Purpose : (1) In general, to provide ophthalmic healthcare to people who live/operate in austere environments (e.g., third world, natural disaster areas, military environments), or are geographically dispersed (e.g., rural populations), where time, cost, and impossibility of travel make access to even adequate medical care difficult if not impossible. (2) In particular, to provide a head-mounted binocular high-speed pupillometer

Fink, Wolfgang

Garcia, Kevin

Tarbell, Mark

Caltech Authors - Main

ARVO 2016 Annual Meeting Abstracts
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/ 
to access the versions of record.
sensitivity measurements, fundus photography and measurements 
with Optical Coherence Tomography. Pupillary measurements were 
obtained twice using NeurOptics® VIP™-200 Pupillometer at 
scotopic, low mesopic, high mesopic and photopic lighting conditions 
by trained observers. A time interval of 30 minutes was provided 
between two sets of measurements and subjects were allowed to dark 
adapt for 1-2 minutes prior to any measurements being performed.
Results: Figure 1 provides the pupillary measurements under 
various illumination conditions. The mean difference in pupillary 
measurements obtained at attempt 1 and attempt 2 were 0.42, 0.62, 
0.79 and 0.73 for the scotopic, low mesopic, high mesopic and 
photopic conditions respectively which was significant (Paired 
samples t-test, p<0.001 for all comparisons). The 95% limits of 
agreement of pupillary measurements is also given in figure 1 and are 
on average -1.99 to +0.70.
Conclusions: Small yet significant differences in pupil measurements 
can occur during repeat measurements which is in the range of 
half a millimeter when measuring with NeurOptics® VIP™-200 
Pupillometer. One should consider multiple measurements at 
different times and averaging the values if accurate pupil dimensions 
are needed.
Commercial Relationships: Cherell Lemons, None; Min Kong, 
None; Danica Quicho, None; Arlene Flores, None; Danielle Ringle, 
None; Katalina Rowland, None; Kaydee McCray, None; 
Jennifer Kurtz; Pinakin G. Davey, None
Program Number: 4562 Poster Board Number: B0348
Presentation Time: 8:30 AM–10:15 AM
Dependence of melanopsin-mediated human pupil responses 
upon light level and stimulus masking
Manuel Spitschan1, Jack Ryan2, David H. Brainard1, 
Geoffrey K. Aguirre2. 1Department of Psychology, University 
of Pennsylvania, Philadelphia, PA; 2Department of Neurology, 
University of Pennsylvania, Philadelphia, PA.
Purpose: We measured how signals from melanopsin (Mel) drive the 
human pupil response as a function of overall light level, and what 
components of the response are altered by stimulus masking.
Methods: We created Mel-directed light steps (method of silent 
substitution, +42% Mel contrast, nominally silent for the LMS 
cones). After removing residual luminance and chromatic stimulus 
components with psychophysical nulling, three observers viewed 
these steps (5.5 sec, 250 msec half-cosine window at on/offset) as 
modulations of a spatially uniform annular field (5° id, 27.5° od, CIE 
x=0.50, y=0.40) at five logarithmically-spaced photopic light levels. 
The viewing eye was pharmacologically dilated and consensual pupil 
responses were recorded in the other eye. Step onset time was jittered 
across the 45 second trials.
Results: At 70 and 240 cd/m2, there was a sustained pupil 
constriction in response to the Mel-directed steps that persisted 
beyond step offset until the end of the trial. Repeat measurements at 
these light levels replicated the effect. The sustained response was 
not clearly different from zero at 20, 895, and 2780 cd/m2. At all 
light levels, there was also a transient pupil constriction at both onset 
and offset of the Mel-directed step. To address the possibility that 
the observed responses were in fact due to residual stimulation of 
the cones and/or awareness of the stimulus, the measurements were 
repeated at 240 cd/m2 with added cone noise (8 Hz noise uniformly 
distributed between ±3% L+M+S and ±3% L–M contrast). This noise 
masked the visibility of the Mel-directed steps, but not that of control 
L+M+S cone-directed steps (+42% contrast). This manipulation 
greatly reduced the transient responses to the Mel-directed steps, but 
left the sustained response unaltered. Transient responses, however, 
remained for the L+M+S cone-directed steps, despite the noise.
Conclusions: Mel-directed contrast steps presented on mid-photopic 
backgrounds evoke sustained pupil responses even when masked by 
cone noise. The magnitude of sustained response depends strongly 
on background light level, with maximal response observed at 70 
and 240 cd/m2. This dependence could be due to properties of the 
