Study Shows NeurOptics Pupillometers Reliably Measure Pupillary Light Reflex, Helping to Predict Survival and Neurological Outcome after Cardiac Arrest

Case series published in illustrates value of infrared pupillometry during CPR

Study Shows NeurOptics Pupillometers Reliably Measure Pupillary Light Reflex, Helping to Predict Survival and Neurological Outcome after Cardiac Arrest

Sullivan & AssociatesBarbara Sullivan, 714-374–6174

A new study showed that NeurOptics Pupillometers reliably measure the presence and quality of the pupillary light reflex after cardiac arrest and during resuscitation, producing readings that correlate with survival and neurological outcomes. The study was published in the October issue of the journal .

The was used to obtain pupillary measurements during 30 cardiopulmonary resuscitations at the University of California, San Francisco Medical Center. The goal of the study was to determine if the light reflex could be objectively measured during cardiopulmonary resuscitation and whether the quality of the reflex was associated with outcome.

The NPi-100 Pupillometer uses infrared imaging technology to measure the pupil’s response to light stimulus, removing subjectivity and variability in the measurement of pupil size and the pupillary light reflex. Results are displayed on an LCD screen—providing a numeric indication of whether the pupillary response falls within or outside a normal range as defined by the NeurOptics NPi™ (Neurological Pupil index™) algorithm and enabling trending of pupillary information.

In the study, the reliability of the presence of the light reflex as a predictor of survival and neurological outcome was analyzed. In 25 of 30 cases (83 percent) the pupillary light reflex was detectable during all or part of the resuscitation. Continuous presence of the light reflex or absence for less than five minutes was associated with early survival and good neurological outcome. Absence of a pupillary light reflex for more than five minutes was correlated with an unfavorable outcome, and no patients without a light reflex or in whom the light reflex was deteriorating survived the code.

Study author Merlin Larson, M.D., said: “This study showed that with infrared pupillometry, the presence or absence of the pupillary light reflex can be detected during CPR. It also showed that a continued presence of the light reflex predicted a favorable neurological outcome if the heart could be resuscitated. Visual inspection with a pen light will often reveal a non-reactive pupil, whereas a subsequent reading with the pupillometer would show the light reflex to be present.”

According to an accompanying editorial by Jan Breckwoldt and colleague from Charité University in Berlin, “Reliable early prognostication of cardiac arrest would be of great value. It would be optimal to provide valid information during CPR, or even before starting it… The development of a portable infrared light pupillometer allows precise measurement of the PLR even in a range which is often missed by conventional pen light examination.”

Kamran Siminou, president and CEO of NeurOptics, said, “The results of this study illustrate the value of having a quantifiable measurement of a patient’s pupillary response, allowing clinicians to trend this important parameter.”

To access the study, “Infrared pupillometry to detect the light reflex during cardiopulmonary resuscitation: A case series,” .

NeurOptics, Inc., based in Irvine, Calif., provides devices that collect and process information from the human eye to facilitate medical decision-making and enable clinical research. The company offers the NPi-100 Pupillometer used in critical care and emergency medicine, as well as pupillometers for ophthalmic surgery and research. The company’s pupillometers are being used by a growing number of leading hospitals and stroke centers across the country. For more information, visit .