Pupilometer

Pupillometer, also spelled pupilometer, is a medical device intended to measure by reflected light the size of the pupil of the eye.[1] In addition to measuring pupil size, current automated pupillometers may also be able to characterize pupillary light reflex. Some instruments for measuring pupillary distance (PD) are often, but incorrectly, referred to as pupilometers.[2]

Manual pupillometry

A manual pupillometer measures pupil size via a comparison chart method. There are several types of manual pupillometers. The most common type is the Haab scale, or Haab's pupillometer, which is a series of graduated filled circles on a slide ruler.[2]

Automated Pupillometry
NPi-300 automated infrared pupillometer (NeurOptics, Inc.)
Automated mobile pupillometer (Reflex by brightlamp, Inc.)

An automated pupillometer is a portable, handheld device that provides a reliable and objective measurement of pupillary size, symmetry, and reactivity through measurement of the pupillary light reflex. Independent of examiner, an automated pupillometer eliminates variability and subjectivity, expressing pupil reactivity numerically so that both pupil size and reactivity can be trended for changes, just like other vital signs. An automated pupillometer also provides a reliable and effective way to quantitatively classify and trend the pupil light response.[3][4][5][6]

Using automated pupillometers and algorithms, NeurOptics' Neurological Pupil index (NPi) can offer a consolidated parametric approach to mitigate subjectivity.[7] The NPi and automated pupillometry have also recently been included in the updated 2020 American Heart Association (AHA) Guidelines for Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) as an objective measurement supporting brain injury prognosis in patients following cardiac arrest.[8] Studies published in peer-reviewed journals continue to demonstrate the effectiveness of NeurOptics' NPi in helping clinicians improve patient outcomes.[9][10][11][12][13][14][15][16][17][18][19][20][21]

The most effective way to use an automated pupillometer is to establish the earliest possible baseline measurement when the patient is admitted into the critical care unit or emergency department, and then trend for changes over time.

NeurOptics, Inc. Pupillometer Results Screens

Pupil response

Many automated pupilometers can also function as a type of pupil response monitor by measuring pupil dilation in response to a visual stimulus.

In ophthalmology, a pupillary response to light is differentiated from a pupillary response to focus (i.e. pupils may constrict on near focus, as with the Argyll Robertson pupil) in the diagnosis of tertiary syphilis. Although a pupillometer can be used, the diagnosis is often made with a penlight & near-point card

The extent of dilation of the pupil in the eye could be an indicator of interest and attention.[22] Methods of reliable measurement of cognitive load, such as the dilation or constriction of the pupils, are used in marketing research to assess the attractiveness of TV commercials. Dilation of the pupils reflects an increase in mental processes, whether it be attentiveness, or psychomotor responsiveness.[23] The pupil response has also been found to reflect long-term memory processes both at encoding, predicting the success of memory formation,[24] and at retrieval reflecting the operation of different recognition outcomes.[25]

Measuring pupillary distance
Main article: Pupillary Distance

In the context of dispensing eyeglasses, some instruments for measuring PD are colloquially referred to as a pupillometer even though "interpupillometer" is the appropriate term for this instrument.[2] There are many ways to measure PD ranging from a simple ruler (or "PD stick") traditionally used by eye care professionals (ECP) to the so-called pupillometers to state of the art digital systems that may offer better accuracy and precision while also allowing for various other measurements (e.g., vertex distance, pantoscopic tilt, wrap, etc.) to be taken.[26] Measurement accuracy is more of a concern for progressive lenses where small deviations can severely impact visual performance.

