New Fresnel lens loupe for nystagmus observation suitable for use by medical staff Iin emergency departments
Dublin Core
Title
New Fresnel lens loupe for nystagmus observation suitable for use by medical staff Iin emergency departments
Subject
Fresnel loupe, Frenzel goggles, Nystagmus, Slow-phase velocity, Visual impact susceptibility, Visual
fixation, Acute vestibular syndrome, Test of skew, STANDING algorithm
fixation, Acute vestibular syndrome, Test of skew, STANDING algorithm
Description
Abstract
Background Reduction of spontaneous nystagmus by fixation, a characteristic feature of peripheral nystagmus, is
important for differentiating between peripheral and central vestibular disorders. In the emergency room, Frenzel
goggles are recommended to observe spontaneous nystagmus for the differential diagnosis of acute vestibular
syndrome. We developed a portable loupe with a Fresnel lens to observe nystagmus. The loupe does not require
power supply and can be used under ceiling lights. The aim of this study was to quantitatively and objectively
compare the abilities of the loupe and conventional Frenzel goggles to observe spontaneous nystagmus and to verify
that the loupe can detect peripheral nystagmus that cannot be observed with the naked eye.
Methods Visual impact susceptibility was compared between the loupe and Frenzel goggles using the slow-phase
velocity of nystagmus induced by the caloric test in 15 participants. Subsequently, under lighting, the nystagmus
observations under the naked eye condition and with the use of the loupe were compared. Furthermore, the visibility
of nystagmus was evaluated from recorded videographic images.
Results In observations of nystagmus induced by the caloric test, the visual impact of the loupe was not inferior to
that of Frenzel goggles. The mean slow-phase velocity of nystagmus recorded with the loupe was significantly higher
than that observed with the naked eye. Nystagmus weakened under bright lighting could be recovered by the loupe
as fixation was blocked and the direction of the nystagmus could be defined.
Conclusions The results showed that the loupe is helpful in observing nystagmus, which is weakly observed with the
naked eye under bright light. This portable, low-cost loupe, which yields superior results, can serve as an alternative to
conventional Frenzel goggles in emergency medical settings where rapid assessment is required.
Keywords Fresnel loupe, Frenzel goggles, Nystagmus, Slow-phase velocity, Visual impact susceptibility, Visual
fixation, Acute vestibular syndrome, Test of skew, STANDING algorithm
Background Reduction of spontaneous nystagmus by fixation, a characteristic feature of peripheral nystagmus, is
important for differentiating between peripheral and central vestibular disorders. In the emergency room, Frenzel
goggles are recommended to observe spontaneous nystagmus for the differential diagnosis of acute vestibular
syndrome. We developed a portable loupe with a Fresnel lens to observe nystagmus. The loupe does not require
power supply and can be used under ceiling lights. The aim of this study was to quantitatively and objectively
compare the abilities of the loupe and conventional Frenzel goggles to observe spontaneous nystagmus and to verify
that the loupe can detect peripheral nystagmus that cannot be observed with the naked eye.
Methods Visual impact susceptibility was compared between the loupe and Frenzel goggles using the slow-phase
velocity of nystagmus induced by the caloric test in 15 participants. Subsequently, under lighting, the nystagmus
observations under the naked eye condition and with the use of the loupe were compared. Furthermore, the visibility
of nystagmus was evaluated from recorded videographic images.
Results In observations of nystagmus induced by the caloric test, the visual impact of the loupe was not inferior to
that of Frenzel goggles. The mean slow-phase velocity of nystagmus recorded with the loupe was significantly higher
than that observed with the naked eye. Nystagmus weakened under bright lighting could be recovered by the loupe
as fixation was blocked and the direction of the nystagmus could be defined.
Conclusions The results showed that the loupe is helpful in observing nystagmus, which is weakly observed with the
naked eye under bright light. This portable, low-cost loupe, which yields superior results, can serve as an alternative to
conventional Frenzel goggles in emergency medical settings where rapid assessment is required.
Keywords Fresnel loupe, Frenzel goggles, Nystagmus, Slow-phase velocity, Visual impact susceptibility, Visual
fixation, Acute vestibular syndrome, Test of skew, STANDING algorithm
Creator
Reiko Tsunoda1,2*, Yumi Dobashi1
, Masao Noda1,3 and Hiroaki Fushiki1,2
, Masao Noda1,3 and Hiroaki Fushiki1,2
Source
https://doi.org/10.1186/s12245-024-00791-2
Date
2024
Contributor
Peri Irawan
Format
PDF
Language
ENGLISH
Type
TEXT
Files
Collection
Citation
Reiko Tsunoda1,2*, Yumi Dobashi1
, Masao Noda1,3 and Hiroaki Fushiki1,2, “New Fresnel lens loupe for nystagmus observation suitable for use by medical staff Iin emergency departments,” Repository Horizon University Indonesia, accessed April 13, 2026, https://repository.horizon.ac.id/items/show/12551.