Correlation of infrared pupillometers and CCD-camera imaging from aberrometry and videokeratography for determining scotopic pupil size.

PURPOSE: To compare 2 infrared pupillometers with a videokeratographer and 2 aberrometers for the determination of scotopic pupil size. SETTING: Department of Ophthalmology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. METHODS: The pupil diameter was measured in 100 eyes of 51 patients after 2 minutes of dark adaptation using the following devices: digital infrared pupillometer (Procyon Instruments Ltd.), handheld infrared pupillometer (Colvard) (Oasis Medical), Zywave aberrometer (Bausch & Lomb), Wasca aberrometer (Asclepion-Meditec-Zeiss), and Orbscan II topography system (Bausch & Lomb Surgical). Measurements taken with the Procyon pupillometer were considered reference values for comparison with the other devices. Statistical evaluation was performed using the Bland-Altmann method for comparison of measurement techniques. RESULTS: The mean pupil size was 6.10 mm +/- 0.86 (SD) with the Procyon pupillometer, 5.68 +/- 1.07 mm with the Colvard pupillometer, 5.91 +/- 1.01 mm with the Zywave aberrometer with the fixating target turned off, 5.09 +/- 1.14 mm with the Zywave aberrometer with the fixating target turned on, 5.59 +/- 0.99 mm with the Wasca aberrometer, and 3.75 +/- 0.67 mm with the Orbscan topographer. The limits of agreement were smallest for measurements between Procyon and Colvard and largest for measurements between Procyon and Orbscan. The sign test revealed statistically significant differences for all devices compared with the Procyon pupillometer (P<.001 in all cases) except the Zywave aberrometer with the fixating target turned off (P=.13). CONCLUSIONS: The Zywave wavefront sensor with the fixating target turned off using the study settings and light conditions provided measurements of scotopic pupil diameter that were closest to the reference values (Procyon). With the other devices (Colvard pupillometer, Zywave aberrometer with the fixating target switched on, Wasca aberrometer, and Orbscan topographer), the difference was statistically significant.

Scotopic pupil size in a normal pediatric population using infrared pupillometry.

PURPOSE: To determine scotopic pupil diameter in a normal pediatric population. METHODS: Scotopic pupil size was measured in 166 eyes of 83 children with a mean age of 6.01+/-4.11 years (range 0.51-14.26 years) using the light and hand-held Colvard infrared pupillometer. Measurements were performed under dim illumination after 2 min of dark adaptation. The Colvard infrared pupillometer utilizes light amplification technology to determine scotopic pupil size. RESULT: The mean scotopic pupil diameter was 6.06+/-0.95 mm (range 4.0-8.5 mm) in the right eyes (OD) and 6.11+/-1.02 mm (range 4.0-8.5 mm) in the left eyes (OS), and 6.09+/-0.98 mm (range 4.0-8.5 mm) for both eyes (OU). An increase in mean scotopic pupil size with age was detected, with a peak of 7.28+/-0.42 mm at the age of 10-11 years. The correlation coefficient for age and scotopic pupil diameter was 0.51 OU (OD 0.52, OS 0.51), and the correlation coefficient for objective refraction (spherical equivalent) and scotopic pupil diameter was 0.05 OU (OD 0.01, OS 0.08). CONCLUSIONS: The scotopic pupil diameter in a pediatric population increases with age until the age of 11 years and then decreases again.

Comparison of a digital and a handheld infrared pupillometer for determining scotopic pupil diameter.

To compare a digital infrared pupillometer with a handheld infrared pupillometer for determining scotopic pupil size. Department of Ophthalmology, Johann Wolfgang Goethe-University, Frankfurt am Main, Germany. In 100 eyes of 50 healthy individuals (mean age 38.8 years +/- 10.7 [SD]), the scotopic pupil size was measured with a digital (Procyon) and a handheld (Colvard) infrared pupillometer. After dark adaptation of 1 minute, measurements were performed with both devices by 2 examiners (E1 and E2). Agreement and repeatability were analyzed using a comparison method described by Bland and Altman. The mean scotopic pupil diameter was 5.90 +/- 0.97 mm (range 3.24 to 7.91 mm) with the Procyon and 5.78 +/- 0.98 mm (range 3.00 to 7.30 mm) with the Colvard pupillometer. The mean difference between the 2 devices was -0.01 mm (E1) and -0.24 mm (E2). The limits of agreement ranged from 2.84 (E1) to 3.24 (E2). The coefficients of repeatability were 0.64 (Procyon) and 1.16 (Colvard). The mean difference between E1 and E2 was -0.10 for the Procyon and 0.13 for the Colvard pupillometer. The limits of agreement ranged from 1.28 (Procyon) to 2.32 (Colvard). The digital infrared pupillometer (Procyon) demonstrated better repeatability and agreement in measuring scotopic pupil size than a handheld device (Colvard).