The PD measuring instruments referred to as a pupillometers are optical devices that rest on the nose bridge similar to eyeglass frames and work by sighting the corneal reflection produced by an internally-mounted coaxial light source (e.g. Essilor Corneal Reflection Pupillometer[27]). These instruments are most commonly used for fitting glasses (i.e., center the lenses on the visual axes). However, they may also be used to verify a PD measurements taken with a PD stick. Since these instruments do not measure any actual pupil parameters (e.g., size, symmetry, reflex, etc.), they do not fall under the medical device definition of a pupillometer.[1]

In addition to having PD measured in a retail setting, a variety of web and mobile (Android and iOS) apps are now widely available. Web apps are used by a variety of online sellers of eyeglasses where an object of known size, such as a credit card, is needed to assist (size reference) the measurement process.[28][29] Some mobile apps have eliminated the need for a reference object to make accurate PD measurements by leveraging depth imaging and advanced algorithms now available on some mobile platforms.[30]

See also

References
  1. 21 CFR Section 886.1700 Pupillometer, Food and Drug Administration, Retrieved 20 February 2023.
  2. thefreedictionary.com, Definition of "pupilometer", Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann. Retrieved 20 February 2023.
  3. Olson D, Fishel M. The use of automated pupillometry in critical care. Critical Care Nursing Clinics North America. 2015;28(2016):101-107.
  4. Meeker M, Du R, Bacchetti P, et al. Pupil examination: validity and clinical utility of an automated pupillometer. J Neurosci Nurs. 2005;37:34–40.
  5. Chen J, Gombart Z, Rogers S, Gardiner S, Cecil S, Bullock R. Pupillary reactivity as an early indicator of increased intracranial pressure: the introduction of the neurological pupil index. Surg Neurol Int. 2011;2:82.
  6. Du R, Meeker M, Bacchetti P, Larson M, Holland M, Manley G. Evaluation of the portable infrared pupillometer. Neurosurgery. 2005 57:198–203.
  7. Olson, D.; Stutzman, S; Saju, C; Wilson, M; Zhao, W; Aiyagari, V (2016). "Interrater Reliability of Pupillary Assessments". Neurocritical Care. 24 (2): 251–7. doi:10.1007/s12028-015-0182-1. PMID 26381281. S2CID 6853532.
  8. Panchal, Ashish R.; Bartos, Jason A.; Cabañas, José G.; Donnino, Michael W.; Drennan, Ian R.; Hirsch, Karen G.; Kudenchuk, Peter J.; Kurz, Michael C.; Lavonas, Eric J.; Morley, Peter T.; O’Neil, Brian J. (2020-10-20). "Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care". Circulation. 142 (16_suppl_2): S366–S468. doi:10.1161/CIR.0000000000000916. ISSN 0009-7322. PMID 33081529.
  9. Al-Obaidi, Sameer (October 2019). "Impact of Increased Intracranial Pressure on Pupillometry: A Replication Study". Critical Care Explorations. 1 (10): e0054. doi:10.1097/CCE.0000000000000054. PMC 7063890. PMID 32166235.
  10. Al-Obaidi, Sameer (October 2019). "Investigating the Association Between Eye Colour and the Neurological Pupil Index" (PDF). Australian Critical Care.
  11. Lussier, Bethany (December 2019). "Distributions and Reference Ranges for Automated Pupillometer Values in Neurocritical Care Patients". Journal of Neuroscience Nursing. 51 (6): 335–340. doi:10.1097/JNN.0000000000000478. PMID 31688284. S2CID 207896754.
  12. Miroz, John-Paul (February 2020). "Neurological Pupil index for Early Prognostication After Venoarterial Extracorporeal Membrane Oxygenation" (PDF). Chest. 157 (5): 1167–1174. doi:10.1016/j.chest.2019.11.037. PMID 31870911. S2CID 209461340.
  13. Kim, Tae Jung (February 2020). "Neurological Pupil Index as an Indicator of Neurological Worsening in Large Hemispheric Strokes" (PDF). Journal of Neurocritical Care. 33 (2): 575–581. doi:10.1007/s12028-020-00936-0. PMID 32096118. S2CID 211266302.
