Purpose:
To evaluate the objective chromatic visual field of normal subjects, retinitis pigmentosa (RP) and glaucoma patients in comparison to the conventional subjective visual field examination.
Methods:
The pupillary light reflex (PLR) response diameters were measured in 13 different points in the visual field. The PLR responses were measured for a short wavelength stimulus (peak 485 nm) and a long wavelength stimulus (peak 620 nm), size V, at a light intensity of 39.8 cd-s/m2 and a duration of 1000 ms. In addition, the following data was collected from each patient: Best-corrected visual acuity (BCVA) with snellen projection charts, measurement of intraocular pressure (IOP), full ophthalmic slit-lamp biomicroscopy, iris architecture, visual field (Humphry or Goldmann) and refraction.
Results:
The RP patient group included 17 eyes of 11 patients and the normal subject group included 25 eyes of 14 subjects. The glaucoma patient group included 6 eyes of 5 patients and the normal subject group included 9 eyes of 6 subjects. The average of the PLR % of change in RP patients was found to be lower than in normals at all respective locations except in the center for the low light intensity short wavelength stimulus (p<0.05). The glaucoma group showed more reduced PLR % of change for the high light intensity short wavelength stimulus, more profound in the nasal area (p<0.05).
Conclusions:
The percentage of change of the pupillary light responses was found to be highly reduced in RP patients for the blue stimulus which corresponds with the loss of rods. A marked decrease in the percentage of change of the pupillary light responses to the higher light intensity blue stimulus in the glaucoma group can suggest that the damage in the ganglion cells can be better detected by this stimulus.
Clinical Trial:
http://www.clinicaltrials.gov NCT01021982
Keywords: pupillary reflex • visual fields • perimetry