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Repeated pupil size measurements in refractive surgery candidates
Christoph Robl1, Ieva Sliesoraityte, Jost Hillenkamp
1Department of Ophthalmology, University Medical Centers, Regensburg, Germany.
Purpose:
To evaluate the individual variation in pupil diameter measurements in refractive surgery candidates under standardized conditions over 2 testing sessions using a digital infrared pupillometer.
Setting:
Department of Ophthalmology, University Medical Center Regensburg, Regensburg, Germany.
Methods:
The pupil size in both eyes of consecutive refractive surgery candidates was measured under 2 illumination levels (scotopic at 0.03 lux, low mesopic at 0.82 lux) with a digital infrared pupillometer (Procyon P2000 SA). Before measurement, a standardized dark-adaptation protocol was used. Measurements were taken twice on separate occasions.
Results:
The study evaluated 318 eyes of 159 patients with a mean age of 36.3 years +/- 10.2 (SD). The mean interval between measurements was 53 +/- 62.8 days. Despite sufficient power (beta < 0.05), there was no statistically significant difference between 2 consecutive measurements under scotopic and low mesopic illumination.
Conclusion:
Using a standardized dark-adaptation protocol, refractive surgery candidates showed no significant variation in scotopic or low mesopic pupil diameter over 2 testing sessions.