melanopsin-containing retinal ganglion cells and/or to the properties 
of the pupil control system.
a) Time average pupil responses as a function of light level in three 
subjects; b) Average pupil time series at 240 cd/m2.
Commercial Relationships: Manuel Spitschan; Jack Ryan, None; 
David H. Brainard, U.S. Patent Application No. 14/852,001 (P); 
Geoffrey K. Aguirre, U.S. Patent Application No. 14/852,001 (P)
Support: NIH Grant EY024681, NIH Grant EY020516, DoD Grant 
W81XWH-15-1-0447, NIH Grant P30 EY001583
Program Number: 4563 Poster Board Number: B0349
Presentation Time: 8:30 AM–10:15 AM
Smartphone-based Head-mounted Binocular High-Speed 
Pupillometer
Wolfgang Fink1, 2, Kevin Garcia3, Mark Tarbell1, 2. 1Dept. of 
Biomedical Engineering, University of Arizona, Tucson, AZ; 2Visual 
and Autonomous Exploration Systems Research Laboratory, Caltech, 
Pasadena, CA; 3Breault Research Organization, Inc., Tucson, AZ.
Purpose: (1) In general, to provide ophthalmic healthcare to 
people who live/operate in austere environments (e.g., third world, 
natural disaster areas, military environments), or are geographically 
dispersed (e.g., rural populations), where time, cost, and impossibility 
of travel make access to even adequate medical care difficult if not 
impossible. (2) In particular, to provide a head-mounted binocular 
high-speed pupillometer.
Methods: Optical add-on adaptors, specifically designed for a variety 
of ophthalmic metrology applications, are developed that act as 
ophthalmic examination extensions to a smartphone. A healthcare 
practitioner attaches such a device to a smartphone and runs a custom 
app to perform a specialized examination of specific areas of the eye. 
The smartphone app submits the collected examination data through 
a wireless connection to a server-backend for medical analysis. The 
analysis results are sent back in near real-time and are displayed 
onscreen to the on-site practitioner to facilitate, e.g., a triage process.
Results: A smart service platform in ophthalmology was devised 
by creating a server-based telediagnostic analysis capability for 
current and future smartphone-based ophthalmic examination 
devices. The first such ophthalmic examination device developed 
ARVO 2016 Annual Meeting Abstracts
These abstracts are licensed under a Creative Commons Attribution-NonCommercial-No Derivatives 4.0 International License. Go to http://iovs.arvojournals.org/ 
to access the versions of record.
is a head-mounted, miniaturized pupillometer, composed of an 
optical add-on adapter coupled to a smartphone, that allows for the 
simultaneous recording of pupillary behavior of both eyes at 120Hz 
in the presence and absence of light stimulation, i.e., pupillary 
light reflex and dark reaction. Examination data gathered are sent 
via Wi-Fi or cell signal through a smartphone app to a server for 
automated video analysis. Analysis results, including the pupillary 
diameter displayed as a function of time for each eye in addition to 
parameters such as pupillary latency, constriction, and dilation times, 
are sent back to the originating smartphone in near real-time for 
further assessment by the on-site practitioner.
Conclusions: In general, the new paradigm of Smart Ophthalmics, 
i.e., smart tele-ophthalmology, may greatly improve remote patient 
screening and triage, and help ensure that undiagnosed eye diseases 
are detected early and treated in time to prevent permanent vision 
impairment. In particular, the binocular pupillometer enables 
performing the swinging flashlight test, and may allow the diagnosis 
of afferent and efferent pupillary defects.
Commercial Relationships: Wolfgang Fink, University of Arizona (P), 
Caltech (P); Kevin Garcia; Mark Tarbell, University of Arizona (P)
Support: NSF Award #IIP-1430062
Program Number: 4564 Poster Board Number: B0350
Presentation Time: 8:30 AM–10:15 AM
Effect of induced glare on pupil size in ocular healthy adults
Arlene Flores1, Danica Quicho1, Min Kong2, Cherell Lemons1, 
Katalina Rowland2, Danielle Ringle2, Kaydee McCray2, 
Jennifer Kurtz2, Pinakin G. Davey2, 1. 1Graduate College of 
Biomedical Sciences, Western University of Health Sciences, 
Pomona, CA; 2College of Optometry, Western University of Health 
Sciences, Pomona, CA.
Purpose: Glare testing in clinical setting is complicated due to the 
lack of clear gold standard. This becomes particularly important when 
evaluating for cataract surgery where decisions are made on the basis 
of changes in visual performance with glare. We sought to investigate 
two calibrated glare inducing systems and evaluate the change in 
pupil size when the light levels were standardized.
Methods: One hundred eyes of 50 individuals in age range 20 to 
35 were included in the study. Subjects underwent an ocular health 
