Clinical Trial Details
— Status: Completed
Administrative data
| NCT number |
NCT05003128 |
| Other study ID # |
A-ER-108-489 |
| Secondary ID |
|
| Status |
Completed |
| Phase |
N/A
|
| First received |
|
| Last updated |
|
| Start date |
July 1, 2020 |
| Est. completion date |
August 22, 2020 |
Study information
| Verified date |
July 2021 |
| Source |
National Cheng-Kung University Hospital |
| Contact |
n/a |
| Is FDA regulated |
No |
| Health authority |
|
| Study type |
Interventional
|
Clinical Trial Summary
Video display terminals (VDTs) are ubiquitous, and engagement in digital screens has grown
substantially across all age groups worldwide. Prolonged exposure to VDTs is associated with
the development of various health problems. By now, it is unclear whether transient exposure
to VDTs leads to ocular surface changes, especially regarding lipid layer thickness (LLT).
This study aim to determine if short-term exposure to light-emitting diodes (LEDs) leads to
ocular parameter changes.
This is a prospective, cross-sectional study. Patients were recruited at the National
Cheng-Kung University Hospital, a tertiary referral center in southern Taiwan, for
examination, including best-corrected visual acuity (BCVA), intraocular pressure (IOP), lipid
layer thickness (LLT), and blink rates and patterns before and after watching an LED display
for 15 minutes. The estimated result is that the LLT and blink rates will decrease after VDT
watching.
Description:
Video display terminals (VDTs) are ubiquitous, and engagement in digital screens has grown
substantially across all age groups worldwide. During the coronavirus disease 2019 (COVID-19)
pandemic, lockdowns and increasing demand for digital learning and working have led to more
frequent and sustained VDT use. Prolonged exposure to VDTs is associated with the development
of various health problems, including psychosocial issues, venous thromboembolism, fatigue,
and visual complaints.
Computer vision syndrome (CVS) is one of the most frequently encountered problems among VDT
users. CVS comprises several visual and musculoskeletal symptoms resulting from VDT use, such
as eye strain, dryness and burning sensation of the eye, blurred vision, and neck and
shoulder pain. A major alteration is the development of dry eye disease (DED), occurring in
60 % of those with CVS. Dry eye symptoms, corneal erosions, short tear-film breakup time
(BUT), low tear meniscus height, and meibomian gland dysfunction (MGD) are all DED
presentations encountered by VDT users. The continuous use of VDTs is an established risk
factor for CVS and DED. However, it is unclear whether transient exposure to VDTs leads to
ocular surface changes, especially regarding lipid layer thickness (LLT).
This study investigated if the short-term use of light-emitting diode (LED) displays (one
type of VDT) changed the ocular parameters, including best-corrected visual acuity (BCVA),
intraocular ocular pressure (IOP), the CVS-Questionnaire (CVS-Q) score, the blink rate, the
partial blink ratio, and LLT. To our knowledge, this is the first study to focus on the
immediate effects of LEDs on the eye.
This prospective clinical study was conducted in the Ophthalmology Department of the National
Cheng Kung University Hospital (NCKUH), Tainan, Taiwan. The study was approved by the
Institutional Review Board of NCKUH and followed the tenets of the Declaration of Helsinki.
Written informed consent was obtained from all the participants.
The inclusion criteria were generally healthy individuals aged between 20 and 65 years who
were willing to participate in the study. The exclusion criteria were ages below 20 or over
65 years, a BCVA score of <0.1 on the Landolt C chart in either eye, a BCVA difference of
>0.2 between the eyes, and a history of ocular diseases or previous ocular surgery.
Participants were instructed to fill out a basic information form, including their name, sex,
age, and contact information. They were also informed to avoid wearing contact lenses for two
days before the test. The experiment was conducted on August 22, 2020. For the baseline test,
the participants were asked to complete the CVS-Q to assess their CVS. Next was a series of
ocular examinations, including BCVA, IOP, LLT, an optical coherence tomography (OCT) scan of
the macula, and fundus autofluorescence (FAF) imaging. The LLT and blink rates were measured
using the LipiView II Ocular Surface Interferometer following the standard protocol
(TearScience, Morrisville, NC, USA). After the examination, the participants watched a short
movie on an LED screen (InnoLux, Taiwan) for 15 minutes in a bright room. The viewing
distance was approximately 1.5 meters. After the movie ended, the participants were
instructed to complete the CVS-Q and undergo the BCVA, IOP, and LLT tests again. The baseline
BCVA, IOP, OCT, and FAF images of each participant were reviewed by three NCKUH
ophthalmologists to screen for clinically significant ocular pathology.
Statistical analyses were performed using R software version 4.1.0 (R Core Team, Vienna,
Austria) and SAS Enterprise Guide (version 9.4; SAS Institute Inc., Cary, NC, USA). Paired
t-tests were used to compare the BCVA, IOP, CVS-Q score, LLT, blink rate, and the partial
blink ratio before and after watching the LED display. Statistical significance was set at P
<0.05.
