Abstract
Purpose: :
Exploring the possibility of using the Pupillary Light Reflex (PLR) for objective perimetry. PLR is currently used to evaluate visual functions in a full field mode. In this study we used PLR in a novel way : Pupillometer-based objective chromatic perimetry.
Methods: :
We used a pupillometer [Ronald Consult, Germany] attached to a Goldmann perimeter to measure the dark-adapted PLR of seven normal individuals and five retinitis pigmentosa (RP) patients. Pupillary diameter changes were measured in each of thirteen different visual field points for short and long wavelength stimuli (peak 485 nm and 620 nm respectively). All stimuli were size V3c, at a light intensity of 39.8 cd-s/m2 and a duration of 1000 ms. Ratios of the PLR diameter for the short and long wavelengths were calculated for each spot.
Results: :
The average of the PLR ratio in the normal subjects was 0.41 + 0.2 (Average + SD). The average of the PLR ratio measurements of the patients in the seeing area of the visual fields was 0.62 + 0.25 and in the non-seeing area was 0.97 + 0.2. The PLR ratio was significantly different between the normal subjects and the RP patients and between seeing areas and non-seeing areas in the visual fields of the RP patients (ANOVA, p<0.001).
Conclusions: :
The PLR ratios of the short and long wavelength stimuli were significantly higher in areas of visual field defects in RP patients. Pupillometer-based chromatic perimetry may possibly be used to objectively measure visual field defects.
Clinical Trial: :
www.clinicaltrials.gov NCT01021982
Keywords: pupillary reflex • perimetry • retinitis