How do drugs affect vision?

Question 1

Desai et al

Answer 1

(1997)
Cocaine affects dopamine neurotransmission
High density of dopamine in the retina = important for colour vision
Compared patients recently withdrawn from cocaine with matched normal controls
RESULTS
Cocaine patients had significantly higher error scores than matched controls on two colour vision tests.

Question 2

Ventura et al

Answer 2

(2003)
Chloroquine used to treat rheumatoid arthritis and malaria
They compared rheumatic patients with no signs of retinopathy (using chloroquine) (n=32) with controls
RESULTS
Patients presented functional alterations in colour discrimination but did not show changes in contrast sensitivity
Colour vision loss increased with accumulated dose values and was present at even the lowest dose
Therefore, visual function during treatment with chloroquine should be monitored closely

Question 3

Klinger et al

Answer 3

(2001)

Found no ophthalmic abnormality in children who were exposed to chloroquine during pregnancy

Question 4

Etminan et al

Answer 4

(2010)
Older generation antidepressants associated with increased risk of cataracts
Newer SSRIs increase the risk of cataracts by 23-39%
Fluvoxamine had the highest risk ratio of 1.39

Question 5

Till et al

Answer 5

(2001)
Looked at offspring who were exposed during pregnancy to organic solvents
RESULTS
Exposed PS showed poorer colour discrimination
13% of males and 6% of females had a clinical red-green colour deficiency vs 0% in controls
Exposed PS showed poorer visual acuity

Question 6

Kelly et al

Answer 6

(2005)
Review of 27 studies researching smoking and cataracts
RESULTS
Found that smoking caused a 3-fold increase on the risk for incident nuclear cataract development
Limited evidence for association between smoking and other types of cataract

Question 7

Evans et al

Answer 7

(2006)
Investigated 75+ group
RESULTS
Current smokers were 2x more likely to develop AMD
Benefit for quitting smoking seen after 10 years
But risks don’t return to default until 20 years of cessation

Question 8

Roquelaure et al

Answer 8

(1995)
measured visual contrast sensitivities 30 alcohol (and tobacco) abusers versus controls
RESULTS

Reduced VCS at all frequencies

Biological proxies (Gamma-Glutamyl-Transpeptidase) of alcohol intake levels correlated with deficit

THEREFORE

VCS test is can detect alcohol related issues, but can’t detect location of damage. However…

Alcohol likely causes toxic injury to optic conduction pathways

• supported by the fact that VCS deficits also seen after optic nerve lesions (Comerford, 1983)

Question 9

Quintyn

Answer 9

(1999)
compared tests when sober and 0.57g/kg (drink driving limit in Fr)
- Tested VCS, VEPs, PVF
Results
- No sig. Difference