Evidence map›Paper›PMID 40020145›Full record

Observational studyMedicine2025

Using smartphone pupillometer application to measure pupil size and light reflex: An unsuccessful prototype and analysis of the causes of failure.

Hung-Hsi Tan, Kuo-Chang Lee, Yi-Rong Chen, Yu-Chin Huang, Rih-Shen Ke, Gwo-Jiun Horng, Kuo-Tai Chen

Abstract readObservational Study
In one paragraph

Observational study in Medicine, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

2 citing papers in PubMed.

  1. Article
  2. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Hung-Hsi TanEmergency Department, Chi-Mei Medical Center, Tainan, Taiwan.
Kuo-Chang LeeEmergency Department, Chi-Mei Medical Center, Tainan, Taiwan.
Yi-Rong ChenDepartment of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
Yu-Chin HuangDepartment of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
Rih-Shen KeDepartment of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
Gwo-Jiun HorngDepartment of Biotechnology, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
Kuo-Tai ChenEmergency Department, Chi-Mei Medical Center, Tainan, Taiwan.ORCID 0000-0001-6147-9498

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

The accurate assessment of pupillary light reflex (PLR) is essential for monitoring critically ill patients, particularly those with traumatic brain injury or stroke and those in postoperative care. Smartphone-based pupillometers represent a potentially cost-effective solution for addressing this need. We developed a smartphone pupillometer application (app) and evaluated its effectiveness against the penlight test and quantitative pupillometry. This study included 50 volunteers aged >20 years and excluded individuals with neurologic or ophthalmic conditions. The app captured pupillary images by displaying a red circle on the screen, and an algorithm processed these images to calculate the pupil constriction percentage (PCP). The results revealed that the smartphone app often required multiple attempts for successful image acquisition. The obtained PCPs were consistently smaller and less variable than those obtained using the penlight test and a commercial pupillometer (app vs penlight for the right eye: 27.0% [27.0%-8.0%] vs 33.0% [32.3%-39.3%]; app vs pupillometer for the right eye: 27.0% [27.0%-28.0%] vs 35.0% [31.8%-38.3%]; app vs penlight for the left eye: 29.0% [28.0%-29.0%] vs 33.0% [29.8%-34.3%]; app vs pupillometer for the left eye: 29.0% [28.0%-29.0%] vs 36.0% [30.8%-38.0%]; P <.001 for all). Notably, the penlight and the pupillometer exhibited comparable PCPs (right eye: penlight vs pupillometer: 33.0% [32.3%-39.3%] vs 35.0% [31.8%-38.3%], P = .469; left eye: penlight vs pupillometer: 33.0% [29.8%-34.3%] vs 36.0% [30.8%-38.0%], P = .148). The app requires further refinement to yield results comparable to those of established methods. Future iterations can include alternative measurement strategies and dynamic assessment. Penlight and quantitative pupillometry remain indispensable as established tools for PLR.

Indexed as

Diagnostic Techniques, OphthalmologicalMobile ApplicationsPupilReflex, PupillarySmartphoneAdultFemaleHumansMaleMiddle Aged

Identifiers

PMID40020145
PMCPMC11875590

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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.