  14. Ahmadieh, Tarek (2021). "Automated Pupillometry as a Triage and Assessment Tool in Patients with Traumatic Brain Injury" (PDF). World Neurosurgery. 145: e163–e169. doi:10.1016/j.wneu.2020.09.152. PMID 33011358. S2CID 222145396.
  15. Godau, Jana (November 2020). "Quantitative Infrared Pupillometry in Nonconvulsive Status Epilepticus" (PDF). Journal of Neurocritical Care. 35 (1): 113–120. doi:10.1007/s12028-020-01149-1. PMID 33215395. S2CID 227066130.
  16. Khadijah, Mazhar (December 2020). "Supratentorial intracerebral hemorrhage volume and other CT variables predict the neurological pupil index" (PDF). Clinical Neurology and Neurosurgery.
  17. Nichols, Aaron (2020). "Objective Measurement of Sustained Pupillary Constriction: A Pilot Study Using an App-Based Pupilometer". Vision Development and Rehabilitation. 6: 57 – via COVD.
  18. Achamallah, Natalie; Fried, Jeffrey; Love, Rebecca; Matusov, Yuri; Sharma, Rohit (April 2021). "Pupillary Light Reflex Is Not Abolished by Epinephrine and Atropine Given During Advanced Cardiac Life Support in Patients Who Achieve Return of Spontaneous Circulation". Journal of Intensive Care Medicine. 36 (4): 459–465. doi:10.1177/0885066620906802. ISSN 0885-0666. PMID 32066312. S2CID 211158534.
  19. Lussier, Bethany L.; Stutzman, Sonja E.; Atem, Folefac; Venkatachalam, Aardhra M.; Perera, Anjali C.; Barnes, Arianna; Aiyagari, Venkatesh; Olson, DaiWai M. (December 2019). "Distributions and Reference Ranges for Automated Pupillometer Values in Neurocritical Care Patients". Journal of Neuroscience Nursing. 51 (6): 335–340. doi:10.1097/JNN.0000000000000478. ISSN 1945-2810. PMID 31688284. S2CID 207896754.
  20. Khadijah, Mazhar (2021-01-01). "Supratentorial intracerebral hemorrhage volume and other CT variables predict the neurological pupil index". Clinical Neurology and Neurosurgery. 200: 106410. doi:10.1016/j.clineuro.2020.106410. ISSN 0303-8467. PMID 33341651. S2CID 227279539.
  21. Cortes, Michaela X.; Siaron, Kathrina B.; Nadim, Hend T.; Ahmed, Khalid M.; Romito, Jia W. (June 2021). "Neurological Pupil Index as an Indicator of Irreversible Cerebral Edema: A Case Series". Journal of Neuroscience Nursing. 53 (3): 145–148. doi:10.1097/JNN.0000000000000584. ISSN 1945-2810. PMID 33782353. S2CID 232419340.
  22. Hess, Eckhard H.; Polt, James M. (5 August 1960). "Pupil Size as Related to Interest Value of Visual Stimuli". Science. 132 (3423): 349–50. Bibcode:1960Sci...132..349H. doi:10.1126/science.132.3423.349. PMID 14401489. S2CID 12857616.
  23. "Dr. John Andreassi, editor of International Journal of Psychphysiology, with guest editor Eric Granholm "Pupillometric Measures of Cognitive and Emotional Processes"" (PDF). Retrieved 2007-07-16.
  24. Kafkas, Alexandros; Montaldi, Daniela (2011). "Recognition Memory Strength is Predicted by Pupillary Responses at Encoding While Fixation Patterns Distinguish Recollection from Familiarity". Quarterly Journal of Experimental Psychology. 64 (10): 1971–1989. doi:10.1080/17470218.2011.588335. PMID 21838656. S2CID 28231193.
  25. Kafkas, Alexandros; Montaldi, Daniela (2012). "Familiarity and recollection produce distinct eye movement, pupil and medial temporal lobe responses when memory strength is matched". Neuropsychologia. 50 (13): 3080–3093. doi:10.1016/j.neuropsychologia.2012.08.001. PMID 22902538. S2CID 8517388.
  26. In German: Moderne Videozentriersysteme und Pupilometer im Vergleich, Teil 1, PD Dr. Wolfgang Wesemann, DOZ 6-2009 Archived 2015-09-24 at the Wayback Machine
  27. Digital C.R.P., Essilor Instruments, Retrieved 21 February 2023.
  28. The Pupil Meter
  29. "The Pupil Meter". Archived from the original on 2015-02-01. Retrieved 2013-06-10.
  30. PD+, on the App Store, Retrieved February 21, 2023.
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