Is the Pupil Involved in Duane Syndrome? Static and Dynamic Pupillometry Characteristics.

Objectives: Duane syndrome (DS) is typically characterized by abduction and/or adduction deficiency accompanied by eyelid and ocular motility disturbances. Maldevelopment or absence of the sixth nerve has been shown to be the causative factor. The aim of the present study was to investigate static and dynamic pupillary characteristics in patients with DS and compare the results with those of healthy eyes. Materials and Methods: Patients with unilateral isolated DS and no history of ocular surgery were enrolled in the study. Healthy subjects with a best corrected visual acuity (BCVA) of 1.0 or higher were assigned to the control group. All subjects underwent complete ophthalmological examination and pupillometry measurements (MonPack One, Vision Monitor System, Metrovision, Perenchies, France) including static and dynamic pupil evaluation. Results: A total of 74 patients (22 with DS and 52 healthy subjects) were included in the study. The mean age of the DS patients and healthy subjects was 11.05±5.19 and 12.54±4.05 years, respectively (p=0.188). There was no difference in sex distribution (p=0.502). Mean BCVA differed significantly between eyes with DS and healthy eyes, and between healthy eyes and the fellow eyes of DS patients (p<0.05). No significant difference was found in any static or dynamic pupillometry parameters (p>0.05 for all). Conclusion: In the light of the results of the present study, the pupil seems to be not involved in DS. Larger studies including more patients with different types of DS in different age groups or comprising patients with non-isolated DS may reveal different findings.