when squinting is not prohibited.”

| SEPT-OCT 2020 | 20 OPTOMETRY NEWS

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