examination that included vision testing, fundus photography and 
measurements with Optical Coherence Tomography. The glare units 
were placed at 8 feet viewing distance from the subject. The glare 
system 1 (GS1) involves LED light illumination and is constructed 
with four LED lights at four corners of the monitor. The glare system 
2 is a retro illuminated chart with two halogen lamps placed at 
either side of the box. The background illumination of GS1 and GS 
2 system measured at 1 foot was 3 and 25 lux. With the glare levels 
turned on both units were set at 48 lux. Pupillary measurements were 
obtained twice using NeurOptics® VIP™-200 with glare system off 
and glare system turned on.
Results: Figure 1 provides the pupil size with and without induced 
glare. The baseline pupil measurements when inducing glare GS1 
LED system had pupil size of 5.93 which decreased to 4.01 mm 
with glare. The baseline pupil measurements when inducing glare 
GS2 halogen system had pupil size of 5.46 which decreased to 3.96 
mm with glare. The change in pupil size was significant with both 
glare systems (Paired samples t-test t=23.77; p<0.001 and t=23.41; 
p<0.001). The pupil measurements without the glare lights on was 
different when using the GS1 versus GS2 with pupil 0.47 mm larger 
when using GS1 (Independent samples t-test t= 7.29; p<0.001). The 
pupil size was not significantly different when the glare lights were 
turned on (Independent samples t-test t= 1.12; p=0.26).
Conclusions: Difference in background illumination of glare 
systems caused a measurable difference in pupil size at baseline. The 
calibration of glare systems is an important factor in predicting the 
outcome of visual performance and should be considered when using 
different glare units. The pupil size is not affected by the glare source; 
LED versus Halogen.
Commercial Relationships: Arlene Flores, None; 
Danica Quicho, None; Min Kong, None; Cherell Lemons, None; 
Katalina Rowland, None; Danielle Ringle, None; Kaydee McCray, 
None; Jennifer Kurtz, None; Pinakin G. Davey, M&S Systems (C)
Program Number: 4565 Poster Board Number: B0351
Presentation Time: 8:30 AM–10:15 AM
Interactions between photic drive responses and multifocal 
pupillography in epilepsy
Ted Maddess1, Eman N. Ali1, Corinne F. Carle1, Andrew C. James1, 
Kate Martin2, Angela Borbelj2, Christian J. Lueck2, 1. 1Neuroscience, 
Australian National University, Canberra, ACT, Australia; 
2Neurology, The Canberra Hospital, Canberra, ACT, Australia.
Purpose: Photic drive responses (PDRs) have been used to explore 
cortical hyper-excitability in neurological disorders. We quantified 
changes PDR in epilepsy patients and looked for interactions 
with responses obtained from multifocal objective pupillographic 
perimetry (mfPOP).
Methods: This was a cross-sectional study of 15 consecutive 
epilepsy patients (8 males; mean age ± SD 47.3 ± 4.6 years), and 15 
controls (9 males; mean age 52.7 ± 4.6 years) undergoing routine 
EEG with standard intermittent photic stimulation (IPS) and testing 
with the mfPOP device. EEG spectral amplitudes during IPS were 
obtained using the Fourier transform. N-fold changes in PDR 
(expressed in dB) when IPS and alpha bands overlapped, the alpha-
band gain, were examined and also their interaction with mfPOP 
responses. Alpha-band gain was determined by comparing eyes-open 
and eyes–closed conditions. mfPOP responses were obtained from 
44 regions/visual field. Response time-to-peak and standardized 
amplitude was recorded for each test region.
Results: A linear model showed that an epileptic attack within 
1 month increased the alpha-band gain by 1.33 dB (p=0.01). 
Generalised epilepsy (i.e. no focal epilepsy) decreased the alpha-
band gain by 1.03 dB (p=0.03). For each decade increase in age the 
gain increased by 0.36 dB (p=0.007). For every 1 dB increase in 
alpha band gain pupil responses were reduced by 0.207 ± 0.09 dB on 
average across the field (p=0.024).
Conclusions: Investigating alpha-band gain offers another way to 
quantify cortical hyper-excitability in epilepsy patients. Responses 
to mfPOP may provide less invasive means to quantify hyper-
excitability.
Commercial Relationships: Ted Maddess, EyeCo Pty Ltd (I), 
nuCoria Pty Ltd (P), nuCoria Pty Ltd (F), nuCoria Pty Ltd (I); 
Eman N. Ali, None; Corinne F. Carle, nuCoria Pty Ltd (F), nuCoria 
Pty Ltd (P), nuCoria Pty Ltd (I); Andrew C. James, nuCoria Pty Ltd 


English

Smartphone-based Head-mounted Binocular High-Speed Pupillometer

https://authors.library.caltech.edu/75472/1/Fink_2016p4563.pdf

Smartphone-based Head-mounted Binocular High-Speed Pupillometer

Abstract

Similar works

Full text

Available Versions

Caltech Authors - Main

Caltech Authors - Main