P 326
Tonic pupil pupillary near response and accommodation
C. Kriegbaum, H. Lüdtke, B. Wilhelm, H. Wilhelm
Purpose: Tonic pupil is caused by a deficit of the cholinergic innervation of the eye. This study was intended to investigate the differences between the affected and the normal eye concerning pupillary near response and accommodation.
Methods: By means of real time (25 Hz) infrared video retinoscopy and simultaneous pupillography, refraction and pupil diameter were recorded during fixation of a target at distances of 2, 3, 4 and 5 diopters in 11 patients with tonic pupil aged between 15 and 38. Measurements were performed with monocular fixation.
The diagnosis of tonic pupil was based on the clinical examination and pharmacological testing with pilocarpin (0.1%), i.e. cholinergic hyper-sensitivity.
Measurements of the affected eye and the normal eye were compared and analysed by paired t-test. Parameters of evaluation were the amplitude of accommodation, the initial pupil size and the pupillary near response.
Results: In tonic pupils amplitudes of accommodation were smaller (mean difference 0.78dpt, t-ratio 2.54, DF 10, p<0.05). The initial pupil size showed no significant effect, however the pupillary near response was significantly smaller in tonic pupils (mean difference 0.55 mm, t-ratio 1.48, DF 10, p<0.01).
Conclusions: In pupillary near response and accommodation could be measured simultaneously in a group of patients with unilateral tonic pupils. The expected decreased accommodation and pupillary near response as a consequence of the parasympathetic deficit compared to the normal eye could be shown. However, the difference between the involved and the normal eye was small.
University Eye Hospital Tübingen, Department of Pathophysiology of Vision and Neuroophthalmology, Schleichstr. 16, D-72076 Tübingen