Comparison of the Colvard, Procyon, and Neuroptics Pupillometers for Measuring Pupil Diameter Under Low Ambient Illumination

Abstract

Pupil diameters under both light conditions were largest with the Neuroptics pupillometer and smallest with the Procyon. The most "examiner independent" Procyon pupillometer performed poorly. The underestimation of the pupil diameter might have severe consequences for refractive surgery patients. The Neuroptics pupillometer showed a high interobserver agreement and repeatability and therefore high safety.

Interrater Reliability of Pupillary Assessments

“…Automated pupillary assessment is now commercially available and is being utilized for patients hospitalized with neurologic injury [18,19]. For example, the NeurOptics Ò NPi TM -100 Pupillometer (Neuroptics Inc., Irvine, CA, USA) is a portable handheld device that provides automated readings of one pupil at a time.…”

Clinical performance of a handheld digital infrared monocular pupillometer for measurement of the dark-adapted pupil diameter

“…Despite a high degree of measurement precision (2 decimal places), the machine was clinically inaccurate 16 and puzzlingly user dependent, with an interobserver difference at 0.4 lux of À1.8 to C2.4 mm. 17 The Procyon pupillometer also had a profound negative bias, with a mean difference compared with the pupillometer we used in our study (Procyon minus NeurOptics) of À0.76 mm at 0.04 lux and À2.10 mm at 0.40 lux. 17 Some authors use a wavefront analyzer or other ''chin on the paper, forehead against the strap'' machines to measure the pupil diameter.…”

Assessment of Pupil Diameters of Emmetropes and Myopes under Photopic, Mesopic and Scotopic Conditions, Using the Infrared Pupillometer Integrated Within Schwind Sirius Multifunctional Diagnostic Device

“…25,26 Even patients with normal pupil sizes are at risk, as the laser loses efficacy on the slope of the cornea resulting in an effective optical zone that is smaller than intended. 27 Large pupil diameters are not the only cause but are considered an important predictor of night-vision disturbances. Therefore, the exact measurement of the pupil diameter is essential before refractive surgery to avoid such postoperative problems and to determine if a patient is suitable for refractive surgery.…”

“…The measurements in 0.1 mm steps is not possible, which causes the readings to be clustered to integer values. 27 Including both eyes of a participant which are clustered to an integer number may be the reason for the difference. Neuroptics pupillometer provides monocular measurement as Colvard pupillometer, since one eye is closed during the measurement of the pupil size.…”

“…Their PD measurements are all larger than the emmetropic and even the myopic PDs in our study. 27 Colvard pupillometer was the first commercially available pupillometer, which used a horizontal milimetric ruler with 0.5 mm precision allowing the measurement of the pupil diameter directly by the examiner. The measurements in 0.1 mm steps is not possible, which causes the readings to be clustered to integer values.…”