@misc{10481/70579,
year = {2021},
month = {8},
url = {http://hdl.handle.net/10481/70579},
abstract = {Purpose: Cannabis is the most widely consumed illicit drug worldwide. It has been
suggested that cannabis could generate blurred vision during reading tasks. The
goal of this study was to objectively assess the acute effects of smoking cannabis
on the dynamics of ocular accommodation. The influence of other factors, including
target distance and the direction of accommodation, as well as personal characteristics,
were also analysed.
Methods: Nineteen young people who were occasional cannabis users participated
in the study (mean age 22.53 [3.12] years). Their usage profiles were evaluated
by means of the Cannabis Use Disorders Identification Test-revised
(CUDIT-r).
The dynamics of the accommodative response were evaluated using an open-field
auto refractor (Grand Seiko WAM-5500).
The participants completed two different
experimental sessions, one week apart, and in random order (baseline session and
after smoking cannabis). During these sessions, the amplitude of the response (D),
mean velocity (D/s), peak velocity (D/s), response time (s), accommodative lag (D)
and accommodation variability (D) were measured.
Results: The results indicated that cannabis use had a significant main effect on the
mean accommodation/disaccommodation velocity (F1,13 = 7.21; p = 0.02; η
2
p = 0.396).
Cannabis consumption also interacted significantly with other factors. Response
time showed a significant two-way
interaction between condition × target distance
(F1,13 = 11.71; p = 0.005; η
2
p = 0.474) and condition × accommodation direction (F1,13 = 8.71;
p = 0.01; η
2
p = 0.401). For mean velocity, two-way
interactions were found between condition
× age (F1,13 = 6.03; p = 0.03; η
2
p = 0.354), condition × CUDIT-r
score (F1,13 = 6.03;
p = 0.03; η
2
p = 0.356) and condition × target distance (F1,13 = 7.20; p = 0.02; η
2
p = 0.396).
Conclusions: These findings suggest that cannabis use can alter the accommodation
process, although further studies should be carried out to explore the role of
attention deficits. According to these results, certain daily activities that depend
on an accurate accommodative function may be affected by cannabis use.},
organization = {Ministry of Economy and Competitiveness (Spain)},
organization = {European Commission	FIS2017-85058-R},
organization = {Ministry of Science, Innovation and Universities (Spain)	FPU15/05571},
organization = {Universidad de Granada/Consorcio de Bibliotecas Universitarias de Andalucia (CBUA)},
publisher = {Wiley-Blackwell Publishing},
keywords = {Accommodation},
keywords = {Accommodation dynamics},
keywords = {Accommodative response},
keywords = {Cannabis},
keywords = {Cigarette},
keywords = {THC},
keywords = {Vision},
title = {Dynamics of the accommodative response after smoking cannabis},
doi = {10.1111/opo.12851},
author = {Ortiz Peregrina, Sonia and Ortiz Herrera, Carolina and Martino, Francesco and Castro Torres, José Juan and González Anera, María Del Rosario},
}