Abstract
Purpose: :
To determine the correlation between the pupil size measured using the OPD–Scan, and the pattern VEP parameters.
Methods: :
Photopic and mesopic pupil diameters (mm) of 38 eyes of 19 subjects were obtained using ARK–10000 pupillometer of OPD–Scan device (NIDEK, Japan). Fifteen of the cases had asymmetric bilateral optic nerve disease (optic neuritis, optic atrophy, glaucoma, temporal pallor), while 4 cases had mild to moderate monoocular involvement with similar optic nerve problems. All the cases also had pattern VEP test using the RETIscan device (Ronald Consult, Germany).
Results: :
Mean age of the subjects was 30.4 years +/– 13.6(SD). There was a negative correlation between the photopic pupil diameter and N135 amplitude (r=–0.396, p=0.014), and a positive correlation between the photopic pupil diameter and N135 latency (r = 0.343, p=0.035). There was a negative correlation between the photopic pupil diameter and P100 amplitude (r=–0.370, p=0.022). There was not a significant correlation between the mesopic pupil diameter and the pattern VEP parameters. When the limit value was assumed as 2.60 mm, sensitivity of the pupil size in detecting optic nerve damage was 97%.
Conclusions: :
It is well known that P100 amplitude and latencies are effected in optic nerve disorders. Although there was a correlation between the pupil size and the P100 amplitude, this was not the case for the P100 latency in our study. It is interesting that there was a moderate correlation between the pupil size and N135 parameters.
Keywords: neuro-ophthalmology: optic nerve • neuro-ophthalmology: diagnosis • imaging/image analysis: clinical